SERUM CYTIDINE DEAMINASE AS A MEASURE OF DISEASE-ACTIVITY IN RHEUMATOID-ARTHRITIS AND SYSTEMIC LUPUS-ERYTHEMATOSUS

Serum cytidine deaminase (CD) as a marker of disease activity was asse ssed in 100 patients with rheumatoid arthritis (RA) and in 102 assessm ents of 85 patients with systemic lupus erythematosus (SLE). In RA CD levels correlated well with clinical assessment of disease activity, b ut were not influenced by varying dosages of ibuprofen as therapy. In SLE significant correlations were found between CD and anti-DNA antibo dy titers, as well as C3 complement levels. A subset of clinically act ive patients with SLE with elevated CD levels but normal anti-DNA tite rs was identified. Serum CD levels may be a clinically useful marker i n RA and in certain subgroups of patients with SLE.