Long-term patterns in CD4 response are determined by an interaction between baseline CD4 cell count, viral load, and time: The Asia Pacific HIV Observational Database (APHOD)

Rapid antiretroviral therapy in primary HIV-1 infection enhances immune recovery

OBJECTIVE

We present findings from a large cohort of individuals treated during primary HIV infection (PHI) and examine the impact of time from HIV-1 acquisition to antiretroviral therapy (ART) initiation on clinical outcomes. We also examine the temporal changes in the demographics of individuals presenting with PHI to inform HIV-1 prevention strategies.

METHODS

Individuals who fulfilled the criteria of PHI and started ART within 3 months of confirmed HIV-1 diagnosis were enrolled between 2009 and 2020. Baseline demographics of those diagnosed between 2009 and 2015 (before preexposure prophylaxis (PrEP) and universal ART availability) and 2015-2020 (post-PrEP and universal ART availability) were compared. We examined the factors associated with immune recovery and time to viral suppression.

RESULTS

Two hundred four individuals enrolled, 144 from 2009 to 2015 and 90 from 2015 to 2020; median follow-up was 33 months. At PHI, the median age was 33 years; 4% were women, 39% were UK-born, and 84% were MSM. The proportion of UK-born individuals was 47% in 2009-2015, compared with 29% in 2015-2020. There was an association between earlier ART initiation after PHI diagnosis and increased immune recovery; each day that ART was delayed was associated with a lower likelihood of achieving a CD4 + cell count more than 900 cells/μl [hazard ratio 0.99 (95% confidence interval, 95% CI 0.98-0.99), P  = 0.02) and CD4/CD8 more than 1.0 (hazard ratio 0.98 (95% CI 0.97-0.99).

CONCLUSION

Early initiation of ART at PHI diagnosis is associated with enhanced immune recovery, providing further evidence to support immediate ART in the context of PHI. Non-UK-born MSM accounts for an increasing proportion of those with primary infection; UK HIV-1 prevention strategies should better target this group.

Spatiotemporal Variation and Predictors of Unsuppressed Viral Load among HIV-Positive Men and Women in Rural and Peri-Urban KwaZulu-Natal, South Africa

Unsuppressed HIV viral load is an important marker of sustained HIV transmission. We investigated the prevalence, predictors, and high-risk areas of unsuppressed HIV viral load among HIV-positive men and women. Unsuppressed HIV viral load was defined as viral load of ≥400 copies/mL. Data from the HIV Incidence District Surveillance System (HIPSS), a longitudinal study undertaken between June 2014 to June 2016 among men and women aged 15−49 years in rural and peri-urban KwaZulu-Natal, South Africa, were analysed. A Bayesian geoadditive regression model which includes a spatial effect for a small enumeration area was applied using an integrated nested Laplace approximation (INLA) function while accounting for unobserved factors, non-linear effects of selected continuous variables, and spatial autocorrelation. The prevalence of unsuppressed HIV viral load was 46.1% [95% CI: 44.3−47.8]. Predictors of unsuppressed HIV viral load were incomplete high school education, being away from home for more than a month, alcohol consumption, no prior knowledge of HIV status, not ever tested for HIV, not on antiretroviral therapy (ART), on tuberculosis (TB) medication, having two or more sexual partners in the last 12 months, and having a CD4 cell count of <350 cells/μL. A positive non-linear effect of age, household size, and the number of lifetime HIV tests was identified. The higher-risk pattern of unsuppressed HIV viral load occurred in the northwest and northeast of the study area. Identifying predictors of unsuppressed viral load in a localized geographic area and information from spatial risk maps are important for targeted prevention and treatment programs to reduce the transmission of HIV.

Factors Influencing Immune Restoration in People Living with HIV/AIDS

Introduction: Immune restoration is a key clinical aspect that is pursued in the care of human immunodeficiency virus (HIV)-infected patients. Despite effective antiretroviral treatment and undetectable viremia, immune recovery is often incomplete. Materials and methods: Data from 311 Caucasian patients were collected. SNP in CCR2(rs1799864), CX3CR1(rs3732378), HLAC-35(rs9264942), and CCR5(promoter, rs1799988); a 32bp deletion(Δ32) in CCR5; and HLA-B*5701 genotypes were correlated with clinical data and selected endpoints. Kaplan−Meier and Cox proportional hazards models were used to analyze the effects of genetic factors over time. Results: For HLA-B*5701, the effect on the CD4+/CD8+ >0.8 cell ratio was lost within 48 months (HR = 2.04, 95% CI: 1.04−4.03), and the effect on the CD4+ cell count >500 cells/µL was lost within 12 months (HR = 2.12, CI: 1.11−4.04). The effect of CCR2 GG on the CD4+/CD8+ >0.8 cell ratio was lost within 36 months (HR = 1.7, CI: 1.05−2.75). For CCR5 wt/Δ32, the effect on the CD4+/CD8+ >1.0 cell ratio was lost within 24 months (HR = 2.0, CI: 1.08−3.69), and the effect on the CD4+ >800 cells/µL cell count was lost within 18 months (HR = 1.98, CI: 1.14−4.73). Conclusions: Selected genetic polymorphisms, namely CCR2 GG and CCR5 Δ32, and the presence of the HLA-B*5701 allele positively influenced immune restoration in cART-treated patients with HIV/AIDS.

Effect of Traditional Chinese Medicine Therapy on the Trend in CD4+ T-Cell Counts among Patients with HIV/AIDS Treated with Antiretroviral Therapy: A Retrospective Cohort Study

This retrospective cohort study was conducted to explore the effect of traditional Chinese medicine (TCM) therapy on the long-term trends in CD4⁺ T-cell count among patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) who were treated with combined antiretroviral therapy (cART) over a 14-year period. A total of 721 individuals were treated with cART alone (cART group), and 307 individuals were treated with both cART and TCM (TCM + cART group). Among all enrolled patients with HIV/AIDS, 99.5% were farmers, 71.1% had more than 6 years of education, and 96.8% were infected with HIV via a paid blood donation. For those patients with HIV/AIDS who had a baseline CD4⁺ T-cell count of <350 cells/mL, the CD4⁺ T-cell count tended to increase to approximately 350 cells/mL more rapidly in the TCM + cART group than in the cART group, but when the baseline CD4⁺ T-cell count was ≥350 cells/mL, there was no difference between the cART and TCM + cART groups. For other patients with HIV/AIDS who had a baseline CD4⁺ T-cell count of 350–500 cells/mL, the CD4⁺ T-cell counts tended to increase slightly, but there was no difference between the two groups. For patients with HIV/AIDS who had a baseline CD4⁺ T-cell count of ≥500 cells/mL, the CD4⁺ T-cell counts tended to be maintained at a particular level, with no difference between the two groups. The results show that the effect of TCM on the CD4⁺ T-cell counts of patients with HIV/AIDS is related to the CD4⁺ T-cell level at the time of initial treatment. TCM can increase the CD4⁺ T-cell count among patients with HIV/AIDS who have a baseline CD4⁺ T-cell count of <350 cells/mL. Sex and age have a slight influence on the therapeutic effect of TCM.

Determinants of suboptimal CD4+ T cell recovery after antiretroviral therapy initiation in a prospective cohort of acute HIV-1 infection

Introduction

Up to 30% of individuals treated with antiretroviral therapy (ART) during chronic HIV fail to recover CD4 counts to >500 cells/mm³ despite plasma viral suppression. We investigated the frequency and associations of suboptimal CD4 recovery after ART started during acute HIV infection (AHI).

