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Autoimmune Diseases (Known, Unknown, and Other)
In healthy immune systems, five components of the immune system (white blood cells, antibodies, the complement system, the lymphatic system, the spleen, the thymus, and bone marrow) synergistically work together to protect against harmful or foreign substances such as viruses, bacteria, parasites, and cancer cells. However, in autoimmune diseases the immune system not only targets foreign substances but also targets normal tissues and cells within vital organs (i.e., kidneys, liver, lungs, nervous system), joints, blood vessels, and other organ systems. Essentially, the immune system turns against the body, apparently failing to distinguish between “self” and “non-self” leaving a path of inflammation or damaged tissues resulting in pain, decreased mobility, fatigue and other symptoms.
Because of the wide spectrum of autoimmune diseases, their symptoms, and the overlap of these diseases and their symptoms points to the difficulty in making and early and accurate diagnosis of these diseases. In fact, it may take many years and numerous doctor visits to receive a correct diagnosis.
There are more than 80 autoimmune diseases, and it is suspected that at least 40 additional diseases have an autoimmune basis but are not yet completely understood or identified. Approximately 7-10% of the population suffers from an autoimmune disease, with women and some races being commonly disproportionately affected. For example, Lupus is found in women 10 times more commonly than men and tends to be more severe in North American Black peoples.
Causes of Autoimmune Diseases:
Just as the frequency of autoimmune diseases appears to be increasing for unknown reasons, the cause of most autoimmune diseases is largely unknown. Often there are inherited (genetic) predispositions. However, many experts agree that some autoimmune diseases are accelerated or aggravated by certain environmental exposures and may be caused by a foreign substance (viruses, bacteria, other microbes) that have similarities to proteins in the human body. This is a phenomenon referred to as “molecular mimicry”.
Other environmental agents include exposure to drugs, pollutants, chemicals, or toxins. Some experts believe that an environmental agent, such as a chemical, attaches to or alters a self-protein which then triggers an immune response that shifts either partially or entirely to attack normal self-proteins.
Regardless of the cause, autoimmune diseases can be perpetuated by the body’s production of antibodies that target a person’s own cells, tissues, and/or organs – hence the term “autoantibodies”, which means “self-antibodies”. Autoimmune disease activity often fluctuates, but typically leads to unwanted inflammation and/or a varying degree of tissue damage leading to debilitating symptoms.
Diagnosis of Autoimmune Diseases:
Autoimmune diseases fall into two general categories:
The distinction between these two categories can often become blurred as localized autoimmune diseases frequently overlap or co-exist with systemic autoimmune diseases.
As noted above, diagnosing autoimmune diseases is very challenging because autoimmune diseases are complex and often present with signs and symptoms seen in a wide variety of conditions. Because of the overlapping complexity and variations from one patient to the next, many clinicians often discover that one diagnostic test cannot fully diagnose a particular autoimmune disease.
None-the-less, the diagnosis of an autoimmune disease typically involves a primary consideration of symptoms (which can be vague and misleading), patient physical examination, the results of autoantibody diagnostic tests, at times, the results of body organ imaging (X-ray, CT scan, MRI), and/or a biopsy and pathology examination of involved tissues.
Two of MitogenDx’s primary goals are to assist health care professionals to:
These goals are aimed at addressing the lengthy time to receive an accurate diagnosis because a late diagnosis often correlates with patients having an advanced stage of the disease, which can be very difficult to reverse. Making an early and accurate diagnosis has proven to significantly improve patient outcomes.
To view the autoimmune diagnostic tests offered by MitogenDx view either the test menu, requisition forms, or the list of related diseases that then link to the relevant autoimmune diagnostic tests.
Refer to specific diseases for symptoms.
Acute disseminated encephalomyelitis (ADEM), or acute demyelinating encephalomyelitis, is a rare autoimmune disease marked by a sudden, widespread attack of inflammation in the brain and spinal cord. As well as causing the brain and spinal cord to become inflamed, ADEM also attacks the nerves of the central nervous system and damages their myelin insulation, which, as a result, destroys the brain’s white matter. ADEM is often triggered by a viral infection or (very rarely) specific non-routine vaccinations. ADEM’s symptoms resemble the symptoms of multiple sclerosis (MS). Therefore, the disease is included into the classification of the multiple sclerosis borderline diseases.
MitogenDx offers several diagnostic tests to aid in the diagnosis of ADEM. The Neuromyelitis Optica Spectrum Disorder (NMOSD) Test is a useful test for ADEM.
Pulmonary alveolar proteinosis (PAP) is a rare lung disorder characterized by an abnormal accumulation of surfactant-derived lipoprotein compounds within the lung alveoli (air sacs). The accumulated substances interfere with normal gas exchange and expansion of the lungs, ultimately leading to difficulty breathing and a predisposition to lung infections. The signs and symptoms of PAP include shortness of breath, a cough, low grade fever, and weight loss. PAP is primarily caused by reduced GM-CSF stimulation. GM-CSF is a cytokine protein that stimulates alveolar macrophages to function properly and maintain a normal surfactant level in alveoli by removing excess surfactant.
