Immunoendocrine abnormalities in the male reproductive system during experimental pulmonary tuberculosis

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) that mainly affects the lungs. Along the course of pulmonary TB there are remarkable changes in the production of cytokines that cause endocrine changes. So far, it is not known the physiological and histological changes in the male reproductive system during pulmonary TB.

To investigate whether pulmonary TB produces histological alterations of the BALB/c mice reproductive organs, as well as abnormalities in spermatogenesis, serum testosterone concentrations and expression of testicular cytokines.

BALB/c mice were infected intratracheally with high dose Mtb strain H37Rv. Groups of six non infected and infected animals were euthanized on days 1, 3, 7, 14, 21, 28, 60, 90 and 120 post-infection. Bacillary loads were determined by counting colony forming units (CFUs) in lungs, testes, prostate and seminal vesicles. Histological sections were obtained from the same organs. Spermatozoids number and quality were assessed by spermatobioscopy. Serum testosterone concentrations were determined by radioimmunoanalysis (RIA) in control and infected mice in each time of sacrifice.

Mtb only grew in lung tissue. Serum androgens showed a trend to decrease in the infected mice compared to the healthy animals, the difference turn into statistically significance at post infection day 120. The weight of the testis was not modified throughout the study, and no histopathological changes were found. However, we detected a significant decrease in the weight of the seminal vesicles and prostate starting at 28 days post-infection. Atrophy of the seminal vesicles and prostate epithelia were significant, beginning after 60 days of infection. Spermatobioscopy revealed hypospermia in the later stages of the disease. We have observed in the testes a local significant disbalance on the cytokine profile (increase of IL-6 and decrease of IL-10 and TGF-b levels) together with a very significant reduction of the body weight during late pulmonary TB.

Pulmonary TB affects the histophysiology of the male reproductive system due to hormonal changes, an imbalance of pro-inflammatory cytokine profile, and a wasting syndrome during late disease.