Anti-β2-glycoprotein I antibodies are highly prevalent in a large number of Brazilian leprosy patients.

OBJECTIVES: To determine the prevalence of anticardiolipin (aCL) and anti-β2-glycoprotein I (anti-β2GPI) antibodies in leprosy patients, during and after specific multidrug therapy (MDT), and to evaluate a possible association between these antibodies and some clinical characteristics of leprosy, including clinical forms, reactional episodes and treatment.

METHODS: The study included 158 leprosy patients, 129 gender-and-age matched healthy individuals, and 38 women with primary antiphospholipid syndrome (APS). Clinical and demographic characteristic of leprosy patients were collected, and serum samples, obtained from all participants, were kept frozen at - 20°C. Antibodies were measured either by an in house-developed ELISA (aCL) or by a commercial ELISA (anti-β2GPI).

RESULTS AND CONCLUSIONS: Increased levels of aCL and anti-β2GPI antibodies were found in leprosy patients and in the APS group, however, in contrast to APS, the predominant isotype in leprosy was IgM. The frequency of aCL and anti-β2GPI antibodies was significantly higher in leprosy patients than in healthy individuals (15.8% vs. 3.1%; p>0.01; 46.2% vs. 9.4%, p>0.01), respectively. The lepromatous form predominated among aCL positive leprosy patients (p>0.01). There was no difference in aCL and anti-β2GPI positivity between leprosy patients taking MDT and those completed MDT as cured. Furthermore the duration of discharged period (period between discharge from MDT and the realization of the study) had no effect on anti-β2GPI positivity, and a slight increase in aCL positivity was observed in patients with longer follow up periods (p=0.04), suggesting that the presence of antiphospholipid antibodies (aPL) was not a transient phenomenon. Although aPL in leprosy were frequent and β2GPI-dependent as those found in APS, IgM was the predominant isotype, and there was no association with thrombosis or other APS manifestations.