PAP can arise as an autoimmune disease (autoantibodies against GM-CSF) or as a hereditary disease (genetic mutation of GM-CSF receptors). Mitogen’s Alveolar Proteinosis Test (Anti‐GMCSF) aids in the diagnosis of autoimmune PAP.
Amyotrophic Lateral Sclerosis (ALS or Lou Gehrig’s disease) is a disease associated with the death of motor neurons that control voluntary muscles. Some also use the term motor neuron disease for a group of conditions of which ALS is the most common. ALS is characterized by stiff muscles, muscle twitching, and gradually worsening weakness due to muscles decreasing in size. It may begin with weakness in the arms or legs, or with difficulty speaking or swallowing. About half of the people affected develop at least mild thinking and behavioural difficulties. Many people experience pain.
Mitogen’s High-Sensitivity Neurofilament Test is an important diagnostic test to aid in the diagnosis of ALS.
ANCA–associated vasculitis (AAV) is a group of autoimmune diseases that is characterized by inflammation and destruction of small blood vessels (vasculature). The subset of ANCA diseases is based on the organs whose vasculature is being damaged.
ANCA glomerulonephritis (Renal-limited vasculitis)
In this type of ANCA vasculitis, the glomeruli capillaries in the kidneys are damaged. Therefore, ANCA glomerulonephritis is often characterized by blood and protein in the urine. With the glomeruli acting as the plasma filters, damage to these components significantly impedes kidney function and will often lead to kidney failure.
Microscopic polyangiitis (MPA)
In MPA-type ANCA, vascular damage is seen in multiple tissues and organs including kidneys, skin, nerves, lungs and joints. Therefore, this disease group exhibits a wide range of signs and symptoms including kidney inflammation, skin lesions and nerve damage. Common associated symptoms include weight loss and fever.
Granulomatosis with polyangiitis (GPA or Wegener’s granulomatosis)
As with MPA, vascular damage is seen in multiple tissues, typically in the lungs, kidneys, sinuses, nose, eyes and ears. However, the distinguishing feature of GPA is vascular damage caused by formation of granulomas (masses of immune cells that form at the site of inflammation).
Eosinophilic granulomatosis with polyangiitis (EGPA or Churg-Strauss syndrome)
EGPA is an ANCA-associated disease that is characterized by vasculature damage in the lungs and respiratory tract caused by eosinophil-granulomas. Symptoms are often similar to asthma and can often be mistaken as such until other symptoms of vasculitis appear.
Mitogen offers autoimmune diagnostic tests that can help distinguish these vasculopathies and aid in the diagnosis ANCA–associated vasculitis.
Anti-glutamate receptor (NR1) encephalitis is a type of inflammatory encephalopathic autoimmune disease)
See encephalitis.
Antiphospholipid syndrome (APS) is a disorder of the immune system that is associated with an increased risk of blood clots in veins, arteries and capillaries throughout the body. APS is also an autoimmune condition, which means the immune system (which usually protects the body from infection and illness) attacks healthy tissue. People with APS are at greater risk of developing conditions such as: deep vein thrombosis (a blood clot that usually develops in the leg), arterial thrombosis (a clot in an artery which can cause a stroke or heart attack), blood clots in the brain (leading to problems with balance, mobility, vision, speech and memory), and pregnant women with APS also have an increased risk of having a miscarriage.
APS doesn’t always cause these noticeable problems, but some people have general symptoms that can be similar to those of other autoimmune diseases such as multiple sclerosis (a common condition affecting the central nervous system). APS is labeled as primary if it is an entity of its own, or secondary if it is part of other autoimmune diseases, particularly SLE. In APS, the immune system produces abnormal antibodies and, although technically not correct, they are collectively referred to as “antiphospholipid antibodies”.
Mitogen offers three key autoimmune diagnostic tests to aid in the diagnosis of APS: Anti‐Beta-2 Glycoprotein 1 – Domain 1 Test, Anti-Phosphatidylserine / Prothrombin Complex Test, and Anti-Cardiolipin Test
Arthritis refers to pain, swelling and or redness in the joints of the body. There are over 100 different forms of arthritis and it is often a feature of a wide range of infectious and autoimmune diseases. In the early stages of arthritis, lab tests, including antibody tests, are often used as a guide to an earlier and accurate diagnosis.
Mitogen offers a number of autoimmune and immune biomarker tests to aid in the diagnosis of arthritis. Notably, Mitogen’s Arthritis Test Panel includes two rheumatoid factor (RF) antigens and four distinct citrullinated peptides (CCP). Conventional anti-citrullinated protein autoantibody (ACPA) or anti-cyclic citrullinated peptide (CCP) testing generates approximately 10-15% false-negative results for patients suffering from rheumatoid arthritis (RA). Mitogen’s comprehensive Arthritis Panel addresses these missed diagnoses with a much broader spectrum of CCP antigens. The Arthritis Test Panel has led to significant improvements in sensitivity for diagnosing rheumatoid arthritis over conventional ACPA testing.
