The purpose of this study is to evaluate risk factors for progression from asymptomatic peripheral neuropathy (APN) to symptomatic peripheral neuropathy (SPN). Antiretroviral therapy (ART)-naïve patients initiating combination ART were followed longitudinally and screened for signs/ symptoms of PN. Having APN was associated with higher odds of future SPN (odds ratio (OR)=1.58, 95 % confidence interval (CI)=(1.08, 2.29), p=0.027). Neurotoxic ART use was associated with increased odds of progression to SPN (OR= 2.16, 95 % CI=(1.21, 3.85), p=0.009) while use of glucose-lowering drugs (non-insulin) was protective (OR=0.12, 95 % CI=(0.02, 0.83), p=0.031). Use of glucose-lowering drugs (non-insulin) may prevent progression from APN to SPN.
Peripheral neuropathy; Symptomatic peripheral neuropathy; Risk factors; HIV; Glucose-lowering drugs
To estimate neuropathic sign/symptom rates with initiation of combination antiretroviral therapy (cART) in HIV-infected ART-naive patients, and to investigate risk factors for: peripheral neuropathy and symptomatic peripheral neuropathy (SPN), recovery from peripheral neuropathy/SPN after neurotoxic ART (nART) discontinuation, and the absence of peripheral neuropathy/SPN while on nART.
AIDS Clinical Trials Group (ACTG) Longitudinal Linked Randomized Trial participants who initiated cART in randomized trials for ART-naive patients were annually screened for symptoms/signs of peripheral neuropathy. ART use and disease characteristics were collected longitudinally.
Peripheral neuropathy was defined as at least mild loss of vibration sensation in both great toes or absent/hypoactive ankle reflexes bilaterally. SPN was defined as peripheral neuropathy and bilateral symptoms. Generalized estimating equation logistic regression was used to estimate associations.
Two thousand, one hundred and forty-one participants were followed from January 2000 to June 2007. Rates of peripheral neuropathy/SPN at 3 years were 32.1/8.6% despite 87.1% with HIV-1RNA 400 copies/ml or less and 70.3% with CD4 greater than 350 cells/µl. Associations with higher odds of peripheral neuropathy included older patient age and current nART use. Associations with higher odds of SPN included older patient age, nART use, and history of diabetes mellitus. Associations with lower odds of recovery after nART discontinuation included older patient age. Associations with higher odds of peripheral neuropathy while on nART included older patient age and current protease inhibitor use. Associations with higher odds of SPN while on nART included older patient age, history of diabetes, taller height, and protease inhibitor use.
Signs of peripheral neuropathy remain despite virologic/immunologic control but frequently occurs without symptoms. Aging is a risk factor for peripheral neuropathy/SPN.
aging; antiretroviral therapy; HIV; neurological; peripheral neuropathy; risk factors
Purpose of review
The dramatic increase in the number and type of immune biomarkers that can be measured, particularly those assessing immune activation, has led to numerous investigations in HIV-infected individuals to explore pathogenesis and to assess therapeutic interventions that aim to attenuate immune activation. An overview is provided on study designs and related statistical and operational issues relevant to these investigations.
Cohort studies and nested case-control studies within these cohorts have identified multiple biomarkers that are associated with increased risk of disease. Early-stage clinical trials of therapies to address these risks in HIV-infected individuals with viral suppression on antiretroviral therapy are a substantial focus of current HIV research.
Appropriate study design is essential in biomarker research.
Observational research; clinical trials; biomarker; measurement error; surrogate marker
In HIV-1-infected patients receiving antiretroviral therapy (ART), the relationship between residual viremia and ex vivo recovery of infectious virus from latently-infected CD4 cells is uncertain.
We measured residual viremia (HIV-1 RNA copies/mL) by single-copy assay (SCA) and the latent reservoir by infectious virus recovery from resting memory CD4 cells (infectious units per million cells [IUPM]) in patients who initiated ART. We assessed immune activation by measuring CD38 expression on T cells.
Ten patients who initiated ART and maintained a plasma HIV-1 RNA level <200 copies/mL had residual viremia and IUPM measured every 24 weeks. Five of 10 patients had longitudinal IUPM measured at weeks 24–96; the remainder had IUPM measured 1–3 times over 24–72 weeks. Analyses of 29 paired measurements revealed a positive association between level of residual viremia and IUPM (0.56 higher log10 HIV-1 RNA copies/mL per 1 log10 higher IUPM, p=0.005). Residual viremia level was positively associated with CD38 density and percentage on CD8+ T-cells in concurrent samples and with pre-ART HIV-1 RNA levels.
