Since the report of the agglutination test with Streptococcus by Cecil in 1931 there appeared many reports dealing with the serum reaction involved in rheumatoid arthritis. Among these the
modified form of sensitized sheep blood cell agglutination test as proposed by WAALER (1940) and ROSE (1948) had been for a long time the only method applied to the diagnosis of rheumatoid arthritis. However, as this method had disadvantages of its complex manipulation and of being relatively sensitive, generally satisfactory results could not be obtained with it. Since then the latex agglutination test by PLATZ and SINGER (1957) was used in conjuction with the bentonite agglutination test by BOZIEVICH (1957). By the RA-test it means the test where agglutination is attained by the combined reaction of the human serum to be tested and the polystyrene latex granules bound to human gamma-globulin, and it is being widely used in daily clinical examinations. For the purpose to know the positive rate of this
test in disesaes other than rheumatoid arthritis, we applied this test to the patients with various diseases both visiting our out-patient clinic and those hospitalized, and studied the results.