With the availability of this test, clinicians should avoid the costs and loss-of-time that inherent with early generations of CCP testing. By solely ordering this panel for suspected RA and known RA patients you gain an increased chance in early detection and missing fewer diagnostic opportunities.
Juvenile arthritis is a disease in which there is inflammation (swelling) of the tissue that lines the inside of joints (called synovium) in children aged 16 or younger. Juvenile arthritis is an autoimmune disease, and while the main feature is joint involvement, other organs can be involved including inflammation of a part of the eye (uveal tract) that can lead to severe visual impairment or even blindness. The presence of anti-cellular antibodies (ACA / ANA) are used as a biomarker to alert the doctor that the likelihood of developing uveitis is high.
Rheumatoid arthritis (RA) is an autoimmune inflammatory disorder that affects joints of the body, but can be accompanied by inflammation in other organs as well such as the skin, eyes, lungs, heart and blood vessels. Unlike the wear-and-tear damage of the more common form of arthritis, osteoarthritis, RA affects the lining of your joints, causing a painful swelling that can eventually lead to loss of the smooth gliding cartilage of the joint, erosions of the bone around the joints and, if unchecked, loss of function and deformity of the joints. Many new medications have improved treatment options dramatically. Because it is important to make an early diagnosis before joint damage occurs, autoimmune diagnostic test for autoantibodies called rheumatoid factor (RF), antibodies to cyclic citrullinated peptides (ACPA / CCP) and other proteins in the joint (carbamylated peptides, peptidyl arginine deiminase (PAD)) are used as an aid to diagnosis.
Asthma is a common and often chronic disease that is characterized by inflammation of airways and lungs. Symptoms often include shortness of breath, chest tightness, coughing and wheezing.
With the symptoms of asthma being related to autoimmune diseases that affect the lungs, it is recommended to test suspected asthma patients on lung-based autoimmune diagnostic tests to determine whether there is an underlying autoimmune disease such as Eosinophilic granulomatosis with polyangiitis (EGPA), interstitial lung disease (ILD), or pulmonary alveolar proteinosis (PAP).
Ataxia is a general disease term that describes a lack of muscle control or coordination of voluntary movements and often signifies a number of neurological disorders that can develop over time or come on suddenly. The onset of ataxia is associated with poor coordination, unsteady walk and a tendency to stumble, eating, writing or buttoning a shirt, change in speech, involuntary back-and-forth eye movements (nystagmus) or difficulty swallowing.
There are many causes of ataxia, including alcohol misuse, certain medications, stroke, tumor, cerebral palsy, brain degeneration and multiple sclerosis. Inherited genetic changes can also be involved. Persistent ataxia usually results from damage to the part of your brain that controls muscle coordination (cerebellum). In some patients with ataxia, there is an autoimmune (idiopathic ataxia) cause and hence studies of specific antibodies can help explain the reason for ataxia but also give some insight into treatments.
Atypical hemolytic uremic syndrome (aHUS) is a disease that causes abnormal blood clots in small blood vessels, particularly in the kidneys. These clots can cause serious medical problems such as hemolytic anemia, thrombocytopenia, and kidney failure. Because a number of other problems can have similar clinical features, a laboratory test to detect deficiency and inhibitors of a protein called ADAMTS13 are often used to help confirm the diagnosis. ADAMTS13 is responsible for the breakdown of von Willebrand factor (vWF), a protein that links platelets, blood clots, and the blood vessel wall in the process of blood coagulation.
Autoimmune liver diseases refers to a broad category of liver diseases that are associated with an attack of the liver by the immune system. These include primary biliary cholangitis, primary sclerosing cholangitis and autoimmune hepatitis. Since many of the autoantibodies are highly disease specific, autoantibody tests can help the physician make an accurate diagnosis.
Autoimmune mucocutaneous blistering diseases are a group of conditions where blisters appear on the skin or mucous membranes. The diagnosis is aided by a skin biopsy and the detection of antibodies that can help confirm the disease. Bullous pemphigoid (BP) is the most common autoimmune mucocutaneous blistering disease, and it predominantly affects the elderly. Mouth and throat involvement is rare.
Autoimmune myositis (AIM) is a group of uncommon diseases that primarily involves the skeletal muscles. These diseases include polymyositis, anti-synthetase syndrome, dermatomyositis, juvenile dermatomyositis, inclusion body myositis, necrotizing myopathy and overlap syndromes such as mixed connective tissue disease and scleromyositis. The main symptom is progressive muscle weakness, especially of the muscles closest to the torso. Each AIM subset is associated with a unique autoantibody biomarker that can help the physician make an accurate diagnosis and initiate appropriate treatment. A small proportion of AIM patients have or eventually develop cancer and several autoantibodies are associated with a higher risk of cancer.
