Antisperm antibody titres, immune complex deposition and immunocompetence in long-term vasectomized mice

Experiments were performed to determine sperm antigen-specific and non-specific immunological changes in long-term vasectomized BDF₁ mice. Circulating antisperm antibodies, detected by immunofluorescence assay, were observed as early as 1 month post-vasectomy; antisperm titres increased with time and were highest in animals that had been vasectomized for over 2 years. Several aged sham-vasectomized mice also had significant antisperm antibody titres, but the development of antisperm antibodies was significantly different from that of the vasectomized group. Tests of general immunocompetence, performed on vasectomized and sham-vasectomized mice at various intervals up to 2·5 years post-surgery, revealed a decrease in mitogenic responsiveness over time in both groups, but no difference between age-matched groups in lymphocyte responses to mitogenic or allogeneic stimulation in vitro, or to in vivo challenge with picryl chloride (delayed hypersensitivity response) or immunization with foreign antigen (humoral response). Most vasectomized mice developed epididymitis and epididymal sperm granulomas by 9 months post-surgery. Patchy regions of hypospermatogenesis were observed in some testes as early as 3 months post-vasectomy, and spermatogenesis was markedly impaired in all long-term vasectomized mice examined. Orchitis lesions characterized by immune complex deposition and lymphocytic infiltration were found in testes from three out of 14 long-term vasectomized mice, as compared to none of the sham-operated group. Studies of vasectomy-associated immune complex deposition in the kidney were inconclusive because aged animals from both vasectomized and sham-vasectomized groups had similar patterns of immunoglobulin and complement deposition in the glomerular basement membranes.