THE MONTPELLIER ANTIPHOSPHOLIPID (MAP) STUDY - PREVALENCE AND CLINICAL-SIGNIFICANCE OF ANTIPHOSPHOLIPID ANTIBODIES IN AN INTERNAL-MEDICINE DEPARTMENT

Antiphospholipid antibodies (aPLA) have been described in many clinica l conditions. However, their clinical and pathogenic significance rema in unclear. The lack of prospective epidemiological data concerning aP LA prompted us to determine the prevalence of these antibodies in a se ries of consecutive patients admitted to a Department of Internal Medi cine. The study also attempted to describe the characteristics and out come of the aPLA-positive patients. From October 1992 to March 1994, 1 014 consecutive patients were tested at least once for aPLA. Elevated aPLA levels were found in 7.1% (72 patients), whereas 2.9% of the cont rol population was aPLA-positive. We compared the clinical data of the aPLA-positive and -negative groups. Concerning the frequency of vascu lar diseases (deep vein thrombosis, pulmonary embolism, arterial disea se, stroke), we failed to find any significant difference between the aPLA-positive and -negative patients. On the other hand, malignancies and alcoholism were more frequent in aPLA-positive patients than in aP LA-negative ones. Thirty-one aPLA-positive patients were subsequently retested for aPLA and lupus anticoagulant (LA) detection; aPLA remaine d positive in 16 patients (52%); LA was detected in 10 patients. Among the latter, 8 remained aPLA-positive, whereas the other 2 aPLA had be come negative when LA was detected, pointing out the possible switch f rom aPLA to LA. These results argue for the use of a combination of se veral coagulation and immunological tests to optimize detection of the se autoantibodies. Further clinical and epidemiological studies using standardized laboratory assays are needed to obtain a better understan ding of aPLA significance.