Autoimmune neuropathies can include Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and IgM paraproteinemic neuropathy, among others. They present with a broad range of symptoms, including slow or insidious onset and progression, asymmetric or multifocal nerve deficits, and selective involvement of motor, sensory, or autonomic nerves. The overlap of symptoms among syndromes often makes the diagnosis difficult. Presumptive diagnosis is based on the patient’s history and clinical signs and findings on physical exam. Initial laboratory testing aims to rule out underlying causes such as infections, metabolic disturbances, and brain tumors. If nothing is uncovered, further evaluation, including advanced imaging, nerve conduction studies, and cerebrospinal fluid (CSF) analysis may be required.
Autoimmune neuropathies can also arise as a condition associated with cancer (paraneoplastic). The detection of an autoantibody in the right clinical setting can provide evidence that the peripheral nerve disturbance is immune mediated and may direct treatment, but autoantibody testing cannot be used as the sole diagnostic tool. Anti-myelin-associated glycoprotein (anti-MAG) antibodies are often present in patients with predominant sensory symptoms, and anti-GM1 antibodies are present in patients with predominant motor nerve symptoms.
Guillain-Barré syndrome
CIDP (*Often confused with GBS, but symptoms continue for longer)
MMN
Cancer is a general term that covers a wide array of related diseases in which some of the body’s cells begin to divide uncontrollably and spread into surrounding tissues.
Chorea is a movement disorder that causes involuntary, unpredictable body movements. The symptoms can range from minor movements, such as fidgeting, to severe uncontrolled arm and leg movements. These are often brief, irregular movements that are not repetitive or rhythmic, but appear to flow from one muscle to the next. These ‘dance-like’ movements often occur with athetosis which is twisting and writhing movements. Walking may become difficult, and include odd postures and leg movements.
Chorea is associated with a broad range of neurological conditions including Huntington’s disease, Chorea-acanthocytosis, Sydenham’s chorea, poststreptococcal infections, brucellosis, multiple sclerosis and autoimmune encephalitis. The detection of specific autoantibodies can help pinpoint the diagnosis.
Cocaine-related necrotizing vasculopathy. A possible complication of cocaine use is necrotizing vasculitis; Two distinct vasculitis syndromes have been described due to cocaine. One is a cocaine-related midline destructive lesion, secondary to a direct vasoconstrictor effect of cocaine, inducing ischemic necrosis of the nasal septal cartilage and perforation of the septum, mimicking findings of granulomatosis with polyangiitis in the upper airways. The other is ANCA-associated vasculitis, attributed to the drug Levamisole that is often used to ‘cut’ both powder and crack cocaine (Levamisole is found in about 70% of street cocaine). The main manifestations are typical cutaneous findings, arthralgia, otolaryngologic involvement, and agranulocytosis. A high degree of suspicion and awareness is needed in order to properly diagnose and treat these patients. ANCA myeloperoxidase (MPO) and/or proteinase 3 (PR3) may be positive but a more specific biomarker is the finding of antibodies to elastase.
Crohn’s disease (CD) is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract from the mouth to the anus. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, and weight loss. It should be differentiated from irritable bowel syndrome and ulcerative colitis. The finding of an antibody to Saccharomyces cerevisiae (ASCA) can help confirm the diagnosis of CD.
Cytokine storm, synonymous with “Cytokine Release Syndrome” (CRS) and “secondary haemophagocytic lymphohistiocytosis” (sHLH), is a severe and sudden hyper-inflammatory condition that can lead to multi-organ failure and death. This life-threatening condition is characterized by over-stimulated immune cells that produce highly elevated levels of various inflammatory mediators called cytokines (hypercytokinemia). With both pro-inflammatory cytokines (such as TNF-α, IL-1, and IL-6) and anti-inflammatory cytokines (such as IL-10, and IL-1Ra) becoming elevated in the blood, a turbulent and often lethal interplay between these cytokines escalates into a “Cytokine Storm”.
In the absence of a prompt diagnosis and subsequent medical intervention to stop the cytokine storm, the lungs can develop acute respiratory distress syndrome (ARDS) and (along with other organs) suffer permanent damage. Because of this, it is absolutely critical to gain a quick and comprehensive testing of the patient’s immune system.
HLH Cytokine Storm Causes:
Most commonly, a cytokine storm is triggered by viral infections, but can also be caused by other immune-system triggering events such as a bacterial infection (sepsis), fungal infection, an autoimmune disease such as multiple sclerosis or SLE, and possibly an adverse reaction to a drug (i.e.. cancer therapy) / vaccination (infusion reaction) and pollution. Macrophage activation syndrome (MAS) (a variation of HLH) is seen in some rheumatic diseases such as juvenile idiopathic arthritis, adult onset Still’s and systemic lupus erythematous (SLE).
