Comparison of delayed type hypersensitivity and T subsets in random and homosexual populations in western Australia

Delayed-type hypersensitivity skin testing: normal values in the Australian population

In our human psychoimmunological studies we have utilized a standardized assessment kit, the cell-mediated immunity (CMI) Multitest system, for determining delayed-type hypersensitivity (DTH) skin responses to a panel of ubiquitous antigens. Although the kit had been assessed in large populations of healthy controls in the U.S.A. and Europe, few data were available with regard to normative values in the Australian population. There are cogent reasons to suspect that results for the test will vary depending on geographical location, age cohort, compliance with specific immunization schedules and rates of natural exposure to certain diseases in differing populations. Most of our patient cohorts have a preponderance of female subjects and most standardization had been conducted in males. We tested medically and psychologically healthy males (n = 66) and females (n = 53). The percentage of positive responses to individual antigens was similar to other Australian studies but lower than that reported internationally. The mean number of positive responses was 3.7 for men and 2.8 for women, while the mean induration diameter was 17.5 mm for men and 12.2 mm for women. Three per cent of men and 5.6% of women were anergic (no positive responses), while a further 10.6% of men and 9.4% of women fell into the "hypoergic" category. These results, and those from other studies, indicate that the pattern of response to the CMI Multitest differs in healthy Australians. Therefore, researchers need to exercise caution when selecting patient and control samples (controlling for exposure factors), applying the test, reporting results (i.e. including all relevant parameters-with an emphasis on dimensional rather than categorical scores) and when designating subjects as having "impaired" responses.

Effect of sexual practices on T cell subsets and delayed hypersensitivity in transsexuals and female sex workers

To determine whether ano-receptive unprotected sexual intercourse (SI) practised by transsexuals produces immunological abnormalities we compared delayed hypersensitivity skin tests (DTH) and T cell helper (CD4) and suppressor (CD8) subsets in 57 transsexuals and 69 female sex worker controls. The populations were matched for age, duration of prostitution, number of clients and previous use of antibiotics. Heterosexual males and females and transsexuals who practised protected SI, were also included as controls. All were HIV negative. There were significantly increased absolute CD4 and CD8 counts and decreased DTH and CD4/CD8 ratios in those who practised unprotected ano-receptive SI. These changes were unlikely to be due to any of the microbial agents tested. We conclude that ano-receptive sexual intercourse results in increased immunological abnormalities in these sex workers possibly as a result of rectal exposure to seminal alloantigens. These abnormalities could play an important role as co-factors in disease transmission.

Correction of human immunodeficiency virus-associated depression of delayed-type hypersensitivity (DTH) after zidovudine therapy: DTH, CD4+ T-cell numbers, and epidermal Langerhans cell density are independent variables

Twenty-four patients with various degrees of human immunodeficiency virus (HIV)-associated immunodeficiency were treated with zidovudine for up to 6 months. Nineteen of these patients had persistent depression of delayed-type hypersensitivity (DTH) responses prior to commencing therapy. In 11 of these 19 patients (58%) there was sustained improvement of DTH responses with the maximal effect occurring at approximately 3 months after therapy was started. DTH declined after 3 months but remained significantly higher than baseline at 6 months. Patients who did not have a sustained increase in DTH responses had more severe disease than those that did. Blood CD4+ T-cell counts increased in the majority of patients on zidovudine therapy, but varied independently of DTH responses. Epidermal Langerhans cell density was lower in HIV-infected patients than controls but also varied independently of DTH responses before and after zidovudine therapy. We suggest that sequential measurement of DTH responses is a valuable means of monitoring the restoration of cell-mediated immune responses by zidovudine in some HIV-infected patients. Our findings also demonstrate the need to define the processes involved in the restoration of DTH responses as this may lead to new approaches to the therapeutic manipulation of cell-mediated immune responses in HIV-infected patients.

Primary sclerosing cholangitis: clinical and immunopathological review of 21 cases

Twenty-one patients with primary sclerosing cholangitis were seen during 1979-87. The mean age at onset of disease was 51.7 years (range: 13-78 years) with a male: female ratio of 2.5:1. Six (29%) were asymptomatic at the time of diagnosis. Eleven patients (52%) had ulcerative colitis. Cholangiography demonstrated abnormalities limited to the intrahepatic ducts in 10 cases, with both intrahepatic and extrahepatic involvement in 11. Histological features on liver biopsy included: portal tract inflammation and cholestasis in all; paucity of bile ducts in 56%; piecemeal necrosis in 19% and cirrhosis in 6%. Circulating autoantibodies and elevated serum immunoglobulins were found in half of the patients and HLA-B8 was detected in 53%. A deficiency of circulating CD3 and CD8 cells was not found in the 12 patients tested. The mean follow-up was 51 months (range: 3-180 months). Three patients died from non-hepatic causes and another has received liver transplantation. A Kaplan-Meier curve predicted 70% survival at 72 months.