Concordant HIV Research Articles

HLA antigens associated with susceptibility/resistance to HIV-1 infection

We studied the distribution of HLA-A, B, C, DR and DQ antigens in a cohort of HIV-1 + individuals and their heterosexual HIV seropositive (concordant) or seronegative (discordant) partners of Black non-Hispanic, Hispanic or Caucasian non-Hispanic ethnicity. The prevalence of DQ7 and Cw7 was significantly higher in the HIV-1 + compared to seronegative Black and Hispanic individuals, respectively. The frequency of DQ4 was significantly elevated in the Black seronegatives, whereas B53 was increased in the Hispanic seronegatives in comparison to the seropositives. No significant differences were observed between the Caucasian HIV infected and non-infected individuals. Analysis of the primary concordant HIV + and discordant HIV + individuals showed a marked increase in the prevalence of B44 in the Hispanic discordant seropositives, whereas the Caucasian primary concordants had a marked increase in the prevalence of A26. The prevalence of DQ7 and Cw7 was significantly increased in the Black and Hispanic secondary concordant seropositives, respectively in comparison to the seronegatives. The proportion of couples with matching HLA antigens was similar among the HIV-1 + concordant and discordant groups. These results provide additional evidence that HLA polymorphism may confer a genetic risk or protection for HIV-1 infection in individuals of various ethnic backgrounds.

Risk factors for concordant HIV infection in heterosexual couples in Trinidad.

Risk factors for HIV infection in partners of HIV-seropositive index cases were investigated in a cross-sectional survey. Between September 1992 and April 1994 a total of 251 HIV-infected persons and 76 of their sexual partners were interviewed at the main sexually transmitted diseases (STDs) clinic in Trinidad. All participants gave signed consent and responded to a questionnaire. Sixty-four couples had risks for HIV infection through heterosexual intercourse only. However, many recruited sex partners (57/64) reported heterosexual intercourse with persons in addition to the index cases. Overall HIV concordance (both index case and partner HIV infected) was 45% in the couples. HIV concordance was not found to be related to the sexual practices within the studied unions nor to the clinical status of the index case. After allowing for confounding factors there was an increased risk for HIV concordance in couples in unions for > or = 1 year (adjusted OR 3.48; 95% CI 0.89-13.69, P = 0.055), and in those in which sex partners had a past history of genital sores (adjusted for prostitution: OR 4.50; 95% CI 1.01-20.4). Interventions targeted at reducing high-risk sexual behaviour, prostitution and cocaine use could be beneficial in reducing the spread of STDs and HIV in Trinidad.

Sexual behaviour related to psycho-social factors in a population of Danish homosexual and bisexual men

An anonymous self-administered questionnaire was distributed to (1) male members of the Danish Gay and Lesbian Association (2) through a gay magazine and (3) to readers of a gay pornographic magazine. For the purpose of this study sexual practices were classified into three categories taking into account the HIV-status of the respondent and his partner(s): safe sex (mutual masturbation, sex with condoms, sex without condoms between two HIV-positives), potentially safe sex (oral-genital sex without condoms irrespective of HIV-status, anal-genital sex without condoms between two HIV-negatives), unsafe sex (anal-genital sex without condoms between discordant partners or partners of unknown HIV status). Of the 2058 respondents 29.7% had had unsafe sex in the last 12 months. Multivariate analysis by recursive graphical models showed that sexual practice was directly related (that is conditionally dependent given the rest of the variables) to having a steady partner. Among men without a steady partner sexual practice was also directly related to age and number of partners showing an increase in unsafe sex with number of partners and a decrease with age. Thus of the men 16–19 years of age 43.5% had had unsafe sex irrespective of number of partners vs 5.7% of men older than 44 years and with one to two partners. Sexual practice was not directly related to any other demographic or psychosocial factor in the study. The adopted classification of sexual practice preclude that the high occurrence of unsafe sex could be explained by unsafe sex taking place among partners of concordant HIV status. The results emphasize the need for further preventive efforts to reduce transmission of HIV among homosexual men.