G.D. Johnson

POSITIVE DIRECT COOMBS TESTS AND ANTINUCLEAR FACTOR IN PATIENTS TREATED WITH METHYLDOPA

Abstract Treatment with α-methyldopa was changed to other antihypertensive drugs in 30 hypertensive patients who had a positive direct Coombs test (D.C.T.). The D.C.T. became negative in 19 of 23 patients who had been off the drug for 6 months and the length of time for the D.C.T. to become negative depended on the initial titre. Reintroduction of methyldopa in 3 patients who had previously had a positive D.C.T., but whose D.C.T. had subsequently become negative, gave a positive D.C.T. again in 1 patient after 4 months, but the D.C.T. was still negative after 6 months in the other 2 patients. Of 38 patients who started methyldopa for the first time, 10 (24%) developed a positive D.C.T. at varying intervals from 3 to 6 months. Antinuclear factor (A.N.F.) was looked for in the serum of 240 hypertensive patients, 158 of whom were on methyldopa. In 23 (14.6%) patients on methyldopa the A.N.F. was positive at titres varying from 1/10 to 1/1250. In 82 hypertensive patients, on other drugs, the A.N.F. was positive in 3.

PRECIPITATING ANTIBODY TO D.N.A. DETECTED BY TWO-STAGE ELECTROIMMUNODIFFUSION: STUDY IN S.L.E. AND IN RHEUMATOID ARTHRITIS

Abstract A method for the detection in human sera of precipitating antibody specific for D.N.A. by two-stage electroimmunodiffusion is described. The results obtained in a pilot study on 351 sera indicate that the significance of this antibody may be different from that attributed to D.N.A. antibodies detected by other procedures, since development of nephropathy in cases of systemic lupus erythematosus was associated with absence of the antibody, while its presence correlated with the occurrence of cutaneous vasculitic lesions.