Longer survival after HIV infection for injecting drug users than for homosexual men: implications for immunology

Predictors of antiretroviral treatment failure to the first line therapy: a cross-sectional study among Iranian HIV-positive adults

BACKGROUND

HIV virological failure is one of the main problems in HIV-infected patients, and identifying the main predictors of such treatment failure may help in combating HIV/AIDS.

METHODOLOGY

This cross-sectional study included 1800 HIV-infected patients with either virological failure or treatment response. HIV viral load, CD4 count, and other tests were performed. Statistical analysis was used to determine the predictors of virological failure.

RESULTS

Clinical stage, treatment with reverse transcriptase inhibitors (RTIs), under therapy for three years or more, suboptimal adherence to antiretroviral treatment (ART), age > 40 years, CD4 count < 200 cells/mm3, unemployment, being infected through sex, and the presence of symptoms were the predominant risk factors for virological failure. In addition, 55% of patients who experienced virological failure failed to experience immunological and/or clinical failure.

CONCLUSION

As the first study in southern Iran and the second in Iran, Iranian policymakers should focus on intensive counseling and adherence support and emphasize more effective treatment regimens such as protease and integrase inhibitors (PIs and INTIs), to increase the chance of a treatment response to ART. The accuracy of identifying clinical and immunological criteria in resource-limited settings is not promising. The present findings can be used to determine effective measures to control HIV treatment failure and design efficient strategies for the ambitious 95-95-95 plan.

Associated factors for progression to AIDS among HIV-infected people who use drugs: a retrospective cohort study in Dongguan, China

OBJECTIVES

Injection drug use is the most important risk factor for the spread of HIV in China over the past two decades. People who use drugs (PWUD) who were diagnosed at an early stage with HIV have gradually developed AIDS. This study investigated the factors associated with disease progression following HIV diagnosis in PWUD.

DESIGN

This study used a retrospective cohort study.

SETTING

This investigation was conducted in Dongguan city, Guangdong Province, China.

PARTICIPANTS

A total of 2969 PWUD with HIV were recruited from 1 January 1995 to 31 December 2014.

PRIMARY AND SECONDARY OUTCOME MEASURES

Kaplan-Meier method, Logistic regression and Cox proportional hazards regression model were applied to identify the related factors of progression to AIDS following HIV diagnosis.

RESULTS

The study revealed that age at diagnosis, marital status, baseline CD4 T-cell counts and highly active antiretroviral therapy (HAART) were statistically significant (p<0.01), either in the patients with HIV or in patients with AIDS. Compared with HIV-infected individuals of 18 years, patients with AIDS who were at least 36 years of age possessed sharply increased HR for developing AIDS (HR=7.016, 95% CI 6.083 to 8.092, p=0.001). The single HIV-positive individuals (HR=0.691, 95% CI 0.588 to 0.811, p=0.001) were less likely to develop AIDS compared with married ones. Increasing baseline CD4 T-cell counts, HAART (HR=0.599, 95% CI 0.517 to 0.693, p=0.001) and condom usage (HR=0.825, 95% CI 0.710 to 0.959, p=0.012) were associated with delayed progression to AIDS.

CONCLUSIONS

Our study found that increasing baseline CD4 T-cell counts, HAART and condom usage might be associated with delayed the progression of HIV to AIDS, while increasing age at diagnosis, marital status increased hazard for developing AIDS.

Overrepresentation of Injection Drug Use Route of Infection Among Human Immunodeficiency Virus Long-term Nonprogressors: A Nationwide, Retrospective Cohort Study in China, 1989-2016

Background

Why some persons living with human immunodeficiency virus (HIV) (PLWH) progress quickly and others remain "healthy" for a decade or more without treatment remains a fundamental question of HIV pathology. We aimed to assess the epidemiological characteristics of HIV long-term nonprogressors (LTNPs) based on a cohort of PLWH in China observed between 1989 and 2016.

Methods

We conducted a nationwide, retrospective cohort study among Chinese PLWH with HIV diagnosed before 1 January 2008. Records were extracted from China's national HIV/AIDS database on 30 June 2016. LTNPs were defined as those with AIDS-free, antiretroviral therapy-naive survival, with CD4 cell counts consistently ≥500/μL for ≥8 years after diagnosis. Prevalence was calculated, characteristics were described, and determinants were assessed by means of logistic regression. Potential sources of bias were also investigated.

Results

Our cohort included 89 201 participants, of whom 1749 (2.0%) were categorized as LTNPs. The injection drug use (IDU) route of infection was reported by 70.7% of LTNPs, compared with only 37.1% of non-LTNPs. The odds of LTNP status were greater among those infected via IDU (adjusted odds ratio [95% confidence interval], 2.28 [1.94-2.68]) and with HIV diagnosed in settings with large populations of persons who inject drugs (1.75 [1.51-2.02] for detention centers, 1.61 [1.39-1.87] for Yunnan, 1.94 [1.62-2.31] for Guangdong, and 2.90 [2.09-4.02] for Xinjiang).

Conclusions

Overrepresentation of the IDU route of infection among LTNPs is a surprising finding worthy of further study, and this newly defined cohort may be particularly well suited to exploration of the molecular biological mechanisms underlying HIV long-term nonprogression.

Association between HIV genotype, viral load and disease progression in a cohort of Thai men who have sex with men with estimated dates of HIV infection

BACKGROUND

Differences between HIV genotypes may affect HIV disease progression. We examined infecting HIV genotypes and their association with disease progression in a cohort of men who have sex with men with incident HIV infection in Bangkok, Thailand.

METHODS

We characterized the viral genotype of 189 new HIV infections among MSM identified between 2006-2014 using hybridization and sequencing. Plasma viral load (PVL) was determined by PCR, and CD4+ T-cell counts were measured by flow cytometry. We used Generalized Estimating Equations to examine factors associated with changes in CD4+ T-cell counts. Factors associated with immunologic failure were analyzed using Cox proportional hazard models.

RESULTS

Among 189 MSM, 84% were infected with CRF01_AE, 11% with recombinant B/CRF01_AE and 5% with subtype B. CD4+ T-cell decline rates were 68, 65, and 46 cells/μL/year for CRF01_AE, recombinants, and subtype B, respectively, and were not significantly different between HIV subtypes. CD4+ T-cell decline rate was significantly associated with baseline PVL and CD4+ T-cell counts (p <0.001). Progression to immunologic failure was associated with baseline CD4+ T-cell ≤ 500 cells/μL (AHR 1.97; 95% CI 1.14-3.40, p = 0.015) and PVL > 50,000 copies/ml (AHR 2.03; 1.14-3.63, p = 0.017). There was no difference in time to immunologic failure between HIV subtypes.

CONCLUSION

Among HIV-infected Thai MSM, low baseline CD4+ T-cell and high PVL are associated with rapid progression. In this cohort, no significant difference in CD4+ T-cell decline rate or time to immunologic failure was seen between CRF01_AE and other infecting HIV subtypes.

