The immunopathology of unilateral vasectomy in the ram

This study investigated the relationship between the local (spermatic granuloma) and systemic events after unilateral vasectomy in six rams. Spermatic microgranulomas were first observed at 4 weeks post vasectomy (PV), at which time lymphocytes, chiefly CD4+ (helper/inducer) cells, were incorporated into the periphery of the phagocytic wall. Although plasma cells accumulated around blood vessels near these early granulomas, they were not incorporated into them. All sectioned vas deferens contained additional microscopic spermatic granulomas away from the point of sectioning, as did one-third of cauda epididymides on the vasectomised side. There were significant (P < 0.001) increases in T-lymphocytes, especially CD4 cells and plasma cells (chiefly IgG-containing) within the granulomas at each successive PV interval. Concurrent enzyme-linked immunosorbent assay indicated initial presence of IgG and IgM antisperm antibody in serum between 2 and 4 weeks PV. There were significant increases of IgG (P < 0.01) and IgM (P < 0.001) throughout the experiment but IgA antisperm antibody was negligible.