In general, the screening HEp-2 IFA titer does not correlate with clinical characteristics such as disease activity or flares, and therefore is not a particularly useful parameter for following the course of the disease or estimating the efficacy of therapy (10;11). It should be emphasized that this conclusion is not based on careful prospective laboratory studies using standardized tests on advanced diagnostic platforms or in defined indices of clinical disease (e.g. SLEDAI, SLAM). In general, titers of Hep-2 IFA may fluctuate over time, and the antibodies tend to be detectable in phases both of disease activity and remission (12;13), although there are reported exceptions. One exception may be the presence of high levels of anti-U1-RNP antibodies that are characteristic of mixed connective tissue disease (14).
Another exception is related to evidence that anti-dsDNA antibody levels often correlate with certain clinical features, e.g. lupus nephritis, and its determination is obligatory in the diagnostic work-up of SLE patients and the follow-up of nephritic cases (15;16). However, it is appreciated that some assays for anti-dsDNA detection are better than others in measuring clinically important shifts in antibody levels.