♂生殖細胞 / ♂生殖腺の免疫学研究のこれから

抄録

This review addresses the testicular autoimmunity that could be one of the causes of idiopathic male infertility. In human male infertility of immunologic origin, the level of anti-sperm antibodies is a well-known parameter. However, detection of the autoantibodies on sera and/or semen is not sufficient to diagnose testicular autoimmunity. The characteristic features of testicular autoimmunity include the detection of inflammatory cell infiltration into the testis(=orchitis), spermatogenic disturbance, T cell responses against target testicular autoantigens, serum autoantibodies against the target antigens, and binding of the autoantibodies to the target antigen-bearing cells inside the testis. Recently, there is increasing evidence that the spermatogenic disturbance of autoimmune origin may be an etiological factor in male reproductive failure, perhaps even more often than expected. However, it is very difficult to estimate the incidence of testicular autoimmunity in men, as most male patients first realize they are infertile when they start trying to conceive a child, and there is a possibility that their testes may already exhibit the end stage of testicular autoimmunity, in which lymphocytic inflammation and immunoglobulin deposition in their testes subsided long ago and only the spermatogenic disturbance such as maturation arrest and Sertoli cell only syndrome remains. On the basis of gradually increasing clinical data, investigation using experimental models of testicular autoimmunity is quite helpful to estimate physiopathology and epidemiology of the spermatogenic disturbance of autoimmune origin. From various results from experimental animals, it appears that although the testis is regarded as an immunologically privileged organ and resistant to inflammation, it is also immunologically fragile and highly susceptible to autoimmune inflammation. In the present review, the author will present future subjects in the field of male reproductive immunology.