The impact of protease inhibitor-containing highly active antiretroviral therapy on progression of HIV disease and its relationship to CD4 and viral load

A simple model of HIV epidemic in Italy: The role of the antiretroviral treatment

In the present paper we propose a simple time-varying ODE model to describe the evolution of HIV epidemic in Italy. The model considers a single population of susceptibles, without distinction of high-risk groups within the general population, and accounts for the presence of immigration and emigration, modelling their effects on both the general demography and the dynamics of the infected subpopulations. To represent the intra-host disease progression, the untreated infected population is distributed over four compartments in cascade according to the CD4 counts. A further compartment is added to represent infected people under antiretroviral therapy. The per capita exit rate from treatment, due to voluntary interruption or failure of therapy, is assumed variable with time. The values of the model parameters not reported in the literature are assessed by fitting available epidemiological data over the decade 2003÷2012. Predictions until year 2025 are computed, enlightening the impact on the public health of the early initiation of the antiretroviral therapy. The benefits of this change in the treatment eligibility consist in reducing the HIV incidence rate, the rate of new AIDS cases, and the rate of death from AIDS. Analytical results about properties of the model in its time-invariant form are provided, in particular the global stability of the equilibrium points is established either in the absence and in the presence of infected among immigrants.

Association of Risk of Viremia, Immunosuppression, Serious Clinical Events, and Mortality With Increasing Age in Perinatally Human Immunodeficiency Virus-Infected Youth

IMPORTANCE

As perinatally human immunodeficiency virus-infected youth (PHIVY) in the United States grow older and more treatment experienced, clinicians need updated information about the association of age, CD4 cell count, viral load (VL), and antiretroviral (ARV) drug use with risk of opportunistic infections, key clinical events, and mortality to understand patient risks and improve care.

OBJECTIVE

To examine the incidence or first occurrence during follow-up of key clinical events (including Centers for Disease Control and Prevention stage B [CDC-B] and stage C [CDC-C] events) and mortality among PHIVY stratified by age, CD4 cell count, and VL and ARV status.

DESIGN, SETTING, AND PARTICIPANTS

Combining data from the Pediatric HIV/AIDS Cohort Study (PHACS) Adolescent Master Protocol and International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) P1074 multicenter cohort studies (March 2007 through April 2015), we estimated event rates during person-time spent in key strata of age (7-12, 13-17, and 18-30 years), CD4 cell count (<200, 200-499, and ≥500/μL), and a combined measure of VL and ARV status (VL <400 or ≥400 copies/mL; ARV therapy or no ARV therapy). A total of 1562 participants in the PHACS Adolescent Master Protocol and IMPAACT P1074 were eligible, and 1446 PHIVY from 41 ambulatory sites in the 12 US states, including Puerto Rico were enrolled. The dates of analysis were March 2015 through January 2017.

MAIN OUTCOMES AND MEASURES

Clinical event rates stratified by person-time in age, CD4 cell count, and VL and ARV categories.

RESULTS

A total of 1446 PHIVY participated in the study (mean [SD] age, 14.6 [4.6] years; 759 female [52.5%]; 953 black [65.9%]). During a mean (SD) follow-up of 4.9 (1.3) years, higher incidences of CDC-B events, CDC-C events, and mortality were observed as participants aged. Older PHIVY (aged 13-17 and 18-30 years) spent more time with a VL of 400 copies/mL or more and with a CD4 cell count of less than 200/µL compared with 7- to 12-year-old participants (30% and 44% vs 22% of person-time with a VL≥400 copies/mL; 5% and 18% vs 2% of person-time with CD4 cell count <200/µL; P < .001 for each comparison). We observed higher rates of CDC-B events, CDC-C events, bacterial infections, and mortality at lower CD4 cell counts, as expected. The mortality rate among older PHIVY was 6 to 12 times that among the general US population. Higher rates of sexually transmitted infections were also observed at lower CD4 cell counts after adjusting for age.

CONCLUSIONS AND RELEVANCE

Older PHIVY were at increased risk of viremia, immunosuppression, CDC-B events, CDC-C events, and mortality. Interventions to improve ARV therapy adherence and optimize models of care for PHIVY as they age are urgently needed to improve long-term outcomes among PHIVY.

Prevention of HIV-associated opportunistic infections and diseases in the age of highly active antiretroviral therapy

Since the introduction of highly active antiretroviral therapy (HAART), the rates of opportunistic infections have decreased markedly as has overall morbidity and mortality from HIV infection in developed countries. However, opportunistic infections remain the most important cause of death in HIV-infected people due to both late presentation of HIV infections and failure of HAART to adequately restore cell-mediated immunity in all individuals. While prophylaxis may be discontinued in patients who have responded to HAART with sustained increases of their CD4 counts above risk thresholds, for those patients who fail HAART, those who are unable to tolerate it, or whose treatments are interrupted, opportunistic-infection prophylaxis remains essential. Some HIV-associated diseases, such as anogenital human papilloma virus-induced neoplasia and hepatitis C infection, have not decreased in frequency with the advent of HAART. For these conditions, effective screening and treatment programs will be necessary to prevent ongoing morbidity. This review will provide an update on HIV-associated opportunistic infections and their prevention in the age of HAART, as well as discuss novel presentations of opportunistic illnesses, such as immune restoration syndromes.

