Diagnostic Tests

CLINICAL ASSOCIATIONS

Mitogen’s Anti‐GABA_B Receptor assay is an autoimmune diagnostic test that detects autoantibodies to Gamma-amino-butyric acid (GABA_B) receptor. GABA_B receptors (GABA_BR) are G-protein-linked transmembrane protein receptors for gamma-aminobutyric acid (GABA). GABA_B receptors are prevalent in the central nervous system and the autonomic division of the peripheral nervous system. GABA_B receptors function to stimulate the opening of neuron’s K+ channels (bringing the neuron closer to the equilibrium potential of K+) and reduce the activity of adenylyl cyclase and Ca2+ channels (via G-proteins). GABA_B receptors are also involved in alcohol-related behaviors, pain, and human development. Anti-GABA_B receptor autoantibodies are associated with an autoinflammatory / limbic encephalitis where there is no evidence of a causative organism. Serum and CSF samples should be analyzed in parallel as intrathecal synthesis may occur even when the serum titer is low or absent. When a positive serological result is obtained, a comprehensive investigation for underlying malignancy is suggested.

References:
Rang HP, Dale MM, Ritter JM, Flower RJ, Henderson G (2016). Rang and Dale’s Pharmacology (8th ed.). Elsevier, Churchill Livingstone. p. 462. ISBN 978-0-7020-5362-7. OCLC 903234097.
Dzitoyeva S, Dimitrijevic N, Manev H (2003). “Gamma-aminobutyric acid B receptor 1 mediates behavior-impairing actions of alcohol in Drosophila: adult RNA interference and pharmacological evidence”. Proc Natl Acad Sci USA. 100 (9): 5485–90. Bibcode:2003PNAS..100.5485D. doi:10.1073/pnas.0830111100. PMC 154371. PMID 12692303.
Manev H, Dimitrijevic N (2004). “Drosophila model for in vivo pharmacological analgesia research”. Eur J Pharmacol. 491 (2–3): 207–8. doi:10.1016/j.ejphar.2004.03.030. PMID 15140638.
Dzitoyeva S, Gutnov A, Imbesi M, Dimitrijevic N, Manev H (2005). “Developmental role of GAB