[Serological demonstration of a Treponema pallidum reinfection].

An improved method for precise separation of 19-S-IgM from other immunoglobulines reveals the reappearance of antitreponemal 19-S-IgM-antibodies after reinfection in five patients. The IgM-FTA-ABS-test with non-separated full-serum was non-reactive in all cases due to competitive inhibition. The new assay apparently permits a clear differentiation between reinfection and non-specific increase of titers in lipoidal antigen tests. Treatment failures can be distinguished from reinfections in cases where this method can continuously be applied.