Helping our patients take HIV pre-exposure prophylaxis (PrEP): a systematic review of adherence interventions.

OBJECTIVES: Adherence is critical for maximizing the effectiveness of pre-exposure prophylaxis (PrEP) in preventing HIV infection. Strategies for promoting adherence to HIV treatment, and their potential application to PrEP adherence, have received considerable attention. However, adherence promotion strategies for prevention medications have not been well characterized and may be more applicable to PrEP. We aimed to identify adherence support interventions that have been effective in other prevention fields and could be applied in the HIV prevention context to support pill taking among PrEP users. METHODS: To identify adherence support interventions that could be evaluated and applied in the PrEP context, we conducted a systematic review across the following prevention fields: hypertension, latent tuberculosis infection, hyperlipidaemia, oral contraceptives, osteoporosis, malaria prophylaxis, and post-exposure prophylaxis for HIV infection. We included randomized controlled trials that evaluated the efficacy of interventions to improve adherence to daily oral medications prescribed for primary prevention in healthy individuals or for secondary prevention in asymptomatic individuals. RESULTS: Our searches identified 585 studies, of which 48 studies met the eligibility criteria and were included in the review; nine evaluated multiple strategies, yielding 64 separately tested interventions. Interventions with the strongest evidence for improving adherence included complex, resource-intensive interventions, which combined multiple adherence support approaches, and low-cost, low-intensity interventions that provided education or telephone calls for adherence support. CONCLUSIONS: Our review identified adherence interventions with strong evidence of efficacy across prevention fields and provides recommendations for evaluating these interventions in upcoming PrEP studies.

A study of perceived racial discrimination in Black men who have sex with men (MSM) and its association with healthcare utilization and HIV testing.

In HPTN 061, a study of Black men who have sex with men (MSM), we evaluated the association of healthcare-specific racial discrimination with healthcare utilization and HIV testing among 1167 HIV-negative participants. Median age was 38 years, 41 % were uninsured, and 38 % had an annual household income <$10,000. Overall, 19 % reported healthcare-specific racial discrimination directed toward family, friend, or self; 61 % saw a healthcare provider in the previous 6 months and 81 % HIV tested within the past year. Healthcare-specific racial discrimination was positively associated with seeing a provider [adjusted odds ratio (AOR) = 1.4 (1.0, 2.0)] and HIV testing [AOR = 1.6 (1.1, 2.4)] suggesting that barriers other than racial discrimination may be driving health disparities related to access to medical care and HIV testing among Black MSM. These results contrast with previous studies, possibly due to measurement or cohort differences, strategies to overcome discrimination, or because of greater exposure to healthcare.

A novel missense mutation T101N in the melanocortin-4 receptor gene associated with obesity.

Mutations in the melanocortin-4 receptor (MC4R) are associated with severe obesity, independent of their effect on cortisol or thyroid-stimulating hormone levels. We examined a morbidly obese male (BMI = 62 kg/m²) with a binge-eating disorder and eight family members for mutations in the MC4R gene and potential differences in leptin levels. Fifty healthy individuals served as controls. Sequence analysis revealed a novel heterozygous missense mutation (c.302 C>A, p.T101N) located in the second transmembrane domain of the receptor, which was not detected in controls. The Fisher exact test revealed an association between the T101N mutation and history of obesity (P < 0.05) in the family. The Kruskal-Wallis test showed an association between the mutation and the leptin/BMI ratio (P < 0.05), while there was no association between the T101N mutation and diabetes or arterial hypertension in the family. Although the available family was small, we could show a significant association between the heterozygous T101N mutation and obesity.

T cell receptor usage and fine specificity of human immunodeficiency virus 1-specific cytotoxic T lymphocyte clones: analysis of quasispecies recognition reveals a dominant response directed against a minor in vivo variant.

