A new model to monitor the virological efficacy of antiretroviral treatment in resource-poor countries

HIV: Inflammatory dermatoses

Patients living with HIV may experience a variety of inflammatory dermatoses, ranging from exacerbations of underlying conditions to those triggered by HIV infection itself. This article presents a current literature review on the etiology, diagnosis and management of atopic dermatitis, psoriasis, pityriasis rubra pilaris, lichen planus, seborrheic dermatitis, eosinophilic folliculitis, pruritic papular eruption and pruritus, in patients living with HIV.

Weight change after antiretroviral therapy initiation among adults living with HIV in Northwest Ethiopia: a longitudinal data analysis

OBJECTIVES

The first objective was to explore weight change in the first 2 years after antiretroviral therapy (ART) initiation in adults living with HIV. The second objective was to identify the predictors of weight change over time among adults living with HIV on ART.

DESIGN

An institution-based retrospective longitudinal study was conducted.

SETTING

The study was conducted at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia.

PARTICIPANTS

The study included 848 randomly selected medical charts of adults living with HIV receiving ART between June 2014 and June 2020.

PRIMARY AND SECONDARY OUTCOMES

The primary outcome was weight change in the first 2 years after ART initiation. The secondary outcome was to identify predictors of weight change. Association between predictor variables and weight change was assessed using an LMM. Variables with p values <0.05 in the final model were considered as statistically significant predictors of weight change.

RESULTS

Of 844 study participants, more than half (n=499; 58.8%) were female. Participants' mean weight increased from 54.2 kg (SD ±9.6 kg) at baseline to 59.5 kg (SD ±10.7 kg) at the end of follow-up. Duration of time on ART, sex, WHO clinical disease staging, functional status, nutritional status and presence of opportunistic infections were significant predictors of weight change at ART initiation. Significant interaction effects were observed between time and sex, WHO clinical disease staging, functional status, isoniazid preventive therapy and nutritional status.

CONCLUSION

We found a linear increment of weight over 24 months of follow-up. Rate of weight gain over time was lower in patients with advanced disease stage and working functional status, whereas weight gain rate was higher in male and underweight patients.

Clinical predictor score to identify patients at risk of poor viral load suppression at six months on antiretroviral therapy: results from a prospective cohort study in Johannesburg, South Africa

Purpose: As countries work toward 90:90:90 targets, early identification of patients with inadequate response to antiretroviral therapy (ART) is critical for achieving optimal HIV treatment outcomes. We developed and evaluated a clinical prediction score (CPS) to identify HIV-positive patients at risk of poor viral load suppression at 6 months on ART. Patients and methods: We conducted a prospective cohort study of HIV-positive ART naïve adults (≥18 years) initiating standard first-line ART between February 2012 and April 2014 at Themba Lethu Clinic in Johannesburg, South Africa. We used Modified Poisson regression to estimate the association between patient characteristics and poor viral load suppression, defined as a viral load ≥400 copies/mL at 6 months on ART. We developed a CPS following the Spiegel Halter and Knill-Jones approach and determined the diagnostic accuracy compared to viral load as the "gold standard". We identified the optimal cutoff at which the CPS would identify those at risk of poor viral load suppression. Results: Among 353 patients, 67.7% had a viral load measurement at 6 months on ART and 30.1% of these were viremic (≥400 copies/mL). Male gender, platelet count <150 cells/mm3, ≥7 days late for ≥2 ARV visits, visual analog scale (VAS) <90% and <14.5 fL increase in mean cell volume from baseline to 6 months were included in the CPS. The optimal cutoff was 5 (≥5 vs <5; sensitivity [Se] 65.3%, specificity [Sp] 46.7%) and the CPS performed better than standard measures of adherence (eg, VAS Se 24.5%; Simplified Medication Adherence Questionnaire Se 26.5%). Conclusion: Our findings suggest a 6-month CPS may have the potential to identify patients at risk of poor viral load suppression. The CPS may be used to target patients who need intensive adherence support, with the caveat that there may be a three- to four-fold increase in the pool of patients identified for adherence counseling.

Determinants of Weight Evolution Among HIV-Positive Patients Initiating Antiretroviral Treatment in Low-Resource Settings

BACKGROUND

In resource-limited settings, clinical parameters, including body weight changes, are used to monitor clinical response. Therefore, we studied body weight changes in patients on antiretroviral treatment (ART) in different regions of the world.

METHODS

Data were extracted from the "International Epidemiologic Databases to Evaluate AIDS," a network of ART programmes that prospectively collects routine clinical data. Adults on ART from the Southern, East, West, and Central African and the Asia-Pacific regions were selected from the database if baseline data on body weight, gender, ART regimen, and CD4 count were available. Body weight change over the first 2 years and the probability of body weight loss in the second year were modeled using linear mixed models and logistic regression, respectively.

RESULTS

Data from 205,571 patients were analyzed. Mean adjusted body weight change in the first 12 months was higher in patients started on tenofovir and/or efavirenz; in patients from Central, West, and East Africa, in men, and in patients with a poorer clinical status. In the second year of ART, it was greater in patients initiated on tenofovir and/or nevirapine, and for patients not on stavudine, in women, in Southern Africa and in patients with a better clinical status at initiation. Stavudine in the initial regimen was associated with a lower mean adjusted body weight change and with weight loss in the second treatment year.

CONCLUSIONS

Different ART regimens have different effects on body weight change. Body weight loss after 1 year of treatment in patients on stavudine might be associated with lipoatrophy.

Factors associated with pruritic papular eruption of human immunodeficiency virus infection in the antiretroviral therapy era

BACKGROUND

Pruritic papular eruption (PPE) of HIV is common in HIV-infected populations living in the tropics. Its aetiology has been attributed to insect bite reactions and it is reported to improve with antiretroviral therapy (ART). Its presence after at least 6 months of ART has been proposed as one of several markers of treatment failure.

OBJECTIVES

To determine factors associated with PPE in HIV-infected persons receiving ART.

METHODS

A case-control study nested within a 500-person cohort from a teaching hospital in Mbarara, Uganda. Forty-five cases and 90 controls were enrolled. Cases had received ART for ≥ 15 months and had an itchy papular rash for at least 1 month with microscopic correlation by skin biopsy. Each case was individually matched with two controls for age, sex and ART duration.

RESULTS

Twenty-five of 45 cases (56%) had microscopic findings consistent with PPE. At skin examination and biopsy (study enrolment), a similar proportion of PPE cases and matched controls had plasma HIV RNA < 400 copies mL(-1) (96% vs. 85%, P = 0·31). The odds of having PPE increased fourfold with every log increase in viral load at ART initiation (P = 0·02) but not at study enrolment. CD4 counts at ART initiation and study enrolment, and CD4 gains and CD8(+) T-cell activation measured 6 and 12 months after ART commencement were not associated with PPE. Study participants who reported daily insect bites had greater odds of being cases [odds ratio (OR) 8·3, P < 0·001] or PPE cases (OR 8·6, P = 0·01).

CONCLUSIONS

Pruritic papular eruption in HIV-infected persons receiving ART for ≥ 15 months was associated with greater HIV viraemia at ART commencement, independent of CD4 count. Skin biopsies are important to distinguish between PPE and other itchy papular eruptions.

Super Learner Analysis of Electronic Adherence Data Improves Viral Prediction and May Provide Strategies for Selective HIV RNA Monitoring

OBJECTIVE

Regular HIV RNA testing for all HIV-positive patients on antiretroviral therapy (ART) is expensive and has low yield since most tests are undetectable. Selective testing of those at higher risk of failure may improve efficiency. We investigated whether a novel analysis of adherence data could correctly classify virological failure and potentially inform a selective testing strategy.

DESIGN

Multisite prospective cohort consortium.

METHODS

We evaluated longitudinal data on 1478 adult patients treated with ART and monitored using the Medication Event Monitoring System (MEMS) in 16 US cohorts contributing to the MACH14 consortium. Because the relationship between adherence and virological failure is complex and heterogeneous, we applied a machine-learning algorithm (Super Learner) to build a model for classifying failure and evaluated its performance using cross-validation.

