       Document 0513
 DOCN  M9640513
 TI    Lower prevalence and incidence of HIV-1 syncytium-inducing phenotype
       among injecting drug users compared with homosexual men.
 DT    9604
 AU    Spijkerman IJ; Koot M; Prins M; Keet IP; van den Hoek AJ; Miedema F;
       Coutinho RA; Department of Public Health and Environment, Municipal
       Health; Service, Amsterdam, The Netherlands.
 SO    AIDS. 1995 Sep;9(9):1085-92. Unique Identifier : AIDSLINE MED/96085726
 AB    OBJECTIVE: To study the prevalence, incidence and predictive value for
       progression to AIDS of the HIV-1 syncytium-inducing (SI) phenotype in
       HIV-infected injecting drug users (IDU) compared with HIV-infected
       homosexual men. DESIGN: Two prospective cohort studies on HIV-1
       infection among IDU and homosexual men. METHODS: HIV-infected IDU (n =
       225) and homosexual men (n = 366) without AIDS were studied from March
       1989 through December 1993. Data on laboratory markers, including the
       presence of SI variants, demographics, behavioural characteristics and
       clinical events were collected at every visit. RESULTS: At baseline, SI
       variants were detected in 4% of IDU and 17% of homosexual men. During
       the study period 18 IDU and 68 homosexual men switched from non-SI to SI
       phenotype (4-year cumulative incidence, 14.6 and 28.4%, respectively)
       before AIDS diagnosis. Among participants with a documented date of HIV
       infection the cumulative incidence of SI was lower among IDU than
       homosexual men (4-year cumulative incidence, 6.2 and 20.7%,
       respectively). At AIDS diagnosis, 21% of all AIDS cases among IDU had
       the SI phenotype compared with 54% among homosexual men. In both risk
       groups an accelerated CD4 decline was found after the non-SI-to-SI
       switch. The SI phenotype appeared to be a predictor of AIDS
       (multivariate relative hazard, 5.33), independent of CD4 cell count and
       p24 antigen at baseline. In the multivariate time-dependent analysis,
       the relative hazard of SI phenotype decreased considerably, which is
       consistent with the hypothesis that the effect of SI phenotype on
       progression to AIDS is mediated by CD4 cell count. CONCLUSION: The SI
       phenotype is associated with accelerated CD4 decline and progression to
       AIDS in both risk groups. The remarkable lower prevalence and incidence
       of the SI phenotype among IDU may implicate a difference in pathogenesis
       and natural history of HIV infection linked to transmission group.
 DE    Adult  Cohort Studies  CD4 Lymphocyte Count  Female  Follow-Up Studies
       Gene Expression Regulation, Viral/PHYSIOLOGY  Giant
       Cells/IMMUNOLOGY/*VIROLOGY  *Homosexuality, Male  Human  HIV
       Seropositivity/IMMUNOLOGY/*TRANSMISSION/VIROLOGY  HIV-1/*GENETICS  Male
       *Phenotype  Prognosis  Substance Abuse, Intravenous/IMMUNOLOGY/*VIROLOGY
       JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