Numerous virus-specific, class I-restricted cytotoxic T lymphocyte (CTL) epitopes have been identified, yet little information is available regarding the specificity of the CTL response in persons of the same human histocompatibility leukocyte antigen (HLA) type. In this study, the human immunodeficiency virus (HIV) 1 envelope-specific CTL response was evaluated in five HLA-B14-positive persons. CTL responses specific for a previously described nine-amino acid epitope in gp41 (aa 584-592, ERYLKDQQL) could be identified in all subjects, and CTL clones specific for this epitope could be isolated from four persons. Despite heterogeneous T cell receptor usage, the fine specificity of the clones was similar, as defined by recognition of alanine-substituted peptides as well as peptides representing natural HIV-1 sequence variants. Correlation with in vivo virus sequences revealed that the dominant species in two of the subjects represented poorly recognized variants, with a K-->Q substitution at amino acid 588, whereas no variants were observed in the other two subjects. Although clonal type-specific responses to these dominant variants could be identified, the magnitude of these responses remained small, and the dominant CTL response was directed at the minor in vivo variant. These studies indicate that despite similar epitope-specific immunologic pressure in persons of the same HLA type, the in vivo quasispecies may differ, and that the major in vivo immune response to a given CTL epitope can be directed at a minor variant.

HLA and HIV-1: heterozygote advantage and B*35-Cw*04 disadvantage.

A selective advantage against infectious disease associated with increased heterozygosity at the human major histocompatibility complex [human leukocyte antigen (HLA) class I and class II] is believed to play a major role in maintaining the extraordinary allelic diversity of these genes. Maximum HLA heterozygosity of class I loci (A, B, and C) delayed acquired immunodeficiency syndrome (AIDS) onset among patients infected with human immunodeficiency virus-type 1 (HIV-1), whereas individuals who were homozygous for one or more loci progressed rapidly to AIDS and death. The HLA class I alleles B*35 and Cw*04 were consistently associated with rapid development of AIDS-defining conditions in Caucasians. The extended survival of 28 to 40 percent of HIV-1-infected Caucasian patients who avoided AIDS for ten or more years can be attributed to their being fully heterozygous at HLA class I loci, to their lacking the AIDS-associated alleles B*35 and Cw*04, or to both.

Genetic restriction of HIV-1 infection and progression to AIDS by a deletion allele of the CKR5 structural gene. Hemophilia Growth and Development Study, Multicenter AIDS Cohort Study, Multicenter Hemophilia Cohort Study, San Francisco City Cohort, ALIVE Study.

The chemokine receptor 5 (CKR5) protein serves as a secondary receptor on CD4(+) T lymphocytes for certain strains of human immunodeficiency virus-type 1 (HIV-1). The CKR5 structural gene was mapped to human chromosome 3p21, and a 32-base pair deletion allele (CKR5Delta32) was identified that is present at a frequency of approximately0.10 in the Caucasian population of the United States. An examination of 1955 patients included among six well-characterized acquired immunodeficiency syndrome (AIDS) cohort studies revealed that 17 deletion homozygotes occurred exclusively among 612 exposed HIV-1 antibody-negative individuals (2.8 percent) and not at all in 1343 HIV-1-infected individuals. The frequency of CKR5 deletion heterozygotes was significantly elevated in groups of individuals that had survived HIV-1 infection for more than 10 years, and, in some risk groups, twice as frequent as their occurrence in rapid progressors to AIDS. Survival analysis clearly shows that disease progression is slower in CKR5 deletion heterozygotes than in individuals homozygous for the normal CKR5 gene. The CKR5Delta32 deletion may act as a recessive restriction gene against HIV-1 infection and may exert a dominant phenotype of delaying progression to AIDS among infected individuals.

Contrasting genetic influence of CCR2 and CCR5 variants on HIV-1 infection and disease progression. Hemophilia Growth and Development Study (HGDS), Multicenter AIDS Cohort Study (MACS), Multicenter Hemophilia Cohort Study (MHCS), San Francisco City Cohort (SFCC), ALIVE Study.