RESULTS

Application of the Super Learner algorithm to MEMS data, combined with data on CD4 T-cell counts and ART regimen, significantly improved classification of virological failure over a single MEMS adherence measure. Area under the receiver operating characteristic curve, evaluated on data not used in model fitting, was 0.78 (95% confidence interval: 0.75 to 0.80) and 0.79 (95% confidence interval: 0.76 to 0.81) for failure defined as single HIV RNA level >1000 copies per milliliter or >400 copies per milliliter, respectively. Our results suggest that 25%-31% of viral load tests could be avoided while maintaining sensitivity for failure detection at or above 95%, for a cost savings of $16-$29 per person-month.

CONCLUSIONS

Our findings provide initial proof of concept for the potential use of electronic medication adherence data to reduce costs through behavior-driven HIV RNA testing.

CD4 criteria improves the sensitivity of a clinical algorithm developed to identify viral failure in HIV-positive patients on antiretroviral therapy

INTRODUCTION

Several studies from resource-limited settings have demonstrated that clinical and immunologic criteria are poor predictors of virologic failure, confirming the need for viral load monitoring or at least an algorithm to target viral load testing. We used data from an electronic patient management system to develop an algorithm to identify patients at risk of viral failure using a combination of accessible and inexpensive markers.

METHODS

We analyzed data from HIV-positive adults initiated on antiretroviral therapy (ART) in Johannesburg, South Africa, between April 2004 and February 2010. Viral failure was defined as ≥ 2 consecutive HIV-RNA viral loads >400 copies/ml following suppression ≤ 400 copies/ml. We used Cox-proportional hazards models to calculate hazard ratios (HR) and 95% confidence intervals (CI). Weights for each predictor associated with virologic failure were created as the sum of the natural logarithm of the adjusted HR and dichotomized with the optimal cut-off at the point with the highest sensitivity and specificity (i.e. ≤ 4 vs. >4). We assessed the diagnostic accuracy of predictor scores cut-offs, with and without CD4 criteria (CD4 <100 cells/mm(3); CD4 < baseline; >30% drop in CD4), by calculating the proportion with the outcome and the observed sensitivity, specificity, positive and negative predictive value of the predictor score compared to the gold standard of virologic failure.

RESULTS

We matched 919 patients with virologic failure (1:3) to 2756 patients without. Our predictor score included variables at ART initiation (i.e. gender, age, CD4 count <100 cells/mm(3), WHO stage III/IV and albumin) and laboratory and clinical follow-up data (drop in haemoglobin, mean cell volume (MCV) <100 fl, CD4 count <200 cells/mm(3), new or recurrent WHO stage III/IV condition, diagnosis of new condition or symptom and regimen change). Overall, 51.4% had a score 51.4% had a score ≥ 4 and 48.6% had a score <4. A predictor score including CD4 criteria performed better than a score without CD4 criteria and better than WHO clinico-immunological criteria or WHO clinical staging to predict virologic failure (sensitivity 57.1% vs. 40.9%, 25.2% and 20.9%, respectively).

CONCLUSIONS

Predictor scores or risk categories, with CD4 criteria, could be used to identify patients at risk of virologic failure in resource-limited settings so that these patients may be targeted for focused interventions to improve HIV treatment outcomes.

Short communication: prospective comparison of qualitative versus quantitative polymerase chain reaction for monitoring virologic treatment failure in HIV-infected patients

Less costly but still accurate methods for monitoring HIV treatment response are needed. We prospectively evaluated if a qualitative polymerase chain reaction (PCR) amplification assay for virologic monitoring could maintain accuracy while reducing costs in Seoul, South Korea. We conducted the first prospective study comparing a qualitative PCR amplification of HIV-1 reverse transcriptase (RT) versus a commercial real time PCR assay (i.e., viral load) for virologic monitoring of 150 patients receiving antiretroviral therapy (ART) between November 2011 and August 2012 at an urban hospital in Seoul, South Korea. A total of 215 blood plasma samples from 150 patients receiving ART for more than 6 months were evaluated. Using the individual viral load assay, 12 of 215 (5.6%) plasma samples had more than 500 HIV RNA copies/ml. The qualitative PCR amplification assay detected individual samples with ≥500 HIV RNA copies/ml with 100% sensitivity. The specificities of the qualitative PCR amplification of the HIV-1 RT assay were 94.1%, 93.6%, and 93.2% compared to the real time PCR at 500, 1,000, and 5,000 threshold of HIV RNA copies/ml, respectively, and $24,940 USD would have been saved for 150 patients during 10 months. The qualitative PCR amplification of the HIV-1 RT assay might be a useful approach to effectively monitor patients receiving ART and save resources.

Simplified clinical prediction scores to target viral load testing in adults with suspected first line treatment failure in Phnom Penh, Cambodia

Background

For settings with limited laboratory capacity, 2013 World Health Organization (WHO) guidelines recommend targeted HIV-1 viral load (VL) testing to identify virological failure. We previously developed and validated a clinical prediction score (CPS) for targeted VL testing, relying on clinical, adherence and laboratory data. While outperforming the WHO failure criteria, it required substantial calculation and review of all previous laboratory tests. In response, we developed four simplified, less error-prone and broadly applicable CPS versions that can be done ‘on the spot’.

Methodology/Principal

Findings From May 2010 to June 2011, we validated the original CPS in a non-governmental hospital in Phnom Penh, Cambodia applying the CPS to adults on first-line treatment >1 year. Virological failure was defined as a single VL >1000 copies/ml. The four CPSs included CPS1 with ‘current CD4 count’ instead of %-decline-from-peak CD4; CPS2 with hemoglobin measurements removed; CPS3 having ‘decrease in CD4 count below baseline value’ removed; CPS4 was purely clinical. Score development relied on the Spiegelhalter/Knill-Jones method. Variables independently associated with virological failure with a likelihood ratio ≥1.5 or ≤0.67 were retained. CPS performance was evaluated based on the area-under-the-ROC-curve (AUROC) and 95% confidence intervals (CI). The CPSs were validated in an independent dataset. A total of 1490 individuals (56.6% female, median age: 38 years (interquartile range (IQR 33–44)); median baseline CD4 count: 94 cells/µL (IQR 28–205), median time on antiretroviral therapy 3.6 years (IQR 2.1–5.1)), were included. Forty-five 45 (3.0%) individuals had virological failure. CPS1 yielded an AUROC of 0.69 (95% CI: 0.62–0.75) in validation, CPS2 an AUROC of 0.68 (95% CI: 0.62–0.74), and CPS3, an AUROC of 0.67 (95% CI: 0.61–0.73). The purely clinical CPS4 performed poorly (AUROC-0.59; 95% CI: 0.53–0.65).

Conclusions

Simplified CPSs retained acceptable accuracy as long as current CD4 count testing was included. Ease of field application and field accuracy remains to be defined.

Pooled nucleic acid testing to identify antiretroviral treatment failure during HIV infection in Seoul, South Korea

BACKGROUND

There have been various efforts to identify less costly but still accurate methods for monitoring the response to HIV treatment. We evaluated a pooling method to determine if this could improve screening efficiency and reduce costs while maintaining accuracy in Seoul, South Korea.

METHODS

We conducted the first prospective study of pooled nucleic acid testing (NAT) using a 5 minipool + algorithm strategy versus individual viral load testing for patients receiving antiretroviral therapy (ART) between November 2011 and August 2012 at an urban hospital in Seoul, South Korea. The viral load assay used has a lower level of detection of 20 HIV RNA copies/ml, and the cost per assay is US$ 136. The 5 minipool +algorithm strategy was applied and 43 pooled samples were evaluated. The relative efficiency and accuracy of the pooled NAT were compared with those of individual testing.

RESULTS

Using the individual viral load assay, 15 of 215 (7%) plasma samples had more than 200 HIV RNA copies/ml. The pooled NAT using the 5 minipool + algorithm strategy was applied to 43 pooled samples; 111 tests were needed to test all samples when virologic failure was defined at HIV RNA ≥ 200 copies/ml. Therefore, 104 tests were saved over individual testing, with a relative efficiency of 0.48. When evaluating costs, a total of US$ 14,144 was saved for 215 individual samples during 10 months. The negative predictive value was 99.5% for all samples with HIV RNA ≥ 200 copies/ml.

CONCLUSIONS

The pooled NAT with 5 minipool + algorithm strategy seems to be a very promising approach to effectively monitor patients receiving ART and to save resources.