Risk Factors for Advanced HIV Disease and Late Entry to HIV Care: National 1994-2012 HIV Surveillance Data for Wuhan, China

Few studies in China have focused on advanced human immunodeficiency virus (HIV) disease (AHD) and late entry to HIV care, which are associated with increased morbidity and mortality. A population-based retrospective study was conducted using 980 national HIV surveillance reports from 1994 to February 2012 in Wuhan, China. AHD was defined as presence of a first-reported CD4 count<200 cells/μL or an acquired immune deficiency syndrome (AIDS)-defining event within 1 month of HIV diagnosis. Late entry to HIV care was defined as patients with a first-reported CD4 cell count>6 months after diagnosis. Non-conditional logistic regression analysis was used to identify factors associated with AHD, late entry to HIV care, and AIDS within 1 year of HIV diagnosis. The proportions of AHD, AIDS within 1 year of HIV diagnosis, and late entry to HIV care were 29.49%, 39.39%, and 20.84%, respectively. Most of the deaths (74.27%, 127/171) occurred within 1 year of diagnosis. Short-term mortality, proportion of AHD, and late entry to HIV care showed a similar downward trend from pre-2003 to 2011 (p<0.001). Age, transmission category, sample source, and occupation were associated with AHD, late entry to HIV care, and AIDS within 1 year of HIV diagnosis in the multivariate logistic regression analysis. These findings indicate that AHD and late entry to HIV care were associated with an increased incidence of AIDS or death, particularly within 1 year of diagnosis. More effort should be made to assure early diagnosis and timely entry to care.

Time from human immunodeficiency virus seroconversion to reaching CD4+ cell count thresholds <200, <350, and <500 Cells/mm³: assessment of need following changes in treatment guidelines

BACKGROUND

Recent updates of human immunodeficiency virus (HIV) treatment guidelines have raised the CD4+ cell count thresholds for antiretroviral therapy initiation from 350 to 500 cells/mm(3) in the United States and from 200 to 350 cells/mm³ in mid- and low-income countries. Robust data of time from HIV seroconversion to CD4+ cell counts of 200, 350, and 500 cells/mm³ are lacking but are needed to inform health care planners of the likely impact and cost effectiveness of these and possible future changes in CD4+ cell count initiation threshold.

METHODS

Using Concerted Action on Seroconversion to AIDS and Death in Europe data from individuals with well-estimated dates of HIV seroconversion, we fitted mixed models on the square root of CD4+ cell counts measured before combined antiretroviral therapy (cART) initiation. Restricting analyses to adults (age >16 years), we predicted time between seroconversion and CD4+ cell count <200, <350, and <500 cells/mm³ as well as CD4+ cell count distribution and proportions reaching these thresholds at 1, 2, and 5 years after seroconversion.

RESULTS

Median (interquartile range [IQR]) follow-up for the 18495 eligible individuals from seroconversion while cART-free was 3.7 years (1.5, 7). Most of the subjects were male (78%), had a median age at seroconversion of 30 years (IQR, 25-37 years), and were infected through sex between men (55%). Estimated median times (95% confidence interval [CI]) from seroconversion to CD4+ cell count <500, <350, and <200 cells/mm(3) were 1.19 (95% CI, 1.12-1.26), 4.19 (95% CI, 4.09-4.28), and 7.93 (95% CI, 7.76-8.09) years, respectively. Almost half of infected individuals would require treatment within 1 year of seroconversion for guidelines recommending its initiation at 500 cells/mm³, compared with 26% and 9% for guidelines recommending initiation at 350 and 200 cells/mm³, respectively.

CONCLUSIONS

These data suggest substantial increases in the number of individuals who require treatment and call for early HIV testing.

The effects of opioids on HIV reactivation in latently-infected T-lymphoblasts

Background

Opioids may have effects on susceptibility to HIV-infection, viral replication and disease progression. Injecting drug users (IDU), as well as anyone receiving opioids for anesthesia and analgesia may suffer the clinical consequences of such interactions. There is conflicting data between in vitro experiments showing an enhancing effect of opioids on HIV replication and clinical data, mostly showing no such effect. For clarification we studied the effects of the opioids heroin and morphine on HIV replication in cultured CD4-positive T cells at several concentrations and we related the observed effects with the relevant reached plasma concentrations found in IDUs.

Methods

Latently-infected ACH-2 T lymphoblasts were incubated with different concentrations of morphine and heroine. Reactivation of HIV was assessed by intracellular staining of viral Gag p24 protein and subsequent flow cytometric quantification of p24-positive cells. The influence of the opioid antagonist naloxone and the antioxidants N-acetyl-cysteine (NAC) and glutathione (GSH) on HIV reactivation was determined. Cell viability was investigated by 7-AAD staining and flow cytometric quantification.

Results

Morphine and heroine triggered reactivation of HIV replication in ACH-2 cells in a dose-dependent manner at concentrations above 1 mM (EC₅₀ morphine 2.82 mM; EC₅₀ morphine 1.96 mM). Naloxone did not interfere with heroine-mediated HIV reactivation, even at high concentrations (1 mM). Opioids also triggered necrotic cell death at similar concentrations at which HIV reactivation was observed. Both opioid-mediated reactivation of HIV and opioid-triggered cell death could be inhibited by the antioxidants GSH and NAC.

Conclusions

Opioids reactivate HIV in vitro but at concentrations that are far above the plasma levels of analgesic regimes or drug concentrations found in IDUs. HIV reactivation was mediated by effects unrelated to opioid-receptor activation and was tightly linked to the cytotoxic activity of the substances at millimolar concentrations, suggesting that opioid-mediated reactivation of HIV was due to accompanying effects of cellular necrosis such as activation of reactive oxygen species and NF-κB.

Determinants of progression to AIDS and death following HIV diagnosis: a retrospective cohort study in Wuhan, China

OBJECTIVE

To identify determinants associated with disease progression and death following human immunodeficiency virus (HIV) diagnosis.

METHODS

Disease progression data from the diagnosis of HIV infection or acquiring immunodeficiency syndrome (AIDS) to February 29, 2012 were retrospectively collected from the national surveillance system databases and the national treatment database in Wuhan, China. Kaplan-Meier method, Logistic regression and Cox proportional hazards model were applied to identify the related factors of progression to AIDS or death following HIV diagnosis.