HIV protease inhibitors alter innate immune response signaling to double-stranded RNA in oral epithelial cells: implications for immune reconstitution inflammatory syndrome?

In this investigation, several HIV protease inhibitors altered the virally associated, double-stranded RNA (dsRNA)-stimulated, innate immune response. Lopinavir, the most potent inducer of interleukin (IL)-8 expression, also inhibited dsRNA-induced monocyte chemotactic protein 1 expression. Further analyses demonstrated that nuclear factor-κB is required for lopinavir's induction of IL-8. These findings demonstrate that protease inhibitors, such as lopinavir, differentially dysregulate innate immune signaling in a manner that could affect immune (reconstitution) inflammatory responses in oral epithelium.

The long-term benefits of genotypic resistance testing in patients with extensive prior antiretroviral therapy: a model-based approach

OBJECTIVES

Resistance testing in HIV disease may provide long-term benefits that are not evident from short-term data. Our objectives were to estimate the long-term effectiveness, cost and cost-effectiveness of genotype testing in patients with extensive antiretroviral exposure.

METHODS

We used an HIV simulation model to estimate the long-term effectiveness and cost-effectiveness of genotype testing. Clinical data incorporated into the model were from NARVAL, a randomized trial of resistance testing in patients with extensive antiretroviral exposure, and other randomized trials. Each simulated patient was eligible for up to three sequential regimens of antiretroviral therapy (i.e. two additional regimens beyond the trial-based regimen) using drugs not available at the time of the study, such as lopinavir/ritonavir, darunavir/ritonavir and enfuvirtide.

RESULTS

In the long term, projected undiscounted life expectancy increased from 132.2 months with clinical judgement alone to 147.9 months with genotype testing. Median survival was estimated at 11.9 years in the resistance testing arm vs 10.4 years in the clinical judgement alone arm. Because of increased survival, the projected lifetime discounted cost of genotype testing was greater than for clinical judgement alone (euro313,900 vs euro263,100; US$399,000 vs US$334,400). Genotype testing cost euro69,600 (US$88,500) per quality-adjusted life year gained compared with clinical judgement alone.

CONCLUSIONS

In patients with extensive prior antiretroviral exposure, genotype testing is likely to increase life expectancy in the long term as a result of the increased likelihood of receiving two active new drugs. Genotype testing is associated with cost-effectiveness comparable to that of strategies accepted in patients with advanced HIV disease, such as enfuvirtide use.

Clinical progression rates by CD4 cell category before and after the initiation of combination antiretroviral therapy (cART)

Objective

Rates of AIDS defining event (ADE), serious ADE and death by CD4 and HIV RNA categories before and after combination antiretroviral therapy (cART) initiation are lacking for high CD4 counts.

Methods

Event rates were estimated within CD4 cell strata using a Poisson regression model adjusting for sex, exposure category, age, and current HIV RNA (<4, 4-4.99, ≥5 log copies/ml), and including an interaction term between the CD4 cell count and cART indicator.

Results

7317 and 6376 persons contributed to "naïve " and "cART " groups respectively, of whom 3911 contributed to both. At the same CD4 level, the risk of ADE was nearly 2 fold higher during naive follow-up compared to cART for CD4 <500 cells/mm³. However, after adjustment for current HIV RNA, the risk of ADE became similar for both groups except for CD4 count <200 cells/mm³ when it is 35% (6-72%) higher for naives. The same results were observed for the risk of serious ADE. There was no evidence of a difference in risk of death between naive and cART follow-up at specific CD4 categories even after adjustment for HIV RNA.

Conclusion

Within CD4 cell strata above 200 cells/mm³, the risk of ADE before ART initiation is higher than it is following cART initiation.

Estimates of opportunistic infection incidence or death within specific CD4 strata in HIV-infected patients in Abidjan, Côte d'Ivoire: impact of alternative methods of CD4 count modelling

CD4 lymphocyte count is an important surrogate marker of HIV disease progression, but it is often unavailable at the time of clinical events. We analysed data from the Cotrame cohort (1999-2004) and the Trivacan Structured Treatment Interruption trial (2002-2005) to estimate the incidence of opportunistic infections and death within specific CD4 strata in HIV-infected patients receiving highly active antiretroviral therapy (HAART) in sub-Saharan Africa. We used three methods of CD4 modelling: the first assumed that CD4 cell count remained constant until the next measurement; the second assumed that it changed immediately to the level of the subsequent measurement; and the third assumed that it followed a linear function between two consecutive CD4 measurements. The cohort used in this analysis consisted of 981 patients. The incidence rates of opportunistic infections were highest in the lower CD4 strata and decreased in the higher CD4 count strata. The incidence rates of mild opportunistic infections and severe bacterial infections, however, remained high in the highest CD4 stratum. Although all confidence intervals overlapped among the three methods, the incidence rate estimates showed differences of up to 74% in the lowest CD4 stratum. Different methods of estimating CD4 counts at the time of clinical events led to minor differences in incidence rates, except in the CD4 stratum <50 cells/mm(3), where the follow-up time was shorter. All of the models indicate that the overall incidence of opportunistic infections under HAART in sub-Saharan Africa is high. This suggests that prophylaxis against opportunistic infections may be needed even for patients receiving HAART.