Changes to antiretroviral drug regimens during integrated TB-HIV treatment: results of the SAPiT trial

BACKGROUND

Frequency of drug changes in combination antiretroviral therapy among patients starting both tuberculosis (TB) and HIV therapy, as a result of treatment-limiting toxicity or virological failure, is not well established.

METHODS

Patients in the Starting Antiretroviral Therapy at Three Points in Tuberculosis (SAPiT) trial were randomized to initiate antiretroviral therapy (ART) either early or late during TB treatment or after completion of TB treatment. Drug changes due to toxicity (defined as due to grade 3 or 4 adverse events) or virological failure (defined as viral load >1,000 copies/ml on two occasions, taken ≥4 weeks apart) were assessed in these patients.

RESULTS

A total of 501 TB-HIV-coinfected patients were followed for a mean of 16.0 months (95% CI 15.5, 16.6) after ART initiation. The standard first-line antiretrovirals used were efavirenz, lamivudine and didanosine. Individual drug switches for toxicity occurred in 14 patients (incidence rate 2.1 per 100 person-years, 95% CI 1.1, 3.5), and complete regimen changes due to virological failure in 25 patients (incidence rate 3.7 per 100 person-years, 95% CI 2.4, 5.5). The most common treatment limiting toxicities were neuropsychiatric effects (n=4, 0.8%), elevated transaminase levels and hyperlactataemia (n=3, 0.6%), and peripheral neuropathy (n=2, 0.4%). Complete regimen change due to treatment failure was more common in patients with CD4(+) T-cell count <50 cells/mm(3) (P<0.001) at ART initiation and body mass index >25 kg/m(2) (P=0.01) at entry into the study.

CONCLUSIONS

Both drug switches and complete regimen change were uncommon in patients cotreated for TB-HIV with the chosen regimen. Patients with severe immunosuppression need to be monitored carefully, as they were most at risk for treatment failure requiring regimen change.

Validation of a clinical prediction score to target viral load testing in adults with suspected first-line treatment failure in resource-constrained settings

BACKGROUND

Although routine viral load (VL) monitoring currently is too costly for poor countries, clinical failure criteria perform poorly. We previously developed an algorithm combining a clinical predictor score (CPS) with targeted VL testing in a Cambodian patient population (derivation population). We now prospectively validate the algorithm in the same clinical setting (validation population), assess its operational performance, and explore its cost-saving potential.

METHODS

We performed a cross-sectional study in a tertiary hospital in Phnom Penh, Cambodia, applying the CPS in adults on first-line antiretroviral treatment for at least 1 year. Treatment failure was defined as a VL >1000 copies per milliliter. The area under the receiver-operating characteristic (AUROC) curve of the CPS to detect treatment failure in the current study population (validation population) was compared with the AUROC of the CPS obtained in the patient population where the CPS was derived from in 2008 in the same study setting (derivation population). Costs related to VL testing and second-line regimens with the different testing strategies were compared.

RESULTS

One thousand four hundred ninety individuals {56.6% female, median age 38 years [interquartile range (IQR): 33-44]} were included, with a median baseline CD4 cell count of 94 cells per microliter (IQR: 28-205). Median time on antiretroviral treatment was 3.6 years (IQR: 2.1-5.1), 45 (3.0%) individuals had treatment failure. The AUROC of the CPS in validation was 0.75 (95% confidence interval: 0.67 to 0.83), relative to an AUROC of 0.70 in the derivation population. At the CPS cutoff ≥ 2, VL was indicated for 164 (11%) individuals, preventing inappropriate switching to second line in 143 cases. Twenty-four cases of treatment failure would be missed. When applied in routine care, the AUROC was 0.69 (95% confidence interval: 0.60 to 0.77). Overall 1-year program costs with targeted VL testing were 4-fold reduced.

CONCLUSIONS

The algorithm performed well in validation and has cost-saving potential. Further studies to assess its performance, feasibility, and impact in different settings are warranted.

Evaluation of clinical and immunological markers for predicting virological failure in a HIV/AIDS treatment cohort in Busia, Kenya

BACKGROUND

In resource-limited settings where viral load (VL) monitoring is scarce or unavailable, clinicians must use immunological and clinical criteria to define HIV virological treatment failure. This study examined the performance of World Health Organization (WHO) clinical and immunological failure criteria in predicting virological failure in HIV patients receiving antiretroviral therapy (ART).

METHODS

In a HIV/AIDS program in Busia District Hospital, Kenya, a retrospective, cross-sectional cohort analysis was performed in April 2008 for all adult patients (>18 years old) on ART for ≥12 months, treatment-naive at ART start, attending the clinic at least once in last 6 months, and who had given informed consent. Treatment failure was assessed per WHO clinical (disease stage 3 or 4) and immunological (CD4 cell count) criteria, and compared with virological failure (VL >5,000 copies/mL).

RESULTS

Of 926 patients, 123 (13.3%) had clinically defined treatment failure, 53 (5.7%) immunologically defined failure, and 55 (6.0%) virological failure. Sensitivity, specificity, positive predictive value, and negative predictive value of both clinical and immunological criteria (combined) in predicting virological failure were 36.4%, 83.5%, 12.3%, and 95.4%, respectively.

CONCLUSIONS

In this analysis, clinical and immunological criteria were found to perform relatively poorly in predicting virological failure of ART. VL monitoring and new algorithms for assessing clinical or immunological treatment failure, as well as improved adherence strategies, are required in ART programs in resource-limited settings.

Weight loss after the first year of stavudine-containing antiretroviral therapy and its association with lipoatrophy, virological failure, adherence and CD4 counts at primary health care level in Kigali, Rwanda

This study was conducted among 609 adults on stavudine-based antiretroviral treatment (ART) for at least one year at health center level in Kigali, Rwanda to (a) determine the proportion who manifest weight loss after one year of ART (b) examine the association between such weight loss and a number of variables, namely: lipoatrophy, virological failure, adherence and on-treatment CD4 count and (c) assess the validity and predictive values of weight loss to identify patients with lipoatrophy. Weight loss after the first year of ART was seen in 62% of all patients (median weight loss 3.1 kg/year). In multivariate analysis, weight loss was significantly associated with treatment-limiting lipoatrophy (adjusted effect/kg/year -2.0 kg, 95% confidence interval -0.6;-3.4 kg; P<0.01). No significant association was found with virological failure or adherence. Higher on-treatment CD4 cell counts were protective against weight loss. Weight loss that was persistent, progressive and/or chronic was predictive of lipoatrophy, with a sensitivity and specificity of 72% and 77%, and positive and negative predictive values of 30% and 95%. In low-income countries, measuring weight is a routine clinical procedure that could be used to filter out individuals with lipoatrophy on stavudine-based ART, after alternative causes of weight loss have been ruled out.

How late is too late? Timeliness to scheduled visits as an antiretroviral therapy adherence measure in Nairobi, Kenya and Lusaka, Zambia

Collecting self-reported data on adherence to highly active antiretroviral therapy (HAART) can be complicated by patients' reluctance to report poor adherence. The timeliness with which patients attend visits might be a useful alternative to estimate medication adherence. Among Kenyan and Zambian women receiving twice daily HAART, we examined the relationship between self-reported pill taking and timeliness attending scheduled visits. We analyzed data from 566 Kenyan and Zambian women enrolled in a prospective 48-week HAART-response study. At each scheduled clinic visit, women reported doses missed over the preceding week. Self-reported adherence was calculated by summing the total number of doses reported taken and dividing by the total number of doses asked about at the visit attended. A participant's adherence to scheduled study visits was defined as "on time" if she arrived early or within three days, "moderately late" if she was four-seven days late, and "extremely late/missed" if she was more than eight days late or missed the visit altogether. Self-reported adherence was <95% for 29 (10%) of 288 women who were late for at least one study visit vs. 3 (1%) of 278 who were never late for a study visit (odds ratios [OR] 10.3; 95% confidence intervals [95% CI] 2.9, 42.8). Fifty-one (18%) of 285 women who were ever late for a study visit experienced virologic failure vs. 32 (12%) of 278 women who were never late for a study visit (OR 1.7; 95% CI 1.01, 2.8). A multivariate logistic regression model controlling for self-reported adherence found that being extremely late for a visit was associated with virologic failure (OR 2.0; 95% CI 1.2, 3.4). Timeliness to scheduled visits was associated with self-reported adherence to HAART and with risk for virologic failure. Timeliness to scheduled clinic visits can be used as an objective proxy for self-reported adherence and ultimately for risk of virologic failure.