RESULTS

By the end of February 2012, 181 of 691 HIV infectors developed to AIDS, and 129 of 470 AIDS patients died among whom 289 cases received concurrent HIV/AIDS diagnosis. Compared with men infected through homosexual behavior, injection drug users possessed sharply decreased hazard ratio (HR) for progression to AIDS following HIV diagnosis [HR = 0.31, 95% confidence interval (CI), 0.18-0.54, P = 4.01×10(-5)]. HIV infectors at least 60 years presented 1.15-fold (HR = 2.15, 95% CI, 1.15-4.03, P = 0.017) increased risk to develop AIDS when compared with those aged 17-29 years. Similarly, AIDS patients with diagnosis ages between 50 and 59 years were at a 1.60-fold higher risk of death (HR = 2.60, 95% CI, 1.18-5.72, P = 0.017) compared to those aged 19-29 years. AIDS patients with more CD4(+) T-cells within 6 months at diagnosis (cell/µL) presented lower risk of death (HR = 0.29 for 50- vs <50, 95% CI, 0.15-0.59, P = 0.001). The highly active antiretroviral therapy (HAART) delayed progression to AIDS from HIV diagnosis (HR = 0.15, 95% CI, 0.07-0.34, P = 6.46×10(-6)) and reduced the risk of death after AIDS diagnosis (HR = 0.02, 95% CI, 0.01-0.04, P = 7.25×10(-25)).

CONCLUSIONS

Progression to AIDS and death following HIV diagnosis differed in age at diagnosis, transmission categories, CD4(+) T-cell counts and HAART. Effective interventions should target those at higher risk for morbidity or mortality, ensuring early diagnosis and timely treatment to slow down the disease progression.

Route of transmission might influence the clinical expression of periodontal lesions in "human immunodeficiency virus" positive patients

BACKGROUND

Various routes have been reported with respect to the transmission of human immunodeficiency virus (HIV) from one individual to another. But it is not clear whether they alter the clinical expression of the disease. This study was conducted to know whether there exists any difference in the occurrence of periodontal lesions among untreated HIV subjects who acquired the disease either through intravenous drug abuse or sexual contact and to correlate those lesions with immune suppression as indicated by CD 4 T lymphocyte counts.

MATERIALS AND METHODS

In this cross-sectional study 213 HIV-positive subjects who had not started on Highly Active Anti Retroviral Therapy (HAART) were selected and divided into two groups intravenous drug users (IVDU) and non-IVDU (NIVDU). CD 4 T lymphocyte counts were evaluated and clinical examination was done to detect the presence of pathologic periodontal lesions.

RESULTS

Mean probing depth (PD) and clinical attachment level (CAL) are significantly higher in drug users than nondrug users. When periodontal lesions are compared with CD 4 cell counts, it is found that significant inverse relation exists between linear gingival erythema, necrotizing ulcerative periodontitis, and CD 4 counts, but only in nondrug users.

CONCLUSION

An inverse correlation between linear gingival erythema, necrotizing ulcerative periodontitis, and CD 4 counts in NIVDU indicating their reliability as a marker for immune suppression. Periodontitis is more prevalent among drug users indicating some difference in disease expression among the groups.

Variability of bio-clinical parameters in Chinese-origin Rhesus macaques infected with simian immunodeficiency virus: a nonhuman primate AIDS model

Background

Although Chinese-origin Rhesus macaques (Ch RhMs) infected with simian immunodeficiency virus (SIV) have been used for many years to evaluate the efficacy of AIDS vaccines and therapeutics, the bio-clinical variability of such a nonhuman primate AIDS model was so far not established.

Methodology/Principal Findings

By randomizing 150 (78 male and 72 female) Ch RhMs with diverse MHC class I alleles into 3 groups (50 animals per group) challenged with intrarectal (ir) SIVmac239, intravenous (iv) SIVmac239, or iv SIVmac251, we evaluated variability in bio-clinical endpoints for 118 weeks. All SIV-challenged Ch RhMs became seropositive for SIV during 1–2 weeks. Plasma viral load (VL) peaked at weeks 1–2 and then declined to set-point levels as from week 5. The set-point VL was 30 fold higher in SIVmac239 (ir or iv)-infected than in SIVmac251 (iv)-infected animals. This difference in plasma VL increased overtime (>100 fold as from week 68). The rates of progression to AIDS or death were more rapid in SIVmac239 (ir or iv)-infected than in SIVmac251 (iv)-infected animals. No significant difference in bio-clinical endpoints was observed in animals challenged with ir or iv SIVmac239. The variability (standard deviation) in peak/set-point VL was nearly one-half lower in animals infected with SIVmac239 (ir or iv) than in those infected with SIVmac251 (iv), allowing that the same treatment-related difference can be detected with one-half fewer animals using SIVmac239 than using SIVmac251.

Conclusion/Significance

These results provide solid estimates of variability in bio-clinical endpoints needed when designing studies using the Ch RhM SIV model and contribute to the improving quality and standardization of preclinical studies.

Stochastic cellular automata model and Monte Carlo simulations of CD4+ T cell dynamics with a proposed alternative leukapheresis treatment for HIV/AIDS

Acquired Immunodeficiency Syndrome (AIDS) is responsible for millions of deaths worldwide. To date, many drug treatment regimens have been applied to AIDS patients but none has resulted in a successful cure. This is mainly due to the fact that free HIV particles are frequently in mutation, and infected CD4(+) T cells normally reside in the lymphoid tissue where they cannot (so far) be eradicated. We present a stochastic cellular automaton (CA) model to computationally study what could be an alternative treatment, namely Leukapheresis (LCAP), to remove HIV infected leukocytes in the lymphoid tissue. We base our investigations on Monte Carlo computer simulations. Our major objective is to investigate how the number of infected CD4(+) T cells changes in response to LCAP during the short-time (weeks) and long-time (years) scales of HIV/AIDS progression in an infected individual. To achieve our goal, we analyze the time evolution of the CD4(+) T cell population in the lymphoid tissue (i.e., the lymph node) for HIV dynamics in treatment situations with various starting times and frequencies and under a no treatment condition. Our findings suggest that the effectiveness of the treatment depends mainly on the treatment starting time and the frequency of the LCAP. Other factors (e.g., the removal proportion, the treatment duration, and the state of removed cells) that likely influence disease progression are subjects for further investigation.

Rapid dissemination of SIV follows multisite entry after rectal inoculation

Receptive ano-rectal intercourse is a major cause of HIV infection in men having sex with men and in heterosexuals. Current knowledge of the mechanisms of entry and dissemination during HIV rectal transmission is scarce and does not allow the development of preventive strategies. We investigated the early steps of rectal infection in rhesus macaques inoculated with the pathogenic isolate SIVmac251 and necropsied four hours to nine days later. All macaques were positive for SIV. Control macaques inoculated with heat-inactivated virus were consistently negative for SIV. SIV DNA was detected in the rectum as early as four hours post infection by nested PCR for gag in many laser-microdissected samples of lymphoid aggregates and lamina propria but never in follicle-associated epithelium. Scarce SIV antigen positive cells were observed by immunohistofluorescence in the rectum, among intraepithelial and lamina propria cells as well as in clusters in lymphoid aggregates, four hours post infection and onwards. These cells were T cells and non-T cells that were not epithelial cells, CD68⁺ macrophages, DC-SIGN⁺ cells or fascin⁺ dendritic cells. DC-SIGN⁺ cells carried infectious virus. Detection of Env singly spliced mRNA in the mucosa by nested RT-PCR indicated ongoing viral replication. Strikingly, four hours post infection colic lymph nodes were also infected in all macaques as either SIV DNA or infectious virus was recovered. Rapid SIV entry and dissemination is consistent with trans-epithelial transport. Virions appear to cross the follicle-associated epithelium, and also the digestive epithelium. Viral replication could however be more efficient in lymphoid aggregates. The initial sequence of events differs from both vaginal and oral infections, which implies that prevention strategies for rectal transmission will have to be specific. Microbicides will need to protect both digestive and follicle-associated epithelia. Vaccines will need to induce immunity in lymph nodes as well as in the rectum.