The Independent Effect of Highly Active Antiretroviral Therapy on Severe Opportunistic Disease Incidence and Mortality in HIV-Infected Adults in Côte D'Ivoire

Background

Studies in developed countries have shown highly active antiretroviral therapy (HAART) decreases incidence of severe opportunistic diseases (ODs) in HIV-infected patients beyond that which is expected from changes in CD4+T-cell count.

Objective

To estimate the independent impact of HAART on reducing ODs and mortality in Côte d'Ivoire.

Methods

Within two longitudinal studies of HIV-infected adults (1996–2003), we identified time on ‘cotrimoxazole alone’ and ‘HAART plus cotrimoxazole’. WHO stage 3–4 defining events and severe malaria were divided into those preventable and not preventable with cotrimoxazole. Incidence of ODs by CD4 count stratum was estimated using incidence density analysis. CD4+ T-cell count at time of OD was estimated using linear interpolation. Using Poisson regression, we estimated the effect of HAART on OD incidence and mortality by CD4 count stratum.

Results

Totals of 446 and 135 adults were followed during 6,216 and 3,412 person-months in the cotrimoxazole alone and HAART plus cotrimoxazole periods, respectively. There was a CD4+ T-cell-independent risk reduction for ODs and mortality during the HAART plus cotrimoxazole period compared with cotrimoxazole alone, which varied by time on HAART, CD4 count stratum and OD type. It was mainly seen after 6 months on HAART and for ODs not preventable by cotrimoxazole. The HAART effect differed significantly by CD4 count stratum ( P=0.02), but was significant in all strata after 6 months on HAART.

Conclusions

In these sub-Saharan African adults, HAART initiation reduced ODs and mortality beyond that which was expected through the HAART-induced CD4+ T-cell increase. Further studies should examine practical implications of this independent ‘HAART effect’ on clinical outcomes in patients on HAART.

Is moderate HIV viremia associated with a higher risk of clinical progression in HIV-infected people treated with highly active antiretroviral therapy: evidence from the Italian cohort of antiretroviral-naive patients study

OBJECTIVE

To assess the risk of clinical progression (CP) according to the duration of time spent without complete viral load (VL) suppression compared with that associated with periods of stably suppressed viremia in HIV-infected people who started highly active antiretroviral therapy (HAART) when previously naïve to antiretrovirals.

DESIGN

A cohort study of patients having started HAART after enrollment in the Italian Cohort of Antiretroviral-Naive Patients (ICoNA) and being followed for at least 6 months.

METHODS

Person-years spent in different categories according to the VL level and the change in VL from the most recent value before the initiation of HAART were calculated. A multivariable Poisson regression model, including potential confounders, was constructed.

RESULTS

A total of 3023 patients were studied. The overall rate of CP was 13.4 per 1000 person-years. Evidence for a higher risk of CP was observed for people with a current VL >10,000 copies/mL. For each year longer spent on HAART with a VL >100,000 copies/mL, a 5-fold increased risk was observed (relative risk [RR] = 5.34, 95% confidence interval [CI]: 2.83 to 1.08; P = 0.0001). An increased risk of CP in patients with current suppression <1.5 log10 copies/mL (RR = 2.34, 95% CI: 1.16 to 4.74; P = 0.02) and in those with no suppression or a VL higher than their set point (RR = 2.39, 95% CI: 1.17 to 4.89; P = 0.02) was observed compared with those with suppression of >3 log10 copies/mL, although it was not significant. Longer duration on HAART with a VL suppressed below set point seemed to confer protection against CP.

CONCLUSIONS

Virologic failure to antiretroviral drugs is common. The risk of CP may remain low despite a low but detectable level of HIV viremia.

Comparison of prognostic importance of latest CD4+ cell count and HIV RNA levels in patients with advanced HIV infection on highly active antiretroviral therapy

The comparative prognostic importance of latest plasma HIV RNA levels (viral loads) and CD4+ cell counts among patients prescribed highly active antiretroviral therapy (HAART) has not been well characterized.

METHOD

We assessed the prognostic value of latest CD4+ cell counts and latest viral loads for progression to AIDS or death and explored their interaction among 432 HIV-infected persons with advanced HIV who were prescribed a protease inhibitor (PI) as their first HAART regimen.

