Clinically, 60-75% of
male infertility cases are categorized as idiopathic spermatogenic disturbance. In previous studies of this condition, lymphocytic infiltration and immune deposits were present in several testis biopsy specimens, indicating that inflammatory or
immunological factors contribute to the occurrence of the lesions. However, there is currently little evidence regarding immunological
infertility in men. Previously, we established an immunological
infertility model, experimental autoimmune
orchitis (EAO), that can be induced in mice by two
subcutaneous injections of viable syngeneic testicular germ cells without the use of any adjuvant. In this EAO model, lymphocytes surround the tubuli recti and then induce spermatogenic disturbance. In addition, after the active
inflammation stage of this model, the seminiferous epithelium is damaged irreversibly, resembling the histopathology of human male idiopathic spermatogenic disturbance. In the majority of patients with testicular autoimmunity, there is a chronic and asymptomatic development of the inflammatory reaction. Therefore, this disease is very difficult to diagnose at the ongoing stage, and it is possible that the histopathology of idiopathic spermatogenic disturbance in the clinic is reported at the post-active
inflammation stage of autoimmune
orchitis. In this review, the histopathology of EAO before and after
inflammation is discussed, comparing it with human
orchitis.