Anti-beta 2 glycoprotein I and anticardiolipin antibodies in leptospirosis, syphilis and Kala-azar

Objective Reports have shown that anticardiolipin (aCL) antibodies present in patients with autoimmune diseases are dependent on the cofactor beta2 gl ycoprotein I (beta2 GPI), as opposed to aCL antibodies seen in infectious d iseases such as syphilis, HIV hepatitis C, etc. The assay for anti-beta 2GP I antibodies has been reported to be more specific for antiphospholipid syn drome (APS). However; the prevalence of these antibodies in diseases such a s leishmaniasis and leptospirosis remains unknown. The aim of the present s tudy was determine the prevalence of antibodies to cardiolipin and to beta 2GPI in patients with different infectious diseases, including leptospirosi s, syphilis and leishmaniasis. Methods Samples from patients with Kala-azar (visceral leishmaniasis), syph ilis or leptospirosis were tested for IgG and IgM anticardiolipin and IgG a nti-beta 2GPI antibodies by ELISA. Results In patients with Kala-azar the prevalence of lgG aCL, IgM aCL and a nti-beta 2GPI was 6% (2/30), 3% (1/30) and 53% (16/30), respectively. In sy philis the prevalence was 18% (14/74), 13% (10/74) and 10% (8/70), respecti vely. In leptospirosis the frequency of these antibodies was 23% (9/39), 10 % (4/39) and 17% (6/34), respectively. There Was no statistical correlation between aCL and anti-beta 2GPI antibodies in these diseases. Discussion This study clearly shows a significant prevalence of anti-beta 2 GPI antibodies in leptospirosis and leishmaniasis and syphilis. This indica tes that the assay for anti-beta 2GPI antibodies should be thoroughly valid ated before it is introduced as a definitive tool for the diagnosis of APS, testing a larger number of sera from patients with a wider range of clinic al conditions.