RESULTS

Pre-HAART median CD4+ cell count and viral load were 41 cells/mm3 and 126,331 copies/mL, respectively. After 12 months of HAART, the median CD4+ cell count was 154 cells/mm3; 39% of patients had a viral load of 400 copies/mL or lower. Over a median follow-up of 33 months, 109 (25%) of the 432 patients experienced an AIDS event or died. The hazard ratio for AIDS or death for those with latest CD4+ cell count <50 cells/mm3 versus > or =200 cells/mm3 was 13.9 (95% CI 6.5 to 29.7) without adjustment for latest viral load measurements and 9.5 (95% CI 4.0 to 22.5) after adjustment for latest viral load. In contrast, the hazard ratio for AIDS or death for those with viral load > or =100,000 versus <400 copies/mL was 4.2 (95% CI 2.3 to 7.7) without adjustment for latest CD4+ level and 1.2 (95% CI 0.6 to 2.4) with adjustment for latest CD4+ cell count.

CONCLUSION

We conclude that when latest CD4+ cell count and viral load are considered separately, both are significantly related to AIDS or death; when these markers are jointly considered, the association of viral load with AIDS or death is substantially diminished. Latest CD4+ levels are more strongly related to AIDS or death than latest viral load levels in patients on HAART.

Response to highly active antiretroviral therapy at 6 months and long-term disease progression in HIV-1 infection

OBJECTIVE

To compare the long-term prognostic significance of different definitions of immunologic and virologic responses to highly active antiretroviral therapy (HAART) at 6 months.

METHODS

This was a prospective study conducted in 68 French hospitals. HAART was initiated in 2236 protease inhibitor-naive patients included in the French Hospital Database on HIV. Multivariate Cox proportional hazard models measuring time from 6 months after starting HAART were used to compare the strength of the association between different definitions of immunologic and virologic responses at 6 months and subsequent progression to AIDS or death. The Akaike's Information Criteria were used to identify the most appropriate model.

RESULTS

During a median follow-up of 58 months, 325 patients experienced an AIDS-defining event or died. The model that fitted best was the model in which the CD4 cell count and plasma HIV-1 RNA values attained at 6 months were considered. The risk of clinical progression at 5 years ranged from 7% (95% confidence interval [CI]: 4-10) in patients whose CD4 cell count at 6 months was >or=350 cells/microL and whose HIV-1 RNA concentration was <3 log10 copies/mL to 63% (95% CI: 52-75) in patients whose CD4 cell count at 6 months was <100 cells/microL and whose HIV-1 RNA concentration was >or=5 log10.

CONCLUSIONS

Plasma HIV-1 RNA concentration and CD4 cell count should be taken into account independently when evaluating early response to treatment. The persistent impact of early response on clinical progression at 5 years emphasizes the major importance of the success of first-line HAART.

Estimating the proportion of patients infected with HIV who will die of comorbid diseases

PURPOSE

Effective antiretroviral therapies have improved the prognosis for patients infected with the human immunodeficiency virus (HIV). We aimed to estimate the likelihood that HIV-infected patients would die of comorbid disease.

METHODS

A probabilistic simulation of antiretroviral-naïve HIV-infected patients in the United States was calibrated with data from an observational cohort (N = 3545) and validated with data from a separate patient cohort (N = 12574). The simulation explicitly represents the 2 main determinants of treatment failure and subsequent death from HIV-related causes: nonadherence to combination therapy and accumulation of phenotypic resistance to combination therapy. The likelihood of deaths not directly attributable to HIV was estimated from the Collaborations in HIV Outcomes Research-US (CHORUS) cohort.

RESULTS

For patients with newly diagnosed HIV infections, CD4 counts of 500 cells/mm3, and viral loads of 10000 copies/mL, the median estimated survival was 26.8 years for 30-year-olds, 24.4 years for 40-year-olds and 14.6 years for 50-year-olds. The proportion of deaths not directly attributable to HIV was 36% for 30-year-olds, 53% for 40-year-olds, and 72% for 50-year-olds. For patients with characteristics similar to CHORUS participants, the median estimated survival approached 20.4 years, the mean age at death approached 60.4 years, and 41% died of illnesses not directly attributable to HIV. These estimates of non-HIV mortality were likely conservative.

CONCLUSION

As HIV-infected patients live longer, our results suggest they will experience increasing mortality from causes not directly attributable to HIV. The projected risk from comorbid disease has clinical and policy implications for future delivery of care to HIV-infected patients.

The benefits of exercise training for quality of life in HIV/AIDS in the post-HAART era

The use of highly active antiretroviral therapy (HAART) has served to significantly reduce the mortality of HIV-infected persons. However, this treatment is associated with a host of adverse effects: fatigue, nausea, pain, anxiety and depression. Rather than utilise traditional pharmacological treatments for these effects, many HIV/AIDS patients are utilising adjunct therapies to maintain their quality of life while they undergo treatment. Exercise has consistently been listed as one of the most popular self-care therapies and a small number of studies have been conducted to examine the impact of exercise on the most common self-reported symptoms of HIV and AIDS and the adverse effects of treatment. Although the results are generally positive, there are clear limitations to this work. The existing studies have utilised small samples and experienced high rates of attrition. In addition, the majority of the studies were conducted prior to the widespread use of HAART, which limits the ability to generalise these data. As a result, data from other chronic disease and healthy samples are used to suggest that exercise has the potential to be a beneficial treatment across the range of symptoms and adverse effects experienced by HIV-infected individuals. However, additional research is required with this population to demonstrate these effects.