Methods

Participants who started ART in Fiebig I to V AHI with ≥48 weeks of continuous documented HIV‐RNA < 50 copies/mL were stratified by CD4 count at latest study visit to suboptimal immune recovery (SIR; CD4 < 350 cells/mm³), intermediate immune recovery (IIR; 350 ≤ CD4 < 500) and complete immune recovery (CIR; CD4 ≥ 500). Clinical and laboratory parameters were assessed at pre‐ART baseline and latest study visit. Additional inflammatory and neurobehavioral endpoints were examined at baseline and 96 weeks.

Results

Of 304 participants (96% male, median 26 years old) evaluated after median 144 (range 60 to 420) weeks of ART initiated at median 19 days (range 1 to 62) post‐exposure, 3.6% (n = 11) had SIR and 14.5% (n = 44) had IIR. Pre‐ART CD4 count in SIR compared to CIR participants was 265 versus 411 cells/mm³ (p = 0.002). Individuals with SIR or IIR had a slower CD4 rate of recovery compared to those with CIR. Timing of ART initiation by Fiebig stage did not affect CD4 count during treatment. Following ART, the CD8⁺T cell count (p = 0.001) and CD4/CD8 ratio (p = 0.047) were lower in SIR compared to CIR participants. Compared to the CIR group at week 96, the combined SIR and IIR groups had higher sCD14 (p = 0.008) and lower IL‐6 (p = 0.04) in plasma, without differences in neuropsychological or psychiatric indices.

Conclusions

Despite immediate and sustained treatment in AHI, suboptimal CD4 recovery occurs uncommonly and is associated with low pre‐ART CD4 count as well as persistent low CD8 count and CD4/CD8 ratio during treatment.

Cell-Associated HIV-1 Unspliced-to-Multiply-Spliced RNA Ratio at 12 Weeks of ART Predicts Immune Reconstitution on Therapy

Human immunodeficiency virus (HIV) infection is currently managed by antiretroviral drugs, which block virus replication and promote immune restoration. However, the latter effect is not universal, with a proportion of infected individuals failing to sufficiently reconstitute their immune function despite a successful virological response to antiretroviral therapy (ART).

Incomplete restoration of CD4⁺ T-cell counts on antiretroviral therapy (ART) is a major predictor of HIV-related morbidity and mortality. To understand the possible mechanisms behind this poor immunological response despite viral suppression, we longitudinally measured more than 50 virological and immunological biomarkers in a cohort of HIV-infected individuals at several time points during the first 96 weeks of virologically suppressive ART. No baseline virological or immunological marker was predictive of the degree of immune reconstitution. However, the cell-associated HIV-1 unspliced-to-multiply-spliced (US/MS) RNA ratio at 12 weeks of ART positively correlated with markers of CD4⁺ T-cell activation and apoptosis and negatively predicted both the absolute and relative CD4⁺ T-cell counts at 48 and 96 weeks. A higher US/MS RNA ratio may reflect the higher frequency of productively infected cells that could exert pressure on the immune system, contributing to persistent immune activation and apoptosis and subsequently to a poor immunological response to ART.

Multilevel ordinal model for CD4 count trends in seroconversion among South Africa women

BACKGROUND

Ordinal health longitudinal response variables have distributions that make them unsuitable for many popular statistical models that assume normality. We present a multilevel growth model that may be more suitable for medical ordinal longitudinal outcomes than are statistical models that assume normality and continuous measurements.

METHODS

The data is from an ongoing prospective cohort study conducted amongst adult women who are HIV-infected patients in Kwazulu-Natal, South Africa. Participants were enrolled into the acute infection, then into early infection subsequently into established infection and afterward on cART. Generalized linear multilevel models were applied.

RESULTS

Multilevel ordinal non-proportional and proportional-odds growth models were presented and compared. We observed that the effects of covariates can't be assumed identical across the three cumulative logits. Our analyses also revealed that the rate of change of immune recovery of patients increased as the follow-up time increases. Patients with stable sexual partners, middle-aged, cART initiation, and higher educational levels were more likely to have better immunological stages with time. Similarly, patients having high electrolytes component scores, higher red blood cell indices scores, higher physical health scores, higher psychological well-being scores, a higher level of independence scores, and lower viral load more likely to have better immunological stages through the follow-up time.

CONCLUSION

It can be concluded that the multilevel non-proportional-odds method provides a flexible modeling alternative when the proportional-odds assumption of equal effects of the predictor variables at every stage of the response variable is violated. Having higher clinical parameter scores, higher QoL scores, higher educational levels, and stable sexual partners were found to be the significant factors for trends of CD4 count recovery.

CD4:CD8 ratio comparison between cohorts of HIV-positive Asians and Caucasians upon commencement of antiretroviral therapy

BACKGROUND

In the era of effective antiretroviral treatment (ART) CD4:CD8 ratio is proposed as a potential marker for HIV-positive (HIV+) patients at increased risk for non-AIDS comorbidities. The current study aims to compare CD4:CD8 ratio between Asian and Caucasian HIV+ patients.

METHODS

HIV+ patients from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD) meeting specific criteria were included. In these analyses Asian and Caucasian status were defined by cohort. Factors associated with a low CD4:CD8 ratio (cutoff <0.2) prior to ART commencement, and with achieving a normal CD4:CD8 ratio (>1) at 12 and 24 months post ART commencement were assessed using logistic regression.

RESULTS

There were 591 patients from AHOD and 2,620 patients from TAHOD who met the inclusion criteria. TAHOD patients had a significantly (P<0.001) lower odds of having a baseline (prior to ART initiation) CD4:CD8 ratio greater than 0.2. After 12 months of ART, AHOD patients were more than twice as likely to achieve a normal CD4:CD8 ratio compared to TAHOD patients (15% versus 6%). However, after adjustment for confounding factors there was no significant difference between cohorts in the odds of achieving a CD4:CD8 ratio >1 (P=0.475).

CONCLUSIONS

We found a significantly lower CD4:CD8 ratio prior to commencing ART in TAHOD compared to AHOD even after adjusting for confounders. However, after adjustment, there was no significant difference between the cohorts in odds of achieving normal ratio. Baseline CD4⁺ and CD8⁺ counts seem to be the main driver for this difference between these two populations.

CD4+ cell count recovery after combined antiretroviral therapy in the modern combined antiretroviral therapy era

OBJECTIVE

To assess CD4 recovery after combined antiretroviral therapy (cART) initiation with sustained virologic control.

DESIGN

Cohort study based on the French Hospital Database on HIV (FHDH-ANRS CO4).

METHODS

We selected naive HIV-1-infected individuals initiating cART between 2006 and 2014 with CD4 cell counts less than 500 cells/μl who achieved virologic control, defined as two consecutive viral loads less than 50 copies/ml. We estimated the cumulative incidence of CD4 recovery at least 500 cells/μl and identified associated factors, considering 'virologic failure,' 'loss to follow-up' and 'death' as competing events.

RESULTS

We analyzed 6050 individuals with a median follow-up of 14.2 months since virologic control. The cumulative incidence for CD4 recovery after 6 years of virologic control reached 69.7%. The main factor associated with CD4 recovery was the CD4 count at treatment initiation [subdistribution hazard ratio (sHR) 9.64, 95% confidence interval (95% CI) 8.12-11.43 for CD4 cell counts between 350 and 500 cells/μl compared with CD4 cell counts <100 cells/μl). A higher CD4/CD8 ratio at initiation was also independently associated with a higher probability of CD4 recovery [sHR 1.67; 95% CI 1.34-2.09] for a CD4/CD8 ratio ≥1.00 vs. < 0.30). Higher viral load at initiation was also associated with a higher probability of CD4 recovery, whereas time to viral suppression was not.

CONCLUSION

After 6 years of sustained virologic control, a large majority of the population achieved CD4 recovery. A higher CD4 cell count at initiation was a strong predictor of CD4 recovery and, to a lesser extent, a higher CD4/CD8 ratio at initiation. These results confirm the necessity of early treatment.