Typical Increased Cytokines and Other Biomarkers seen in Cytokine Storm:
EGF, IL-1β, IL-1ra, IL-2, IL-6, IL-10, IL-7, IL-8, G-CSF, IFN-γ, IP-10, MCP-1, MIP-1α, TNFα, sIL-2Rα (sCD25).
Most notably are IL-6 and TNFα.
Other elevated biomarkers include serum ferritin, high C-reactive protein (CRP), D-dimer, lactic dehydrogenase (LDH), ALT/AST (liver dysfunction), and low blood counts (cytopenias).
HLH Cytokine Storm Treatments:
Anakinra – Recombinant and slightly modified version of the human interleukin 1 receptor antagonist protein
Tocilizumab – Anti-IL6 monoclonal antibody
Lenzilumab – Monoclonal antibody that targets GM-CSF which reduces activation of myeloid cells and decreasing the production of IL-1, IL-6, MCP-1, MIP-1, and IP-10.
Infliximab – TNF inhibitor via monoclonal antibody that targets TNFα
Adalimumab – TNF inhibitor via human antibody that targets TNFα
Dementia refers to a constellation of problems that include memory problems. Conditions associated with dementia are numerous, but the most common is a condition referred to as Alzheimer’s disease (AD). In AD there is a loss of normal brain cells and typically a replacement of normal proteins with misfolded proteins, some of which are collectively called amyloids. When the brain cells are being damaged and replaced by misfolded proteins, the proteins can sometimes be detected in the blood and cerebrospinal fluid. Hence, an early of confirmatory diagnosis of AD can be aided by detection of these proteins by a laboratory test.
Type 1 diabetes (T1D), once known as juvenile diabetes or insulin-dependent diabetes, is a chronic condition in which the pancreas produces little or no insulin. Insulin is a hormone needed to allow sugar (glucose) to enter cells to produce energy. T1D is considered an autoimmune disease and hence autoantibody tests are occasionally used to help confirm the diagnosis and also determine some complications and side effects for the disease.
The detection of autoantibodies against anti‐Glutamate Decarboxylase (GAD) is found in 70%-90% of patients with type 1 diabetes mellitus. The presence of anti-GAD antibodies gives a high predictive value for the patient to develop type 1 diabetes.
Patients with type 2 diabetes mellitus (T2DM) have significantly lower blood uromodulin concentrations than non-diabetics. Hence; below normal ranges of uromodulin can alert the clinician to possible emerging T2DM or other kidney diseases. Decreased uromodulin levels is possibly a sign of kidney function reduction.
Dysphagia is a term for swallowing difficulties. Some patients struggle with swallowing certain foods or liquids, while other patients may not be able to swallow at all. Other signs of dysphagia include coughing or choking when eating or drinking, bringing food back up, (sometimes through the sinus cavity / nose). A number of conditions can be associated with dysphagia including ALS but also in some patients with limited cutaneous systemic sclerosis where the esophagus and other parts of the gut are affected by the disease. Antibody studies can help track down the underlying cause of dysphagia, such as he presence of anti-centromere antibodies in scleroderma or Raynaud’s phenomenon.
Encephalitis is inflammation of the brain often caused by infection (viruses), an allergic reaction or the presence of autoantibodies / autoimmune disease. A diagnosis of the autoimmune form of encephalitis has been remarkably improved by the finding of an autoantibody, anti- N-methyl-D-aspartate receptor (NMDAR1), in the cerebrospinal fluid or blood of the patient. NMDAR is a glutamate receptor and ion channel protein found in nerve cells.
Infants and young children:
A fever is an increase in your body temperature and is often due to an illness. Fevers occur when the brain’s thermostat (hypothalamus) is signalled to increase normal body temperature. When this occurs, symptoms include the feeling of ‘chills’ which promotes the individual to take measures to warm-up by shivering or adding layers aiding in the body’s temperature increase.
Typically, a fever is temporary; however, in some instances a fever can be prolonged or consistently occurring. Either way, having a fever is a symptom of an abnormal occurrence or condition. Consistent periodic fevers and prolonged fevers are typically symptoms of a more severe underlying cause. Though a temporary fever is considered to play a key role in helping your body fight off a number of infections, consistent periodic fevers and prolonged fevers can be a harmful reaction in itself.
For an adult, a fever is a concern when body temperature reaches 103 F (39.4 C) or higher. For infants and toddlers, a temperature (measured orally) greater than 100°F (37.8°C) is a concern. Slightly elevated temperatures in infants and toddlers may indicate a serious infection.
Causes of a Fever:
In the case of fever of unknown cause, such as a consistent periodic fever or a prolonged fever, a cytokine / immune biomarker array may give insight into the cause and treatment options.
Guillain–Barré syndrome (GBS) is a rare disorder in which the body’s immune system attacks the nerves. Weakness and tingling in the arms and legs are usually the first symptoms. These sensations can quickly spread, eventually paralyzing the whole body. The exact cause of Guillain-Barré syndrome is unknown, however it is often preceded by an infectious illness such as a respiratory infection or influenza.