Determinants of long-term highly active antiretroviral treatment efficacy

OBJECTIVES

Predictors of the efficacy of highly active antiretroviral therapy (HAART) have been investigated in several studies. To increase current knowledge, the study aimed to acquire comprehensive data over an extended observation time, to obtain information on possible performance differences among individual drugs, and to identify factors with influence on the initial response to a HAART regimen and the sustainability of the response.

METHODS

The data were obtained from a prospective, single University Medical School HIV cohort. Clinical, laboratory, and treatment parameters for 475 patients were collected over 4.5 years. HAART efficacy was determined by analysis of variance and multivariate survival analysis.

RESULTS

The overall initial complete response (CR) (<500 HIV-1 RNA copies/mL) was 76.3%. Use of indinavir [odds ratio (OR)=2.747, P=0.0009] and the number of new nucleoside reverse transcriptase inhibitors (NRTIs) (OR=1.862, P=0.0017) were positively associated with CR, while initial peripheral blood HIV RNA concentration (OR=0.383, P<0.0001), use of saquinavir hard gel capsules (OR=0.531, P=0.0302), the number of successive HAART regimens (OR=0.631, P<0.0001), and the number of previously used NRTIs (OR=0.728, P=0.0081) were negatively associated with CR. Sustainability of CR was positively correlated with use of indinavir [hazard ratio of relapse (HR)=0.255, P<0.0001] and haemoglobin levels (HR=0.873, P=0.0124), but negatively correlated with initial HIV RNA concentration (HR=1.273, P=0.0003) and the number of previously used NRTIs (HR=1.587, P<0.0001). A higher number of consecutive HAART regimens was associated with a markedly reduced CR, but with only a slightly higher risk of relapse.

CONCLUSIONS

The initial response to HAART, as well as long-term efficacy, depends strongly on a few fundamental parameters that can easily be assessed in a clinical setting. There is a need for effective suppression of HIV replication over decades, and these factors should be considered early in treatment planning to identify patients with an unfavourable profile of risk factors for treatment failure.

Dissociation of CD4+ cell counts from viral load and association with immune complexes in HIV+ hemophilia patients

OBJECTIVE

We have postulated that the host autoimmune response regulates and mediates CD4 depletion during HIV infection by opsonization of circulating CD4(+) lymphocytes carrying autoreactive immune complexes (IC) consisting of complement-fixing IgM and IgG, and during advanced stages of HIV disease of IgM/ IgG/gp120 complexes. In this retrospective study, we investigated whether HIV causes CD4 depletion by direct cytotoxicity or indirectly by induction of a host autoimmune response.

PATIENTS AND METHODS

In 1996, 12 HIV(+) hemophilia patients were converted to highly active antiretroviral therapy (HAART), while 10 other patients were maintained on conventional antiretroviral treatment and another 11 patients refused to be treated with antiretroviral drugs. The host immune response of these 33 HIV(+) patients was studied during the periods of minimum viral replication (Interval 1), subsequent rise in viral replication with strong replication dynamic (Interval 2), and maximum viral replication (Interval 3). The patients were categorized into three groups according to viral load (VL). Group A: patients with low level VL (n=10) showed a modest increase from <80 to <4 log 10 HIV-1 RNA copies per milliliter plasma during the observation period; Group B: patients with medium level VL (n=12) showed a stronger increase from <80 to >4 log 10 copies per milliliter plasma; and Group C: patients with high level VL (n=11) consistently had a median of >4 log 10 copies per milliliter plasma, during Intervals 1-3, with the exception of one patient who during Interval 2 had 4800 copies per milliliter. Blood lymphocyte subpopulations, proportions of CD4(+) blood lymphocytes coated with IgM, IgG, C3d and/or gp120, in vitro responses to mitogens and pooled allogeneic stimulator cells, as well as numbers of HIV-1 RNA copies per milliliter plasma were measured.

RESULTS

Sequential analysis of VL, IC load on CD4(+) blood lymphocytes and CD4 counts showed that an increasing VL was not associated with CD4 depletion, when the proportion of IC-coated circulating CD4(+) blood lymphocytes remained stable. When, CD4 counts and IC load were analyzed during corresponding intervals of retroviral replication in the three patient groups, a higher VL was associated with lower CD4 counts only when the IC load (IgG or gp120/IgG) on CD4(+) lymphocytes was higher as well.

CONCLUSION

These data suggest that HIV regulates and mediates CD4 depletion in part by the induction of autoreactive ICs against CD4(+) lymphocytes, especially complement-fixing autoreactive IgG and gp120/IgG complexes.

