[The reactivity of lupus erythematosus serum with native and denatured DNA of various origins].

The serum of a female suffering from Lupus erythematosus visceralis was investigated by complement fixation for the reaction with native and denatured DNA's of various base composition. The reaction with native DNA is independent on the (G+C)-content of the DNA. It is apparent that the responsible antibodies react with determinants of the helical conformation, which are identical in the various DNA-molecules. Quantitative differences are found with denatured DNA's. The strongest complement fixation is observed with (G+C)-rich denatured DNA. The reaction with denatured DNA is only partially inhibited by DNA digest. These antibodies obviously react with sequential determinants containing bases. Therefore, they are induced by a different mechanism of sensitization.