Anti La(SSB) identifies a distinctive subgroup of systemic lupus erythematosus

The relevance of antibodies for La(SSB) as a marker of a distinctive systemic lupus erythematosus (SLE) subset was studied in 185 lupus patients. Anti La was detected in 39 (21%) and was accompanied invariably by anti Ro. Clinically, anti La-positive patients were distinguished by a later age of disease onset, and a low frequency of lupus nephritis. In common with other anti Ro-positive patients they showed a high frequency of keratoconjunctivitis sicca. Anti La identified patients with higher titres of anti Ro antibodies and was significantly associated with HLA-DR3. Serological markers such as these are useful for identifying more homogeneous populations of SLE patients for studies of aetiology and pathogenesis.