False positive reactions to the Reiter protein complement-fixation (RPCF) test.

As previously reported (Pillot, Betz, Colombani, and Ripault, 1965), the Reiter Protein ComplementFixation (RPCF) test gives false positive reactions in 0 05 to 0 5 per cent. of cases as a consequence of an antipolysaccharide antibody present in the serum of some individuals. Since, during the years 1960-67, we have performed this test routinely on every patient hospitalized in our clinic, we have found it essential to estimate the incidence of false positive RPCF reactions and to classify them with regard to duration. At the same time, it was possible to compare the RPCF result with clinical data, in the hope that correlations with the serological findings would be revealed.