In patients with HIV-1 RNA levels <200 copies/mL 24–96 weeks after initiating ART, the level of viremia is positively associated with infectious virus recovery from resting memory CD4 cells. Whether this association persists after longer-term suppressive ART needs to be determined. If additional studies show that residual viremia measured by SCA reflects the size of the latent reservoir in patients who have had virologic suppression for longer periods of time, this could facilitate testing of potentially curative strategies to reduce this important reservoir.
HIV-1; reservoir; residual viremia; single-copy assay
India has a wide range of nutrition and health problems which require professionals with appropriate skills, knowledge and trans-disciplinary collaborative abilities to influence policy making at the national and global level.
The Bangalore Boston Nutrition Collaborative (BBNC) was established as collaboration between St. John’s Research Institute (SJRI), Harvard School of Public Health and Tufts University, with a focus on nutrition research and training. The goals of the BBNC were to conduct an interdisciplinary course, develop web-based courses and identify promising Indian students and junior faculty for graduate training in Boston.
From 2010, an annual two-week short course in nutrition research methods was conducted on the SJRI campus taught by international faculty from Indian and US universities. More than 100 students applied yearly for approximately 30 positions. The course had didactic lectures in the morning and practical hands-on sessions in the afternoon. Student rating of the course was excellent and consistent across the years. The ratings on the design and conduct of the course significantly improved (p <0.001) from 2010 to 2012. Through open-ended questions, students reported the main strengths of the course to be the excellent faculty and practical “hands-on” sessions. A web based learning system TYRO, was developed, which can be used for distance learning. Four faculty members/graduate students from SJRI have visited Boston for collaborative research efforts.
The BBNC has become a well-established capacity building and research training program for young professionals in nutrition and global health. Efforts are ongoing to secure long term funding to sustain and expand this collaboration to deliver high quality nutrition and global health education enabled by information and communication technologies.
Nutrition; Global Health; Education; Training; Research
HIV-1-infected individuals with plasma RNA <50 copies/mL on antiretroviral therapy (ART) may have residual, low-level viremia detectable by PCR assays which can detect a single copy of viral RNA (single-copy assay, SCA). The clinical predictors of residual viremia in patients on long-term suppressive ART are incompletely understood.
We evaluated factors associated with residual viremia in patients on suppressive ART who underwent screening for a raltegravir intensification trial (ACTG A5244). The screened population was HIV-1-infected adults receiving ART for ≥12 months with pre-ART HIV-1 RNA >100,000 copies/mL and on-therapy RNA levels below detection limits of commercial assays for ≥6 months.
Of 103 patients eligible for analysis, the median age was 46 years and the median duration of viral suppression was 4.8 years. Sixty-two percent had detectable viremia (>0.2 copies/mL) by SCA (median 0.2 copies/mL; quartile [Q] 1, Q3 [<0.2, 1.8]). Younger patients had lower HIV-1 RNA levels than older individuals (r=0.27, p=0.005). Patients with virologic suppression on ART for 2 years or less had higher residual viremia than those with suppression for more than 2 years (median 2.3 vs. 0.2 copies/mL, p=0.016).
Among HIV-1-infected patients with pre-ART HIV-1 RNA >100,000 copies/mL, residual viremia was detectable in the majority (62%) despite many years of suppressive ART. Higher level viremia was associated with older age and less than 2 years of virologic suppression on ART. These findings should help in selection of candidates for clinical trials of interventions designed to eliminate residual viremia.
HIV-1; Single-copy assay; residual viremia
Valproic acid and intensified antiretroviral therapy may deplete resting CD4+ T-cell HIV infection. We tested the ability of valproic acid to deplete resting CD4+ T-cell infection in patients receiving standard antiretroviral therapy.
Resting CD4+ T-cell infection was measured in 11 stably aviremic volunteers twice prior to, and twice after Depakote ER 1000 mg was added to standard antiretroviral therapy. Resting CD4+ T-cell infection frequency was measured by outgrowth assay. Low-level viremia was quantitated by single copy plasma HIV RNA assay.
A decrease in resting CD4+ T-cell infection was observed in only four of the 11 patients. Levels of immune activation and HIV-specific T-cell response were low and stable. Valproic acid levels ranged from 26 to 96 μg/ml when measured near trough. Single copy assay was performed in nine patients. In three patients with depletion of resting CD4+ T-cell infection following valproic acid, single copy assay ranged from less than 1–5 copies/ml. Continuous low-level viremia was observed in three patients with stable resting CD4+ T-cell infection (24–87, 8–87, and 1–7 copies/ml respectively) in whom multiple samples were analyzed.
