Specific testing for "isolated" anti-52 kDa SSA/Ro antibodies during standard anti-extractable nuclear antigen testing is of limited clinical value

Abstract

Aim: To ascertain whether specific testing for "isolated" anti-52 kDa SSA/Ro antibodies (a-SSA/Ro52) during standard anti-extractable nuclear antigen (ENA) testing is clinically useful. Methods: 1438 consecutive sera submitted for anti-ENA testing over 1 year were evaluated for a-SSA/Ro52 using various assays. Results: 7 of 1438 (0.48%) patients were found to have a-SSA/Ro52 without SSA/Ro60 antibodies. Subsequent testing detected a further five patients. Clinical follow-up was possible in 10/12 patients. 2 of these 10 patients had evidence of primary Sjögren's syndrome (SS) and one had systemic lupus erythematosus (SLE), with sicca symptoms and abnormal Schirmer's tests. Five other patients had sicca symptoms, of which four had abnormal Schirmer's tests. Conclusions: "Isolated" anti-52 kDa SSA/Ro antibodies were detected in approximately 0.5% of standard anti-ENA requests, in which their presence was generally not associated with underlying SS or SLE. In view of the increased testing complexity and costs in detecting and confirming these antibodies, specific testing for isolated a-SSA Ro52 antibodies during standard anti-ENA testing seems to be of limited clinical value in a non-obstetric population.