A search for optimal criteria in initiating antiretroviral therapy in chronic human immunodeficiency virus infection focusing on CD4 count and HIV RNA

The study objective was to identify optimal starting criteria regarding levels of CD4 cells and human immunodeficiency virus (HIV) RNA at initiation of highly active antiretroviral therapy (HAART) in chronically HIV-infected people. All 162 treatment-naive patients in the centre who were treated for at least 180 d with 2 nucleoside reverse transcriptase inhibitors plus at least 1 protease inhibitor or 1 non-nucleoside reverse transcriptase inhibitor were included. The patients were stratified according to their levels of CD4 cells and HIV RNA at initiation of therapy. Baseline CD4 groups were: group 1: CD4 < 0.1 x 10(9)/l; group 2: CD4 > or = 0.1 and < 0.2 x 10(9)/l; group 3: CD4 > or = 0.2 and < 0.35 x 10(9)/l; and group 4: CD4 > or = 0.35 x 10(9)/l. Two patients died and 38 developed an HIV-related disease (Centers for Disease Control category B or C) during the study. The prevalence of HIV-related disease before HAART was significantly increased in groups 1 and 2 compared with groups 3 and 4. The level of HIV RNA was not associated with HIV-related disease either before or after treatment initiation. Subjects in group 1 had an increased risk of HIV-related disease after treatment initiation both in univariate Cox analysis and after adjustment for HIV RNA, gender, mode of transmission and age, compared with group 2 [adjusted risk ratio with 95% confidence interval: 3.76 (1.48-9.61)], group 3 [5.90 (2.07-16.95)] and group 4 [5.05 (1.96-12.90)]. The association between CD4 count and morbidity appeared to be particularly strong for older subjects. In conclusion, this study suggests that in chronically HIV-infected individuals, in most cases HAART can be withheld until the CD4 cell count falls towards 0.2 x 10(9)/l.

The role of observational data in monitoring trends in antiretroviral treatment and HIV disease stage: results from the Australian HIV observational database

OBJECTIVES

To illustrate how human immunodeficiency virus (HIV) observational databases may be used to monitor trends in HIV treatment and HIV disease outcomes through data reported from the Australian HIV Observational Database (AHOD).

METHODS

Time trends in the use of antiretroviral treatment, and changes in treatment strategies were calculated in patients recruited to AHOD from HIV specialist clinics including hospitals, sexual health clinics and general practices. These results were then compared to trends reported from other observational cohorts.

RESULTS

By September 2001, 1961 patients were recruited to AHOD. Since entering AHOD, 3% of patients have been diagnosed with an AIDS defining illness, and 2% of patients have died, of which, 54% were non-HIV related deaths. The proportion of patients receiving antiretroviral therapy increased from 66% between January and June 1998 and 77% between July and September 2001. The most commonly received treatment regimen was triple therapy including a protease inhibitor (PI), ranging between 36% in January and June 1998 and 31% in July to September 2001. Triple therapy including a non-nucleoside reverse transcriptase inhibitor (NNRTI) more than doubled to 32% between July and September 2001. The proportion of patients receiving either stavudine (d4T) or zidovudine (AZT) treatment regimens decreased from 92% between January and June 1998 to 76% between July and September 2001. Patients receiving ritonavir in combination with another PI increased, as did the proportion of patients interrupting therapy for more than 3 months.

CONCLUSION

These findings suggest there have been changes in the way antiretroviral treatments have been used in Australia, and are consistent with the current literature. Furthermore, these findings demonstrate the usefulness of observational cohorts as a surveillance tool monitoring trends in treatment and disease progression.

Simplification of Protease Inhibitor-Containing Regimens with Efavirenz, Nevirapine or Abacavir: Safety and Efficacy Outcomes

Objective

To describe the immunological and virological outcome, and the factors associated to discontinuation in patients switching to a regimen containing efavirenz (EFV), nevirapine (NVP) or abacavir (ABC) after long-term viral suppression under protease inhibitor-including HAART.

Design

Observational study at three outpatient clinics for HIV care in Italy.

Methods

Patients with HIV RNA <80 copies/ml and CD4 >200 cells/ml for at least 6 months on a protease inhibitor-containing treatment who switched to NVP, EFV or ABC were included in the study. End-points were immunological failure, virological failure and discontinuation due to toxicity. Survival analyses were performed to find out any independent variables predictive of reaching the end-points.

Results

177 patients were enrolled; 85 started EFV, 54 NVP and 38 ABC as part of the simplification regimen. 16/159 patients experienced immunological failure: the variables associated to CD4 count decrease were HIV RNA set point value (HR 2.32 for each log10 copies more, P=0.040) and intolerance/toxicity as reason for simplification (HR 3.96, P=0.05). 13/151 subjects showed virological failure; an AIDS diagnosis (HR 6.04, P=0.021) and the use of NVP (HR 7.98, P=0.027) were associated to a worse virological outcome, while patients naive before HAART showed a lower risk of failure (HR 0.008, P=0.007). 16/177 patients discontinued simplification regimen due to toxicity; longer HAART duration before switch was associated to risk reduction (HR 0.92, P=0.004).

