D.J. Jeffries

STUDIES OF CELLULAR IMMUNITY IN MALE HOMOSEXUALS IN LONDON

97 symptom-free homosexuals were studied clinically, serologically, and with in-vivo and in-vitro tests of cellular immune function in the context of the acquired immunodeficiency syndrome (AIDS). A high proportion of these men showed abnormalities: lymphopenia (33%), decreased T-helper/T-suppressor (Th/Ts) cell ratios (43%), both these abnormalities (12%), decreased total T-helper cells (15%), monocyte chemotactic (10%) and phagocytic (27%) defects, anergy to three recall antigens (32%), and anergy to purified protein derivative despite BCG inoculation (55%). The lymphocyte abnormalities and anergy characteristic of AIDS were seen in 5%. No clear clinical or serological associations were seen for the AIDS-like defects. Trends of association were seen between higher lymphocyte counts, lower Th/Ts ratios, more T-suppressor cells and serological evidence of previous virus infection. The combination of lymphocyte abnormalities and anergy observed in these symptom-free homosexuals may represent a latent phase of AIDS.

LOW PREVALENCE IN THE UK OF HTLV-I AND HTLV-II INFECTION IN SUBJECTS WITH AIDS, WITH EXTENDED LYMPHADENOPATHY, AND AT RISK OF AIDS

Antibodies reacting selectively with human T-cell leukaemia virus type I (HTLV-I) were detected in approximately 5% patients with extended lymphadenopathy syndrome (ELAS) and in less than 1% of unselected homosexual patients and drug abusers. None of 22 patients with acquired immunodeficiency syndrome (AIDS) had HTLV-I antibodies and neither did 85 haemophiliacs and 940 blood donors. 3 out of 113 drug addicts had high titres of antibodies to human T-cell leukaemia virus type II (HTLV-II). A T-cell line was derived from 1 of the seropositive ELAS patients. This line was found to be infected with, and releasing, HTLV-I. Infection by HTLV-I and HTLV-II retroviruses thus occurs more frequently in ELAS patients and drug addicts than in the UK population as a whole, but the low prevalence of these infections in ELAS and AIDS patients indicates that these two strains of lymphotropic retroviruses have no aetiological role in ELAS and AIDS.

Is Entamoeba histolytica in homosexual men a pathogen

Entamoeba histolytica (EH) in homosexual men is generally considered to be pathogenic. To test this hypothesis, the generally accepted features of invasion (haematophagous trophozoites in faeces; high-titre serum antibody; moderate to severe acute inflammatory change; and presence of EH in the mucosa on rectal biopsy) and the zymodeme pattern of cultured trophozoites were assessed in twenty-three EH excretors and eleven control homosexual men. No trophozoites or antibody to EH were found in either group. When other pathogens were excluded, no patient in either group had severe, acute histopathological proctitis. Moderately severe change was seen in 38% of EH excretors and 18% of controls (not significant). All the zymodemes were non-pathogenic. Successful eradication of EH did not result in even a trend towards normalisation of the moderate inflammatory histopathology. There are, therefore, no data here to suggest that EH is a pathogen in homosexual men.

Viral transmission and fibreoptic endoscopy

Fibreoptic endoscopes have been responsible for outbreaks of infection with bacteria although viral transmission has been reported only once. The emergence of human immunodeficiency virus (HIV) has prompted a review of infection control practices in endoscopy units because of the theoretical possibility that HIV might be transmitted at endoscopy. Recent studies have shown that bronchoscopes and gastroscopes used on AIDS patients become contaminated with HIV genetic material although cleaning equipment in detergent removes all traces of the virus. Thorough precleaning has been shown to eliminate even high titres of HIV from endoscopes and 2% alkaline glutaraldehyde has been found to inactivate the virus rapidly even if the virus is dried in serum to a surface. These findings support the British Society of Gastroenterology recommendations for the cleaning and disinfection of endoscopic equipment and demonstrate that a uniform policy of infection control is practicable in endoscopy units.