Non-injection drug use and HIV disease progression in the era of combination antiretroviral therapy

Little is known about the effects of non-injection drug use (NIDU) on HIV antiretroviral treatment outcomes. We conducted a systematic literature search and identified nine publications from prospective cohort studies investigating the relationship between NIDU and clinical HIV disease progression. Hazard ratios from studies estimating the effect of drug use on time to AIDS-related mortality ranged from 0.89 to 3.61, and only two of these were statistically significant. Hazard ratios from studies assessing time to an AIDS-defining event ranged from 1.19 to 2.51, with 8 of the 14 estimates falling between 1.55 and 1.65 regardless of drug use definition and measurement of use or frequency. It is suggested that NIDU may have a moderate effect of increasing the risk of progression to AIDS, but its impact on AIDS-related mortality is uncertain. NIDU may affect HIV antiretroviral treatment outcomes primarily through interaction with antiretroviral therapy and, to a lesser extent, through immune modulation and deterioration of general health. The limitations about published studies are discussed, and future perspectives on research on this topic are provided.

Vaccine immunogenicity in injecting drug users: a systematic review

Injection drug use is a prevalent global phenomenon; one not bound by a country's level of development or geographical location. Injection drug users (IDUs) are at high risk for a variety of parenterally acquired and transmitted infections. Licensed vaccines are available for some of these infectious diseases, such as tetanus, influenza, and hepatitis A and B viruses; however, there have been conflicting reports as to their immunogenicity in IDUs. We summarise the lessons learned from studies evaluating the immunogenicity of vaccination strategies in IDUs. A common theme across these diseases is that although there is a tendency towards decreased antibody responses after immunisation, there is no conclusive evidence linking these observations to a decrease in clinical protection from infection. There is a clear need for definitive studies of vaccination strategies in IDUs; however, a synthesis of the available published evidence suggests that immunisation does result in effective clinical protection from disease in this population. The inclusion of IDUs as a high-risk study population in future trials evaluating HIV and hepatitis C virus vaccines will help to assess the immunogenicity of candidate vaccines against parenteral exposure, and also to evaluate the efficacy of candidates as promising antigens become available.

Comparative studies on mucosal and intravenous transmission of simian immunodeficiency virus (SIVsm): evolution of coreceptor use varies with pathogenic outcome

Coreceptor usage of isolates from 30 cynomolgus macaques infected intrarectally (n=22) or intravenously (n=8) with simian immunodeficiency virus of sooty mangabey origin (SIVsm) was evaluated in U87.CD4 and GHOST(3) cell lines. Based on progression rate, the animals were divided into progressors (18 animals), slow progressors (five animals) and long-term non-progressors (seven animals). There was no difference in how many or which coreceptors were used according to route of infection. All isolates but one used CCR5 for cell entry, and CCR5 was also the major coreceptor in 70 out of 105 isolates tested. In general, early isolates were multitropic, using CCR5, CXCR6 and/or gpr15. Interestingly, CXCR4-using viruses could be isolated on human peripheral blood mononuclear cells (PBMCs), but not on cynomolgus macaque PBMCs, suggesting that human PBMCs select for variants with CXCR4 use. Even though CXCR4-using SIV isolates have been reported rarely, we could recover CXCR4-using viruses from 13 monkeys. CXCR4 use either appeared early during the acute phase of infection and disappeared later or only appeared late in infection during immunodeficiency. Surprisingly, one late isolate from a progressor monkey did not use CCR5 at all and used the CXCR4 receptor with high efficiency. The ability to use many different receptors decreased over time in long-term non-progressor monkeys, whilst the majority of progressor monkeys showed broadening of coreceptor use, stable coreceptor use or fluctuation between the different coreceptor-usage patterns. The results indicate that, in the infected host, evolution of SIV coreceptor usage occurs, involving changes in the mode of coreceptor use.

Comparative studies on mucosal and intravenous transmission of simian immunodeficiency virus (SIVsm): the kinetics of evolution to neutralization resistance are related to progression rate of disease

The kinetics of appearance of autologous neutralizing antibodies were studied in cynomolgus macaques infected with simian immunodeficiency virus (SIVsm) by the intravenous (IV) route (six monkeys) or the intrarectal (IR) route (ten monkeys). The SIVsm inoculum virus and reisolates obtained at 2 weeks, 3 or 4 months and later than 1 year were tested in a GHOST(3) cell line-based plaque-reduction assay with autologous sera collected at the same sampling times. All monkeys developed a neutralizing-antibody response to the inoculum virus, those infected by the IV route earlier than monkeys infected by the IR route. Animals were divided into progressor (P), slow-progressor (SP) and long-term non-progressor (LTNP) monkeys, based on progression rate. In P monkeys, neutralization escape could be demonstrated by 3 months post-infection. Neutralization-resistant variants also emerged in SP and LTNP monkeys, but were much delayed compared with P monkeys. Evolution of neutralization resistance was also demonstrated by a positive-control serum in the heterologous reaction. Pooled sera from four LTNP monkeys showed a broad neutralizing capacity, including neutralization of escape variants. These results from a large group of infected monkeys showed that SIV evolves to neutralization resistance in the infected host and that the kinetics of this evolution are related to the route of transmission and the progression rate of SIV disease. The results suggest an important role for neutralizing antibodies in controlling viraemia. Although this control is transient in the infected host, neutralization resistance is relative and variant viruses may be neutralized by a broadly cross-neutralizing serum pool.

