Immunological studies in patients with mumps orchitis.

Seventy patients with mumps orchitis were investigated. Serological tests for antitesticular antibodies, using four different techniques showed positive results in 25 patients. Antivirus antibodies were detected and they reached higher values during the remission period of acute cases. Delayed hypersensitivity was studied by means of skin tests using homologous antigenic material. Several patients gave definite positive reactions. Testicular biopsies performed in some patients showed a histological picture similar to that obtained in experimental human or animal auto- or iso-sensitization. All patients in whom testicular damage was present also showed positive skin tests, ascertained by histology of the site of reaction, but none of them exhibited circulating antibodies in meaningful titers. The skin hypersensitivity suggest some correlation between this type of reaction and the development of the testicular lesions as shown in several other diseases in which an immune mechanism could be involved.