The prevalence and clinical significance of antiphospholipid antibodies in the patients with systemic sclerosis--preliminary report.

Purpose: The aim of our study was to evaluate the prevalence of anticardiolipin and anti-beta2-glikoprotein I (anti-beta2GPI) antibodies in patients with systemic sclerosis (SSc) and to correlate the presence of these antibodies with clinical and serological features of the disease.

Material and methods: 22 patients (21 women and 1 man) fulfilling the ACR classification criteria of SSc were included into the study. In all SSc patients a detailed clinical evaluation including skin and internal organ involvement was performed. Moreover, the measurements of antitopoisomerase I (anti-Scl-70) and anticentromere (ACA) antibodies were done in all patients studied. Anticardiolipin antibodies in IgM and IgG class and anti-beta2GPI antibodies in IgM, IgG and IgA class were evaluated using ELISA kits (Hycor Biomedical and DiaSorin).

Results: Anticardiolipin antibodies were found in 10/22 (45.5%) patients with SSc, in 6/12 (50%) with diffuse SSc and in 4/10 (40%) with the limited SSc. Anticardiolipin antibodies in the IgG class were observed in 4/22 (18.2%) patients, and in the IgM class in 9/22 (40.9%) subjects. Anti-beta2GPI antibodies were found in 9/22 patients (40.9%), of which 3/22 (13.6%) had antibodies in IgG class, 4/22 (18.2%) in IgM class and 3/22 (13.6%) in the IgA class. Anti-beta2GPI antibodies were found exclusively in the patients in whom the anticardiolipin antibodies were also present. An association between the presence of antiphospholipid antibodies and internal organ involvement (pulmonary fibrosis, pulmonary hypertension and the alterations of oesophageal function) was not significant. No significant correlation was found between the presence of anticardiolipin or anti-beta2GPI antibodies and the presence of anti-Scl-70 or ACA antibodies.

Conclusions: The results of our study indicate that the prevalence of anticardiolipin antibodies and anti-beta2GPI antibodies is relatively high in patients with SSc. A more detailed assessment of the relationship between the presence of antiphospholipid antibodies and the clinical and serological features of SSc requires further studies on the larger group of patients and a several years of follow-up.