Long terms trends in CD4+ cell counts, CD8+ cell counts, and the CD4+ : CD8+ ratio

Supplemental Digital Content is available in the text

Objective:

Model trajectories of CD4⁺ and CD8⁺ cell counts after starting combination antiretroviral therapy (ART) and use the model to predict trends in these counts and the CD4⁺ : CD8⁺ ratio.

Design:

Cohort study of antiretroviral-naïve HIV-positive adults who started ART after 1997 (ART Cohort Collaboration) with more than 6 months of follow-up data.

Methods:

We jointly estimated CD4⁺ and CD8⁺ cell count trends and their correlation using a bivariate random effects model, with linear splines describing their population trends, and predicted the CD4⁺ : CD8⁺ ratio trend from this model. We assessed whether CD4⁺ and CD8⁺ cell count trends and the CD4⁺ : CD8⁺ ratio trend varied according to CD4⁺ cell count at start of ART (baseline), and, whether these trends differed in patients with and without virological failure more than 6 months after starting ART.

Results:

A total of 39 979 patients were included (median follow-up was 53 months). Among patients with baseline CD4⁺ cell count at least 50 cells/μl, predicted mean CD8⁺ cell counts continued to decrease between 3 and 15 years post-ART, partly driving increases in the predicted mean CD4⁺ : CD8⁺ ratio. During 15 years of follow-up, normalization of the predicted mean CD4⁺ : CD8⁺ ratio (to >1) was only observed among patients with baseline CD4⁺ cell count at least 200 cells/μl. A higher baseline CD4⁺ cell count predicted a shorter time to normalization.

Conclusion:

Declines in CD8⁺ cell count and increases in CD4⁺ : CD8⁺ ratio occurred up to 15 years after starting ART. The likelihood of normalization of the CD4⁺ : CD8⁺ ratio is strongly related to baseline CD4⁺ cell count.

Thai national guidelines for antiretroviral therapy in HIV-1 infected adults and adolescents 2010

In Thailand, more than 150,000 patients are currently treated with antiretroviral drugs under the support of the National AIDS Program (NAP). The appointed Adults and Adolescents Committee consisted of 28 members who are experts in HIV research, patient care or health care policy. Relevant published literature, guidelines, and the most recent relevant clinical trials presented internationally were reviewed. Several peer review and clinical studies conducted in Thailand were included in the review process. Special considerations for patients with co-infection of tuberculosis or hepatitis B were incorporated. Appropriate cut-off of CD4+ T-cell counts when to commence ART among Thai patients have been considered. It is now recommended to start ART at CD4+ T-cell count <350 cells/mm3. For treatment-naive patients, the preferred initial therapy is a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen containing lamivudine plus zidovudine or tenofovir. Stavudine will be phased out in a two-year plan at the national program level. Viral load and CD4+ T-cell counts should be monitored at least once and twice a year. To achieve long-term treatment success, enhancing adherence together with the proper management of antiretroviral-related toxicity is critical. In summary, the major changes from the Thai 2008 guidelines include commencing ART earlier. ART is recommended regardless of CD4+ T cell count if patients have an indication to treat their HBV co-infection. Preferred first regimen uses AZT or TDF, not d4T as the NRTI-backbone. Furthermore, efavirenz is now considered a preferred NNRTI, along with nevirapine.

Prevalence of self-reported comorbidities in HIV positive and HIV negative men who have sex with men over 55 years-The Australian Positive & Peers Longevity Evaluation Study (APPLES)

In Australia, almost half of HIV-positive people are now aged over 50 and are predominately gay and bisexual men (GBM). Compared to the general HIV-negative population, GBM engage more in behaviours that may increase the risk of age-related comorbidities, including smoking, high alcohol consumption and recreational drug use. The objective of APPLES was to compare comorbidities and risk factors in HIV-positive older GBM with an appropriate control group of HIV-negative GBM. We undertook a prospectively recruited cross-sectional sample of HIV-positive and HIV-negative GBM ≥ 55 years. Detailed data collection included clinic data, a health and lifestyle survey, and blood sample collection. We report key demographic, laboratory markers and self-reported comorbidities by HIV status. For selected comorbidities we also adjust HIV status a priori for age, smoking and body mass index. Over 16 months 228 HIV-positive and 218 HIV-negative men were recruited. Median age was 63 years (IQR: 59-67). Although more HIV-positive men reported having ever smoked, smoking status was not statistically different between HIV positive and HIV negative men (p = 0.081). Greater alcohol use was reported by HIV-negative men (p = 0.002), and recreational drug use reported more often by HIV-positive men (p<0.001). After adjustment, HIV-positive men had significantly increased odds of diabetes (adjusted Odds ratio (aOR): 1.97, p = 0.038), thrombosis (aOR: 3.08, p = 0.007), neuropathy (aOR: 34.6, P<0.001), and non-significantly increased odds for heart-disease (aOR: 1.71, p = 0.077). In conclusion, HIV-positive GBM have significantly increased odds for key self-reported comorbidities. This study underscores the importance of an appropriate HIV-negative control group for more accurate evaluation of the risk and attribution of age-related comorbidities in HIV-positive people.

Virologic and Immunologic Outcomes of the Second-Line Regimens of Antiretroviral Therapy Among HIV-Infected Patients in Thailand

Goal of the second-line therapy among HIV-1-infected patients is to re-establish virological suppression, although treatment options in resource-limited settings are limited. An observational cohort of patients with first-line antiretroviral therapy (ART) failure was conducted in a university hospital in Thailand. Of 95 patients, mean age 39 years, 65% were male. Median CD4 and HIV-1 RNA at second-line ART initiation were 158 cells/mm(3) and 4.1 copies/mL, respectively. Boosted protease inhibitor plus 2 nucleoside reverse transcriptase inhibitors (NRTIs), indicated by genotype results, was commonly used as second-line regimen. At 6, 12, 24, and 36 months of second-line ART, 67%, 62%, 84%, and 90% of patients achieved HIV-1 RNA <50 copies/mL; median CD4 were 258, 366, 444, and 522 cells/mm( 3), respectively. Good adherence, high baseline CD4, and early Centers for Centers for Disease Control and Prevention (CDC) staging were associated with virologic success (P < .05). Second-line ART based on the results of genotype testing yields the good virologic and immunologic outcomes in a resource-limited setting, and scaling-up of second-line ART is indicated.

Pattern and predictors of immunologic recovery in HIV infected patients

Background

Although anti-retroviral therapy has generally improved the survival of HIV infected patients in many developing countries including Ghana, specific socio-demographic factors could still influence outcome of treatment. This study was designed to identify patient-specific factors that could influence the immune recovery of absolute CD4 count in HIV infected patients.

Findings

Hospital records were extracted from two health facilities in Ghana. The impact of socio-demographic factors type of ART and baseline category of CD4 counts were assessed at six monthly interval using robust linear mixed models.

Results

A total of 214 follow up records were reviewed at Komfo Anokye Teaching Hospital (KATH) and the Kumasi South Hospital (KSH). One hundred (46.7 %) were from KATH and 114 (53.3 %) were from KSH. There was a general increase in the level of CD4 counts with time, however this increase significantly slowed down with subsequent reviews (p < 0.001). On the average the rate of CD4 count recovery slowed down by 43.6 cells/µl for every 6 months of follow up (SE = 7.69; p < 0.001). Similarly the recovery of CD4 counts in subjects with an initial high baseline CD4 counts decreased by 192.6 cells/µl (SD error = 42.3, p value ≤0.001). All other variables were not significantly associated with recovery of CD4 counts.

