RESUMEN
OBJECTIVE: To evaluate sera titers for antibodies anti-cyclic citrullinated peptide and their correlation against sera levels of anti-topoisomerase I and anti-centromere antibodies in Mexican patients with systemic sclerosis. PATIENTS AND METHODS: Consecutive outpatients with systemic sclerosis who attending to rheumatology clinic at a second level hospital facility. The antibodies anti-cyclic citrullinated peptide, anti-topoisomerase I and anti-centromere were determined by enzymatic immunoassay (ELISA). STATISTICAL ANALYSIS: Spearman for correlation between numerical variables with nonparametric distribution. Fisher exact test or chi2 to compare proportions and Student t test for dimensional variables. RESULTS: Thirty female patients were included; aged 53 +/- 13, the disease duration at the time of the study was 10 +/- 9. Twenty-three patients (77%) exhibited diffuse disease. Anti-centromere, anti-topoisomerase I, and anti-cyclic citrullinated peptide were detected in nine, nine and three patients respectively. The correlation analysis showed the independence of autoantibodies anti-centromere and anti-topoisomerase I with respect to the levels of anti-cyclic citrullinated peptide. CONCLUSIONS: This study confirms the low frequency of anti-cyclic citrullinated peptide antibodies in patients with systemic sclerosis. A lack of correlation between autoantibodies considered as "mutually excluded" anti-topoisomerase I and anti-centromere, indicating that the analysis of the relevance for anti-cyclic citrullinated peptide in systemic sclerosis must include other clinical and serological variables.