Restricted specificity of anti-ribosomal P antibodies to SLE patients in Israel

Objective. Anti-ribosomal P antibod- ies (aRib-P Ab) are highly specific for systemic lupus erythematosus (SLE), but their correlatation with disease activity and manifestations including renal, hepatic and central nervous sys- tem (CNS) involvement is still contro- versial. The aim of our study was to evaluate the prevalence of aRib-P Ab and their correlation with clinical man- ifestations and anti-dsDNA antibodies in SLE patients from Israel. Methods. Elevated titers of aRib-P Ab utilizing the ELISA method were ana- lyzed in 141 sera samples from 44 SLE patients, 20 Familial Mediterranean Fever (FMF) patients, 22 primary anti- phospholipid syndrome (PAPS) pat- ients, 12 patients with infections, and 43 healthy individuals. The SLEDAI score was utilized for assessing SLE disease activity. Results. Elevated titers of aRib-P Ab were present in 11% of SLE patients (n = 6). The mean SLEDAI was 7 (range: 3-10). No statistically significant asso- ciation was observed between the pres- ence of aRib-P Ab and disease manifes- tations present in the SLEDAI. The 6 SLE patients had renal disease (n = 1), leucopenia (n = 1), rash (n = 3), and CNS involvement manifested as psy- chosis (n = 1) or depression (n = 1). Elevated titers of anti-dsDNA antibod- ies were found in 50% of patients with elevated titers of aRib- P Ab. Patients with PAPS, FMF, infections or healthy controls did not harbor elevated titers of aRib-P Ab. Conclusion. Elevated titers of aRib-P Ab were restricted to SLE patients. We confirm previously reported associa- tions of aRib-P Ab reactivity with dis- ease activity and elevated anti-dsDNA Ab titers. No significant correlation with a specific manifestation described on the SLEDAI score was established in this small cohort of patients.