Antibodies to a putative HIV gp41 immunosuppressive peptide, pHIVIS (583-599), do not correlate significantly with outcome in HIV infection.

We have studied the prevalence of antibodies to peptides derived from the transmembrane protein of HIV, gp41. Previous work has suggested that the presence of antibodies to the gp41 peptide known as pHIVIS (env 583-599) is associated with protection from immunosuppression in HIV infection. We studied 171 sequential sera from 55 HIV-1-infected people in various clinical stages of disease. There was no significant association between antibodies to pHIVIS and clinical status in this study. Although pHIVIS has sequence similarity to the putative immunosuppressive region of the C-type oncornaviruses (p15E), antibodies to this peptide do not appear to be associated with protection from immunosuppression in natural HIV infection.

Trends in sexual behaviour in a cohort of homosexual men: a 7 year prospective study.

A cohort of homosexual men at risk for human immunodeficiency virus (HIV) infection were studied prospectively over a 7-year period (1982/88) to assess trends in sexual behaviour and amyl nitrite intake. During the period, there were dramatic declines in the proportion of HIV seropositive and seronegative subjects reporting multiple casual partners for anal intercourse, unprotected anal intercourse and recreational use of amyl nitrite. Reported rates of orogenital intercourse remained the same during the period, whilst the total number of seroconversions fell from 17 for the period 1982-84 to 8 for 1985-88. High-risk sexual and related social behaviour among homosexual men, as assessed by patterns of anal intercourse behaviour and nitrite intake, changed over the 7-year period, with the greatest changes apparent before the widespread availability of HIV antibody testing and public education campaigns. This highlights the effectiveness of peer-group and community-based programmes in modifying the sexual behaviour of their members.

Eight year prospective study of HIV infection in a cohort of homosexual men--clinical progression, immunological and virological markers.

Three hundred and fourteen homosexual/bisexual men at risk for human immunodeficiency virus (HIV) infection (170 seroprevalent HIV-positive, 144 seronegative) were prospectively studied over 8 years to assess rates of HIV infection and disease progression, in conjunction with cellular and HIV serological markers. In HIV-positive subjects, CD4+ lymphocyte counts rose strikingly during the period surrounding seroconversion, then fell progressively over the intervening period to a mean level of 300 cells/mm3 when AIDS developed. Changes in CD8+ lymphocyte counts were less consistent. The trend for HIV serological markers over the study period was of progressive decline in the proportion of subjects with anti-p24 antibody, associated with an increase in the proportion of subjects with detectable HIV antigenaemia. However, only 45% of subjects tested had lost anti-p24 antibody by the time of AIDS diagnosis, and HIV antigen was detectable up to 4 years before this. Different HIV serological patterns were also observed in subjects presenting either with Kaposi's sarcoma or opportunist infections. Our data support the continued use of cellular and virological markers in the evaluation of HIV disease; however, the variability observed in this study highlights their limited ability in predicting specific clinical events. Care should therefore be taken to encompass both clinical and laboratory information in the medical assessment of the HIV-infected individual.

Preferential activation of CD4 T lymphocytes in the lamina propria of gluten-sensitive enteropathy.

The distribution and activation of T-lymphocyte subsets in the small intestinal mucosa of coeliac disease and dermatitis herpetiformis subjects on a normal diet has been studied and compared to normal controls. Double-labelling immunofluorescence techniques with monoclonal antibodies were used on cryostat tissue sections. Intestinal epithelial cells demonstrated staining for HLA-DR, the intensity being proportional to the degree of enteropathy. In both patients and controls nearly all (97%) intra-epithelial lymphocytes were of the CD8 subset and not activated as judged by HLA-DR expression. In the lamina propria there was an approximate 50-fold increase in T cells in the patients as compared with the controls. Whilst the ratio of total CD4 to total CD8 cells was unchanged, the CD4 subset was preferentially activated in the patients. Thus in the normal controls the median ratio of activated CD4 cells to activated CD8 cells was 1.67 whilst for dermatitis herpetiformis and coeliac disease it was 3.42 and 6.07 respectively. These findings suggest that the lamina propria is a site of vigorous T-cell activity in gluten-sensitive individuals and is consistent with the view that the enteropathy of dermatitis herpetiformis and coeliac disease is the result of a delayed-type hypersensitivity against gliadin.

Fat absorption and exocrine pancreatic function in human immunodeficiency virus infection.

Exocrine pancreatic function and fat absorption were determined using a 'tubeless' test in 25 human immunodeficiency virus (HIV) antibody positive subjects (23 males, two females), CDC criteria groups II (four), III (one), and IV (20). In 12 fat absorption was poor but in only three of these were the results indicative of pancreatic insufficiency and in all three this was mild. In nine of the cases the results were compatible with small intestinal malabsorption. Mild, but not severe, exocrine pancreatic insufficiency may occur in acquired immune deficiency syndrome; however fat malabsorption is more commonly associated with a small intestinal cause.