Control of viral infections in hospitals

In recent years, certain viruses, in particular hepatitis B and human immunodeficiency virus (HIV), have come to play an increasingly important role in the spectrum of hospital disease and infection. In addition, extensive vaccination programmes and better living conditions have altered the populations at risk from other viruses, e.g. measles and polio. Severe disease due to measles and mumps, although occurring rarely, is almost as common amongst hospital patients, notably the immunosuppressed, as in the healthy population (Moore et al., 1982; Badenoch, 1988). Outbreaks of viral diarrhoea also occur with equal, if not increased, frequency in hospitals, particularly amongst the young and elderly. Clear and practical policies are necessary to enable safe and efficient control of viral infections in hospitals.

Psychological aspects of recurrences of genital herpes

Fifty-seven patients presenting with virologically confirmed first attacks of genital herpes were assessed for risk factors for time to the first recurrence. These factors included demographic details, personality traits, recent life events, herpes simplex biotype, frequency of orogenital intercourse and psychiatric illness as measured by the General Health Questionnaire (GHQ). This and our similar previous study (58 patients) were analysed separately and combined using a novel statistical technique (Coxs proportional hazards model). In the previous study there was a significant association only for GHQ score (p less than 0.02). For the present study age was the only statistical significant factor (the younger the patient the more likely a recurrence sooner (p less than 0.05), although there was a trend for high GHQ scorers to have recurrences sooner than low scorers. Data of the two studies combined showed that the only significant association with time to recurrence was the GHQ (p less than 0.02). These data support the notion that there is an association between psychiatric illness and recurrence of genital herpes.

Enteroviruses, endoscopy and infection control: an applied study

Decontamination methods for medical equipment are based largely on bacterial studies yet enteroviruses are more resistant to disinfection than most vegetative bacteria and other viruses. To study the elimination of enteroviruses from endoscopes, poliovirus was aspirated into the suction-biopsy channels of five gastroscopes. Endoscopes were cleaned in detergent and disinfected in 2% alkaline glutaraldehyde. Contamination was measured before and after cleaning and after various periods of disinfection by irrigating the channels with viral medium and quantifying surviving virus by plaque assay. The effectiveness of glutaraldehyde against cell-free and cell-associated polio virus, dried to a surface in a protein coagulum, was also studied. Cleaning reduced virus by a mean of 4.6 log10 plaque forming units (pfu) ml-1. Samples were virus-free after 2 min disinfection. Virus dried on surfaces was inactivated in 1 min by 2% and 1% glutaraldehyde, with a reduction of > 6 log10 pfu ml-1. Thus, cleaning was effective against heavy viral contamination while glutaraldehyde rapidly inactivated poliovirus even when dried to a surface in serum.

Longitudinal Immunological Studies on a Cohort of Initially Symptom-Free Homosexual Men in London with Respect to HTLV-III Serology

In late 1981, when AIDS was becoming increasingly well-documented in the USA, we set up a study to examine cellular immmunity in symptom-free homosexuals in London. We felt that if AIDS did not develop, it would be of interest to determine why not, since the life-style of this community was kncwn to be similar to that in New York. On the other hand, if the disease were indeed to develop, we had an important opportunity to study the background cellular immunological profile of sexually active gay men before the disease emerged; such a high-risk, low-incidence population was not as readily studied in the USA. It has since been shown that AIDS is an infectious disease caused by the novel retrovirus HTLV-III/LAV. An epidemic of this infection has occurred in the UK following that in the US by some three years. By December 1984 there had been 102 cases in the UK (35 at St Mary’s), compared with 28 at the same time in 1983 and 7 at the end of 1982. Persistent generalised lymphadenopathy (PGL) has also increased over the same period: at the Praed Street Clinic, a large clinic for sexually transmitted diseases, we had seen a total of only 7 cases in 1982, but this had risen to 47 by the end of 1983 and to 150 at the present. A recent study on the prevalence of antibodies to HTLV-III in the UK (Cheingsong-Popov et al, 1984) has shown that 17% of symptom-free homosexuals were seropositive.