Evidence for oligoclonal B cell expansion in the peripheral blood of patients with rheumatoid arthritis.

Peripheral blood lymphocytes from patients with rheumatoid arthritis and osteoarthritis were examined for evidence of oligoclonal B cell expansion using the computer assisted flow cytometric technique of kappa-lambda (kappa-lambda) analysis. Eleven of 29 patients with rheumatoid arthritis but only one of 16 with osteoarthritis gave abnormal results (p less than 0.025). Abnormal kappa-lambda determinations did not correlate with age, duration of disease, presence of rheumatoid factor, or other clinical and laboratory parameters. Therapy with oral or intramuscular gold compounds appeared to diminish the incidence of kappa-lambda abnormality. These findings may indicate defective control of clonal B cell proliferation in rheumatoid arthritis.