Conclusion

Our study has demonstrated the well-known phenomenon of CD4 counts increasing after administration of ARTs. CD4 counts increased more rapidly in those with relatively lower initial counts, catching up with those with high CD4 count by 2 years post treatment.

Influence of lifelong cumulative HIV viremia on long-term recovery of CD4+ cell count and CD4+/CD8+ ratio among patients on combination antiretroviral therapy

OBJECTIVE

We explored the impact of lifelong cumulative HIV viremia on immunological recovery during antiretroviral therapy, according to the timing of treatment initiation.

METHODS

We estimated lifelong cumulative HIV viremia in patients followed in the ANRS PRIMO cohort since primary infection, including 244 patients who started treatment during PHI and had at least one treatment interruption, and 218 patients who started treatment later but with no interruptions. The impact of cumulative viremia on current immunological status was analysed using linear and logistic regression models.

RESULTS

At the last visit on treatment, median CD4 cell count was 645 cells/μl in the early/intermittent treatment group (median time from infection 9.5 years, 4.8 years of continuous treatment since last resumption), and 654 cells/μl in the deferred/continuous treatment group (median time from infection 6.1 years, 3.0 years of continuous treatment). Only 36.1 and 39.8% of patients achieved a CD4/CD8 ratio of more than 1, respectively. Current CD4 cell count was not associated with cumulative HIV viremia in either group. In contrast, patients with high cumulative HIV viremia (>66th percentile vs. <33rd percentile) were less likely to achieve a CD4/CD8 ratio of more than 1 (26.8 vs. 43.3%, P = 0.003), even after controlling for the baseline CD4/CD8 ratio, treatment duration, sex and age. Much higher CD4 cell count and CD4/CD8 ratio were reached in early/continuous treatment, that is low viremia exposure group.

CONCLUSION

Our results underline the critical need in early-treated patients to maintain adherence, in order to limit cumulative HIV viremia and optimize immunological recovery, notably the CD4/CD8 ratio.

HIV and aging: insights from the Asia Pacific HIV Observational Database (APHOD)

OBJECTIVES

The proportion of people living with HIV/AIDS in the ageing population (>50 years old) is increasing. We aimed to explore the relationship between older age and treatment outcomes in HIV-positive persons from the Asia Pacific region.

METHODS

Patients from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD) were included in the analysis. We used survival methods to assess the association between older age and all-cause mortality, as well as time to treatment modification. We used regression analyses to evaluate changes in CD4 counts after combination antiretroviral therapy (cART) initiation and determined the odds of detectable viral load, up to 24 months of treatment.

RESULTS

A total of 7142 patients were included in these analyses (60% in TAHOD and 40% in AHOD), of whom 25% were >50 years old. In multivariable analyses, those aged > 50 years were at least twice as likely to die as those aged 30-39 years [hazard ratio (HR) for 50-59 years: 2.27; 95% confidence interval (CI) 1.34-3.83; HR for > 60 years: 4.28; 95% CI 2.42-7.55]. The effect of older age on CD4 count changes was insignificant (p-trend=0.06). The odds of detectable viral load after cART initiation decreased with age (p-trend=< 0.0001). The effect of older age on time to first treatment modification was insignificant (p-trend=0.21). We found no statistically significant differences in outcomes between AHOD and TAHOD participants for all endpoints examined.

CONCLUSIONS

The associations between older age and typical patient outcomes in HIV-positive patients from the Asia Pacific region are similar in AHOD and TAHOD. Our data indicate that 'age effects' traverse the resource-rich and resource-limited divide and that future ageing-related findings might be applicable to each setting.

In vivo HIV-1 hypermutation and viral loads among antiretroviral-naive Brazilian patients

Hypermutation alludes to an excessive number of specific guanine-to-adenine (G- >A) substitutions in proviral DNA and this phenomenon is attributed to the catalytic activity of cellular APOBECs. Population studies relating hypermutation and the progression of infection by human immunodeficiency virus type 1 (HIV-1) have been performed to elucidate the effect of hypermutation on the natural course of HIV-1 infection. However, the many different approaches employed to assess hypermutation in nucleotide sequences render the comparison of results difficult. This study selected 157 treatment-naive patients and sought to correlate the hypermutation level of the proviral sequences in clinical samples with demographic variables, HIV-1 RNA viral load, and the level of CD4(+) T cells. Nested touchdown polymerase chain reaction (PCR) was performed with specific primers to detect hypermutation in the region of HIV-1 integrase, and the amplified sequences were run in agarose gels with HA-Yellow. The analysis of gel migration patterns using the k-means clustering method was validated by its agreement with the results obtained with the software Hypermut. Hypermutation was found in 31.2% of the investigated samples, and a correlation was observed between higher hypermutation levels and higher viral load levels. These findings suggest a high frequency of hypermutation detection in a Brazilian cohort, which can reflect a particular characteristic of this population, but also can result from the method approach by aiming at hypermutation-sensitive sites. Furthermore, we found that hypermutation events are pervasive during HIV-1 infection as a consequence of high viral replication, reflecting its role during disease progression.

High rates of tuberculosis in patients accessing HAART in rural South Africa

BACKGROUND

The challenge of early tuberculosis (TB) infection among rural patients accessing highly active antiretroviral therapy (HAART) in a resource-limited setting with high HIV and TB burden has not been fully quantified.

METHODS

This is a retrospective study nested within a prospective study of 969 patients consecutively initiated onto HAART at the CAPRISA AIDS Treatment programme in rural KwaZulu-Natal between January 2007 and December 2010. Patients were screened for clinical symptoms consistent with TB using a standardized checklist, and routine clinical investigations that included sputum microscopy and chest x-ray diagnosis.

RESULTS

Of 969 HIV-infected patients initiated on HAART, 173 [17.9%; 95% confidence interval (CI): 15.5 to 20.4] had active TB at HAART initiation. TB incidence rates were 3-fold higher in the first 3 months (early incident TB) after HAART initiation [11.5/100 person-years (py); 95% CI: 7.1 to 17.5] compared with 4-24 months (late incident TB) post-HAART initiation (3.2/100 py; 95% CI: 2.2 to 4.5; incidence rate ratio: 3.6; 95% CI: 2.0 to 6.4; P < 0.001). Immune status of patients at HAART initiation did not impact TB incidence rates in patients with CD4 counts of <50 (5.3/100) and >200 (4.9/100 py; P = 0.81) cells per cubic millimeter. CD4 count gains achieved 12 months post-HAART initiation were significantly different in patients with early incident TB versus late incident TB; P = 0.03.

CONCLUSIONS

Rural HIV treatment programmes in TB-endemic settings experience high rates of TB irrespective of immunologic status of patients at HAART initiation, or duration on HAART.

The immunological response of HIV-positive patients initiating HAART at the Komfo Anokye Teaching Hospital, Kumasi, Ghana

OBJECTIVE

The study sought to document the experience of immunological improvement among Ghanaian PLHIV on HAART comparing different categories of patients.

SETTING

Serology Unit, Komfo Anokye Teaching Hospital, Kumasi, Ghana.

PARTICIPANTS

The study comprised a convenient sample of 303 treatment naïve HIV patients due to start HAART.

METHODS

Questionnaires were used to collect patient demographic and clinical data. Four CD4 counts were measured at six-monthly intervals to determine rates of CD4 change. These were pre-therapy, 1(st) post-therapy, 2(nd) post-therapy, and 3(rd) post-therapy counts. The rates of CD4 change among the different categories of patients were also compared.