Antiretroviral therapy optimisation without genotype resistance testing: a perspective on treatment history based models

Background

Although genotypic resistance testing (GRT) is recommended to guide combination antiretroviral therapy (cART), funding and/or facilities to perform GRT may not be available in low to middle income countries. Since treatment history (TH) impacts response to subsequent therapy, we investigated a set of statistical learning models to optimise cART in the absence of GRT information.

Methods and Findings

The EuResist database was used to extract 8-week and 24-week treatment change episodes (TCE) with GRT and additional clinical, demographic and TH information. Random Forest (RF) classification was used to predict 8- and 24-week success, defined as undetectable HIV-1 RNA, comparing nested models including (i) GRT+TH and (ii) TH without GRT, using multiple cross-validation and area under the receiver operating characteristic curve (AUC). Virological success was achieved in 68.2% and 68.0% of TCE at 8- and 24-weeks (n = 2,831 and 2,579), respectively. RF (i) and (ii) showed comparable performances, with an average (st.dev.) AUC 0.77 (0.031) vs. 0.757 (0.035) at 8-weeks, 0.834 (0.027) vs. 0.821 (0.025) at 24-weeks. Sensitivity analyses, carried out on a data subset that included antiretroviral regimens commonly used in low to middle income countries, confirmed our findings. Training on subtype B and validation on non-B isolates resulted in a decline of performance for models (i) and (ii).

Conclusions

Treatment history-based RF prediction models are comparable to GRT-based for classification of virological outcome. These results may be relevant for therapy optimisation in areas where availability of GRT is limited. Further investigations are required in order to account for different demographics, subtypes and different therapy switching strategies.

Pneumocystis jirovecii prophylaxis discontinuation based upon total lymphocyte count in HIV-infected adults treated with antiretroviral therapy

Pneumocystis jirovecii pneumonia (PCP) prophylaxis may be discontinued when CD4 is ≥200 cells/mm3 for three months in response to highly active antiretroviral therapy (HAART). Unlike CD4, the total lymphocyte count (TLC) is inexpensive and widely available in resource-constrained countries. Paired TLC and CD4 values of HIV-infected patients attending an HIV clinic from 1998 to 2005 were analysed by Spearman's correlation. The sensitivity, specificity, positive predictive value, negative predictive value and receiver operating characteristics (ROC) using TLC cut-off points between ≥1400 and ≥2000 cells/mm3 to predict CD4 ≥200 cells/mm3 were calculated. Next, a cohort of patients who had a TLC ≤ 1200 cells/mm3 and subsequently achieved various TLC cut-off points sustained over three months while receiving HAART was identified. Subjects with subsequent CD4 ≥200 cells/mm3 in response to HAART were considered to have negligible risk for PCP. There was significant correlation between TLC and CD4 in 46,250 observations from 4307 individuals ( r = 0.695, P ≤ 0.001). The area under the ROC curve was 0.85 (95% CI = 0.85–0.86). In the historical cohort analysis, 85% and 70% of subjects who achieved TLC ≥ 2000 cells/mm3 and ≥1400, respectively, had a corresponding CD4 ≥ 200 cells/mm3. A sustained rise in TLC in response to HAART may potentially serve as a criterion for discontinuing PCP prophylaxis in resource-constrained countries.

The use of pooled viral load testing to identify antiretroviral treatment failure

BACKGROUND

To develop less costly methods to virologically monitor patients receiving antiretroviral therapy, we evaluated methods that use pooled blood samples and quantitative information available from viral load assays to monitor a cohort of patients on first-line antiretroviral therapy for virologic failure.

METHODS

We evaluated 150 blood samples collected after 6 months of therapy from participants enrolled in a San Diego primary infection program between January 1998 and January 2007. Samples were screened for virologic failure with individual viral load testing, 10 x 10 matrix pools and minipools of five samples. For the pooled platforms (matrix and minipools), we used a search and retest algorithm based on the quantitative viral load data to resolve samples that remained ambiguous for virologic failure. Viral load thresholds were more than 500 and more than 1500 copies/ml for the matrix and more than 250 and more than 500 copies/ml for the minipool. Efficiency, accuracy and result turnaround times were evaluated.

RESULTS

Twenty-three percent of cohort samples were detectable at more than 50 HIV RNA copies/ml. At an algorithm threshold of more than 500 HIV RNA copies/ml, both minipool and matrix methods used less than half the number of viral load assays to screen the cohort, compared with testing samples individually. Both pooling platforms had negative predictive values of 100% for viral loads of more than 500 HIV RNA copies/ml and at least 94% for viral loads of more than 250 HIV RNA copies/ml.

CONCLUSION

In this cohort, both pooling methods improved the efficiency of virologic monitoring over individual testing with a minimal decrease in accuracy. These methods may allow for the induction and sustainability of the virologic monitoring of patients receiving antiretroviral therapy in resource-limited settings.

An algorithm to optimize viral load testing in HIV-positive patients with suspected first-line antiretroviral therapy failure in Cambodia

OBJECTIVE

To develop an algorithm for optimal use of viral load testing in patients with suspected first-line antiretroviral treatment (ART) failure.

METHODS

Data from a cohort of patients on first-line ART in Cambodia were analyzed in a cross-sectional way to detect markers for treatment failure. Markers with an adjusted likelihood ratio <0.67 or >1.5 were retained to calculate a predictor score. The accuracy of a 2-step algorithm based on this score followed by targeted viral load testing was compared with World Health Organization criteria for suspected treatment failure.

RESULTS

One thousand eight hundred three viral load measurements of 764 patients were available for analysis. Prior ART exposure, CD4 count below baseline, 25% and 50% drop from peak CD4 count, hemoglobin drop of > or =1 g/dL, CD4 count <100 cells per microliter after 12 months of treatment, new onset of papular pruritic eruption, and visual analog scale <95% were included in the predictor score. A score >or=2 had the best combination of sensitivity and specificity and required confirmatory viral load testing for only 9% of patients. World Health Organization criteria had a similar sensitivity but a lower specificity and required viral load testing for 24.9% of patients.

CONCLUSION

An algorithm combining a predictor score with targeted viral load testing in patients with an intermediate probability of failure optimizes the use of scarce resources.

Comparative evaluation of the ExaVir Load version 3 reverse transcriptase assay for measurement of human immunodeficiency virus type 1 plasma load

In resource-limited settings, the virological monitoring of antiretroviral therapy is limited by high cost and the lack of infrastructure. The Cavidi ExaVir Load assay employs a simple and inexpensive enzyme-linked immunosorbent assay format to measure human immunodeficiency virus (HIV) reverse transcriptase activity, which correlates with plasma RNA load. The version 3 assay has been described as having improved precision and sensitivity. There are limited data on its performance relative to those of current real-time assays. Our objective was to compare HIV type 1 (HIV-1) RNA load measurement in plasma by ExaVir Load version 3 (designated ExaVir), Abbott M2000sp/M2000rt RealTime HIV-1 assay (designated RealTime), and Roche COBAS Ampliprep/COBAS TaqMan HIV-1 version 1 assay (designated TaqMan). Plasma from 119 patients (34 with subtype B infection, 85 with non-subtype B infection [A-H, CRF01, CRF02, CRF06, CRF12, CRF14, and complex]; 48 subjects were treatment experienced, 71 were naive) and serial dilutions of the second international standard (IS) were tested. Assay relationship and agreement were determined by linear regression, correlation analysis, and the Bland-Altman method. The ExaVir assay quantified 77/83 (92.8%) samples with viral loads of >2.3 log10 copies/ml by the molecular assays. Results were linearly associated and strongly correlated with RealTime and TaqMan measurements (R of 0.94 and 0.92, respectively) for both subtype B (R of 0.97 and 0.95, respectively) and non-subtype B (R of 0.93 and 0.91, respectively) samples. Mean differences were 0.28 and 0.18 log10 copies/ml in favor of the two molecular assays; 7/119 (5.9%) and 5/119 (4.2%) samples were outside the 95% level of agreement. ExaVir underquantified the IS by a mean of 0.2 (range, 0.0 to 0.5) log10 copies/ml. The ExaVir assay showed excellent concordance with real-time molecular assays, offering a suitable option for virological monitoring in settings with limited infrastructure.

