Differential sheep cell agglutination test in rheumatoid arthritis.

In March, 1948, Rose and others described a test for rheumatoid arthritis which depended on the ability of serum from patients with rheumatoid arthritis to agglutinate " sensitized " sheep erythrocytes in much higher titre than normal sheep erythrocytes. The authors reported results in 110 patients, of whom 27 had active rheumatoid arthritis and 16 inactive rheumatoid arthritis, 3 Still's disease, and 5 Marie-Struimpell arthritis: 59 were nonrheumatic controls. Only the patients with rheumatoid arthritis and related diseases showed an elevation of the agglutination titre for " sensitized " sheep cells. The authors reported that the active fraction was found in the beta gamma globulin fraction of electrophoretically separated serum. Sulkin and others (1948) reported on 149 patients including 35 with active rheumatoid arthritis, I with Still's disease, and 7 with Marie-Striimpell spondylitis. Forty-six per cent. of these patients and none of the controls had a raised titre for agglutinins of "sensitized " sheep cells. The authors correlate the presence of a raised titre with greater severity and increased duration of the disease. Jawetz and Hook (1949) reported the results of this test in 161 patients of whom 78 had rheumatoid arthritis. In this study 65 per cent. of the patients with markedly active rheumatoid arthritis and 13 5 per cent. of the group classified as mildly or moderately active had an elevation of the agglutination titre for " sensitized " sheep erythrocytes; none of the inactive group had a raised titre. In the controls there were two patients, one with hepatitis and one with ankylosing spondylitis, who had a raised titre for the " sensitized " sheep cells. Our report presents the results of the sheep-cell agglutination test performed on sera of 164 patients and 13 normal adult males. The cases studied included rheumatoid arthritis, and, as controls,