RESULTS

At baseline, women had higher CD4 count (mean of 77.4 cells/μl), and mean age of participants was 40 years. The CD4 count increased from a mean baseline of 70.2 cells/μl to 229.2, 270.0, and 297.6 cells/μl at 6, 12, and 18 months of treatment respectively (P < 0.0001 at each time point). There were no gender (P=0.46) and age (P=0.96) differences in treatment response. There was no difference (P=0.18) in treatment response comparing those with CD4 <250 cells/μl and those whose CD4 count was between 250 and 350 cells/μl at baseline although patients with baseline CD4 count <250 cells/μl showed larger increases after 12 months of treatment. Out of 282 patients with pre-therapy CD4 count ≤250 cells/μl, 241 (85.5%) and 41 (14.5%) were adherents and nonadherents respectively. Mean rate of increase was 15.2 and 8.4 cells/μl/month in adherent and non-adherent patients respectively (p=0.2).

CONCLUSION

The study suggests that a sustained CD4 increase could be achieved in adherent patients commencing therapy with baseline CD4 count ≤250 cells/μl, and that these patients have greater ability for immunological recovery during 12 months of treatment The study, therefore, concludes that significant immunological improvement is possible among Ghanaian PLHIV on HAART as long as a high level of treatment adherence is observed.

Among patients with sustained viral suppression in a resource-limited setting, CD4 gains are continuous although gender-based differences occur

INTRODUCTION

There is conflicting data on long-term CD4 immune recovery after combination antiretroviral therapy (ART) in resource-limited settings. Virologic suppression is rarely documented in cohorts from sub-Saharan Africa so objective evidence of adherence is biologically unsubstantiated. We sought to investigate long-term patterns of immune recovery in Ugandan patients on ART with sustained viral suppression.

METHODS

A prospective cohort of patients starting ART between April, 2004 and April, 2005 at the Infectious Diseases Institute with sustained viral suppression (viral load ≤ 400 copies/ml at month 6 and 12) while on first-line ART. Propensity scores were used to adjust for treatment allocation (nevirapine or efavirenz) at ART initiation. Data were analyzed using Kaplan Meier methods and cross-sectional time series regression.

RESULTS

Three hundred and fifty-six patients were included in the analysis.71.6% were female, 87% in WHO stage 3 or 4, median age was 37 years, (IQR:32-43), and median CD4 count was 108 cells/µL, (IQR:35-174) at ART start. At multivariable analysis, lower immune recovery (measured by change in CD4 from ART start at each time interval) was associated with male-gender (-59, 95% CI: 90, -28, P<0.001), baseline CD4 count of 101-200 cells/µL (-35, 95% CI: 62, -9, P=0.009) and >200 (-64, 95% CI: 101, -26, P=0.001), and use of AZT at baseline (-47, 95% CI: -74, -20, P=0.001). Median time to reach >400 cells/µL was longer in males (197.4 weeks, IQR:119.9-312.0), compared to females (144.7 weeks, IQR:96.6-219.7, P<0.001). The cumulative probability of attaining CD4 >400 cells/µL over 7 years was higher in females compared to males (P<0.001).

CONCLUSIONS

There was long-term, continuous, immunologic recovery up to 7 years after ART initiation in an urban Ugandan cohort. Virologically suppressed women had better sustained immune recovery than men. Men take longer to immune reconstitute and have a lower probability of reaching a CD4 cell count >400 cells/µL. The biologic mechanisms of these gender differences need further exploration.

Accounting for baseline differences and measurement error in the analysis of change over time

If change over time is compared in several groups, it is important to take into account baseline values so that the comparison is carried out under the same preconditions. As the observed baseline measurements are distorted by measurement error, it may not be sufficient to include them as covariate. By fitting a longitudinal mixed-effects model to all data including the baseline observations and subsequently calculating the expected change conditional on the underlying baseline value, a solution to this problem has been provided recently so that groups with the same baseline characteristics can be compared. In this article, we present an extended approach where a broader set of models can be used. Specifically, it is possible to include any desired set of interactions between the time variable and the other covariates, and also, time-dependent covariates can be included. Additionally, we extend the method to adjust for baseline measurement error of other time-varying covariates. We apply the methodology to data from the Swiss HIV Cohort Study to address the question if a joint infection with HIV-1 and hepatitis C virus leads to a slower increase of CD4 lymphocyte counts over time after the start of antiretroviral therapy.

Virologic and immunologic outcome of HAART in Human Immunodeficiency Virus (HIV)-1 infected patients with and without tuberculosis (TB) and latent TB infection (LTBI) in Addis Ababa, Ethiopia

BACKGROUND

HIV/TB coinfection remains a major challenge even after the initiation of HAART. Little is known about Mycobacterium tuberculosis (Mtb) specific immune restoration in relation to immunologic and virologic outcomes after long-term HAART during co-infections with latent and active TB.

METHODS

A total of 232 adults, including 59 HIV patients with clinical TB (HIV + TB+), 125 HIV patients without clinical TB (HIV + TB-), 13 HIV negative active TB patients (HIV-TB+), and 10 HIV negative Tuberculin Skin TST positive (HIV-TST+), and 25 HIV-TST- individuals were recruited. HAART was initiated in 113 HIV + patients (28 TB + and 85 TB-), and anti-TB treatment for all TB cases. CD4+ T-cell count, HIV RNA load, and IFN-γ responses to ESAT-6/CFP-10 were measured at baseline, 6 months (M6), 18 months (M18) and 24 months (M24) after HAART initiation.

RESULTS

The majority of HIV + TB- (70%, 81%, 84%) as well as HIV + TB + patients (60%, 77%, 80%) had virologic success (HIV RNA < 50 copies/ml) by M6, M18 and M24, respectively. HAART also significantly increased CD4+ T-cell counts at 2 years in HIV + TB + (from 110.3 to 289.9 cells/μl), HIV + TB- patients (197.8 to 332.3 cells/μl), HIV + TST- (199 to 347 cells/μl) and HIV + TST + individuals (195 to 319 cells/μl). Overall, there was no significant difference in the percentage of patients that achieved virologic success and in total CD4+ counts increased between HIV patients with and without TB or LTBI. The Mtb specific IFN-γ response at baseline was significantly lower in HIV + TB + (3.6 pg/ml) compared to HIV-TB + patients (34.4 pg/ml) and HIV + TST + (46.3 pg/ml) individuals; and in HIV-TB + patients compared to HIV-TST + individuals (491.2 pg/ml). By M18 on HAART, the IFN-γ response remained impaired in HIV + TB + patients (18.1 pg/ml) while it normalized in HIV + TST + individuals (from 46.3 to 414.2 pg/ml).

CONCLUSIONS

Our data show that clinical and latent TB infections do not influence virologic and immunologic outcomes of ART in HIV patients. Despite this, HAART was unable to restore optimal TB responsiveness as measured by Mtb specific IFN-γ response in HIV/TB patients. Improvement of Mtb-specific immune restoration should be the focus of future therapeutic strategies.

Rates and factors associated with major modifications to first-line combination antiretroviral therapy: results from the Asia-Pacific region

BACKGROUND

In the Asia-Pacific region many countries have adopted the WHO's public health approach to HIV care and treatment. We performed exploratory analyses of the factors associated with first major modification to first-line combination antiretroviral therapy (ART) in resource-rich and resource-limited countries in the region.

METHODS

We selected treatment naive HIV-positive adults from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD). We dichotomised each country's per capita income into high/upper-middle (T-H) and lower-middle/low (T-L). Survival methods stratified by income were used to explore time to first major modification of first-line ART and associated factors. We defined a treatment modification as either initiation of a new class of antiretroviral (ARV) or a substitution of two or more ARV agents from within the same ARV class.