The prospective addition of valproic acid to stable antiretroviral therapy reduced the frequency of resting CD4+ T-cell infection in a minority of volunteers. In patients in whom resting CD4+ T-cell infection depletion was observed, viremia was rarely detectable by single copy assay.
antiretroviral therapy; HIV; latency; resting CD4+ T cells; valproic acid
Background. Although specific human immunodeficiency virus type 1 (HIV-1) drug resistance mutations are well studied, little is known about cumulative amino acid changes, or how regimen and participant characteristics influence these changes.
Methods. In the AIDS Clinical Trials Group randomized study A5202 of treatment-naive HIV-infected participants, cumulative HIV-1 amino acid changes from pretreatment to virologic failure were evaluated in protease and reverse transcriptase (RT) gene sequences.
Results. Among 265 participants with virologic failure, those assigned atazanavir plus ritonavir (ATV/r) did not have significantly more protease changes compared with those assigned efavirenz (EFV) (P ≥ .13). In contrast, participants with virologic failure assigned EFV had more RT changes, including and excluding known resistance codons (P < .001). At pretreatment, lower CD4 cell count, major resistance, more amino acid mixtures (all P < .001), hepatitis C antibody negativity (P = .05), and black race/ethnicity (P = .02) were associated with more HIV-1 amino acid changes.
Conclusions. Virologic failure following EFV-containing treatment was associated with more HIV-1 amino acid changes compared to failure of ATV/r-containing treatment. Furthermore, we show that non–drug resistance mutations occurred more frequently among those failing EFV, the clinical relevance of which warrants further investigation. Pretreatment immunologic status may play a role in viral evolution during treatment, as evidenced by increased amino acid changes among those with lower pretreatment CD4 count.
Clinical Trials Registration. NCT00118898.
Vitamin D is an immunomodulator and can alter response to tuberculosis (TB) treatment, though randomised trials have been inconclusive to date. We present one of the first comprehensive analysis of the associations between vitamin D status and TB treatment, T-cell counts and nutritional outcomes by HIV status.
Outpatient clinics in Tanzania.
25-hydroxyvitamin D levels were assessed in a cohort of 677 patients with TB (344 HIV infected) initiating anti-TB treatment at enrolment in a multivitamin supplementation (excluding vitamin D) trial (Clinicaltrials.gov identifier: NCT00197704).
Primary and secondary outcome measures
Information on treatment outcomes such as failure and relapse, HIV disease progression, T-cell counts and anthropometry was collected routinely, with a median follow-up of 52 and 30 months for HIV-uninfected and HIV-infected patients, respectively. Cox and binomial regression, and generalised estimating equations were used to assess the association of vitamin D status with these outcomes.
Mean 25-hydroxyvitamin D concentrations at enrolment were 69.8 (±21.5) nmol/L (27.9 (±8.6) ng/mL). Vitamin D insufficiency (<75 nmol/L) was associated with a 66% higher risk of relapse (95% CI 4% to 164%; 133% higher risk in HIV-uninfected patients). Each unit higher 25-hydroxyvitamin D levels at baseline were associated with a decrease of 3 (p=0.004) CD8 and 3 (p=0.01) CD3 T-cells/µL during follow-up in patients with HIV infection. Vitamin D insufficiency was also associated with a greater decrease of body mass index (BMI; –0.21 kg/m2; 95% CI −0.39 to −0.02), during the first 8 months of follow-up. No association was observed for vitamin D status with mortality or HIV disease progression.
Adequate vitamin D status is associated with a lower risk of relapse and with improved nutritional indicators such as BMI in patients with TB, with or without HIV infection. Further research is needed to determine the optimal dose of vitamin D and effectiveness of daily vitamin D supplementation among patients with TB.
HIV; Africa; Vitamin D
While persistent T-cell activation has been cross-sectionally associated with poor CD4+ T-cell restoration in HIV-infected individuals maintaining antiretroviral treatment (ART)–mediated viral suppression, it remains unclear whether CD8+ T-cell activation is of predictive effect on CD4+ T-cell recovery.
We assessed whether the extent of persistent CD8+ T-cell activation (% CD38+/HLA-DR+) in the fi rst few years of ART-mediated viral suppression predicted subsequent CD4+ T-cell recovery in 95 subjects with up to 15 years of observation on suppressive ART.
Lower CD8+ T-cell activation and higher naïve CD4+ T-cell frequencies (CD45RA+/CD62L+) measured at year 3 to 5 after starting ART independently predicted greater subsequent CD4+ T-cell increases. The mean CD4 count increase from year 0 to year 5 and the increase to the average of year 10 to 15 in the low CD8 activation group (≤18.5%; mean = 13%) were 342 and 458 cells/mm,3 and the increases were 248 and 349 cells/mm3 for the high CD8 activation group (>18.5%; mean = 29%) (P = .002 and P = .016, respectively, comparing groups). At years 10 to 15, the mean CD4 counts in the groups were 579 and 484 cells/mm3, respectively (P = .026).
