HOST RESPONSE TO MYCOBACTERIAL INFECTION IN THE ALCOHOLIC RAT - MALE AND FEMALE DIMORPHISM

Increased susceptibility to tuberculosis occurs in the alcoholic. One explanation for the altered susceptibility is a change in T-lymphocyte modulation. To evaluate this, 24 male and 24 female Sprague-Dawley ra ts were treated with either a Lieber-type liquid ethanol diet (LED) or an isocaloric control (LCD). After 2 weeks, half the subjects were in fected with BCG (10(8) colony-forming units) and sacrificed after 42 d ays. Splenic helper (CD4) and suppressor/cytoxic (CD8) cells were quan titated by flow cytometry. By three-way analysis of variance, splenic cellularity was significantly increased by infection (p < 0.0001) but suppressed by LED (p = 0.0002). There was a marginal sexual difference (p = 0.065) with females exhibiting a 35% lower response while on alc ohol. Examining lymphocyte subsets, the most significant changes were observed after infection (BCG) and alcohol treatment (LED). CD4 levels were deminished by LED (p = 0.0002) but markedly increased by infecti on (p < 0.0001), producing a highly significant interaction that affec ted both absolute number (p < 0.0001) and relative percent present (p = 0.0078). CD8 was influenced only by infection (p < 0.0001). This res ulted in a infection-related increase in the CD4/CD8 ratio which was l ower with LED (p = 0.0032). Splenic T-lymphocytes, predominately CD4, are involved in the host response to BCG hepatitis and are adversely i nfluenced by LED, which may contribute to increased susceptibility. Pu blished by Elsevier Science Inc.