Response to zidovudine/didanosine-containing combination antiretroviral therapy among HIV-1 subtype C-infected adults in Botswana: two-year outcomes from a randomized clinical trial

BACKGROUND

Numerous national antiretroviral (ARV) treatment initiatives offering protease inhibitor-sparing combination antiretroviral therapy (cART) have recently commenced in southern Africa, the first of which began in Botswana in January 2002. Evaluation of the efficacy and tolerability of various protease inhibitor-sparing cART regimens requires intensive study in the region, as does investigation of the development of drug resistance and the optimal means of sustaining adherence. The "Tshepo" Study is the first large-scale, randomized, clinical trial that addresses these important issues among HIV-1 subtype C-infected ARV treatment-naive adults in southern Africa.

METHODS

The Tshepo Study is a completed, open-labeled, randomized study that enrolled 650 ARV-naive adults between December 2002 and 2004. The study is a 3 x 2 x 2 factorial design comparing the efficacy and tolerability among factors: (1) 3 combinations of nucleoside reverse transcriptase inhibitors (NRTIs): zidovudine (ZDV) + lamivudine (3TC), ZDV + didanosine (ddI), and stavudine (d4T) + 3TC; (2) 2 different nonnucleoside reverse transcriptase inhibitors (NNRTIs): nevirapine and efavirenz; and (3) 2 different adherence strategies: the current national "standard of care" versus an "intensified adherence strategy" incorporating a "community-based directly observed therapy." Study patients were stratified into 2 balanced CD4 T-cell count groups: less than 201 versus 201-350 cells per cubic millimeter with viral load greater than 55,000 copies per milliliter. Following Data Safety Monitoring Board recommendations in April 2006, ZDV/ddI-containing arms were discontinued due to inferiority in primary end point, namely, virologic failure with resistance. We report both overall data and pooled data from patients receiving ZDV/ddI- versus ZDV/3TC- and d4T/3TC-containing cART through April 1, 2006.

RESULTS

Four hundred fifty-one females (69.4%) and 199 males with a median age of 33.3 years were enrolled into the study. The median follow-up as of April 1, 2006, was 104 weeks, and loss to follow-up rate at 2 years was 4.1%. The median baseline CD4 T-cell count was 199 cells per cubic millimeter [interquartile ratio (IQR) 136-252], and the median plasma HIV-1 RNA level was 193,500 copies per milliliter (IQR 69-250, 472-500). The proportion of participants with virologic failure and genotypic resistance mutations was 11% in those receiving ZDV/ddI-based cART versus 2% in those receiving either ZDV/3TC- or d4T/3TC-based cART (P = 0.002). The median CD4 T-cell count increase at 1 year was 137 cells per cubic millimeter (IQR 74-223) and 199 cells per cubic millimeter (IQR 112-322) at 2 years with significantly lower gain in the ZDV/ddI arm. At 1 and 2 years, respectively, 92.0% and 88.8% of patients had an undetectable plasma HIV-1 RNA level (< or = 400 copies/mL). Kaplan-Meier survival estimates at 1 and 2 years were 96.6% and 95.4%. One hundred twenty patients (18.2%) had treatment-modifying toxicities, of which the most common were lipodystrophy, anemia, neutropenia, and Stevens-Johnson syndrome. There was a trend toward difference in time to treatment-modifying toxicity by pooled dual-NRTI combination and no difference in death rates.

CONCLUSIONS

The preliminary study results show overall excellent efficacy and tolerability of NNRTI-based cART among HIV-1 subtype C-infected adults. ZDV/ddI-containing cART, however, is inferior to the dual NRTIs d4T/3TC or ZDV/3TC when used with an NNRTI for first-line cART.

Diagnosis of antiretroviral therapy failure in Malawi: poor performance of clinical and immunological WHO criteria

OBJECTIVES

In antiretroviral therapy (ART) scale-up programmes in sub-Saharan Africa viral load monitoring is not recommended. We wanted to study the impact of only using clinical and immunological monitoring on the diagnosis of virological ART failure under routine circumstances.

METHODS

Clinicians in two urban ART clinics in Malawi used clinical and immunological monitoring to identify adult patients for switching to second-line ART. If patients met clinical and/or immunological failure criteria of WHO guidelines and had a viral load <400 copies/ml there was misclassification of virological ART failure.

RESULTS

Between January 2006 and July 2007, we identified 155 patients with WHO criteria for immunological and/or clinical failure. Virological ART failure had been misclassified in 66 (43%) patients. Misclassification was significantly higher in patients meeting clinical failure criteria (57%) than in those with immunological criteria (30%). On multivariate analysis, misclassification was associated with being on ART <2 years [OR = 7.42 (2.63, 20.95)] and CD4 > 200 cells/microl [OR = 5.03 (2.05, 12.34)]. Active tuberculosis and Kaposi's sarcoma were the most common conditions causing misclassification of virological ART failure.

CONCLUSION

Misclassification of virological ART failure occurs frequently using WHO clinical and immunological criteria of ART failure for poor settings. A viral load test confirming virological ART failure is therefore advised to avoid unnecessary switching to second-line regimens.

Resistance profiles after different periods of exposure to a first-line antiretroviral regimen in a Cameroonian cohort of HIV type-1-infected patients

Background

The lack of HIV type-1 (HIV-1) viral load (VL) monitoring in resource-limited settings might favour the accumulation of resistance mutations and thus hamper second-line treatment efficacy. We investigated the factors associated with resistance after the initiation of antiretroviral therapy (ART) in the absence of virological monitoring.

Methods

Cross-sectional VL sampling of HIV-1-infected patients receiving first-line ART (nevirapine or efavirenz plus stavudine or zidovudine plus lamivudine) was carried out; those with a detectable VL were genotyped.

Results

Of the 573 patients undergoing VL sampling, 84 were genotyped. The mean number of nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) mutations increased with the duration of ART exposure ( P=0.02). Multivariable analysis showed that patients with a CD4+ T-cell count ≤50 cells/ mm3 at ART initiation (baseline) had a higher mean number of both NRTI and non-NRTI (NNRTI) mutations than those with a baseline CD4+ T-cell count >50 cells/mm3 (2.10 versus 0.56; P<0.0001; and 1.65 versus 0.76; P=0.005, respectively). A baseline CD4+ T-cell count ≤50 cells/mm3 predicted ≥1 NRTI mutation (adjusted odds ratio [AOR] 7.49, 95% confidence interval [CI] 2.20-32.14), ≥1 NNRTI mutation (AOR 4.25, 95% CI 1.36-15.48), ≥1 thymidine analogue mutation (AOR 8.45, 95% CI 2.16-40.16) and resistance to didanosine (AOR 6.36, 95% CI 1.49-32.29) and etravirine (AOR 4.72, 95% CI 1.53-15.70).

Conclusions

Without VL monitoring, the risk of drug resistance increases with the duration of ART and is associated with lower CD4+ T-cell counts at ART initiation. These data might help define strategies to preserve second-line treatment options in resource-limited settings.

CD4+ T-cell count monitoring does not accurately identify HIV-infected adults with virologic failure receiving antiretroviral therapy

BACKGROUND

CD4 T-lymphocyte (CD4) counts are widely used to monitor response to antiretroviral therapy (ART) in resource-limited settings. However, the utility of such monitoring in terms of predicting virologic response to therapy has been little studied.

METHODS

We studied participants aged 18 years and older who initiated ART in Tororo, Uganda. CD4 counts, CD4 percentages, and viral load (VL) were examined at 6-monthly intervals. Various definitions of immunologic failure were examined to identify individuals with VLs>or=50, >or=500, >or=1000, or >or=5000 copies per milliliter at 6, 12, and 18 months after treatment initiation.

RESULTS

One thousand sixty-three ART-naive persons initiated ART. The proportion of individuals with virologic failure ranged between 1.5% and 16.4% for each time point. The proportion with no increase in CD4 count from baseline did not differ between those with suppressed or unsuppressed VLs at 6, 18, and 24 months after ART initiation. No increase in CD4 cell counts at 6 months had a sensitivity of 0.04 [95% confidence interval (CI) 0.00 to 0.10] and a positive predictive value of 0.03 (95% CI 0.00 to 0.09) for identifying individuals with VL>or=500 copies per milliliter at 6 months. The best measure identified was an absolute CD4 cell count<125 cells per microliter at 21 months for predicting VL>or=500 copies per milliliter at 18 months which had a sensitivity of 0.13 (95% CI 0.01 to 0.21) and a positive predictive value of 0.29 (95% CI 0.10 to 0.44).

