ANTIENDOTHELIAL CELL ANTIBODIES IN SYSTEMIC-SCLEROSIS - SIGNIFICANT ASSOCIATION WITH VASCULAR INVOLVEMENT AND ALVEOLO-CAPILLARY IMPAIRMENT

Objective To assess the frequency of antiendothelial cell autoantibodi es (AECAs) in a group of patients with systemic sclerosis (SSc) and po ssible associations with clinical and serologic features of the diseas e. Methods Sera from 50 patients with SSc (38 with the limited and 12 with the diffuse form) were screened for AECA (ELISA). The reference l imits were were 56.6% for the IgM isotype and 3.3.5% for the IgG isoty pe. RECA results were analyzed ill relation to lung involvement (chest x-ray, high resolution computed tomography (HRCT), ventilation scinti scan with radioaereosol (DTPA), pulmonary pressure (echodoppler techni que): heart involvement (EKG, 24 hr ambulatory EKG, echocardiography), cutaneous involvement (skin score), capilaroscopic characteristics an d digital ulcers. AECA were also correlated with the erythrocyte sedim entation rate (ESR), anticentromere (ACA) and antitopoisomerase I (ATA ) autoantibodies, and angiotensin converting enzyme plasma levels (ACE ). Results The AECA IgG prevalence was 40% (22/50) for the SSc group a s a whole without significant differences between subsets. A significa nt negative correlation was shown between the AECA and ACE plasma leve ls in both subsets. In the diffuse form, a significant positive correl ation was found between AECA and ESR and significant associations were found between AECA and the parameters reflecting alveolo-capillary in volvement (DLco, DTPA), the pulmonary al artery pressures, digital ulc ers and capillaroscopic abnormalities. No statistically significant co rrelations were found between AECA and heart involvement, the skin sco re of pulmonary interstitial fibrosis. Conclusions These data suggest that in SSc the anti-endothelial cell antibodies are directly linked t o vascular injury mid could reflect endothelial damage. Further studie s are needed to verify whether AECA might identify a subgroup of patie nts at higher risk for the development of vascular crises and whether they might therefore be considered a predictor of outcome in SSc patie nts.