RESULTS

A total of 4250 patients had 961 major modifications to first-line ART in the first five years of therapy. The cumulative incidence (95% CI) of treatment modification was 0.48 (0.44-0.52), 0.33 (0.30-0.36) and 0.21 (0.18-0.23) for AHOD, T-H and T-L respectively. We found no strong associations between typical patient characteristic factors and rates of treatment modification. In AHOD, relative to sites that monitor twice-yearly (both CD4 and HIV RNA-VL), quarterly monitoring corresponded with a doubling of the rate of treatment modifications. In T-H, relative to sites that monitor once-yearly (both CD4 and HIV RNA-VL), monitoring twice-yearly corresponded to a 1.8 factor increase in treatment modifications. In T-L, no sites on average monitored both CD4 & HIV RNA-VL concurrently once-yearly. We found no differences in rates of modifications for once- or twice-yearly CD4 count monitoring.

CONCLUSIONS

Low-income countries tended to have lower rates of major modifications made to first-line ART compared to higher-income countries. In higher-income countries, an increased rate of RNA-VL monitoring was associated with increased modifications to first-line ART.

The interplay between CD4 cell count, viral load suppression and duration of antiretroviral therapy on mortality in a resource-limited setting

OBJECTIVE

To examine the interaction between CD4 cell count, viral load suppression and duration of antiretroviral therapy (ART) on mortality.

METHODS

Cohort analysis of HIV-infected patients initiating ART between April 2004 and June 2011 at a large public sector clinic in Johannesburg, South Africa. A log-linear model with Poisson distribution was used to estimate risk of death as a function of the interaction between current CD4 count, current viral load suppression and duration on ART in 12-month intervals. We calculated predicted mortality using estimated coefficients within combinations of predictors.

RESULTS

Amongst 14 932 ART patients, 1985 (13.3%) died. Current CD4 was the strongest predictor of death (<50 vs. ≥550 cells/mm(3) - RR: 46.3; 95% CI: 26.8-80), while unsuppressed current viral load vs. suppressed (RR: 1.8; 95% CI: 1.5-2.1) and short duration of ART (0-11.9 vs. 66-71.9 months RR: 1.7; 95% CI: 1.2-2.3) also predicted death. Our interaction model showed that mortality was highest in the first 12 months on treatment across all CD4 and viral load strata. As current CD4 and duration on ART increased and viral load suppression occurred, mortality dropped. CD4 count was the strongest predictor of death. The relative effect of current CD4 count varied strongly by viral load and duration of ART (from 1.3 to 55). Lack of suppression increased the risk of mortality upwards of six-fold depending on time on ART and current CD4.

CONCLUSIONS

Our findings show that while CD4 count is the strongest predictor of death, the effect is modified by viral load and the duration of ART. Assessment of risk should take into account all three factors.

Women experience a better long-term immune recovery and a better survival on HAART in Lao People's Democratic Republic

Background

In April 2003, Médecins Sans Frontières launched an HIV/AIDS programme to provide free HAART to HIV-infected patients in Laos. Although HIV prevalence is estimated as low in this country, it has been increasing in the last years. This work reports the first results of an observational cohort study and it aims to identify the principal determinants of the CD4 cells evolution and to assess mortality among patients on HAART.

Methods

We performed a retrospective database analysis on patients initiated on HAART between 2003 and 2009 (CD4<200cells/μL or WHO stage 4). We excluded from the analysis patients who were less than 16 years old and pregnant women. To explore the determinants of the CD4 reconstitution, a linear mixed model was adjusted. To identify typical trajectories of the CD4 cells, a latent trajectory analysis was carried out. Finally, a Cox proportional-hazards model was used to reveal predictors of mortality on HAART including appointment delay greater than 1 day.

Results

A total of 1365 patients entered the programme and 913 (66.9%) received an HAART with a median CD4 of 49 cells/μL [IQR 15–148]. High baseline CD4 cell count and female gender were associated with a higher CD4 level over time. In addition, this gender difference increased over time. Two typical latent CD4 trajectories were revealed showing that 31% of women against 22% of men followed a high CD4 trajectory. In the long-term, women were more likely to attend appointments without delay. Mortality reached 6.2% (95% CI 4.8-8.0%) at 4 months and 9.1% (95% CI 7.3-11.3%) at 1 year. Female gender (HR=0.17, 95% CI 0.07-0.44) and high CD4 trajectory (HR=0.19, 95% CI 0.08-0.47) were independently associated with a lower death rate.

Conclusions

Patients who initiated HAART were severely immunocompromised yielding to a high early mortality. In the long-term on HAART, women achieved a better CD4 cells reconstitution than men and were less likely to die. This study highlights important differences between men and women regarding response to HAART and medical care, and questions men’s compliance to treatment.

Unrecognised tuberculosis at antiretroviral therapy initiation is associated with lower CD4+ T cell recovery

OBJECTIVES

To investigate whether an unrecognised diagnosis of tuberculosis (TB) at the start of antiretroviral therapy (ART) influences subsequent CD4+ T cell (CD4) count recovery in an urban HIV clinic in Uganda.

METHODS

In a retrospective cohort study, a multivariable polynomial mixed effects model was used to estimate CD4 recovery in the first 96 weeks of ART in two groups of patients: prevalent TB (started ART while on TB treatment), unrecognised TB (developed TB within 6 months after start ART).

RESULTS

Included were 511 patients with a median baseline CD4 count of 57 cells/mm(3) (interquartile range: 22-130), of whom 368 (72%) had prevalent TB and 143 (28%) had unrecognised TB. Compared with prevalent TB, unrecognised TB was associated with lower CD4 count recovery at 96 weeks: -22.3 cells/mm(3) (95% confidence interval -43.2 to -1.5, P = 0.036). These estimates were adjusted for gender, age, baseline CD4 count and the use of zidovudine-based regimen.

CONCLUSIONS

Unrecognised TB at the time of ART initiation resulted in impaired CD4 recovery compared with TB treated before ART initiation. More vigilant screening with more sensitive and rapid TB diagnostics prior to ART initiation is needed to decrease the risk of ART-associated TB and sub-optimal immune reconstitution.

Ageing and long-term CD4 cell count trends in HIV-positive patients with 5 years or more combination antiretroviral therapy experience

OBJECTIVES

The aim of this study was to describe the long-term changes in CD4 cell counts beyond 5 years of combination antiretroviral therapy (cART). If natural ageing leads to a long-term decline in the immune system via low-grade chronic immune activation/inflammation, then one might expect to see a greater or earlier decline in CD4 counts in older HIV-positive patients with increasing duration of cART.

METHODS

Retrospective and prospective data were examined from long-term virologically stable HIV-positive adults from the Australian HIV Observational Database. We estimated mean CD4 cell count changes following the completion of 5 years of cART using linear mixed models.

RESULTS

A total of 37 916 CD4 measurements were observed for 892 patients over a combined total of 9753 patient-years. Older patients (> 50 years old) at cART initiation had estimated mean (95% confidence interval) changes in CD4 counts by year-5 CD4 count strata (< 500, 500-750 and > 750 cells/μL) of 14 (7 to 21), 3 (-5 to 11) and -6 (-17 to 4) cells/μL/year. Of the CD4 cell count rates of change estimated, none were indicative of long-term declines in CD4 cell counts.

CONCLUSIONS

Our results suggest that duration of cART and increasing age do not result in decreasing mean changes in CD4 cell counts for long-term virologically suppressed patients, indicating that the level of immune recovery achieved during the first 5 years of treatment is sustained through long-term cART.

HIV RNA suppression and immune restoration: can we do better?