These fi ndings support the need to identify approaches to reduce immune activation in treated HIV disease.
antiretroviral therapy; CD4+ T-cell counts; HIV; immune activation
Predictors and consequences of childhood anaemia in settings with high HIV prevalence are not well known. The aims of the present study were to identify maternal and child predictors of anaemia among children born to HIV-infected women and to study the association between childhood anaemia and mortality.
Prospective cohort study. Maternal characteristics during pregnancy and Hb measurements at 3-month intervals from birth were available for children. Information was also collected on malaria and HIV infection in the children, who were followed up for survival status until 24 months after birth.
Dar es Salaam, Tanzania.
The study sample consisted of 829 children born to HIV-positive women.
Advanced maternal clinical HIV disease (relative risk (RR) for stage ≥2 v. stage 1: 1.31, 95% CI 1.14, 1.51) and low CD4 cell counts during pregnancy (RR for <350 cells/mm3
v. ≥350 cells/mm3: 1.58, 95% CI 1.05, 2.37) were associated with increased risk of anaemia among children. Birth weight <2500 g, preterm birth (<34 weeks), malaria parasitaemia and HIV infection in the children also increased the risk of anaemia. Fe-deficiency anaemia in children was an independent predictor of mortality in the first two years of life (hazard ratio 1.99, 95 % CI 1.06, 3.72).
Comprehensive care including highly active antiretroviral therapy to eligible HIV-infected women during pregnancy could reduce the burden of anaemia in children. Programmes for the prevention of mother-to-child transmission of HIV and antimalarial treatment to children could improve child survival in settings with high HIV prevalence.
HIV; Malaria; Anaemia; Child mortality; Sub-Saharan Africa
Anaemia is prevalent among children born to HIV-positive women, and it is associated with adverse effects on cognitive and motor development, growth, and increased risks of morbidity and mortality.
To examine the effect of daily multivitamin supplementation on haematologic status and mother-to-child transmission (MTCT) of HIV through breastfeeding.
A total of 2387 infants born to HIV-positive women from Dar es Salaam, Tanzania were enrolled in a randomized, double-blind, placebo-controlled trial, and provided a daily oral supplement of multivitamins (vitamin B complex, C and E) or placebo at age 6 weeks for 24 months. Among them, 2008 infants provided blood samples and had haemoglobin concentrations measured at baseline and during a follow-up period. Anaemia was defined as haemoglobin concentrations<11 g/dL and severe anaemia<8.5 g/dL.
Haemoglobin concentrations among children in the treatment group were significantly higher than those in the placebo group at 12 (9.77 vs. 9.64 g/dL, p=0.03), 18 (9.76 vs. 9.57 g/dL, p=0.004), and 24 months (9.93 vs. 9.75 g/dL, p=0.02) of follow-up. Compared to those in the placebo group, children in the treatment group had a 12% lower risk of anaemia (hazard ratio (HR): 0.88; 95% CI: 0.79–0.99; p=0.03). The treatment was associated with a 28% reduced risk of severe anaemia among children born to women without anaemia (HR: 0.72; 95% CI: 0.56–0.92; p=0.008), but not among those born to women with anaemia (HR: 1.10; 95% CI: 0.79–1.54; p=0.57; p for interaction=0.007). One thousand seven hundred fifty three infants who tested HIV-negative at baseline and had HIV testing during follow-up were included in the analysis for MTCT of HIV. No association was found between multivitamin supplements and MTCT of HIV.
Multivitamin supplements improve haematologic status among children born to HIV-positive women. Further trials focusing on anaemia among HIV-exposed children are warranted in the context of antiretroviral therapy.
multivitamins; haemoglobin; anaemia; mother-to-child transmission; randomized controlled trial; Tanzania
To determine whether human immunodeficiency virus (HIV) infection is associated with increased risk of malaria incidence and recurrence in children.
Newborn infants of HIV-infected mothers were enrolled at 6 weeks and followed for 2 years. HIV status was assessed by enzyme-linked immunosorbant assay and confirmed by HIV DNA polymerase chain reaction. Malaria was defined as (1) physician-diagnosed clinical malaria; (2) probable malaria, in which laboratory testing is requested for parasitemia; and (3) blood smear–confirmed malaria. Cox proportional hazards models estimated hazard ratios (HRs) for development of first and second malaria episodes, and generalized estimating equation models estimated malaria rate differences per 100-child-years in relation to time-updated HIV status.