The critical role of chemokine receptors (CCR5 and CXCR4) in human immunodeficiency virus-type 1 (HIV-1) infection and pathogenesis prompted a search for polymorphisms in other chemokine receptor genes that mediate HIV-1 disease progression. A mutation (CCR2-64I) within the first transmembrane region of the CCR2 chemokine and HIV-1 receptor gene is described that occurred at an allele frequency of 10 to 15 percent among Caucasians and African Americans. Genetic association analysis of five acquired immunodeficiency syndrome (AIDS) cohorts (3003 patients) revealed that although CCR2-64I exerts no influence on the incidence of HIV-1 infection, HIV-1-infected individuals carrying the CCR2-64I allele progressed to AIDS 2 to 4 years later than individuals homozygous for the common allele. Because CCR2-64I occurs invariably on a CCR5-+-bearing chromosomal haplotype, the independent effects of CCR5-Delta32 (which also delays AIDS onset) and CCR2-64I were determined. An estimated 38 to 45 percent of AIDS patients whose disease progresses rapidly (less than 3 years until onset of AIDS symptoms after HIV-1 exposure) can be attributed to their CCR2-+/+ or CCR5-+/+ genotype, whereas the survival of 28 to 29 percent of long-term survivors, who avoid AIDS for 16 years or more, can be explained by a mutant genotype for CCR2 or CCR5.

Genetic acceleration of AIDS progression by a promoter variant of CCR5.

The CCR5 gene encodes a cell surface chemokine receptor molecule that serves as the principal coreceptor, with CD4, for macrophage-tropic (R5) strains of human immunodeficiency virus-type 1 (HIV-1). Genetic association analysis of five cohorts of people with acquired immunodeficiency syndrome (AIDS) revealed that infected individuals homozygous for a multisite haplotype of the CCR5 regulatory region containing the promoter allele, CCR5P1, progress to AIDS more rapidly than those with other CCR5 promoter genotypes, particularly in the early years after infection. Composite genetic epidemiologic analyses of genotypes bearing CCR5P1, CCR5-Delta32, CCR2-64I, and SDF1-3'A affirmed distinct regulatory influences for each gene on AIDS progression. An estimated 10 to 17 percent of patients who develop AIDS within 3.5 years of HIV-1 infection do so because they are homozygous for CCR5P1/P1, and 7 to 13 percent of all people carry this susceptible genotype. The cumulative and interactive influence of these AIDS restriction genes illustrates the multigenic nature of host factors limiting AIDS disease progression.

Genetic restriction of AIDS pathogenesis by an SDF-1 chemokine gene variant. ALIVE Study, Hemophilia Growth and Development Study (HGDS), Multicenter AIDS Cohort Study (MACS), Multicenter Hemophilia Cohort Study (MHCS), San Francisco City Cohort (SFCC)

Stromal-derived factor (SDF-1) is the principal ligand for CXCR4, a coreceptor with CD4 for T lymphocyte cell line-tropic human immunodeficiency virus-type 1 (HIV-1). A common polymorphism, SDF1-3'A, was identified in an evolutionarily conserved segment of the 3' untranslated region of the SDF-1 structural gene transcript. In the homozygous state, SDF1-3'A/3'A delays the onset of acquired immunodeficiency syndrome (AIDS), according to a genetic association analysis of 2857 patients enrolled in five AIDS cohort studies. The recessive protective effect of SDF1-3'A was increasingly pronounced in individuals infected with HIV-1 for longer periods, was twice as strong as the dominant genetic restriction of AIDS conferred by CCR5 and CCR2 chemokine receptor variants in these populations, and was complementary with these mutations in delaying the onset of AIDS.

Aryl hydrocarbon receptor interacting protein gene (AIP) mutations are rare in patients with hormone secreting or non-secreting pituitary adenomas.