HAART has significantly changed the natural history of HIV infection: patients receiving antiretrovirals are usually able to control viremia, even though not all virological responders adequately recover their CD4+ count. The reasons for poor immune restoration are only partially known and they include genetic, demographic and immunologic factors. A crucial element affecting immune recovery is immune activation, related to residual viremia; indeed, a suboptimal virological control (i.e., low levels of plasma HIV RNA) has been related with higher levels of chronic inflammation and all-cause mortality. The sources of residual viremia are not yet completely known, even though the most important one is represented by latently infected cells. Several methods, including 2-LTR HIV DNA and unspliced HIV RNA measurement, have been developed to estimate residual viremia and predict the outcome of antiretroviral therapy. Considering that poor immunologic responders are exposed to a higher risk of both AIDS-related and non-AIDS-related diseases, there is a need of new therapeutic strategies, including immunomodulators and drugs targeting the latent viral reservoirs, in order to face residual viremia but also to “drive” the host immunologic responses.

Race and CD4+ T-cell count in HIV prognosis and treatment

CD4+ T-cell count is known to vary by race in HIV-negative individuals. While people of certain races, such as blacks and Asians, continue to be disproportionately burdened by HIV/AIDS, they remain under-represented in most HIV clinical studies. Recent studies suggest that CD4+ count evolution in HIV, before and after therapy, may differ by race. In this review, we summarize the evidence from prospective cohorts comparing CD4+ count trajectories by race, and whether it is of any clinical significance. We find that although minor differences in CD4+ count trajectories exist between people of diverse races, socioeconomic, cultural and environmental differences are far more important in predicting clinical outcomes than racial differences in CD4+ count. Furthermore, current evidence does not support the need for any race or ethnicity-specific CD4+ thresholds for ART and prophylactic therapy initiation. Future long-term trials in racially diverse populations are required to substantiate these findings.

Cost-effectiveness of combination therapy with etravirine in treatment-experienced adults with HIV-1 infection

OBJECTIVE

To assess the cost-effectiveness of etravirine (INTELENCE), a novel nonnucleoside reverse transcriptase inhibitor, used in combination with a background regimen that included darunavir/ritonavir, from a Canadian Provincial Ministry of Health perspective.

DESIGN

A Markov model with a 3-month cycle time and six health states based on CD4 cell count ranges was developed to follow a hypothetical cohort of treatment-experienced adults with HIV-1 infection through initial and subsequent treatment regimens.

METHODS

Costs (in 2009 Canadian dollars), utilities, and HIV-related mortality data for each health state as well as non-HIV-related mortality data were estimated from Canadian sources and published literature. Transition probabilities between health states and first-year hospitalization and mortality rates were derived from clinical trial data. Incremental 1-year costs per additional adult with viral load less than 50 copies/ml at 48 weeks and incremental lifetime costs per quality-adjusted life-year (QALY) gained were estimated using a 5% discount rate. Sensitivity and variability analyses and model validation were performed.

RESULTS

Etravirine was associated with an increased probability of achieving less than 50 copies/ml at 48 weeks of 0.205 and an estimated gain of 0.66 discounted (1.48 undiscounted) QALYs over a lifetime. The incremental 1-year cost per additional person with viral load less than 50 copies/ml was $23,862. The lifetime incremental cost per QALY gained was $49,120. For the uncertainty ranges and variability scenarios tested for the lifetime horizon, the cost-effectiveness ratio was between $28,859 and 66,249.

CONCLUSION

When compared with optimized standard of care including darunavir/ritonavir, adding etravirine represents a cost-effective option for treatment-experienced adults in Canada.

CD4 cell responses to combination antiretroviral therapy in patients starting therapy at high CD4 cell counts

OBJECTIVE

To examine CD4 cell responses to combination antiretroviral therapy (cART) in patients enrolled in the Australian HIV Observational Database who commenced cART at CD4 cell counts >350 cells per microliter.

METHODS

CD4 cell counts were modelled using random effects, repeated measurement models in 432 HIV-infected adults from Australian HIV Observational Database who commenced their first cART regimen and had a baseline CD4 count >350 cells per microliter. Using published AIDS and/or death incidence rates combined with the data summarized by time and predicted CD4 cell count, we calculated the expected reduction in risk of an event for different starting baseline CD4 strata.

RESULTS

Mean CD4 counts increased above 500 cells per microliter in all baseline CD4 strata by 12 months (means of 596, 717, and 881 cells/μL in baseline CD4 strata 351-500, 501-650, and >650 cells/μL, respectively) and after 72 months since initiating cART, mean CD4 cell counts (by increasing baseline CD4 strata) were 689, 746, 742 cells per microliter. The expected reduction in risk of mortality for baseline CD4 counts >650 cells per microliter relative to 351-500 cells per microliter was approximately 8%, an absolute risk reduction 0.33 per 1000 treated patient-years.

CONCLUSIONS

Patients starting cART at high CD4 cell counts (>650 cells/μL) tend to maintain this immunological level over 6 years of follow-up. Patients starting from 351 to 500 CD4 cells per microliter achieve levels of >650 cells per microliter after approximately 3 years of cART. Initiating cART with a baseline CD4 count 501-650 or >650 cells per microliter relative to 351-500 cells per microliter indicated a minimal reduction in risk of AIDS incidence and/or death.

Long-term immunological outcomes in treated HIV-infected individuals in high-income and low-middle income countries

PURPOSE OF REVIEW

To summarize the recent findings on long-term (at least 3-4 years) immunological responses to combination antiretroviral therapy (cART) and to compare and contrast the findings between cohorts from high-income and low-middle income countries (LMICs).

RECENT FINDINGS

Cohort studies from high-income settings suggest that a majority of treated HIV-infected patients who maintain suppressed HIV viremia experience a gradual increase in CD4 cell counts for several years to normal levels. However, those who start cART at CD4 cell counts less than 200 cells/μl (as opposed to CD4 cell counts>200 cells/μl) spend several more years below the safe CD4 cell count threshold of 500 cells/μl. Cohorts from LMICs also report persistent improvements in CD4+ cell counts over first 4-5 years of follow-up. However, low-CD4 cell counts (<200 cells/μl) at the start of cART, high early mortality, and loss to follow-up in LMICs settings suggest that the observed optimistic responses may be affected by survivorship bias and should be cautiously interpreted as the optimal, rather than an average, response in LMICs populations.

SUMMARY

LMICs cohorts report similar immunological responses to cART as high-income countries in first 4-5 years of follow-up. Sustaining success in these settings is dependent on timely access to first-line and future cART options, efforts to reduce loss to follow-up, and implementation of treatment guidelines. Cohorts from LMICs are encouraged to continue improving treatment programs and to continue reporting outcomes over the next decade, as surveillance for potential future blunting in responses.

Clinical predictors of immune reconstitution following combination antiretroviral therapy in patients from the Australian HIV Observational Database

Background

A small but significant number of patients do not achieve CD4 T-cell counts >500cells/µl despite years of suppressive cART. These patients remain at risk of AIDS and non-AIDS defining illnesses. The aim of this study was to identify clinical factors associated with CD4 T-cell recovery following long-term cART.

Methods

Patients with the following inclusion criteria were selected from the Australian HIV Observational Database (AHOD): cART as their first regimen initiated at CD4 T-cell count <500cells/µl, HIV RNA<500copies/ml after 6 months of cART and sustained for at least 12 months. The Cox proportional hazards model was used to identify determinants associated with time to achieve CD4 T-cell counts >500cells/µl and >200cells/µl.