Effect of hard-drug use on CD4 cell percentage, HIV RNA level, and progression to AIDS-defining class C events among HIV-infected women

In vitro and animal studies suggest that cocaine and heroin increase HIV replication and suppress immune function, whereas epidemiologic studies are inconclusive regarding their effect on HIV infection progression. The authors prospectively examined the association between illicit-drug use and 4 outcome measures (CD4 cell percentage, HIV RNA level, survival to class C diagnosis of HIV infection, and death) in a national cohort of HIV-infected women. Women enrolled between 1989 and 1995 were followed for 5 years and repeatedly interviewed about illicit ("hard")--drug use. Up to 3 periodic urine screens validated self-reported use. Outcomes were compared between hard-drug users (women using cocaine, heroin, methadone, or injecting drugs) and nonusers, adjusting for age, antiretroviral therapy, number of pregnancies, smoking, and baseline CD4 cell percentage. Of 1148 women, 40% reported baseline hard-drug use during pregnancy. In multivariate analyses, hard-drug use was not associated with change in CD4 cell percentage (P = 0.84), HIV RNA level (P = 0.48), or all-cause mortality (relative hazard = 1.10; 95% confidence interval, 0.61-1.98). Hard-drug users did, however, exhibit a higher risk of developing class C diagnoses (relative hazard = 1.65; 95% confidence interval, 1.00-2.72), especially herpes, pulmonary tuberculosis, and recurrent pneumonia. Hard-drug-using women may have a higher risk for nonfatal opportunistic infections.

Do HIV Disease Progression and HAART Response Vary among Injecting Drug Users in Europe?

Prior to HAART availability, there was no evidence of a geographical variation in HIV disease progression among injecting drug users (IDU) from different European regions. Nowadays, factors of importance regarding HIV disease progression in the face of HAART availability, such as HAART access, adherence, and the organization of care for IDU may differ across Europe. Therefore we studied HIV disease progression in a European study of IDU with known dates of HIV-seroconversion. Results show that with ongoing HAART availability, the risk of HIV disease progression has continued to decrease. When accounting for pre-AIDS death (in AIDS analyses) and non-natural deaths (suicide, overdose, accidents and homicide, in analyses of death) which are common among IDU, the risk of AIDS and death has decreased by as much as 65% and 75%, respectively, in 2000/2001. Results show little geographic variation in progression to AIDS. All-cause mortality was higher in IDU from Glasgow than elsewhere, while in the Valencian region (Spain) IDU were at a significantly lower risk of non-natural deaths. The timing of HAART initiation by treatment-naïve IDU likewise differed across Europe: IDU in Amsterdam, Innsbruck, and Edinburgh started at significantly lower CD4 counts than IDU in Paris, Geneva, Glasgow, and the Valencian region, but the subsequent short-term immune response was similar. In conclusion, the risk in progression to AIDS or natural death is similar across western Europe although IDU across Europe differ in other factors, such as the risk of non-natural death and the timing of HAART initiation.

HIV-1 binding and neutralizing antibodies of injecting drug users

Previous studies have demonstrated a stronger seroreactivity against some synthetic peptides responsible for inducing neutralizing antibodies in injecting drug users (IDU) compared to that of individuals sexually infected with HIV-1 (S), but the effectiveness in terms of the neutralizing ability of these antibodies has not been evaluated. Our objective was to study the humoral immune response of IDU by determining the specificity of their antibodies and the presence of neutralizing antibodies. The neutralization capacity against the HIV-1 isolate MN (genotype B), the primary HIV-1 isolate 95BRRJ021 (genotype F), and the seroreactivity with peptides known to induce neutralizing antibodies, from the V2 and V3 loops of different HIV-1 subtypes, were analyzed. Seroreactivity indicates that IDU plasma are more likely to recognize a broader range of peptides than S plasma, with significantly higher titers, especially of V3 peptides. Similar neutralization frequencies of the MN isolate were observed in plasma of the IDU (16/47) and S (20/60) groups in the 1:10 dilution. The neutralization of the 95BRRJ021 isolate was more frequently observed for plasma from the S group (15/23) than from the IDU group (15/47, P = 0.0108). No correlation between neutralization and seroreactivity with the peptides tested was observed. These results suggest that an important factor responsible for the extensive and broad humoral immune response observed in IDU is their infection route. There was very little difference in neutralizing antibody response between the IDU and S groups despite their differences in seroreactivity and health status.

Delayed viral replication and CD4+ T cell depletion in the rectosigmoid mucosa of macaques during primary rectal SIV infection

Rectal infection of macaques by SIV is a model for rectal HIV transmission. We focus here on the digestive tract during days 7-14 of primary rectal infection by SIV in 15 rhesus macaques. Surprisingly, we did not detect productively infected cells in the rectosigmoid colon at early stages of viral dissemination. This strongly suggests that there is no massive viral amplification in the rectosigmoid colon prior to viral dissemination. As dissemination proceeds, productively infected T cells are observed in the rectosigmoid colon and small intestine, with rectosigmoid colon showing the heaviest viral load. Lymphoid follicles are infected prior to lamina propria at both sites. When viral dissemination is widespread, inflammatory infiltrates are visible in the rectosigmoid colon, but not in the small intestine. An important decrease in CD4(+) T cells is then observed in the lamina propria of the rectosigmoid colon only.

A 25-year follow-up study of drug addicts hospitalised for acute hepatitis: present and past morbidity

The aim of the study was to investigate present and past morbidity in drug addicts, 25 years after hospitalisation for acute hepatitis B or hepatitis nonA-nonB. The hospital records for 214 consecutively admitted patients were analysed, and a follow-up study on 66 of the 144 patients still alive was performed. At follow-up, 1 of 54 (1.8%) hepatitis B patients was still HBsAg positive. Twelve patients originally diagnosed as hepatitis nonA-nonB were all among 54 found to be anti-hepatitis C virus (anti-HCV) positive, and the total anti-HCV prevalence was 81.8%. Twelve (22.2%) of the HCV cases were unknown before the follow-up examination. Four (6.1%) participants were anti-human immunodeficiency virus positive, only 1 was on antiretroviral therapy, and none had developed AIDS. Other chronic somatic diseases were a minor problem, whereas drug users reported skin infections as a frequent complication. Forty-three patients (65%) had abandoned addictive drugs since the hospital stay. Serious mental disorders were reported by 19 patients (28.8%), and 17 (25.8%) regarded themselves as present (9) and former (8) compulsive alcohol drinkers. A large proportion of the participants were granted disability pension (39%), a majority because of psychiatric disorders, drug and alcohol abuse.

Anti-human immunodeficiency virus-1 antibody titers in injection drug users compared to sexually infected individuals

Sera from infected injection drug users (IDU) have shown to have antibodies against synthetic human immunodeficiency virus-1 (HIV-1) envelope peptides more frequently. In this study, reactivity of 48 IDU plasma were compared to 60 plasmas obtained from sexually infected individuals (S). The overall reactivity of plasma from IDU compared to S was higher, and the reactivity titers were much higher for IDU plasma than S. IDU plasma also showed a broader antibody response. The higher reactivity titers were observed mainly for the gp41 immunodominant epitope and V3 peptides corresponding to the consensus sequences of HIV-1 subtypes/variants prevalent in Brazil (B, F, C) indicating the specificity in the higher immune response of IDU.