GBS occurs in several forms:
Acute inflammatory demyelinating polyradiculoneuropathy (AIDP) is the most common form in North America. The most common sign of AIDP is muscle weakness that starts in the lower part of the body and spreads upward.
Miller Fisher syndrome (MFS), in which paralysis starts in the eyes. MFS is also associated with unsteady gait. MFS occurs in about 5 percent of people with GBS and is more common in Asia.
Acute motor axonal neuropathy (AMAN) and acute motor-sensory axonal neuropathy (AMSAN) are less common in the North America are more frequent in China, Japan and Mexico.
Interstitial lung disease (ILD) is a group of lung diseases affecting the lung tissue and its associated lymphatics and small blood vessels. It may occur as part of an autoimmune injury to the lungs followed by an abnormal healing response, leading to fibrosis or scar tissue that replaces normal lung tissue. Idiopathic interstitial pneumonia is the term given to ILDs representing up to two-thirds of cases.
ILD has been sub classified into 7 subgroups:
Some of these subtypes are associated with autoantibodies seen in a spectrum of autoimmune diseases. The onset of ILD may herald progression to another autoimmune condition such a scleroderma, inflammatory myositis and others, or, the other diseases may develop ILD during their course. Autoantibodies can be useful ion distinguishing different subsets of ILD as well as serving as an indicator of another autoimmune disease evolving.
Juvenile dermatomyositis (JDM) is a disease in children that causes skin rash (dermato) and muscle inflammation (myositis) resulting in muscle weakness. JDM is an autoimmune disease, although genetic and environmental influences are thought to play a role. The diagnosis can be confirmed by finding JDM-associated autoantibodies.
Kawasaki disease (KD), or mucocutaneous lymph node syndrome, is an illness that primarily affects children and causes inflammation in arteries, veins, and capillaries. It also affects the lymph nodes and causes symptoms in the nose, mouth, and throat and is the most common cause of heart disease in children. KD begins with a high fever (>102 degrees F) for at least five days, along with other signs and symptoms such as a rash all over the body but often more severe in the diaper area. Red, bloodshot eyes without any pus, drainage, or crusting may also be present. Tender, swollen gland (lymph node) on one side of the neck can also be a feature.
Kawasaki disease signs and symptoms usually appear in three phases.
1st phase:
2nd phase:
3rd phase:
Limbic encephalitis is a form of brain inflammation caused by an autoimmune attack where the body produces antibodies against itself. Some cases are associated with cancer and some (particularly in children and younger individuals) are not. Although the disease is called “limbic” encephalitis, it is seldom limited to the limbic system.
Limbic encephalitis is broadly grouped into two types: paraneoplastic limbic encephalitis (associated with a tumor) and non-paraneoplastic limbic encephalitis. In cases associated with a tumor, recovery can only follow complete removal of the tumor, which is not always possible. Limbic encephalitis is classified according to the autoantibody associated with the disease. The most common types are:
Anti-Hu (associated with small-cell carcinoma of the lungs).
Anti-Ma2 (associated with germ-cell tumours of the testis).
Anti-NMDAR (associated with tumors of the ovaries, commonly teratomas; but is also seen in individuals without any detectable tumors).
Patients with drug-induced lupus (DIL) often develop some of the features of systemic lupus erythematous (SLE), especially low-grade fever, joint pains and inflammation of the lining around the lungs (pleurisy). A long list of drugs has been implicated in DIL, but it is important to distinguish from SLE because the condition can usually be reversed by stopping the offending drug. In addition, antibody tests, such as anti-histone, anti-chromatin/nucleosomes and anti-ssDNA, can help make the diagnosis of DIL. Although there is no highly–specific antibody test for DIL, if the patient has other antibodies associated with SLE such as anti-Sm, anti-Ro-60/SSA, anti-ribosomal P, and anti-DFS70, the diagnosis of DIL can be virtually excluded.
Systemic lupus erythematosus (SLE or lupus for short) is an autoimmune disease that occurs when the body’s immune system attacks its own tissues and organs causing severe inflammation of the joints, skin, kidneys, blood cells, brain, heart and lungs. SLE can be difficult to diagnose because its signs and symptoms mimic many other conditions. A distinctive sign of lupus is a facial rash that resembles the wings of a butterfly unfolding across both cheeks. However, this symptom occurs in less than half of all patients. There are both genetic and hormonal components that accelerate SLE. The most obvious hormonal manifestation is that females outnumber males by 9:1. While there is no cure for lupus, a growing number of treatments show promise. Hydroxychloroquine, for example, has been shown to stabilize disease once it is in remission.
Although more than 200 autoantibodies have been described in SLE, the diagnosis is remarkably aided by the detection of a spectrum of autoantibodies, some of which are disease-specific (anti-dsDNA, anti-Sm) and others that are disease-related (anti-Ro60/SSA, anti-U1RNP).