Child HIV infection was associated with clinical (HR, 1.34; 95% confidence interval [CI], 1.12–1.61), probable (HR, 1.47; 95% CI, 1.19–1.81), and confirmed (HR, 1.67; 95% CI, 1.18–2.36) malaria episodes. Per 100 child-years, HIV-infected children experienced 88 (95% CI, 65–113), 36 (95% CI, 19–53), and 20 (95% CI, 9–31) more episodes of clinical, probable, and confirmed malaria episodes, respectively, than HIV-uninfected children. Among children with ≥1 malaria episodes, those with HIV infection developed second clinical (HR, 1.28; 95% CI, 1.04–1.57), probable (HR, 1.60; 95% CI, 1.26–2.14), and confirmed (HR, 2.27; 95% CI, 1.06–3.89) malaria sooner than HIV-uninfected children.
HIV infection is a risk factor for the development of malaria. Proactive malaria disease prevention and treatment is warranted for all children, particularly those with HIV infection in settings of coendemicity.
Children born to HIV-infected women are susceptible to undernutrition, but modifiable risk factors and the time course of the development of undernutrition have not been well characterized.
To identify maternal, socioeconomic, and child characteristics that are associated with stunting, wasting, and underweight among Tanzanian children born to HIV-infected mothers, followed from 6 weeks for 24 months.
Maternal and socioeconomic characteristics were recorded during pregnancy, data pertaining to the infant’s birth were collected immediately after delivery, morbidity histories and anthropometric measurements were performed monthly. Multivariate Cox proportional hazards methods were used to assess the association between potential predictors and the time to first episode of stunting, wasting, and underweight.
2387 infants (54.0% male) were enrolled and followed for a median duration of 21.2 months. The respective prevalence of prematurity (<37 weeks) and low birthweight (<2500g) was 15.2% and 7.0%; 11.3% of infants were HIV-positive at 6 weeks. Median time to first episode of stunting, wasting, and underweight was 8.7, 7.2, and 7.0 months, respectively. Low maternal education, few household possessions, low infant birthweight, child HIV infection and male sex were all independent predictors of stunting, wasting, and underweight. In addition, preterm infants were more likely to become wasted and underweight, whereas those with a low Apgar score at birth were more likely to become stunted.
Interventions to improve maternal education and nutritional status, reduce mother-to-child transmission of HIV, and increase birth weight may lower the risk of undernutrition among children born to HIV-infected women.
Child undernutrition; child growth; HIV
In a large North American cohort study, anal cancer incidence rates were substantially higher for HIV-infected men who have sex with men, other men, and women compared with HIV-uninfected individuals. Rates increased from 1996–1999 to 2000–2003 but plateaued by 2004–2007.
Background. Anal cancer is one of the most common cancers affecting individuals infected with human immunodeficiency virus (HIV), although few have evaluated rates separately for men who have sex with men (MSM), other men, and women. There are also conflicting data regarding calendar trends.
Methods. In a study involving 13 cohorts from North America with follow-up between 1996 and 2007, we compared anal cancer incidence rates among 34 189 HIV-infected (55% MSM, 19% other men, 26% women) and 114 260 HIV-uninfected individuals (90% men).
Results. Among men, the unadjusted anal cancer incidence rates per 100 000 person-years were 131 for HIV-infected MSM, 46 for other HIV-infected men, and 2 for HIV-uninfected men, corresponding to demographically adjusted rate ratios (RRs) of 80.3 (95% confidence interval [CI], 42.7–151.1) for HIV-infected MSM and 26.7 (95% CI, 11.5–61.7) for other HIV-infected men compared with HIV-uninfected men. HIV-infected women had an anal cancer rate of 30/100 000 person-years, and no cases were observed for HIV-uninfected women. In a multivariable Poisson regression model, among HIV-infected individuals, the risk was higher for MSM compared with other men (RR, 3.3; 95% CI, 1.8–6.0), but no difference was observed comparing women with other men (RR, 1.0; 95% CI, 0.5–2.2). In comparison with the period 2000–2003, HIV-infected individuals had an adjusted RR of 0.5 (95% CI, .3–.9) in 1996–1999 and 0.9 (95% CI, .6–1.2) in 2004–2007.
Conclusions. Anal cancer rates were substantially higher for HIV-infected MSM, other men, and women compared with HIV-uninfected individuals, suggesting a need for universal prevention efforts. Rates increased after the early antiretroviral therapy era and then plateaued.
Controversy continues regarding the extent of ongoing viral replication in HIV-1-infected patients on effective antiretroviral therapy (ART). Adding an additional potent agent, such as raltegravir, to effective ART in patients with low-level residual viremia may reveal whether there is ongoing HIV-1 replication.