Conclusions

Simplification is safe and effective, but it should be offered to patients with shorter treatment duration, and in good clinical and immunovirological conditions.

Prevention of human immunodeficiency virus-related opportunistic infections in France: a cost-effectiveness analysis

A simulation model of human immunodeficiency virus (HIV) disease, which incorporated French data on the progression of HIV disease in the absence of antiretroviral therapy and on cost, was used to determine the clinical impact and cost-effectiveness of different strategies for the prevention of opportunistic infections in French patients who receive highly active antiretroviral therapy (HAART). Compared with use of no prophylaxis, use of trimethoprim-sulfamethoxazole (TMP-SMZ) increased per-person lifetime costs from euro 185,600 to euro 187,900 and quality-adjusted life expectancy from 112.2 to 113.7 months, for an incremental cost-effectiveness ratio of euro 18,700 per quality-adjusted life-year (euro/QALY) gained. Compared with use of TMP-SMZ alone, use of TMP-SMZ plus azithromycin cost euro 23,900/QALY gained; adding fluconazole cost an additional euro 54,500/QALY gained. All strategies that included oral ganciclovir had cost-effectiveness ratios that exceeded euro 100,000/QALY gained. In the era of HAART, on the basis of French data, prophylaxis against Pneumocystis carinii pneumonia, toxoplasmic encephalitis, and Mycobacterium avium complex bacteremia is cost-effective. Prophylaxis against fungal and cytomegalovirus infections is less cost-effective than are other therapeutic options for HIV disease and should remain of lower priority.

Neurocognitive Manifestations of Human Immunodeficiency Virus

Is human immunodeficiency virus still a terminal condition? Recent advances in treatment have significantly reduced both mortality and morbidity associated with HIV, but these treatments have not been successful in eradicating the virus itself. As such, HIV has evolved into a chronic condition that is complicated by neurocognitive factors. Cognitive difficulties associated with HIV are characterized by a subcortical pattern with primary deficits in information processing speed and psychomotor speed. These deficits interfere with the ability of patients to complete important instrumental activities of daily living even in the absence of dementia. Treatment of HIV improves neurocognitive functioning, but the regimens are complex and patient adherence is critical. Cognitive factors can negatively impact treatment adherence, which in turn results in poorer immunological, cognitive, and psychiatric outcome. This cycle emphasizes the important interrelationships between symptom expression and treatment outcome in patients with HIV. The nature of these relationships will change with further developments in treatment regimens such as once-daily dosing. Less complex treatment approaches should improve health outcome as well as provide additional opportunities to further understand the impact of HIV on brain function.

Markers of HIV-1 disease progression in individuals with haemophilia coinfected with hepatitis C virus: a longitudinal study

BACKGROUND

Low serum albumin concentration is associated with short-term survival in individuals with HIV-1. However, few investigators have assessed whether individuals with a low serum albumin concentration have delayed progression to AIDS, or survive in the long term. We aimed to assess the relation between markers of liver function and progression to AIDS and death in individuals with haemophilia infected with HIV-1 and hepatitis C virus.

METHODS

We measured markers of liver function and took CD4 counts every 3 months in 111 patients registered at the Royal Free Hospital Haemophilia Centre, London, UK. HIV RNA concentrations were measured yearly and then every 3-6 months from 1996. We used Cox's regression models to assess the independent prognostic value of these markers for AIDS and death.

FINDINGS

As a fixed covariate, albumin concentrations measured shortly after HIV-1 seroconversion were associated with risk of AIDS (relative hazard 0.91 [95% CI 0.84-1.00], p=0.04) and death (0.89 [0.82-0.96], p=0.004) over a 15-year period. These findings were independent of the CD4 count and HIV-1 RNA concentration. As a time-updated covariate, after adjustment for CD4 count and HIV-1 RNA concentrations, albumin was not associated with progression to AIDS (0.96 [0.90-1.01], p=0.13), but was strongly associated with death (0.88 [0.84-0.93], p<0.0001) in the short term.

INTERPRETATION

Low concentrations of albumin in individuals infected with HIV-1 could indicate a poor outlook and should therefore prompt concern at any stage of infection.