HIV prevalence among foreign- and US-born clients of public STD clinics

OBJECTIVES

We examined differences in HIV seroprevalence and the likely timing of HIV infection by birth region.

METHODS

We analyzed unlinked HIV antibody data on 61 120 specimens from 7 public health centers in Los Angeles County from 1993 to 1999.

RESULTS

Most (87%) immigrant clients were Central American/Mexican-born. HIV prevalence was similar for US- and foreign-born clients (1.8% [95% confidence interval (CI) = 1.7%, 1.9%] and 1.6% [95% CI = 1.5%, 1.8%], respectively). Seroprevalence was high among sub-Saharan African females and low among Asian/Pacific Islander males and females. For HIV-positive immigrants, the average age at and time since immigration were 20.6 years and 12.3 years, respectively.

CONCLUSIONS

The relatively young age at arrival and long time since arrival for HIV-positive foreign-born clients suggest that most were infected after immigration.

Improved methods and assumptions for estimation of the HIV/AIDS epidemic and its impact: Recommendations of the UNAIDS Reference Group on Estimates, Modelling and Projections

UNAIDS and WHO produce biannual country-specific estimates of HIV/AIDS and its impact. These estimates are based on methods and assumptions that reflect the best understanding of HIV epidemiology and demography at the time. Where significant advances are made in epidemiological and demographic research, the methods and assumptions must evolve to match these advances. UNAIDS established an Epidemiology Reference Group in 1999 to advise them and other organisations on HIV epidemiology and methods for making estimates and projections of HIV/AIDS. During the meeting of the reference group in 2001, four priority areas were identified where methods and assumptions should be reviewed and perhaps modified: a) models of the HIV epidemic, b) survival of adults with HIV-1 in low and middle income countries, c) survival of children with HIV-1 in low and middle income countries, and d) methods to estimate numbers of AIDS orphans. Research and literature reviews were carried out by Reference Group members and invited specialists, prior to meetings held during 2001-2. Recommendations reflecting the consensus of the meeting participants on the four priority areas were determined at each meeting. These recommendations were followed in UNAIDS and WHO development of country-specific estimates of HIV/AIDS and its impact for end of 2001.

Does access to health care impact survival time after diagnosis of AIDS?

Lack of access to health care is often blamed for poor health outcomes, but this effect is not supported by existing HIV/AIDS literature. The authors examined the association between access to care and survival time after progression to AIDS, using survival analysis methods. This study combined data from two CDC sponsored studies of HIV-infected persons, a cross-sectional interview study and a longitudinal medical record review study. Study subjects included 752 persons who progressed to AIDS before December 31, 1999, and were patients at either of two major HIV care facilities in Detroit, MIchigan. Separate statistical models were used to test associations between survival time after meeting the criteria for AIDS and two indicators of access to health care: (1) perceived access to health care and (2) health care utilization patterns. Perceived access was not associated with survival time after AIDS, but patterns of health care utilization were significantly associated with survival time after AIDS (HR = 2.04, p < 0.001). Individuals who received a greater proportion of their care in the ER had a worse survival prognosis than those who received more of their health care in an outpatient clinic setting. It is crucial that we provide HIV-infected populations with tools that enable them to access a regular source of health care.

HIV-1 infection in rural Africa: is there a difference in median time to AIDS and survival compared with that in industrialized countries?

OBJECTIVES

To describe the progression times of HIV-1 infection from seroconversion to AIDS and to death, and time from first developing AIDS to death in rural Uganda. Also, to describe the proportion of individuals within the cohort dying with AIDS and the CD4 lymphocyte count before death.

DESIGN

A prospective, longitudinal, population-based cohort.

METHODS

Since 1990, 107 HIV-prevalent cases, 168 incident cases and 235 HIV-seronegative controls have been recruited into a cohort in rural Uganda. Participants are recruited from the general population and they are reviewed routinely every 3 months and at other times when ill.

RESULTS

The median time from seroconversion to death was 9.8 years. Age over 40 years at seroconversion was associated with more rapid progression (P < 0.001, log rank test). For the first 4 years of the study, HIV contributed little to the death rates in the HIV incident cases, but after 5 years, the contribution of HIV became greater and was particularly marked in the oldest age group. Survival rates in the cohort were similar to those in the general population. The median time from seroconversion to AIDS was 9.4 years and from AIDS to death was 9.2 months. Of those infected with HIV-1, 80% died with AIDS and 20% had a CD4 count < 10 x 106 cells/l.

CONCLUSIONS

Survival with HIV-1 infection is similar in Africa to industrialized countries before the use of antiretroviral therapy; when they do die, many of those in Africa are severely immunosuppressed and most have clinical features of AIDS.

Health and federal budgetary effects of increasing access to antiretroviral medications for HIV by expanding Medicaid

OBJECTIVES. This study modeled the health and federal fiscal effects of expanding Medicaid for HIV-infected people to improve access to highly active antiretroviral therapy.

METHODS

A disease state model of the US HIV epidemic, with and without Medicaid expansion, was used. Eligibility required a CD4 cell count less than 500/mm3 or viral load greater than 10,000, absent or inadequate medication insurance, and annual income less than $10,000. Two benefits were modeled, "full" and "limited" (medications, outpatient care). Federal spending for Medicaid, Medicare, AIDS Drug Assistance Program, Supplemental Security Income, and Social Security Disability Insurance were assessed.

RESULTS

An estimated 38,000 individuals would enroll in a Medicaid HIV expansion. Over 5 years, expansion would prevent an estimated 13,000 AIDS diagnoses and 2600 deaths and add 5,816 years of life. Net federal costs for all programs are $739 million (full benefits) and $480 million (limited benefits); for Medicaid alone, the costs are $1.43 and $1.17 billion, respectively. Results were sensitive to awareness of serostatus, highly active antiretroviral therapy cost, and participation rate. Strategies for federal cost neutrality include Medicaid HIV drug price reductions as low as 9% and private insurance buy-ins.

CONCLUSIONS

Expansion of the Medicaid eligibility to increase access to antiretroviral therapy would have substantial health benefits at affordable costs.

Antibody responses to HIV-1 antigens are higher in HIV-1(+) intravenous drug users than in HIV-1(+) homosexuals

Immune responses to HIV-1 infection of 42 HIV-1-positive asymptomatic intravenous drug users (IVDUs) were compared with those of 135 HIV-1-infected asymptomatic homosexual men in the present study. Twenty-five HIV-1(-) individuals served as normal controls. The comparison included antibody responses to five computer-predicted epitopes of HIV-1 p17, and viral proteins gp120 and p24 as well as p17. Major immunophenotypes were also investigated. Results showed that antibody responses to the five epitopes were significantly higher in the IVDUs. A larger proportion of the IVDUs, with respect to that of homosexuals, showed positive antibody responses to p24 and p17, respectively. However, the antibody response to gp120 was similar between the two cohorts. Immunophenotyping showed that HIV-1(+) homosexuals had higher profiles in most of the major subsets than did the IVDUs, especially in the total count of lymphocytes, absolute numbers of CD3+ cells and CD8+ cells. It appeared that the HIV-1(+) IVDU cohort had higher antibody responses to most of the viral antigens, but had lower levels of lymphocyte subsets in comparison with HIV(+) homosexuals.