We previously reported the outcome of a randomized, placebo-controlled study of raltegravir intensification in patients on ART with HIV-1 RNA <50 copies/mL that showed no effect on residual viremia measured by single copy assay (SCA). We now report the effects of raltegravir intensification in that trial on other potential measures of ongoing HIV-1 replication: 2-LTR HIV-1 circles, total cellular HIV-1 DNA and T cell activation.
Of 50 patients tested, 12 (24%) had 2-LTR-circles detected at baseline. Patients who were 2-LTR-positive had higher plasma HIV-1 RNA and HIV-1 DNA levels than 2-LTR-negative individuals. At week 12 of raltegravir intensification, there was no change from baseline in 2-LTR circles, in total HIV-1 DNA or in the ratio of 2-LTR circles to total HIV-1 DNA. There was also no change in markers of T cell activation.
In HIV-1-infected individuals on effective antiretroviral therapy, we find no evidence of ongoing viral replication in the blood that is suppressible by raltegravir intensification. The results imply that raltegravir intensification alone will not eradicate HIV-1 infection.
Raltegravir; HIV-1; viral replication; reservoirs; 2-LTR circles; HIV-1 DNA; T cell activation
HIV-1 reservoirs preclude virus eradication in patients receiving highly active antiretroviral therapy (HAART). The best characterized reservoir is a small, difficult-to-quantify pool of resting memory CD4+ T cells carrying latent but replication-competent viral genomes. Because strategies targeting this latent reservoir are now being tested in clinical trials, well-validated high-throughput assays that quantify this reservoir are urgently needed. Here we compare eleven different approaches for quantitating persistent HIV-1 in 30 patients on HAART, using the original viral outgrowth assay for resting CD4+ T cells carrying inducible, replication-competent viral genomes as a standard for comparison. PCR-based assays for cells containing HIV-1 DNA gave infected cell frequencies at least 2 logs higher than the viral outgrowth assay, even in subjects who started HAART during acute/early infection. This difference may reflect defective viral genomes. The ratio of infected cell frequencies determined by viral outgrowth and PCR-based assays varied dramatically between patients. Although strong correlations with the viral outgrowth assay could not be formally excluded for most assays, correlations achieved statistical significance only for integrated HIV-1 DNA in peripheral blood mononuclear cells and HIV-1 RNA/DNA ratio in rectal CD4+ T cells. Residual viremia was below the limit of detection in many subjects and did not correlate with the viral outgrowth assays. The dramatic differences in infected cell frequencies and the lack of a precise correlation between culture and PCR-based assays raise the possibility that the successful clearance of latently infected cells may be masked by a larger and variable pool of cells with defective proviruses. These defective proviruses are detected by PCR but may not be affected by reactivation strategies and may not require eradication to accomplish an effective cure. A molecular understanding of the discrepancy between infected cell frequencies measured by viral outgrowth versus PCR assays is an urgent priority in HIV-1 cure research.
Efforts to cure HIV-1 infection have focused on a small pool of CD4+ T cells that carry viral genetic information in a latent form. These cells persist even in patients on optimal antiretroviral therapy. Novel therapeutic strategies targeting latently infected cells are being developed, and therefore practical assays for measuring latently infected cells are urgently needed. These cells were discovered using a virus culture assay in which the cells are induced to release virus particles that are then expanded in culture. This assay is difficult, time-consuming, and expensive. Here we evaluate alternative approaches for measuring persistent HIV-1, all of which rely on the detection of viral genetic information using the polymerase chain reaction (PCR). None of the PCR-based assays correlated precisely with the virus culture assay. The fundamental problem is that infected cell frequencies determined by PCR are at least 2 logs higher than frequencies determined by the culture assay. Much of this difference may be due to cells carrying defective forms of the virus. These cells may not be eliminated by strategies designed to target latently infected cells. In this situation, successful clearance of latently infected cells might be masked by a large unchanging pool of cells carrying defective HIV-1.
To examine the association between changes in glomerular filtration rates (GFR) and antiretroviral therapy (ART)-mediated suppression of plasma HIV-1 viremia.
Observational, prospective, multicenter cohort study.
ART regimens or treatment strategies in HIV-1-infected subjects were implemented through randomized clinical trials; 1776 ambulatory subjects from these trials also enrolled in this cohort study.
The association between suppression of viremia and GFR changes from baseline was examined using the abbreviated Modification of Diet and Renal Disease equation in mixed effects linear models.
GFR improvement was associated with ART-mediated suppression of plasma viremia in subjects with both chronic kidney disease stage ≥2 and low baseline CD4 cell counts (< 200 cells/µl). In this subset, viral suppression (by > 1.0 log10 copies/ml or to < 400 copies/ml) was associated with an average increase in GFR of 9.2 ml/min per 1.73 m2 from baseline (95% confidence interval, 1.6–16.8; P = 0.02) over a median follow-up of 160 weeks. The magnitude of this association increased in subjects who had greater baseline impairment of renal function, and it did not depend on race or sex.