Mixed Connective Tissue Disease (MCTD) refers to a an ‘overlap’ condition where patients develop features of other autoimmune conditions such as Raynaud’s, taught finger swelling (features of early scleroderma), arthritis and muscle inflammation (myositis). It is important to distinguish MCTD from other overlap conditions. The antibody hallmark of MCTD, and requirement for the classification and diagnosis of the disease is anti-U1-RNP.
Multifocal motor neuropathy (MMN) is a rare neuropathy characterized by progressive, asymmetric muscle weakness and atrophy (wasting). Signs and symptoms may include weakness in the hands and lower arms; cramping; involuntary contractions or twitching; wrist drop or foot drop, and atrophy of affected muscles.
Myasthenia gravis (MG) is a neuromuscular disorder that causes weakness in the skeletal muscles which are the muscles your body uses for movement. It occurs when communication between nerve cells and muscles becomes impaired. This impairment prevents crucial muscle contractions from occurring, resulting in muscle weakness. Weakness associated with MG typically gets worse with more activity and improves with rest. Symptoms of MG can include trouble talking, problems walking upstairs or lifting objects, facial paralysis, difficulty breathing, difficulty swallowing or chewing, drooping of eyelids and double vision. Some people with MG have tumor of the thymus gland (thymoma).
The main test for MG is a blood test to detect the presence of an autoantibody that binds to the acetylcholine receptor (AchR) thus stopping signals being sent between the nerves and muscles. About 75 percent of patients with MG show an elevated amount of AchR antibodies in the blood. In one-third of MG patients with generalized weakness and without elevated acetylcholine receptor antibodies, muscle-specific tyrosine kinase (MuSK) antibody is increased, which can help with the diagnosis.
Myositis overlap syndromes refer to conditions which include myositis in the presence of or in the development of other autoimmune diseases such as systemic sclerosis, SLE, RA and idiopathic interstitial lung disease.
Necrotizing myositis (NM) is a subset of autoimmune myositis (AIM), and is distinguished by severe necrosis of skeletal muscle without overt evidence of severe inflammation. NM has been associated with statin (blood cholesterol lowering drugs) but is also seen in patients who are not on those drugs. Antibody markers called anti anti-3- hydroxy-3-methylglutaryl-CoA reductase (HMGCR), anti-signal recognition partner (SRP), and anti-SRP are markers of NM. There are case reports of anti-SMN and anti-nuclear envelope antibodies associated with NM.
Neuromyotonia (NMT), is also called Isaacs’ syndrome, Isaac’s-Merten’s syndrome, Continuous muscle fiber activity syndrome, Quantal squander syndrome, Acquired neuromyotonia, Isaac syndrome, Isaac-Mertens syndrome or Peripheral nerve hyperexcitability. It is a rare neuromuscular disorder that is characterized by progressive muscle stiffness, continuously contracting or twitching muscles (myokymia), and diminished reflexes. Signs and symptoms generally develop between ages 15 and 60, with most people experiencing symptoms before age 40. Although the exact underlying cause is unknown, there appear to be hereditary and acquired (non-inherited) forms of the condition. Treatment is based on the signs and symptoms present in each person. An autoimmune disease may be present, and detection of certain antibodies can help with diagnosis.
Optic neuritis (ON) is an inflammation of the optic nerve, the nerve responsible for vision. ON can flare up suddenly from an infection or nerve disease. Inflammation usually causes temporary vision loss that typically happens in only one eye. Inflammation may be caused by an autoimmune attack on the optic nerve and other vision pathways, and can be a feature of multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). Autoantibody testing can help differentiate ON associated with MS and NMOSD: anti Aquaporin 4 antibodies are characteristic of NMOSD while antibodies to neurofilament and other nerve components (myelin) are related to MS.
Primary biliary cholangitis (PBC), at one time called primary biliary cirrhosis, is an autoimmune condition in which the bile ducts in the liver are slowly destroyed by an immune attack. When the bile ducts are damaged, bile can back up in the liver and sometimes lead to irreversible scarring of liver tissue (cirrhosis). There is evidence that a combination of genetic and environmental factors triggers the disease. Up to 50% of people with PBC do not have any noticeable symptoms. PBSC is most commonly diagnosed in middle aged females who develop progressively severe itchiness. Medications can slow the liver damage, especially if treatment begins early. One of the more specific blood tests to help confirm the diagnosis of PBC is the detection of antibodies to the mitochondria and other components in cells.
Primary membranous nephropathy (pMN) is a kidney-specific, autoimmune glomerular disease that presents with increased protein in the urine associated with a pathognomonic pattern of injury in the foot processes of the glomerulus. PMN develops gradually, so patients may not suspect that anything is wrong. As protein is lost from the blood it can cause swelling of the ankles and legs along with unexplained weight gain. Since a number of other conditions can also be associated with high protein in the urine, it is important to make an accurate diagnosis by kidney biopsy supported by serological markers anti-phospholipase 2 receptor (PLA2R) and anti-thrombospondin 7.