The impact of the M184V substitution in HIV-1 reverse transcriptase on treatment response

The M184V mutation in the HIV-1 reverse transcriptase gene is primarily associated with rapid, high-level lamivudine (3TC) resistance. It has also been observed to arise under selective pressure by abacavir, to which it confers low-level resistance. Although the development of viral drug resistance remains a major concern in antiretroviral therapy, it is known that some immunological and clinical benefit can still be derived from highly active antiretroviral therapy (HAART) regimens despite resistance-associated virological failure. This residual benefit on a failing regimen is commonly attributed to the preservation of fitness-reducing protease inhibitor (PI) resistance mutations under continued drug pressure. However, fitness-reducing nucleoside reverse transcriptase inhibitor (NRTI) mutations may also contribute to the effect. M184V is both common in the treated population and fitness-reducing. A number of studies, both of dual nucleoside therapy and HAART, have noted a residual treatment effect for 3TC despite the assumed or observed presence of M184V and high-level phenotypic resistance. The speed and consistency with which this mutation is selected by 3TC under suboptimal viral suppression therefore makes M184V a particularly interesting model for further clinical studies on the association of drug resistance with ongoing treatment benefit. While fitness considerations are likely to be a major contributor to the clinical observations noted, there are a number of other potential mechanisms that may contribute to a continuing response to 3TC in the presence of M184V. These include the delay and reversal of zidovudine (ZDV) resistance, hypersensitization to other NRTIs, reduced reverse transcriptase (RT) processivity and a possible reduction in RT pyrophosphorolysis. The full impact of M184V on therapeutic prospects will require further elucidation; ideally, the risk/benefit of preserving this substitution would be investigated in randomized trials. However, existing data suggest that the presence of this mutation may preserve some benefit in spite of the loss of 3TC susceptibility which, with further study, may prove valuable.

Health-related quality of life in individuals infected with HIV in the era of HAART

PURPOSE

To compare health-related quality of life (HR-QOL) in individuals infected with HIV to general population levels and to assess the relationship between HR-QOL and markers of disease progression in the era of highly active antiretroviral therapy (HAART).

METHOD

This was a cross-sectional questionnaire-based study. This study included 154 individuals at least 18 years old with HIV who either were attending a London hospital or were visited by a community team in Brighton. Study participants were asked to complete two HR-QOL questionnaires. This study used HR-QOL, as measured using the Medical Outcome Study HIV Health Survey (MOS-HIV) and EuroQoL self-report (EQ-5D) questionnaires, as the main outcome measure. Responses on the EQ-5D were compared with a published general population data set. The relationships between scores on the MOS-HIV and EQ-5D questionnaires and a number of independent variables including CD4 count and viral load were also assessed.

RESULTS

Each analysis was based on the results of at least 128 questionnaires. The mean MOS-HIV mental and physical component scores were 43.2 (SD = 12.2) and 41.8 (SD = 13.2), respectively. After adjusting for differences in age and gender, it was shown that individuals with HIV reported significantly lower EQ-5D(utility) ( p =.0001) and EQ-5D(VAS) ( p =.0001) compared with the general population. However, further analysis revealed few significant associations between markers of disease progression and HR-QOL.

CONCLUSION

Individuals with HIV generally recorded significantly lower HR-QOL compared with the general population. Thus, prevention of further transmissions of the virus is still likely to prevent significant morbidity losses in addition to mortality losses, despite the availability of HAART. However, disease progression as measured is not clearly related to further reductions in HR-QOL.

International perspectives on antiretroviral resistance. Resistance to protease inhibitors

The availability of protease inhibitors (PIs) and their combination with nucleoside reverse transcriptase inhibitors marked the passage of antiretroviral therapy (ART) from potential for control to effective suppression and thus substantially reduced rates of morbidity and mortality related to HIV. Even so, what was first hoped to be an immutable HIV DNA treatment target has proved to be prone to resistance mutations, with substitutions identified at more than 20 amino acid sites, which reduces PI susceptibility and increases resistance to treatment. The mutation patterns associated with each PI have been defined, and have been observed to occur at one of two locations: at or near the active site, or in the substrate cleavage site. The natural history of PI resistance has been extensively studied, and the genetic and cellular pathways are described in detail in this article. In addition, cross-resistance among PIs is now recognized to be fairly extensive, although the degree of cross-resistance varies with the number of mutations and the variants selected by drug pressure. Thus, it is still possible to salvage a response with another PI after a first regimen with another PI has failed. The extensive basic science and clinical experience with PIs in the fight against HIV are reviewed in this article, which provides data on resistance-mutation profiles, cellular resistance mechanisms, viral fitness studies, and clinical outcome trials with various first-line and subsequent regimens that contain PIs. It is hoped that the information provided will guide physicians in best using PIs as part of a logical and successful ART strategy.

Structured treatment interruptions in antiretroviral management of HIV-1

The consequences of treatment interruptions have been investigated in various patient populations. For patients with controlled viraemia, treatment interruption allowing viral rebound may boost HIV-1-specific immunity. The hypothesis that this will be sufficient to control HIV replication in the absence of treatment has received support in studies of patients initiating treatment during primary infections. In patients with chronic infection, treatment interruption has been shown to boost HIV-1-specific immunity in some cases. In patients with virological failure, despite drug-resistant virus, treatment appears to provide benefit, in that interruption results in a decrease in the CD4 cell count and increases in plasma HIV-1-RNA levels. The removal of drug pressure allows the rapid shift to wild-type virus. Whether this will be of benefit to the patient is not clear. Treatment interruption may help reduce the accumulation of long-term toxicities.