Viral suppression was associated with GFR improvements in those with both low CD4 cell counts and impaired baseline renal function, supporting an independent contribution of HIV-1 replication to chronic renal dysfunction in advanced HIV disease. GFR improvement not associated with viral suppression also was observed in subjects with higher CD4 cell counts.
antiretroviral therapy; chronic kidney disease; HIV-1 viremia; HIV-associated nephropathy
Patients with tuberculosis (TB) often suffer from profound malnutrition.
To examine the patterns and predictors of change in nutritional and hemoglobin status during and after TB treatment.
A total of 471 HIV-positive and 416 HIV-negative adults with pulmonary TB were prospectively followed in Dar es Salaam, Tanzania. All patients received 8 months TB treatment following enrollment.
About 40% of HIV-positive and 47% of HIV-negative TB patients had BMI <18.5 kg/m2 at baseline. About 94% of HIV-positive and 84% of HIV-negative participants were anemic at baseline. Both HIV-positive and HIV-negative patients experienced increases in BMI and hemoglobin concentrations over the course of TB treatment. Among HIV-positive patients, older age, low CD4 cell counts, and high viral load were independently associated with a smaller increase in BMI from baseline to 8 months. Female sex, older age, low CD4 cell counts, previous TB infection, and less money spent on food were independently associated with a smaller improvement in hemoglobin among HIV-positive patients during treatment.
HIV- positive TB patients, especially those with low CD4 cell counts, showed poor nutritional recovery during TB treatment. Adequate nutritional support should be considered during TB treatment.
tuberculosis; HIV; malnutrition; anemia
Background. Screening for tuberculosis prior to highly active antiretroviral therapy (HAART) initiation is not routinely performed in low-incidence settings. Identifying factors associated with developing tuberculosis after HAART initiation could focus screening efforts.
Methods. Sixteen cohorts in the United States and Canada contributed data on persons infected with human immunodeficiency virus (HIV) who initiated HAART December 1995–August 2009. Parametric survival models identified factors associated with tuberculosis occurrence.
Results. Of 37845 persons in the study, 145 were diagnosed with tuberculosis after HAART initiation. Tuberculosis risk was highest in the first 3 months of HAART (20 cases; 215 cases per 100000 person-years; 95% confidence interval [CI]: 131–333 per 100000 person-years). In a multivariate Weibull proportional hazards model, baseline CD4+ lymphocyte count <200, black race, other nonwhite race, Hispanic ethnicity, and history of injection drug use were independently associated with tuberculosis risk. In addition, in a piece-wise Weibull model, increased baseline HIV-1 RNA was associated with increased tuberculosis risk in the first 3 months; male sex tended to be associated with increased risk.
Conclusions. Screening for active tuberculosis prior to HAART initiation should be targeted to persons with baseline CD4 <200 lymphocytes/mm3 or increased HIV-1 RNA, persons of nonwhite race or Hispanic ethnicity, history of injection drug use, and possibly male sex.
Antiretroviral therapy (ART) introduced during primary HIV infection followed by treatment interruption (TI) is postulated to enhance virologic control through induction of HIV-specific CD4+ T-cells, which foster virus-specific CD8+ T-cells that suppress virus replication. This hypothesis was evaluated in 21 subjects enrolled in ACTG 709, a substudy of ACTG 371, which prospectively evaluated subjects who received ≥1 year of ART initiated in acute or recent HIV infection followed by TI.
Lymphoproliferation was assessed by [methyl-3H]thymidine incorporation and HIV-specific CD8+ T-cell interferon-gamma responses by enzyme-linked immunospot-forming (ELISPOT) assays. Virologic success was defined as sustained viral load <5,000 copies/mL for 24 weeks after TI.
HIV-specific lymphoproliferative responses were detected at least once in 5 (24%) of 21 subjects, were generally transient, and were unrelated to HIV-specific interferon-gamma responses (p>0.4). HIV-specific CD8+ interferon-gamma responses increased after 48 weeks of ART (p=0.03), but failed to predict virologic success (p=0.18). Compared to seronegative subjects, lymphoproliferation to Candida, cytomegalovirus, and alloantigens was similar in HIV-infected subjects during ART, but lower during TI (p≤0.04).
HIV-specific CD8+ T-cell interferon-gamma responses expand during ART following primary HIV infection, but are not related to HIV-specific lymphoproliferative responses nor virologic success. Impaired non-HIV antigen-specific lymphoproliferation associated with TI suggests this strategy could be deleterious.