OBJECTIVE: Recent data suggest that mutations in the aryl hydrocarbon receptor interacting protein gene (AIP) are associated with pituitary adenomas. AIP is considered to be a tumour suppressor gene. METHODS: 110 Caucasian patients living in Germany with pituitary adenoma (55 hormone secreting, 55 non-functioning) were examined for AIP mutations. RESULTS: Three patients (2.7%) harboured an AIP germline mutation. A heterozygous mutation, R16H (c.47G>A), was found in two patients and a heterozygous G>C change in the 3'UTR, 60 bp downstream of the termination codon, in one patient. All three patients suffered from non-functioning adenoma. Additionally, a silent polymorphism, D172D (c.516C>T), was found in 3 patients with non-functioning adenoma, in 2 patients with prolactinoma and in one patient with acromegaly. CONCLUSIONS: AIP mutations are rare in sporadic pituitary adenomas in the German population and occur independently from a hormone secretion of the adenoma.

The DG10S478 variant in the TCF7L2 gene is not associated with microvascular complications in type 2 diabetes.

OBJECTIVE: The DG10S478 variant in the transcription factor 7-like 2 (TCF7L2) gene is a tetranucleotide repeat with six alleles. Alleles 0, 8 and 12 were found to account for 98% of chromosomes in population based controls. The composite allele X (non zero) has been associated with type 2 diabetes while allele 0 (no insertion) was described as protective. However, no data exist about the influence of DG10S478 variants on manifestation of diabetes and development of diabetic complications. METHODS: 250 patients with type 2 diabetes were tested for the DG10S478 allele X and its association with diabetic complications, age at diagnosis of diabetes and BMI. RESULTS: Allele 0 was found in 42.4% of the examined patients, 45.2% of the participants were found to be heterozygous and 12.4% homozygous for the composite allele X. The correlation of allele X with the age at diagnosis of diabetes was not significant. There was also no association of allele X with retinopathy, nephropathy or neuropathy. Only the correlation with BMI was statistically significant. CONCLUSIONS: The DG10S478 variant seems to have no influence on manifestation of diabetes and the development of microvascular complications.

Lack of strong immune selection pressure by the immunodominant, HLA-A*0201-restricted cytotoxic T lymphocyte response in chronic human immunodeficiency virus-1 infection.

Despite detailed analysis of the HIV-1-specific cytotoxic T lymphocyte response by various groups, its relation to viral load and viral sequence variation remains controversial. We analyzed HLA-A*0201 restricted cytotoxic T lymphocyte responses in 17 HIV-1-infected individuals with viral loads ranging from < 400 to 221,000 HIV RNA molecules per milliliter of plasma. In 13 out of 17 infected subjects, CTL responses against the SLYNTVATL epitope (p17 Gag; aa 77-85) were detectable, whereas two other HLA-A*0201 restricted epitopes (ILKEPVHGV, IV9; and VIYQYMDDL, VL9) were only recognized by six and five individuals out of 17 individuals tested, respectively. Naturally occurring variants of the SL9 epitope were tested for binding to HLA-A*0201 and for recognition by specific T cell clones generated from five individuals. Although these variants were widely recognized, they differed by up to 10,000-fold in terms of variant peptide concentrations required for lysis of target cells. A comparison of viral sequences derived from 10 HLA-A*0201-positive individuals to sequences obtained from 11 HLA-A*0201-negative individuals demonstrated only weak evidence for immune selective pressure and thus question the in vivo efficacy of immunodominant CTL responses present during chronic HIV-1 infection.

Heterozygosity for a defective gene for CC chemokine receptor 5 is not the sole determinant for the immunologic and virologic phenotype of HIV-infected long-term nonprogressors.

