Antiinfection immunity and autoimmunity.

This review summarizes findings that indicate that immune reactions of T and B cells depend on thresholds of the binding avidity of the receptor, on antigen amounts, on the time period during which antigen is available in secondary lymphatic tissues, as well as on the detection methods used. Usually immunologically ignored, strictly extralymphatic host cells or their antigens may be released by infection or immunopathology to reach lymphatic organs and induce autoimmune diseases. If we know the infection, we call the disease immunopathologically mediated; if we do not recognize or know it, we call the disease autoimmune.