In HIV-infected individuals on antiretroviral treatment with viral suppression, structured treatment interruptions are designed to allow exposure to endogenous HIV antigens and to thereby boost HIV-specific immunity. AIDS Clinical Trials Group A5132 was an exploratory 2-arm randomized trial that evaluated two 4-week treatment interruptions in combination with 2 strategies for administering interleukin-2 (IL-2): 2.0 million international units of IL-2 subcutaneously daily during the final 2 weeks of treatment interruption and the first week of treatment reinitiation (arm A), or 4.5 million international units of IL-2 subcutaneously twice a day during the first 5 days of treatment reinitiation (arm B). Twenty-one subjects with HIV-1 RNA <50 copies/mL and CD4+ T cell counts ≥300 (median 615) cells/mm3 were randomized. The primary endpoint was the viral setpoint measured 11–12 weeks after a third treatment interruption (observed for 7 Arm A and 9 Arm B). The median HIV-1 RNA setpoints were 4.3 and 4.5 log10 copies/mL for Arm A and Arm B, respectively; there was no evidence of a difference between arms (P = 0.50, rank-sum test, worst rank for unobserved viral setpoint). The current study, the first to evaluate IL-2 during repeated short-term treatment interruptions, revealed no evidence for augmentation of HIV immunity. Viral setpoints were similar to historical controls, emphasizing the need for new strategies to enhance HIV-specific immunity.
Experimental data suggest a role for iron in the course of tuberculosis (TB) infection, but there is limited evidence on the potential effects of iron deficiency or iron overload on the progression of TB disease in humans. The aim of the present analysis was to examine the association of iron status with the risk of TB progression and death.
We analyzed plasma samples and data collected as part a randomized micronutrient supplementation trial (not including iron) among HIV-infected and HIV-uninfected TB patients in Dar es Salaam, Tanzania. We prospectively related baseline plasma ferritin concentrations from 705 subjects (362 HIV-infected and 343 HIV-uninfected) to the risk of treatment failure at one month after initiation, TB recurrence and death using binomial and Cox regression analyses. Overall, low (plasma ferritin<30 µg/L) and high (plasma ferritin>150 µg/L for women and>200 µg/L for men) iron status were seen in 9% and 48% of patients, respectively. Compared with normal levels, low plasma ferritin predicted an independent increased risk of treatment failure overall (adjusted RR = 1.95, 95% CI: 1.07 to 3.52) and of TB recurrence among HIV-infected patients (adjusted RR = 4.21, 95% CI: 1.22 to 14.55). High plasma ferritin, independent of C-reactive protein concentrations, was associated with an increased risk of overall mortality (adjusted RR = 3.02, 95% CI: 1.95 to 4.67).
Both iron deficiency and overload exist in TB patients and may contribute to disease progression and poor clinical outcomes. Strategies to maintain normal iron status in TB patients could be helpful to reduce TB morbidity and mortality.
Detectable HIV-1 in body compartments can lead to transmission and antiretroviral resistance. Although sex differences in viral shedding have been demonstrated, mechanisms and magnitude are unclear. We compared RNA levels in blood, genital-secretions and saliva; and drug resistance in plasma and genital-secretions of men and women starting/changing antiretroviral therapy (ART) in the AIDS Clinical Trials Group (ACTG) 5077 study.
Blood, saliva and genital-secretions (compartment fluids) were collected from HIV-infected adults (≥13 years) at 14 United-States sites, who were initiating or changing ART with plasma viral load (VL) ≥2,000 copies/mL. VL testing was performed on all compartment fluids and HIV resistance genotyping on plasma and genital-secretions. Spearman rank correlations were used to evaluate concordance and Fisher’s and McNemar’s exact tests to compare VL between sexes and among compartments.
Samples were available for 143 subjects; 36% treated (23 men, 29 women) and 64% ‘untreated’ (40 men, 51 women). RNA detection was significantly more frequent in plasma (100%) than genital-secretions (57%) and saliva (64%) (P<0.001). A higher proportion of men had genital shedding versus women (78% versus 41%), and RNA detection was more frequent in saliva versus genital-secretions in women when adjusted for censoring at the limit of assay detection. Inter-compartment fluid VL concordance was low in both sexes. In 22 (13 men, 9 women) paired plasma-genital-secretion genotypes from treated subjects, most had detectable resistance in both plasma (77%) and genital-secretions (68%). Resistance discordance was observed between compartments in 14% of subjects.
HIV shedding and drug resistance detection prior to initiation/change of ART in ACTG 5077 subjects differed among tissues and between sexes, making the gold standard blood-plasma compartment assessment not fully representative of HIV at other tissue sites. Mechanisms of potential sex-dependent tissue compartmentalization should be further characterized to aid in optimizing treatment and prevention of HIV transmission.