CONCLUSIONS

CD4 cell count monitoring does not accurately identify individuals with virologic failure among patients taking ART.

Development and evaluation of a clinical algorithm to monitor patients on antiretrovirals in resource-limited settings using adherence, clinical and CD4 cell count criteria

Background

Routine viral load monitoring of patients on antiretroviral therapy (ART) is not affordable in most resource-limited settings.

Methods

A cross-sectional study of 496 Ugandans established on ART was performed at the Infectious Diseases Institute, Kampala, Uganda. Adherence, clinical and laboratory parameters were assessed for their relationship with viral failure by multivariate logistic regression. A clinical algorithm using targeted viral load testing was constructed to identify patients for second-line ART. This algorithm was compared with the World Health Organization (WHO) guidelines, which use clinical and immunological criteria to identify failure in the absence of viral load testing.

Results

Forty-nine (10%) had a viral load of >400 copies/mL and 39 (8%) had a viral load of >1000 copies/mL. An algorithm combining adherence failure (interruption >2 days) and CD4 failure (30% fall from peak) had a sensitivity of 67% for a viral load of >1000 copies/mL, a specificity of 82%, and identified 22% of patients for viral load testing. Sensitivity of the WHO-based algorithm was 31%, specificity was 87%, and would result in 14% of those with viral suppression (<400 copies/mL) being switched inappropriately to second-line ART.

Conclusion

Algorithms using adherence, clinical and CD4 criteria may better allocate viral load testing, reduce the number of patients continued on failing ART, and limit the development of resistance.

Evaluation of the WHO criteria for antiretroviral treatment failure among adults in South Africa

OBJECTIVE

To assess the performance of WHO clinical and CD4 cell count criteria for antiretroviral treatment (ART) failure among HIV-infected adults in a workplace HIV care programme in South Africa.

DESIGN

Cohort study.

METHODS

We included initially ART-naive participants who remained on first-line therapy and had an evaluable HIV viral load result at the 12-month visit. WHO-defined clinical and CD4 cell count criteria for ART failure were compared against a gold standard of virological failure.

RESULTS

Among 324 individuals (97.5% men, median age 40.2, median starting CD4 cell count and viral load 154 cells/mul and 47,503 copies/ml, respectively), 33 (10.2%) had definite or probable virological failure at 12 months, compared with 19 (6.0%) and 40 (12.5%) with WHO-defined CD4 and clinical failure, respectively. CD4 criteria had a sensitivity of 21.2% and a specificity of 95.8% in detecting virological failure, and clinical criteria had sensitivity of 15.2% and specificity of 88.1%. The positive predictive value of CD4 and clinical criteria in detecting virological failure were 36.8 and 12.8%, respectively. Exclusion of weight loss or tuberculosis failed to improve the performance of clinical criteria.

CONCLUSION

WHO clinical and CD4 criteria have poor sensitivity and specificity in detecting virological failure. The low specificities and positive predictive values mean that individuals with adequate virological suppression risk being incorrectly classified as having treatment failure and unnecessarily switched to second-line therapy. Virological failure should be confirmed before switching to second-line therapy.

Simple adherence assessments to predict virologic failure among HIV-infected adults with discordant immunologic and clinical responses to antiretroviral therapy

We evaluated the association between two antiretroviral therapy (ART) adherence measurements--the medication possession ratio (MPR) and patient self-report--and detectable HIV viremia in the setting of rapid service scale-up in Lusaka, Zambia. Drug adherence and outcomes were assessed in a subset of patients suspected of treatment failure based on discordant clinical and immunologic responses to ART. A total of 913 patients were included in this analysis, with a median time of 744 days (Q1, Q3: 511, 919 days) from ART initiation to viral load (VL) measurement. On aggregate over the period of follow-up, 531 (58%) had optimal adherence (MPR > or =95%), 306 (34%) had suboptimal adherence (MPR 80-94%), and 76 (8%) had poor adherence (MPR <80%). Of the 913 patients, 238 (26%) had VL > or =400 copies/ml when tested. When compared to individuals with optimal adherence, there was increasing risk for virologic failure in those with suboptimal adherence [adjusted relative risk (ARR): 1.3; 95% confidence interval (CI): 1.0, 1.6] and those with poor adherence (ARR: 1.7; 95% CI: 1.3, 2.4) based on MPR. During the antiretroviral treatment course, 676 patients (74%) reported no missed doses. The proportion of patients with virologic failure did not differ significantly among those reporting any missed dose from those reporting perfect adherence (26% vs. 26%, p = 0.97). Among patients with suspected treatment failure, a lower MPR was associated with higher rates of detectable viremia. However, the suboptimal sensitivity and specificity of MPR limit its utility as a sole predictor of virologic failure.

Second-line antiretroviral therapy in resource-limited settings: the experience of Médecins Sans Frontières

OBJECTIVES

To describe the use of second-line protease-inhibitor regimens in Médecins Sans Frontières HIV programmes, and determine switch rates, clinical outcomes, and factors associated with survival.

DESIGN/METHODS

We used patient data from 62 Médecins Sans Frontières programmes and included all antiretroviral therapy-naive adults (> 15 years) at the start of antiretroviral therapy and switched to a protease inhibitor-containing regimen with at least one nucleoside reverse transcriptase inhibitor change after more than 6 months of nonnucleoside reverse transcriptase inhibitor first-line use. Cumulative switch rates and survival curves were estimated using Kaplan-Meier methods, and mortality predictors were investigated using Poisson regression.

RESULTS

Of 48,338 adults followed on antiretroviral therapy, 370 switched to a second-line regimen after a median of 20 months (switch rate 4.8/1000 person-years). Median CD4 cell count at switch was 99 cells/microl (interquartile ratio 39-200; n = 244). A lopinavir/ritonavir-based regimen was given to 51% of patients and nelfinavir-based regimen to 43%; 29% changed one nucleoside reverse transcriptase inhibitor and 71% changed two nucleoside reverse transcriptase inhibitors. Median follow-up on second-line antiretroviral therapy was 8 months, and probability of remaining in care at 12 months was 0.86. Median CD4 gains were 90 at 6 months and 135 at 12 months. Death rates were higher in patients in World Health Organization stage 4 at antiretroviral therapy initiation and in those with CD4 nadir count less than 50 cells/microl.

CONCLUSION

The rate of switch to second-line treatment in antiretroviral therapy-naive adults on non-nucleoside reverse transcriptase inhibitor-based first-line antiretroviral therapy was relatively low, with good early outcomes observed in protease inhibitor-based second-line regimens. Severe immunosuppression was associated with increased mortality on second-line treatment.

Utility of CD4 cell counts for early prediction of virological failure during antiretroviral therapy in a resource-limited setting

BACKGROUND

Viral load monitoring is not available for the vast majority of patients receiving antiretroviral therapy in resource-limited settings. However, the practical utility of CD4 cell count measurements as an alternative monitoring strategy has not been rigorously assessed.

METHODS

In this study, we used a novel modelling approach that accounted for all CD4 cell count and VL values measured during follow-up from the first date that VL suppression was achieved. We determined the associations between CD4 counts (absolute values and changes during ART), VL measurements and risk of virological failure (VL > 1,000 copies/ml) following initial VL suppression in 330 patients in South Africa. CD4 count changes were modelled both as the difference from baseline (DeltaCD4 count) and the difference between consecutive values (CD4 count slope) using all 3-monthly CD4 count measurements during follow-up.

RESULTS

During 7093.2 patient-months of observation 3756 paired CD4 count and VL measurements were made. In patients who developed virological failure (n = 179), VL correlated significantly with absolute CD4 counts (r = - 0.08, P = 0.003), DeltaCD4 counts (r = - 0.11, P < 0.01), and most strongly with CD4 count slopes (r = - 0.30, P < 0.001). However, the distributions of the absolute CD4 counts, DeltaCD4 counts and CD4 count slopes at the time of virological failure did not differ significantly from the corresponding distributions in those without virological failure (P = 0.99, P = 0.92 and P = 0.75, respectively). Moreover, in a receiver operating characteristic (ROC) curve, the association between a negative CD4 count slope and virological failure was poor (area under the curve = 0.59; sensitivity = 53.0%; specificity = 63.6%; positive predictive value = 10.9%).

