Lupus anticoagulant, high levels of anticardiolipin, and anti-beta2-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-beta2- glycoprotein I (anti-beta2-GPI) and prothrombin antibodies in patients with pulmonary hypertension (PH).


METHODS
Fifty-four consecutive patients with PH were studied: 23 with primary, 20 secondary, and 11 chronic thromboembolic PH. LAC was diagnosed by screening and confirmatory coagulation tests, while aCL, anti-beta2-GPI, and prothrombin antibodies were measured by ELISA.


RESULTS
Prevalence of aPL was higher in patients with chronic thromboembolic PH compared to the other 2 groups. The prevalence in chronic thromboembolic PH vs primary and secondary PH was: 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-beta2-GPI-IgG 36.4 vs 0 and 0%, p < 0.001; and prothrombin antibodies-IgG 36.4 vs 8.7 and 5.0%, p < 0.05. No differences between groups were found for any antibody of IgM isotype. Antibodies detected in patients with primary and secondary PH were of low titer, so considering only moderate or high titers these differences were greater for aCL-IgG (odds ratio, OR 24.6, confidence interval, CI 3.0-282, p = 0.0004) and IgM (OR 35.0, CI 2.9-1692, p = 0.0007) and remained significant for anti-beta2-GPI-IgG (OR = undefined, p = 0.006). Multivariate analysis showed that only LAC and aCL-IgG at moderate or high levels were independent variables associated with chronic thromboembolic PH.


CONCLUSIONS
The presence of LAC, moderate or high levels of aCL-IgG, or anti-beta2-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 patients with aPL.
Institute of Cardiology and Cardiovascular Surgery, Division of Hematology, Favaloro Foundation, Buenos Aires, Argentina.
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Carreras
D000328:Adult; D000906:Antibodies / Q000097:blood; D017153:Antibodies, Anticardiolipin / Q000097:blood*; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000276:immunology*; D016682:Lupus Coagulation Inhibitor / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011516:Prothrombin / Q000276:immunology; D011655:Pulmonary Embolism / Q000276:immunology*; D053482:beta 2-Glycoprotein I
D000906:Antibodies; D017153:Antibodies, Anticardiolipin; D006023:Glycoproteins; D016682:Lupus Coagulation Inhibitor; D053482:beta 2-Glycoprotein I; D011516:Prothrombin