Results

501 patients were eligible for inclusion from AHOD (n = 2853). The median (IQR) age and baseline CD4 T-cell counts were 39 (32–47) years and 236 (130–350) cells/µl, respectively. A major strength of this study is the long follow-up duration, median (IQR) = 6.5(3–10) years. Most patients (80%) achieved CD4 T-cell counts >500cells/µl, but in 8%, this took >5 years. Among the patients who failed to reach a CD4 T-cell count >500cells/µl, 16% received cART for >10 years. In a multivariate analysis, faster time to achieve a CD4 T-cell count >500cells/µl was associated with higher baseline CD4 T-cell counts (p<0.001), younger age (p = 0.019) and treatment initiation with a protease inhibitor (PI)-based regimen (vs. non-nucleoside reverse transcriptase inhibitor, NNRTI; p = 0.043). Factors associated with achieving CD4 T-cell counts >200cells/µl included higher baseline CD4 T-cell count (p<0.001), not having a prior AIDS-defining illness (p = 0.018) and higher baseline HIV RNA (p<0.001).

Conclusion

The time taken to achieve a CD4 T-cell count >500cells/µl despite long-term cART is prolonged in a subset of patients in AHOD. Starting cART early with a PI-based regimen (vs. NNRTI-based regimen) is associated with more rapid recovery of a CD4 T-cell count >500cells/µl.

The Clinical Significance of CD4 Counts in Asian and Caucasian HIV-Infected Populations: Results from TAHOD and AHOD

The significance of interethnic variation in CD4 counts between Asian and Caucasian populations is not known. Patients on combination antiretroviral therapy from Treat Asia and Australian HIV Observational Databases (TAHOD, predominantly Asian, n = 3356; and AHOD, predominantly Caucasian, n = 2312, respectively) were followed for 23 144 person-years for AIDS/death and all-cause mortality endpoints. We calculated incidence-rates and used adjusted Cox regression to test for the interaction between cohort (TAHOD/AHOD) and time-updated CD4 count category (lagged by 3 months) for each of the endpoints. There were 382 AIDS/death events in TAHOD (rate: 4.06, 95%CI: 3.68-4.50) and 305 in AHOD (rate: 2.39, 95%CI: 2.13-2.67), per 100 person-years. At any given CD4 count category, the incidence-rates of endpoints were found to be similar between TAHOD and AHOD (in the adjusted models, P > .05 for the interaction term between cohort type and latest CD4 counts). At any given CD4 count, risk of AIDS or death was not found to vary by ethnicity, suggesting that the CD4 count thresholds for predicting outcomes defined in Caucasian populations may be equally valid in Asian populations.

Trends in CD4 counts in HIV-infected patients with HIV viral load monitoring while on combination antiretroviral treatment: results from The TREAT Asia HIV Observational Database

Background

The aim of this study was to examine the relationship between trends in CD4 counts (slope) and HIV viral load (VL) after initiation of combination antiretroviral treatment (cART) in Asian patients in The TREAT Asia HIV Observational Database (TAHOD).

Methods

Treatment-naive HIV-infected patients who started cART with three or more and had three or more CD4 count and HIV VL tests were included. CD4 count slopes were expressed as changes of cells per microliter per year. Predictors of CD4 count slopes from 6 months after initiation were assessed by random-effects linear regression models.

Results

A total of 1676 patients (74% male) were included. The median time on cART was 4.2 years (IQR 2.5-5.8 years). In the final model, CD4 count slope was associated with age, concurrent HIV VL and CD4 count, disease stage, hepatitis B or C co-infection, and time since cART initiation. CD4 count continues to increase with HIV VL up to 20 000 copies/mL during 6-12 months after cART initiation. However, the HIV VL has to be controlled below 5 000, 4 000 and 500 copies/mL for the CD4 count slope to remain above 20 cells/microliter per year during 12-18, 18-24, and beyond 24 months after cART initiation.

Conclusions

After cART initiation, CD4 counts continued to increase even when the concurrent HIV VL was detectable. However, HIV VL needed to be controlled at a lower level to maintain a positive CD4 count slope when cART continues. The effect on long-term outcomes through the possible development of HIV drug resistance remains uncertain.

Immunovirological outcomes and resistance patterns at 4 years of antiretroviral therapy use in HIV-infected patients in Cambodia

OBJECTIVES

To report immunovirological outcomes and resistance patterns in adults treated with triple combination antiretroviral therapy (cART) for 4 years in an HIV programme of Phnom Penh, Cambodia.

METHODS

It is a longitudinal study and cross-sectional evaluation of adults receiving cART for 4 years. CD4 cell counts and HIV-1 RNA were quantified, and resistance patterns were determined. Drug-related toxicity was assessed by clinicians and through laboratory testing.

RESULTS

After 4 years of cART start, the cumulative probability of retention in care was 0.80 and survival among patients not lost to follow-up was 0.85. A total of 349 patients (98% of eligible) participated in the cross-sectional evaluation. Ninety per cent were receiving first-line therapy, 29% stavudine- and 58% zidovudine-containing regimens (compared with 94% and 3% at cART initiation). Ninety-three per cent of patients were clinically asymptomatic, and severe lipodystrophy and dyslipidemia were diagnosed in 7.2% and 4.0%, respectively. Good treatment adherence was reported by 83% of patients. Median CD4 T-cell count was 410 cells/μl [IQR 290-511], and 90% of patients had >200 cells/μl. Only 15 (4%) patients had detectable HIV viral load (eight had <200 CD4 cells/μl), five had thymidine analogue mutations, and nine were resistant to two drug classes. In an intention-to-treat analysis, 26.1% (95% CI 22.0-30.5) of patients had failed first-line therapy.

CONCLUSIONS

In this Cambodian cohort of adults who started cART at an advanced stage of HIV disease, we observed good clinical and immunovirological outcomes and self-reported treatment adherence at 4 years of therapy.

Incident tuberculosis during antiretroviral therapy contributes to suboptimal immune reconstitution in a large urban HIV clinic in sub-Saharan Africa

BACKGROUND

Antiretroviral therapy (ART) effectively decreases tuberculosis (TB) incidence long-term, but is associated with high TB incidence rates in the first 6 months. We sought to determine the incidence and the long-term effects of TB during ART on HIV treatment outcome, and the risk factors for incident TB during ART in a large urban HIV clinic in Uganda.

METHODOLOGY/PRINCIPAL FINDINGS

Routinely collected longitudinal clinical data from all patients initiated on first-line ART was retrospectively analysed. 5,982 patients were included with a median baseline CD4+ T cell count (CD4 count) of 117 cells/mm(3) (interquartile range [IQR]; 42, 182). In the first 2 years, there were 336 (5.6%) incident TB events in 10,710 person-years (py) of follow-up (3.14 cases/100 pyar [95% CI 2.82-3.49]); incidence rates at 0-3, 3-6, 6-12 and 12-24 months were 11.25 (9.58-13.21), 6.27 (4.99-7.87), 2.47 (1.87-3.36) and 1.02 (0.80-1.31), respectively. Incident TB during ART was independently associated with baseline CD4 count of <50 cells/mm(3) (hazard ratio [HR] 1.84 [1.25-2.70], P = 0.002) and male gender (HR 1.68 [1.34-2.11], P<0.001). After two years on ART, the patients who had developed TB in the first 12 months had a significantly lower median CD4 count increase (184 cells/mm(3) [IQR; 107, 258, n = 118] vs 209 cells/mm(3) [124, 309, n = 2166], P = 0.01), a larger proportion of suboptimal immune reconstitution according to two definitions (increase in CD4 count <200 cells/mm(3): 57.4% vs 46.9%, P = 0.03, and absolute CD4 count <200 cells/mm(3): 30.4 vs 19.9%, P = 0.006), and a higher percentage of immunological failure according to the WHO criteria (13.6% vs 6.5%, P = 0.003). Incident TB during ART was independently associated with poor CD4 count recovery and fulfilling WHO immunological failure definitions.

CONCLUSIONS/SIGNIFICANCE

Incident TB during ART occurs most often within 3 months and in patients with CD4 counts less than 50 cells/mm(3). Incident TB during ART is associated with long-term impairment in immune recovery.