CONCLUSION

CD4 count changes correlated significantly with VL at group level but had very limited utility in identifying virological failure in individual patients. CD4 count is an inadequate alternative to VL measurement for early detection of virological failure.

Absolute CD4+ T-lymphocyte count as a surrogate marker of pediatric human immunodeficiency virus disease progression

BACKGROUND

Traditionally in pediatric HIV, the CD4+ T-lymphocyte percent is used to monitor disease progression because of the variability in absolute CD4+ T-lymphocyte numbers. Because of the high cost of equipment, sophisticated and delicate technology, most laboratories in resource-limited settings use simple protocols that enumerate only the absolute CD4+ T-lymphocyte counts. We assessed the use of absolute CD4+ T-lymphocyte count as a surrogate marker of pediatric HIV disease progression.

METHODS

We analyzed the CD4+ T-lymphocytes and HIV viral load over a 10-year period (1996-2006) of 97 HIV-infected children enrolled in the Yale Prospective Longitudinal Pediatric HIV Cohort using generalized linear mixed models. Both CD4+ T-lymphocytes and HIV viral load were assessed at baseline and every 2-3 months. The modeling approach used in this study allows the intercept and the rate at which outcome variables change over time to vary across participants.

RESULTS

We determined that absolute CD4+ T-lymphocytes count was just as reliable at monitoring pediatric HIV as CD4+ T-lymphocyte percentage. Antiretroviral treatment, regardless of the regimen used, was associated with higher CD+ T-lymphocytes count (P < 0.01). Race was significantly associated with CD4+ T-lymphocytes counts (with lower values for blacks compared with nonblacks; P < 0.01). The presence of other infections was associated with lower CD4+ T-lymphocyte count (P = 0.01) and higher viral load (P < 0.01), respectively.

CONCLUSIONS

In situations where determination of CD4+ T-lymphocyte percentages is not readily available, the absolute count may provide an affordable and accessible laboratory surrogate marker of HIV disease progression in children.

Pharmacy refill adherence compared with CD4 count changes for monitoring HIV-infected adults on antiretroviral therapy

BACKGROUND

World Health Organization (WHO) guidelines for monitoring HIV-infected individuals taking combination antiretroviral therapy (cART) in resource-limited settings recommend using CD4(+) T cell (CD4) count changes to monitor treatment effectiveness. In practice, however, falling CD4 counts are a consequence, rather than a cause, of virologic failure. Adherence lapses precede virologic failure and, unlike CD4 counts, data on adherence are immediately available to all clinics dispensing cART. However, the accuracy of adherence assessments for predicting future or detecting current virologic failure has not been determined. The goal of this study therefore was to determine the accuracy of adherence assessments for predicting and detecting virologic failure and to compare the accuracy of adherence-based monitoring approaches with approaches monitoring CD4 count changes.

METHODOLOGY AND FINDINGS

We conducted an observational cohort study among 1,982 of 4,984 (40%) HIV-infected adults initiating non-nucleoside reverse transcriptase inhibitor-based cART in the Aid for AIDS Disease Management Program, which serves nine countries in southern Africa. Pharmacy refill adherence was calculated as the number of months of cART claims submitted divided by the number of complete months between cART initiation and the last refill prior to the endpoint of interest, expressed as a percentage. The main outcome measure was virologic failure defined as a viral load > 1,000 copies/ml (1) at an initial assessment either 6 or 12 mo after cART initiation and (2) after a previous undetectable (i.e., < 400 copies/ml) viral load (breakthrough viremia). Adherence levels outperformed CD4 count changes when used to detect current virologic failure in the first year after cART initiation (area under the receiver operating characteristic [ROC] curves [AUC] were 0.79 and 0.68 [difference = 0.11; 95% CI 0.06 to 0.16; chi(2) = 20.1] respectively at 6 mo, and 0.85 and 0.75 [difference = 0.10; 95% CI 0.05 to 0.14; chi(2) = 20.2] respectively at 12 mo; p < 0.001 for both comparisons). When used to detect current breakthrough viremia, adherence and CD4 counts were equally accurate (AUCs of 0.68 versus 0.67, respectively [difference = 0.01; 95% CI -0.06 to 0.07]; chi(2) = 0.1, p > 0.5). In addition, adherence levels assessed 3 mo prior to viral load assessments were as accurate for virologic failure occurring approximately 3 mo later as were CD4 count changes calculated from cART initiation to the actual time of the viral load assessments, indicating the potential utility of adherence assessments for predicting future, rather than simply detecting current, virologic failure. Moreover, combinations of CD4 count and adherence data appeared useful in identifying patients at very low risk of virologic failure.

CONCLUSIONS

Pharmacy refill adherence assessments were as accurate as CD4 counts for detecting current virologic failure in this cohort of patients on cART and have the potential to predict virologic failure before it occurs. Approaches to cART scale-up in resource-limited settings should include an adherence-based monitoring approach.

Can response of a pruritic papular eruption to antiretroviral therapy be used as a clinical parameter to monitor virological outcome?

BACKGROUND

A pruritic papular eruption (PPE) is a common skin manifestation observed in 12-46% of persons with HIV infection living in tropical countries.

OBJECTIVE

To determine whether PPE responds to HAART and whether monitoring PPE severity could be used as a clinical marker to predict virological outcome in resource-limited settings where viral load testing is not available.

METHODS

The study enrolled 53 patients with PPE for at least 1 month before starting a first-line HAART regimen as part of a prospective study. CD4 cell count and viral load were measured at enrolment and every 3 months. A scoring system was developed to evaluate the PPE severity by asking two questions. Over the last month how itchy has your skin been? Over the last month how has itching interfered with your sleep?

RESULTS

Median CD4 cell count was 15 cells/mul and median viral load 268 663 copies/ml. All patients initiated a regimen containing a nonnucleoside reverse transcriptase inhibitor. Mean PPE score declined from 3.9 at enrolment to 0.1 at 24 months. In 37 (86%) of the 43 patients with at least 6 months of follow-up data, the PPE disappeared and never returned. Patients with viral load > 400 copies/ml at months 9 and/or 12 had significantly higher PPE scores at months 9 to 12 than the patients with < 400 copies/ml.

CONCLUSIONS

In most patients, PPE disappears during HAART and PPE severity scores were higher in patients whose first-line HAART failed to control plasma viral load.

Positive outcomes of HAART at 24 months in HIV-infected patients in Cambodia

OBJECTIVES

African and Asian cohort studies have demonstrated the feasibility and efficacy of HAART in resource-poor settings. The long-term virological outcome and clinico-immunological criteria of success remain important questions. We report the outcomes at 24 months of antiretroviral therapy (ART) in patients treated in a Médecins Sans Frontières/Ministry of Health programme in Cambodia.

METHODS

Adults who started HAART 24 +/- 2 months ago were included. Plasma HIV-RNA levels were assessed by real-time polymerase chain reaction. Factors associated with virological failure were analysed using logistic regression.

RESULTS

Of 416 patients, 59.2% were men; the median age was 33.6 years. At baseline, 95.2% were ART naive, 48.9% were at WHO stage IV, and 41.6% had a body mass index less than 18 kg/m. The median CD4 cell count was 11 cells/microl. A stavudine-lamivudine-efavirenz-containing regimen was initiated predominantly (81.0%). At follow-up (median 23.8 months), 350 (84.1%) were still on HAART, 53 (12.7%) had died, six (1.4%) were transferred, and seven (1.7%) were lost to follow-up. Estimates of survival were 85.5% at 24 months. Of 346 tested patients, 259 (74.1%) had CD4 cell counts greater than 200 cells/microl and 306 (88.4%) had viral loads of less than 400 copies/ml. Factors associated with virological failure at 24 months were non-antiretroviral naive, an insufficient CD4 cell gain of less than 350 cells/microl or a low trough plasma ART concentration. In an intention-to-treat analysis, 73.6% of patients were successfully treated.

CONCLUSION

Positive results after 2 years of advanced HIV further demonstrate the efficacy of HAART in the medium term in resource-limited settings.