HIV-1-infected long-term nonprogressors are a heterogeneous group of individuals with regard to immunologic and virologic markers of HIV-1 disease. CC chemokine receptor 5 (CCR5) has recently been identified as an important coreceptor for HIV-1 entry into CD4+ T cells. A mutant allele of CCR5 confers a high degree of resistance to HIV-1 infection in homozygous individuals and partial protection against HIV disease progression in heterozygotes. The frequency of CCR5 heterozygotes is increased among HIV-1- infected long-term nonprogressors compared with progressors; however, the host defense mechanisms responsible for nonprogression in CCR5 heterozygotes are unknown. We hypothesized that nonprogressors who were heterozygous for the mutant CCR5 gene might define a subgroup of nonprogressors with higher CD4+ T cell counts and lower viral load compared with CCR5 wild-type nonprogressors. However, in a cohort of 33 HIV-1-infected long-term nonprogressors, those who were heterozygous for the mutant CCR5 gene were indistinguishable from CCR5 wild-type nonprogressors with regard to all measured immunologic and virologic parameters. Although epidemiologic data support a role for the mutant CCR5 allele in the determination of the state of long-term nonprogression in some HIV-1- infected individuals, it is not the only determinant. Furthermore, long-term nonprogressors with the wild-type CCR5 genotype are indistinguishable from heterozygotes from an immunologic and virologic standpoint.

Reduced risk of AIDS lymphoma in individuals heterozygous for the CCR5-delta32 mutation.

Non-Hodgkin's lymphoma (NHL) has been increasing in frequency in the industrialized world, but the environmental and genetic factors that contribute to susceptibility are not known. B-cell lymphomas represent a major cause of morbidity and mortality in HIV-infected individuals. The identification of a deletion in the CCR5 chemokine receptor gene that alters the risk for infection and progression to AIDS led us to examine a potential role of this gene in AIDS lymphoma. A matched case-control analysis was performed using all eligible NHL cases in the Multicenter AIDS Cohort Study. Patients were matched for age, study center, time AIDS-free, and slope of the CD4+ T-cell decline. The CCR5-delta32 allele was found to be associated with a 3-fold lower risk of NHL among individuals after controlling for time of infection and progression toward AIDS. The CCR5 gene was not associated with a difference in risk for Kaposi's sarcoma, another common malignancy in AIDS patients, or opportunistic infections. Costimulation of normal phorbol 12-myristate 13-acetate-treated B cells with the CCR5 ligand RANTES induced a proliferative response, indicating that RANTES is a mitogen for B cells. Taken together, these findings suggest that the CCR5 gene plays a role in the risk of NHL in HIV-infected patients, perhaps through a mechanism involving a decreased response of B cells to the mitogenic activity of RANTES.

The association of clinical conditions and serologic tests with CD4+ lymphocyte counts in HIV-infected subjects without AIDS.

Early intervention guidelines in HIV infection require knowledge of CD4+ lymphocyte count; however, CD4+ determinations require special laboratory procedures and may not be readily available in all situations. Using data from 207 HIV-seropositive homosexual men without AIDS, we evaluated the association of difference clinical conditions or serologic tests with CD4+ count. Men with conditions including seborrheic dermatitis, hairy leukoplakia, oral candidiasis and chronic diarrhea, and men with beta2-microglobulin levels greater than or equal to 4.0 mg/l had significantly lower CD4+ counts. However, the probability that a subject with such parameters had less than 200 x 10(6)/l CD4+ cells was limited (25-63%). Although the probability that a subject with such parameters had less than 500 x 10(6)/l CD4+ cells was better (76-88%), the probability that a person without these parameters had greater than or equal to 500 x 10(6)/l CD4+ cells was only 45-50%. Clinical and serologic parameters may provide important prognostic information, but cannot be used to reliably determine the level of CD4+ cells.

Long-term HIV-1 infection without immunologic progression.

