Biological false positive test for syphilis in lepromatous leprosy patients with concomitant hepatitis B virus infection.

Within the wide range of immunological abnormalities occurring in lepromatous leprosy (LL), antiphospholipid antibodies unrelated to treponemal infection, the so-called biological false positive test for syphilis (BFP), have long been recognized. Considering that BFP may also be encountered in different clinical situations, the fact that whether BFP in LL occurs solely or is associated with other concomitant infections or serological abnormalities was investigated. For this purpose, two groups of LL patients with similar clinical features and no evidence of treponemal infection were studied, one group with BFP (n = 21) and the other without BFP (n = 13). At the time of study, patients underwent the following tests: hepatitis B surface antigen (HBsAg), anti-Trypanosoma cruzi specific antibodies, infectious mononucleosis-associated heterophil antibodies, rheumatoid factors, antinuclear antibodies, anti-dsDNA antibodies and gamma-globulin serum levels. Except for HBsAg, which was more frequently detected in patients with BFP (p < 0.02), the other variables showed no significant differences between groups. This finding suggests the possibility that simultaneous infection with hepatitis B virus could contribute, to some extent as an additional factor, to the generation of an altered humoral immune response. The possible physiopathologic significance of anti-phospholipid antibodies, in the light of current knowledge, is also discussed.