Current hemoglobin levels are more predictive of disease progression than hemoglobin measured at baseline in patients receiving antiretroviral treatment for HIV type 1 infection

The role of hemoglobin levels as an independent prognostic marker of progression to AIDS and/or death in HIV-infected patients starting combination antiretroviral therapy (cART) was investigated. A total of 2,579 patients from the EuroSIDA cohort with hemoglobin, CD4 cell count, and HIV RNA viral load measured 6 months prior to starting cART was included in the analyses. Anemia was defined as mild (<or=14 g/dl males, <or=12 g/dl females) and severe (<8 g/dl both genders). Poisson regression was used to determine factors related to clinical progression (new AIDS/death). Hemoglobin levels increased by a median of +0.48 g/dl (IQR -0.4 to +1.3) in the first year of cART. During 14,272 person years of follow-up (PYFU) there were 505 new AIDS/deaths. Of the patients 304 (11.8%) developed mild and 19 severe anemia (0.7%). In multivariate analysis baseline hemoglobin was significantly associated with progression to AIDS/death after starting cART with an IRR of 1.07 per 1 g/dl lower (95% CI 1.01-1.13; p = 0.023). When hemoglobin was fitted as a time-updated variable the IRR increased to 1.36 per 1 g/dl lower (95% CI 1.30-1.42; p < 0.001). Starting cART was associated with an increase in hemoglobin levels. Lower hemoglobin values, particularly the latest measured, were associated with an increased risk of disease progression.

International perspectives, progress, and future challenges of paediatric HIV infection

Paediatric HIV infection is a growing health challenge worldwide, with an estimated 1500 new infections every day. In developed countries, well established prevention programmes keep mother-to-child transmission rates at less than 2%. However, in developing countries, where transmission rates are 25-40%, interventions are available to only 5-10% of women. Children with untreated natural infection progress rapidly to disease, especially in resource-poor settings where mortality is greater than 50% by 2 years of age. As in adult infection, antiretroviral therapy has the potential to rewrite the natural history of HIV, but is accessible only to a small number of children needing therapy. We focus on the clinical and immunological features of HIV that are specific to paediatric infection, and the formidable challenges ahead to ensure that all children worldwide have access to interventions that have proved successful in developed countries.

Predictors of failure of first-line antiretroviral therapy in HIV-infected adults: Indian experience

OBJECTIVES

To study the incidence and risk factors for failure of treatment with antiretroviral therapy among adults in the national treatment program in India, and to estimate the possible number of persons living with human immunodeficiency virus (HIV) who will need a second-line treatment regimen in the next 3 and 3.5 years.

DESIGN AND SETTING

Data of a cohort of HIV-positive adult patients, who were enrolled in the government-sponsored antiretroviral therapy program, were obtained from the electronic medical record system of the largest HIV care center in India and subjected to analysis.

MAIN OUTCOMES

Treatment failure defined by the World Health Organization criteria, assessed immunologically on the basis of CD4 T cell count, with a minimum period of 12 months of follow-up and with a minimum of two CD4 T cell follow-up measures.

RESULTS

The cumulative incidence of treatment failure in the 1370 adult patients included in the study was 3.9% (95% confidence interval [CI] 2.9 to 4.9). Men had a 3.5 (1.6 to 7.4) times significantly greater risk of treatment failure. Patients who had negative changes in absolute lymphocyte count, hemoglobin concentration and body weight had 3.1 (1.6 to 6.2), 3.2 (1.6 to 6.2), and 3.5 (1.9 to 6.4) times significantly greater risk of treatment failure. In India, after 2007, by 2, 3, and 3.5 years, respectively, an estimated 16 000, 35 000, and 51 000 patients receiving antiretroviral therapy are likely to require second-line treatment.

CONCLUSION

Monitoring of hemoglobin concentration, absolute lymphocyte count, and body weight during follow-up emerged as inexpensive predictors of treatment failure in a resource-poor setting. A significant number of patients will need second-line therapy as a result of failure of their first-line antiretroviral therapy regimen in 3 and 3.5 years in India, and therefore the development of an appropriate policy for second-line drugs is urgently needed.

Conservation of First-Line Antiretroviral Treatment Regimen where Therapeutic Options are Limited

Objectives

To determine rates and causes of switching from first- to second-line antiretroviral treatment (ART) regimens in a large treatment-naive cohort (a South African community-based ART service) where a targeted adherence intervention was used to manage initial virological breakthrough.

Methods

ART-naive adults ( n=929) commencing first-line non-nucleoside-based ART [according to WHO (2002) guidelines] between September 2002 and August 2005 were studied prospectively. Viral load (VL) and CD4+ T-cell counts were monitored every 4 months. All drug switches were recorded. Counsellor-driven adherence interventions were targeted to patients with a VL >1,000 copies/ml at any visit (virological breakthrough) and the VL measurement was repeated within 8 weeks. Two consecutive VL measurements >1,000 copies/ml was considered virological failure, triggering change to a second-line regimen.

Results

During 760 person-years of observation [median IQR) 189 (85–441) days], 823 (89%) patients were retained on ART, 2% transferred elsewhere, 7% died and 3% were lost to follow-up. A total of 893 (96%) patients remained on first-line therapy and 16 (1.7%) switched to second-line due to hypersensitivity reactions ( n=9) or lactic acidosis ( n=7). A Kaplan-Meier estimate for switching to second-line due to toxicity was 3.0% at 32 months. Virological breakthrough occurred in 67 (7.2%) patients, but, following use of a targeted adherence intervention, virological failure was confirmed in just 20 (2.2%). Kaplan-Meier estimates at 32 months were 20% for virological breakthrough but only 5.6% for confirmed virological failure.

Conclusion

Regimen switches were due to virological failure or toxicity. Although follow-up time was limited, over 95% of individuals remained on first-line ART using a combination of viral monitoring and a targeted adherence intervention.

HIV viral load monitoring in resource-limited regions: optional or necessary?

Although it is a standard practice in high-income countries, determination of the human immunodeficiency virus (HIV) load is not recommended in developing countries because of the costs and technical constraints. As more and more countries establish capacity to provide second-line therapy, and as costs and technological constraints associated with viral load testing decrease, the question of whether determination of the viral load is necessary deserves attention. Viral load testing could increase in importance as a guide for clinical decisions on when to switch to second-line treatment and on how to optimize the duration of the first-line treatment regimen. In addition, the viral load is a particularly useful tool for monitoring adherence to treatment, performing sentinel surveillance, and diagnosing HIV infection in children aged <18 months. Rather than considering viral load data to be an unaffordable luxury, efforts should be made to ensure that viral load testing becomes affordable, simple, and easy to use in resource-limited settings.

Predictors of early death in a cohort of Ethiopian patients treated with HAART

Background

HAART has improved the survival of HIV infected patients. However, compared to patients in high-income countries, patients in resource-poor countries have higher mortality rates. Our objective was to identify independent risk factors for death in Ethiopian patients treated with HAART.

Methods

In a district hospital in Ethiopia, we treated adult HIV infected patients with HAART based on clinical and total lymphocyte count (TLC) criteria. We measured body weight and complete blood cell count at baseline, 4 weeks later, then repeated weight every month and complete blood cell count every 12 weeks. Time to death was the main outcome variable. We used the Kaplan Meier and Cox regression survival analyses to identify prognostic markers. Also, we calculated mortality rates for the different phases of the follow-up.

Results

Out of 162 recruited, 152 treatment-naïve patients contributed 144.1 person-years of observation (PYO). 86 (57%) of them were men and their median age was 32 years. 24 patients died, making the overall mortality rate 16.7 per 100 PYO. The highest death rate occurred in the first month of treatment. Compared to the first month, mortality declined by 9-fold after the 18^th week of follow-up. Being in WHO clinical stage IV and having TLC<= 750/mcL were independent predictors of death. Haemoglobin (HGB) <= 10 g/dl and TLC<= 1200/mcL at baseline were not associated with increased mortality. Body mass index (BMI) <= 18.5 kg/m2 at baseline was associated with death in univariate analysis. Weight loss was seen in about a third of patients who survived up to the fourth week, and it was associated with increased death. Decline in TLC, HGB and BMI was associated with death in univariate analysis only.

Conclusion

The high mortality rate seen in this cohort was associated with advanced disease stage and very low TLC at presentation. Patients should be identified and treated before they progress to advanced stages. The underlying causes for early death in patients presenting at late stages should be investigated.