Anticardiolipin antibodies in Behcet's disease: a reassessment

Objective. To assess the frequency and clinical relevance of anticardiolipi n antibodies (aCL) in Behcet's disease (BD). Methods. IgG, IgM and IgA aCL isotypes were investigated by ELISA in 128 pa tients with BD, 143 healthy controls and 20 systemic lupus erythematosus (S LE) patients. Results. The IgA binding index (BI) was slightly elevated in BD compared wi th healthy controls (120 +/- 53 vs 107 +/- 46, P = 0.02), whereas IgG and I gM aCL levels were not significantly different (IgG, BD 2.5 +/- 2.4 G phosp holipid (GPL), healthy controls 2.8 +/- 3.6 GPL, P = 0.6; IgM, BD 0.7 +/- 0 .9 M phospholipid (MPL), healthy controls 0.9 +/- 1.3 MPL, P = 0.6). The fr equency of aCL positivity was 7% in BD (IgG 0.8%, IgM 1.6%, IgA 4.6%), 50% in SLE and 5.6% in healthy controls. IgA BI was elevated in the BLA-B5-nega tive group compared with HLA-B5-positive patients (P < 0.005). In a literat ure review, the frequency of aCL was found to be 9.5% in studies from Turke y compared with 25.5% in other series (P < 0.0001). Conclusion. These results do not suggest a primary role for aCL in BD. A si gnificantly lower frequency of aCL in Turkish BD patients than in other ser ies indicate that regional determinants, whether environmental or genetic, might also play a role in controlling aCL production in BD.