OBJECTIVE: To identify and describe a subgroup of men infected with HIV for 10-15 years without immunologic progression, and to evaluate the effect of sexually transmitted diseases (STD) and recreational drug use on delayed HIV disease progression. DESIGN: Inception cohort study. SETTING: Municipal STD clinic. PARTICIPANTS: A total of 588 men with well documented dates of HIV seroconversion and 197 HIV-seronegative controls. MAIN OUTCOME MEASURES: AIDS, CD4+ count, rate of CD4+ cell loss, CD8+ count, beta 2-microglobulin, complete blood count, p24 antigen and HIV-related symptoms. RESULTS: Of 588 men, 69% had developed AIDS by 14 years after HIV seroconversion (95% confidence interval, 64-73%). Of 539 men with HIV seroconversion dates prior to 1983, 42 men (8%) were healthy long-term HIV-positives (HLP), HIV-infected > or = 10 years without AIDS and with CD4+ counts > 500 x 10(6)/l. When compared with progressors (men with HIV seroconversion prior to 1983 but with AIDS or CD4+ counts < 200 x 10(6)/l), HLP had a significantly slower rate of CD4+ decline (6 versus 85 x 10(6)/l cells/year), and less abnormal immunologic, hematologic and clinical parameters. However, when compared with HIV-uninfected controls, HLP demonstrated lower CD4+ counts and mild hematologic abnormalities. There were no consistent differences between HLP and progressors in prior exposure to recreational drugs or STD. CONCLUSION: There are individuals with long-term HIV infection who appear clinically and immunologically healthy 10-15 years after HIV seroconversion, with stable CD4+ counts. Lack of exposure to STD or recreational drugs does not appear to explain the delayed course of disease progression in HLP.

Use of therapeutic and prophylactic drugs for AIDS by homosexual and bisexual men in three US cities.

OBJECTIVE: To determine the use of AIDS drugs and therapies by populations with relatively good access to health care. DESIGN: Prospective cohort study, with interview and examination twice a year since 1988. SETTING: Two public-health departments (San Francisco Department of Health and Denver Disease Control Service) and a private clinic (Howard Brown Memorial Clinic, Chicago). PARTICIPANTS: HIV-seropositive homosexual and bisexual men in San Francisco (311 men), Denver (120 men) and Chicago (59 men). INTERVENTIONS: HIV counseling and testing at each visit. MAIN OUTCOME MEASURES: Time and duration of use of drugs used for AIDS and Pneumocystis carinii pneumonia (PCP) treatment and prophylaxis. RESULTS: Zidovudine and pentamidine use increased from 1987 through 1989 in all three cities. In San Francisco in 1987, only 17 out of 110 (15%) HIV-seropositive men without AIDS reported taking zidovudine. By 1990, over 90% of AIDS patients and approximately 80% of HIV-seropositive men with low CD4+ cell counts (< 200 x 10(6)/l) had taken zidovudine; most men who by 1990 had never taken zidovudine (82%) or PCP prophylaxis (95%) had not been recommended these therapies because they did not have symptoms and their absolute CD4+ cell counts were > 200 x 10(6)/l. However, overall in the three cities, only 68% of the AIDS patients and 63% of the men with low CD4+ cell counts had taken zidovudine for more than 6 months by 1990. Most men who had stopped taking zidovudine (67%) did so because of toxicity; however, 64% of respondents gave reasons other than drug toxicity as a or the sole reason why they discontinued zidovudine. CONCLUSIONS: AIDS therapeutic and prophylactic drugs were increasingly (and appropriately) recommended to and accepted by these cohorts after 1987, but had limited consistent use because of toxicity, adverse side-effects, and several other less readily appreciated reasons. These data do not indicate that zidovudine use in San Francisco would mainly account for the observed slowing in the rate of increase of AIDS cases in homosexual and bisexual men in this city after 1987.

The prevalence of oral lesions in HIV-infected homosexual and bisexual men: three San Francisco epidemiological cohorts.

