LUPUS ANTICOAGULANT, HIGH-LEVELS OF ANTICARDIOLIPIN, AND ANTI-BETA(2)-GLYCOPROTEIN-I ANTIBODIES ARE ASSOCIATED WITH CHRONIC THROMBOEMBOLIC PULMONARY-HYPERTENSION

Objective. To evaluate the prevalence of lupus anticoagulant (LAC) and anticardiolipin antibodies (aCL), and that of anti-beta(2)- glycoprot ein I (anti-beta(2)-GPI) and prothrombin antibodies in patients with p ulmonary hypertension (PH). Methods. Fifty-four consecutive patients w ith PH were studied: 23 with primary, 20 secondary, and 11 chronic thr omboembolic PH. LAC was diagnosed by screening and confirmatory coagul ation tests, while aCL, anti-beta(2)-GPI, and prothrombin antibodies w ere measured by ELISA. Results. Prevalence of aPL was higher in patien ts with chronic thromboembolic PH compared to the other 2 groups. The prevalence in chronic thromboembolic PH vs primary and secondary PH wa s: LAC 63.6 vs 13.0 and 10.0%, p < 0.001; aCL-IgG 54.5 vs 17.4 and 15. 0%, p < 0.02; anti-beta(2)-GPI-IgG 36.4 vs 0 and 0%, p < 0.001; and pr othrombin antibodies-IgG 36.4 vs 8.7 and 5.0%, p < 0.05. No difference s between groups were found for any antibody of IgM isotype. Antibodie s detected in patients with primary and secondary PH were of low titer , so considering only moderate or high titers these differences were g reater for aCL-IgG (odds ratio, OR 24.6, confidence interval, CI 3.0-2 82, p = 0.0004) and IgM (OR 35.0, CI 2.9-1692, p = 0.0007) and remaine d significant for anti-beta(2)-GPI-IgG (OR = undefined, p = 0.006). Mu ltivariate analysis showed that only LAC and aCL-IgG at moderate or hi gh levels were independent variables associated with chronic thromboem bolic PH. Conclusion. The presence of LAG, moderate or high levels of aCL-IgG, or anti-beta(2)-GPI-IgG was strongly associated with that of chronic thromboembolic PH. These data are in agreement with the close relationship observed among these 3 variables and thromboembolism in p atients with aPL.