Significance of HIV-1 genetic subtypes

HIV is the most significant new pathogen that emerged during the twentieth century. Since the recognition of AIDS in 1981, HIV has caused a worldwide epidemic. HIV-1 mutates extensively and shows high genetic diversity and thereby poses significant challenges for effective surveillance and disease control. At the beginning of the 1990s phylogenetic analyses of HIV-1 sequences from different sources of the world epidemic revealed that HIV-1 can be divided into different clades or subtypes. However, most of the knowledge from that time was based on information from western countries, where subtype B predominated. Important questions were raised about the possibility that genetic and phenotypic differences in HIV-1 may affect transmissibility, infectivity and pathogenicity, in addition to responses to therapy and vaccines. On this basis this study was initiated in 1994, and presented as a thesis in 1999. This paper gives an overview of the results from this thesis (based on 6 original papers) and the conclusions drawn. In summary, determination of the genetic subtype of HIV-1 probably has little value for routine clinical care of individual patients, but provides a powerful tool for monitoring changes in local and global transmission patterns.

Does European or non-European origin influence health care and prognosis for HIV patients in Europe? The EuroSIDA Study Group

BACKGROUND

Previous studies, especially in North America, have shown that socio-economic factors may influence the prognosis for patients with HIV. This study was performed in order to determine if European or non-European origin influence provision of health-care and survival among HIV patients in Europe.

METHODS

Fifty HIV clinics in 17 European countries are involved in a European prospective, observational multicentre study. In total, 7230 consecutive patients with HIV attending a routine clinic visit were included in the study. Data on demographics, treatment and laboratory results were collected at time of recruitment into the study and thereafter every 6 months.

RESULTS

The median CD4+ lymphocyte count at AIDS diagnosis was 60/mm3, and was similar for all ethnic groups (P = 0.87, Kruskall-Wallis test). The median terminal CD4+ lymphocyte count was 17/mm3 and, again, there was no significant difference between continents of origin (P = 0.35, Kruskall-Wallis test). Antiretroviral drugs were initiated at similar median CD4+ lymphocyte counts and there was no statistically significant difference in survival after a diagnosis of AIDS.

CONCLUSIONS

AIDS was diagnosed at the same level of immunodeficiency independent of European or non-European origin and antiretroviral drugs were provided at similar levels of immunodeficiency. No differences in survival depending on continent of origin was found. In spite of these encouraging findings concerns remain that belonging to an ethnic minority can be an obstacle in getting into contact with treatment facilities and thus benefiting from developments in the management of HIV.

Stavudine, lamivudine and indinavir in drug abusing and non-drug abusing HIV-infected patients: adherence, side effects and efficacy

OBJECTIVES

To compare adherence and clinical outcome with highly active antiretroviral therapy (HAART) in intravenous drug users (IDUs) and subjects with other HIV risk behaviours (non-IDUs).

METHODS

A total of 133 non-naive HIV-infected patients, 95 (71%) IDUs and 38 (29%) non-IDUs received triple drug therapy with stavudine, lamivudine, and indinavir. Adherence, side effects, and immunological and virological efficacy of treatment were assessed every 3 months.

RESULTS

During a median follow-up of 12 months, 43 patients (32% of the total) showed adequate adherence in all clinical appointments. Adherence was superior in non-IDUs than in IDUs in every visit, but a significant difference was found only at 6 months, when 22 (58%) non-IDUs versus 37 (39%) IDUs were adherent (P = 0.047). Mildly increased bilirubin was observed in 69 (52%) patients, and renal colic in 34 (26%). No difference in side effects was found between IDUs and non-IDUs. After 6 months of treatment, 35 (43%) participants presented a CD4 cell count increase >100x10(6)/l, and 47 (58%) achieved undetectable HIV RNA (lower limit of detection: 200 copies/ml). CD4 cell count and HIV RNA responses were similar in both groups.

CONCLUSIONS

Adherence to the employed HAART regimen was poor. Non-IDUs were more adherent than IDUs, but the difference between both groups was small. Side effects and efficacy were similar in IDUs and non-IDUs.

Lack of legal income is strongly associated with an increased risk of AIDS and death in HIV-infected injecting drug users

The aim of the study was to analyze the impact of soci-economic status in addition to other risk factors in the progression of HIV disease in a cohort of injecting drug users (IDUs) with a mean follow-up of two years. Between 1989 and 1992, 124 HIV-infected IDUs were recruited in a primary care outpatient clinic providing free consultations and free access to therapy. The main outcome measures were death and AIDs-defining events. The proportion of current daily injectors at entry in the study and at the end of follow-up was 67.7% and 57.2%, respectively. The proportion of individuals on maintenance opioid therapy at entry in the study and at the end of follow-up was 0 and 12.1%, respectively. CD4 cell counts below 200 x 10(6)/L at baseline, positive p24 antigenemia at baseline, the lack of legal income and occasional drug use at entry were risk factors for clinical progression and death. When adjusted in a multivariate analysis, the absence of legal income remained associated with death and occurrence of an AIDS-defining event with a relative risk of 5.2 (1.5-18.1) (p = 0.004). Lack of legal income is a strong risk factor for progression of HIV disease in IDUs, that is independent of CD4 cell count and p24 antigenemia.

Dissemination of SIV after rectal infection preferentially involves paracolic germinal centers

Homosexual transmission remains a major mode of contamination in developed countries. Early virological and immunological events in lymphoid tissues are known to be important for the outcome of HIV infections. Little data are available, however, on viral dissemination during primary rectal infection. We therefore studied this aspect of rectal infection in rhesus macaques inoculated with the biological isolate SIVmac251. We show that infection is established initially in lymph nodes draining the rectum. Infected cells and virions are localized mainly in germinal centers at that stage. With increasing viral burden, infected cells are found throughout the lymph node parenchyma. In addition the difference in viral load between lymph nodes draining the rectum and other lymph nodes is attenuated or abolished. We discuss this pattern of viral dissemination with respect to the physiology of the mucosal immune system. The pattern and kinetics of viral dissemination after rectal infection have important implications for the development of efficient mucosal vaccines.