To establish the prevalence of HIV-related oral lesions, we performed oral examinations of members of three San Francisco epidemiological cohorts of homosexual and bisexual men over a 3-year period. Hairy leukoplakia, pseudomembranous and erythematous candidiasis, angular cheilitis, Kaposi's sarcoma, and oral ulcers were more common in HIV-infected subjects than in HIV-negative subjects. Among HIV-infected individuals, hairy leukoplakia was the most common lesion [20.4%, 95% confidence interval (CI) 17.5-23.3%] and pseudomembranous candidiasis was the next most common (5.8%, 95% CI 4.1-7.5%). Hairy leukoplakia, pseudomembranous candidiasis, angular cheilitis and Kaposi's sarcoma were significantly more common in patients with lower CD4 lymphocyte counts (P less than 0.05). The prevalence of erythematous candidiasis and Kaposi's sarcoma increased during the 3-year period. Careful oral examinations may identify infected patients and provide suggestive information concerning their immune status.

Readiness of high-risk populations in the HIV Network for Prevention Trials to participate in HIV vaccine efficacy trials in the United States.

OBJECTIVE: To determine the willingness of populations at high risk of HIV-1 infection to participate in HIV vaccine efficacy trials, determine factors influencing decision-making, and evaluate knowledge levels of vaccine trial concepts. DESIGN: Cross-sectional study. METHODS: HIV-1-negative homosexual men, male and female injecting drug users and non-injecting women at heterosexual risk were recruited in eight cities in the United States (n=4892). RESULTS: A substantial proportion of the study population (77%) would definitely (27%) or probably (50%) be willing to participate in a randomized vaccine efficacy trial. Increased willingness was associated with high-risk behaviors, lower education level, being uninsured or covered by public insurance, and not having been in a previous vaccine preparedness study. Altruism and a desire for protection from the vaccine were major motivators for participation. Major concerns included positive HIV-1 antibody test due to vaccine, safety of the vaccine, and possible problems with insurance or foreign travel. Baseline knowledge of vaccine trial concepts was low. CONCLUSIONS: It is likely that high-risk volunteers will be willing to enroll in HIV vaccine efficacy trials. A variety of participant and community educational strategies are needed to address participant concerns, and to ensure understanding of key concepts prior to giving consent for participation.

The association between cigarette smoking and selected HIV-related medical conditions.

OBJECTIVE: To clarify the effect of cigarette smoking on the development of conditions associated with HIV infection. DESIGN: Prospective and retrospective cohort study, with interview and examination twice a year since 1988. METHODS: Data on 516 HIV-infected men from cohorts of homosexual and bisexual men in San Francisco, Denver and Chicago, who were repeatedly interviewed and examined between 1988 and 1992, were analysed. After excluding men who did not have well-defined dates of seroconversion and those who were classified as ex- or intermittent smokers, 232 men remained for analysis: 106 were smokers and 126 were non-smokers. Univariate and Kaplan-Meier survival analyses were performed to assess the relationship between cigarette smoking and loss of CD4+ T-lymphocytes, diagnosis of any AIDS-defining illness, and specific diagnosis of Kaposi's sarcoma, Pneumocystis carinii pneumonia (PCP), oral candidiasis, hairy leukoplakia, and community-acquired pneumonia. RESULTS: By univariate analyses, cigarette smoking was not associated with clinical AIDS, loss of CD4+ cells, Kaposi's sarcoma or PCP, but was significantly associated with oral candidiasis [relative risk (RR), 1.32; 95% confidence interval (CI), 1.02-1.70], hairy leukoplakia (RR, 1.51; 95% CI, 1.15-1.99), and community-acquired pneumonia (RR, 2.62; 95% CI, 1.30-5.27). Dose-response effect was also evident for these three conditions (all P < 0.01). Kaplan-Meier survival analysis indicated no association between cigarette smoking and time of progression to clinical AIDS, Kaposi's sarcoma (KS), or PCP (P = 0.62, 0.54 and 0.11, respectively) but showed that cigarette smokers developed oral candidiasis, hairy leukoplakia, and pneumonia more quickly than non-smokers (P = 0.031, 0.006 and 0.009, respectively). CONCLUSIONS: Cigarette smoking was not associated with an increased likelihood or rate of developing KS, PCP or AIDS, but was associated with developing community-acquired pneumonia, oral candidiasis, and hairy leukoplakia in these HIV-infected men.