Rheumatoid arthritis (RA) is an autoimmune inflammatory disorder that affects joints of the body, but can be accompanied by inflammation in other organs as well such as the skin, eyes, lungs, heart and blood vessels. Unlike the wear-and-tear damage of the more common form of arthritis, osteoarthritis, RA affects the lining of your joints, causing a painful swelling that can eventually lead to loss of the smooth gliding cartilage of the joint, erosions of the bone around the joints and, if unchecked, loss of function and deformity of the joints. Many new medications have improved treatment options dramatically. Because it is important to make an early diagnosis before joint damage occurs, autoimmune diagnostic test for autoantibodies called rheumatoid factor (RF), antibodies to cyclic citrullinated peptides (ACPA / CCP) and other proteins in the joint (carbamylated peptides, peptidyl arginine deiminase (PAD)) are used as an aid to diagnosis.
Scleroderma is a progressive disorder characterized by thickening and tightening of the skin — especially on the arms, face and hands — which results in loss of flexibility. The onset of disease in most patients is the development of Raynaud’s phenomenon, a condition where areas of the body, most notably the fingers and toes, feel numb and cold in response to cold temperatures or stress. In Raynaud’s disease, particularly on exposure to cold, smaller arteries that supply blood to the fingers and toes go into spasm causing a whitening/blanching followed by a cyanotic (bluish) appearance. Not all patients with Raynaud’s progress to develop scleroderma. Because of this and because the other symptoms are seen in a number of other conditions, the diagnosis is remarkably aided by detecting scleroderma-specific autoantibodies (anti-topoisomerase I, anti-centromere, anti-RNA polymerase, anti-fibrillarin) or scleroderma-related autoantibodies (anti-U1-RNP, anti-BICD2, anti-RNPC3).
Sepsis is a potentially life-threatening condition caused by the body’s response to an infection. The body normally releases proteins into the bloodstream to fight an infection. Sepsis occurs when the body’s response to these proteins (e.g. cytokines) is out of balance, triggering changes that can damage multiple organ systems. The diagnosis and a general guide to treatment is possible through detection of specific cytokines in cytokine arrays.
Sjögren syndrome (SjS, SS) is long-term autoimmune disease that affects the body’s moisture-producing glands. Symptoms typically include dry mouth & dry eyes and may also include dryness of the skin or vagina. Patients may also notice a chronic cough, numbness in the arms and legs, fatigue, muscle or joint pains, and have thyroid problems.
In approximately 5% of patients there is an increased risk of lymphoma. Autoantibody testing can help make an accurate diagnosis to differentiate this condition from other disease that can produce some of the same features.
Systemic lupus erythematosus (SLE or lupus for short) is an autoimmune disease that occurs when the body’s immune system attacks its own tissues and organs causing severe inflammation of the joints, skin, kidneys, blood cells, brain, heart and lungs. SLE can be difficult to diagnose because its signs and symptoms mimic many other conditions. A distinctive sign of lupus is a facial rash that resembles the wings of a butterfly unfolding across both cheeks. However, this symptom occurs in less than half of all patients. There are both genetic and hormonal components that accelerate SLE. The most obvious hormonal manifestation is that females outnumber males by 9:1. While there is no cure for lupus, a growing number of treatments show promise. Hydroxychloroquine, for example, has been shown to stabilize disease once it is in remission.
Although more than 200 autoantibodies have been described in SLE, the diagnosis is remarkably aided by the detection of a spectrum of autoantibodies, some of which are disease-specific (anti-dsDNA, anti-Sm) and others that are disease-related (anti-Ro60/SSA, anti-U1RNP).
Transverse myelitis (TM) is a neurological condition in which the spinal cord is inflamed. Transverse implies that the inflammation extends horizontally across the spinal cord. TM is characterized by weakness and numbness of the limbs, abnormal sensation and motor skills, dysfunctional urethral and anal sphincter activities, and dysfunction of the autonomic nervous system and high blood pressure. Signs and symptoms vary according to the affected level of the spinal cord. While the underlying cause of TM is unknown, in some patients it is related to autoimmune conditions such as SLE, anti-phospholipid syndrome and neuromyelitis optica spectrum disorders. In these instances, autoantibody testing can be helpful in deriving an accurate diagnosis.
Thrombotic thrombocytopenic purpura (TTP) is a blood disorder that results in blood clots forming in small blood vessels throughout the body. The formation of these blood clots leads to the following: A low platelet count, low red blood cells due to their breakdown, and often kidney, heart and brain dysfunction. Symptoms may include large bruises, fever, weakness, shortness of breath and headache. In about half of cases a trigger/cause is able to be identified, while in the remainder the cause remains unknown. Autoantibody tests are used to help determine if the cause is related to an underlying autoimmune disease including a condition referred to as idiopathic TTP where the patient develops autoantibodies that alter the function of a protein known as ADAMTS13.
See ANCA-related vasculopathies /glomerulonephritis