Pain in ambulatory HIV-infected patients with and without intravenous drug use

The prevalence of pain in 211 HIV-infected patients with and without intravenous drug use was assessed and the prognostic information inherent in pain reporting was evaluated, using a questionnaire on pain and HIV-related symptoms combined with data on disease classification, route of HIV transmission, CD4+ lymphocyte counts in blood (CD4) and mortality rates at 15 months after completing the questionnaire. The pain prevalence was significantly higher among intravenous drug users (IDUs) compared with non-IDUs [76/89 (85%) vs 87/122 (71%);p<0.05], especially among the patients classified as asymptomatic [43/53 (81%) vs 35/59 (59%);p = 0.01]. No significant difference was found among AIDS patients. In non-IDUs, a strong correlation was found between HIV disease stages according to the Centers for Disease Control classification (CDC) and pain prevalence (CDC A: 59%vs B: 74%vs C: 96%, p<0.001), and between the number of concurrent pain sites and both the CD4 levels (no pains: CD4 0.26 x 10(9)/l vs 1-2 pain sites: CD4 0.22 vs>2 pain sites: CD4 0.09;r = 0.35, p<0.001), and the mortality rate [no pains: 2/35 (6%) vs 1-2 pain sites: 8/45 (18%) vs> 2 pain sites: 12/42 (29%), p<0.01]. In IDUs, no such correlations were found. Our data demonstrates differences in the development, prevalence and prognostic value of pain among HIV-infected patients, with and without intravenous drug use, clearly indicating the need to differentiate risk groups in pain related studies. Copyright 1999 European Federation of Chapters of the International Association for the Study of Pain.

Similar rate of disease progression among individuals infected with HIV-1 genetic subtypes A-D

OBJECTIVE

HIV-1 is characterized by a high degree of genetic variation and can be divided into at least 10 distinct genetic subtypes. The purpose of this study was to investigate whether the rate of disease progression shows subtype-specific differences.

DESIGN

The investigation was divided into two parts; one study in which 49 ethnic Africans were compared with 49 ethnic Swedes irrespective of the subtype of the infecting virus, and a second study in which 126 individuals infected with different genetic subtypes (28 with subtype A, 59 with subtype B, 21 with subtype C and 18 with subtype D) were compared.

METHODS

CD4 cell counts, the rate of CD4 cell decline, plasma HIV-1 RNA levels, clinical status and antiviral treatment were prospectively and retrospectively recorded. The HIV-1 subtype had previously been determined by direct sequencing of the V3 domain of the env gene.

RESULTS

There were no significant differences in the rate of CD4 cell decline or clinical disease progression between Africans and Swedes over an observation period of 2 years. Similarly, there were no differences in the rate of CD4 cell decline, clinical progression or plasma HIV-1 RNA levels between individuals infected with subtypes A, B, C or D over a mean observation period of 44 months.

CONCLUSION

Neither the genetic subtype of the virus nor the ethnicity of the host appear to be major determinants of disease progression.

An analysis of optimal resource allocation for prevention of infection with human immunodeficiency virus (HIV) in injection drug users and non-users

Millions of dollars are spent annually to prevent infection with human immunodeficiency virus (HIV) without a thorough understanding of the most effective way to allocate these resources. The authors' objective was to determine the allocation of new resources among prevention programs targeted to a population of injection drug users (IDUs) and a population of non-injection drug users (non-IDUs) that would minimize the total number of incident cases of HIV infection over a given time horizon. They developed a dynamic model of HIV transmission in IDUs and non-IDUs and estimated the relationship between prevention program expenditures and reductions in HIV transmission. They evaluated three prevention programs: HIV testing with routine counseling, HIV testing with intensive counseling, and HIV testing and counseling linked to methadone maintenance programs. They modeled a low-risk IDU population (5% HIV prevalence) and a moderate-risk IDU population (10% HIV prevalence). For different available budgets, they determined the allocation of resources among the prevention programs and populations that would minimize the number of new cases of HIV infection over a five-year period, as well as the incremental value of additional prevention funds. The study framework provides a quantitative, systematic approach to funding programs to prevent HIV infection that accounts for HIV transmission dynamics, population size, and the costs and effectiveness of the interventions in reducing HIV transmission. The approach is general and can be used to evaluate a broader group of prevention programs and risk populations. This framework thus could enable policy makers and clinicians to identify a portfolio of programs that provide, collectively, the most benefit for a given budget.

A prospective study of tuberculosis and HIV disease progression

OBJECTIVE

To determine whether active tuberculosis alters the rate of progression of HIV infection in dually infected patients.

METHODS

HIV-seropositive patients at two Bronx, New York hospitals with tuberculosis confirmed by culture from July 1992 to February 1995, who survived the initial hospitalization for tuberculosis, were matched on gender, age, CD4+ percentage, and calendar time with HIV-seropositive patients without tuberculosis participating in a study of the natural history of HIV infection. Patients received follow-up observation prospectively until May 23, 1995 to determine survival rates and development of AIDS-defining opportunistic infections (OIs).

RESULTS

70 patients had tuberculosis; 120 did not. Mean CD4+ percentages were 12.4% and 12.5%, respectively. At study entry, 27% of those with tuberculosis had prior AIDS-defining OIs other than tuberculosis, compared with 10% of those without tuberculosis (p = .004). In multivariate survival analysis, controlling for CD4+ level, tuberculosis was not an independent predictor of increased other causes of AIDS-related mortality. However, in a logistic regression model, independent predictors of subsequent OIs included tuberculosis (hazard ratio, 4.1; 95% confidence intervals [CI], 1.9, 8.7), CD4+ count <100/mm3 (hazard ratio, 2.4; 95% CI, 1.1, 5.0) and prior OIs (hazard ration, 3.3; 95% CI, 1.3, 8.3).

CONCLUSIONS

Tuberculosis was not an independent predictor of increased non-tuberculosis-related mortality in HIV-seropositive patients but was associated with increased risk of development of OIs.

Low relative frequencies of CD26(+) CD4(+) cells in long-term nonprogressing human immunodeficiency virus type 1-infected subjects

A broad antibody panel was used for immunophenotyping of human immunodeficiency virus type 1 (HIV-1)-infected patients who were long-term nonprogressors (LTNP). The LTNP were compared with patients in the early phase of infection and patients who had progressed to advanced immunodeficiency. Changes in CD8(+) subset distribution were observed mainly at acquisition of HIV-1 infection, whereas CD4(+) subset changes appeared during progression of HIV-1 infection. The decreasing levels of CD4(+) cells were characterized by an increasing frequency of cells expressing the activation markers HLA-Dr and CD45RO but not the CD28 surface antigen. The LTNP exhibited significant changes compared to HIV-negative patients in almost all markers. Compared to patients in the early phase of infection, the only difference was a relatively lower frequency of CD4(+) cells expressing CD26 among the LTNP. The results show that HIV-1-infected persons who have no signs of immunodeficiency despite many years of infection have an immunophenotypic pattern that is substantially different from that of noninfected persons. Despite the long duration of infection, the LTNP exhibit a pattern similar to that of newly infected persons, with the exception of lower expression of CD26 on CD4(+) cells.