The Raji cell radioimmunoassay in patients with systemic lupus erythematosus: clinical significance and relationship to other serologic variables assessed by discriminant analysis

Abstract

Our aim was to determine the clinical usefulness of the Raji cell radioimmunoassay (RIA) in 30 patients with systemic lupus erythematosus (SLE) studied over a 30-month period. Raji RIA correlated positively (p less than 0.001) with antibodies to dsDNA, anti-Sm, erythrocyte sedimentation rate and central nervous system involvement and inversely with the white blood count, hematocrit and CH50. There was a lack of correlation (p greater than 0.05) between the Raji RIA and cryoglobulins, Clq binding assay, lymphocyte count, rheumatoid factor and anti-RNP. Raji RIA values paralleled disease activity in 50% and were predictive of flares in 17%. By discriminant analysis, the Raji RIA could not predict nephritis as well as a variety of routine laboratory tests in SLE. The Raji RIA, while helpful in SLE, does not appear to offer any advantage over standard assays in monitoring SLE disease activity.