Specific antinuclear antibodies are associated with clinical features in systemic lupus erythematosus

Objectives: To study associations between antinuclear antibodies (ANA) and signs/symptoms in patients with systemic lupus erythematosus (SLE). Methods: A consecutive cohort of 289 patients with SLE was included; 235 fulfilled ACR criteria for SLE and were further analysed. ANA profiles were determined by line immunoassay and by indirect immunofluorescence on Crithidia luciliae. An extensive list of signs/symptoms was evaluated. Results: Five clusters of antibodies were defined by cluster analysis: 1 - antibodies to SmB, SmD, RNP-A, RNP-C, and RNP-70k; 2 - antibodies to Ro52, Ro60, and SSB; 3, 4, and 5 - antibodies to ribosomal P, histones and dsDNA, respectively. Significant associations ( pless than or equal to 0.01) were found between anti-RNP-70k, anti-RNP-A, anti-RNP-C and Raynaud's phenomenon, between anti-RNP-A, anti-RNP-70k and leucopenia, and between anti-RNP-A, anti-RNP-C and a lower prevalence of urine cellular casts. Anti-SSA, anti-SSB were associated with xerostomia, and anti-SSB with pericarditis. Antibodies to ribosomal P were associated with haemolytic anaemia, leucopenia, and alopecia. Patients with anti-dsDNA antibodies had a higher risk for cellular casts and a lower risk for photosensitivity. Antihistone antibodies were associated with arthritis. Conclusions: In a large and consecutive cohort of patients with SLE, clusters of antibodies were identified. Previously reported associations of antibodies with symptoms were confirmed and new associations found.