To investigate the impact of HAART-induced HIV suppression on levels of 24 serological biomarkers of inflammation and immune activation.
Prospective cohort study.
Biomarkers were measured with multiplex assays in centralized laboratories using stored serum samples contributed by 1,697 men during 8,903 person-visits in the Multicenter AIDS Cohort Study (MACS) from 1984–2009. Using generalized gamma models, we compared biomarker values across three groups, adjusting for possible confounders: HIV-uninfected (NEG); HIV+, HAART-naïve (NAI); and HAART-exposed with HIV RNA suppressed to <50 copies/mL plasma (SUP). We also estimated changes in biomarker levels associated with duration of HIV suppression, using splined generalized gamma regression with a knot at one year.
Most biomarkers were relatively normalized in the SUP group relative to the NAI group; however, 12 biomarkers in the SUP group were distinct (p<0.002) from NEG values: CXCL10, CRP, sCD14, sTNFR2, TNF-α, sCD27, sGP130, IL-8, CCL13, BAFF, GM-CSF, and IL-12p70. Thirteen biomarkers exhibited significant changes in the first year after viral suppression, but none changed significantly after that time.
Biomarkers of inflammation and immune activation moved toward HIV-negative levels within the first year after HAART-induced HIV suppression. Although several markers of T cell activation returned to levels present in HIV-negative men, residual immune activation, particularly monocyte/macrophage activation, was present. This residual immune activation may represent a therapeutic target to improve the prognosis of HIV-infected individuals receiving HAART.
Acquired Immunodeficiency Syndrome; Antiretroviral Therapy, Highly Active; Biological Markers; Inflammation; Prospective Studies; Male
To determine whether markers of systemic inflammation are associated with the presence of moderate-to-severe obstructive sleep apnea (OSA), and whether this association differs based on HIV and HIV treatment status.
HIV-uninfected men (HIV−; n=60), HIV-infected men receiving HAART (HIV+/HAART; n=58), and HIV-infected men not receiving HAART (HIV+/ No HAART; n=41) underwent polysomnograpy and measurement of plasma levels of TNF-alpha, soluble TNF-alpha receptors I and II (sTNFRI and sTNFRII) and IL-6. The relationship between moderate-severe OSA (respiratory disturbance index ≥15 apnea/hypopnea events/hour) and inflammatory markers was assessed with multivariable regression models.
Compared to the HIV− men, HIV+/HAART men and HIV+/No HAART men had higher levels of TNF-alpha, sTNFRI, and sTNFRII, independent of age, race, smoking status, obstructive lung disease (OLD), and BMI. Moderate-to-severe OSA was present in 48% of the sample (HIV−:57%; HIV+/HAART: 41%; HIV+/No HAART: 44%). Among the HIV+/No HAART men, but not in the other groups, TNF-alpha, sTNFRII, and IL-6 levels were higher in those with moderate-severe OSA compared to men with no-to-mild OSA after adjustment for age, race, smoking status, OLD, and BMI. Within this group, the association of high TNF-alpha concentrations with moderate-severe OSA was also independent of CD4 cell count and plasma HIV RNA concentration.
Compared to HIV-infected men on HAART and HIV-uninfected men, markers of systemic inflammation were higher in HIV-infected men not receiving HAART. In these men, TNF-alpha was significantly related to obstructive sleep apnea, independent of HIV-related covariates.
The latent reservoir for HIV-1 in resting memory CD4+ T cells is a major barrier to eradication. In vitro models involving transformed cell lines have been used to search for small molecules that reactivate latent HIV-1. Histone deacetylase (HDAC) inhibitors can reverse HIV-1 latent infection. Most studies on HDAC inhibitors have been performed in cell line models that differ in important aspects from the resting CD4+ T cells that harbour latent HIV-1 in vivo. Therefore, we evaluated the potency and kinetics of HDAC inhibitors in a primary cell model of HIV-1 latency that involves resting CD4+ T cells.
A green fluorescent protein (GFP)-expressing reporter virus NL4-3-Δ6-drGFP was used to generate latent infection in Bcl-2-transduced primary CD4+ T cells. Seventeen HDAC inhibitors were tested in this primary cell model. The effects of these HDAC inhibitors on the reactivation of latent HIV-1 were determined and compared with anti-CD3 and anti-CD28 co-stimulation.
In Bcl-2-transduced primary CD4+ T cells, short-term treatment with HDAC inhibitors resulted in very limited reactivation of latent HIV-1, while prolonged treatment greatly enhanced drug efficacy. The effects of HDAC inhibitors in reactivating latent HIV-1 correlated with their inhibitory effects on class I HDACs. Importantly, HIV-1 reactivated by HDAC inhibitors can quickly re-establish latent infection upon drug removal.
We identified unique features of HDAC inhibitor-induced reactivation of latent HIV-1 in primary CD4+ T cells. Our findings may be useful for the design of eradication trials.
latent reservoir; cytotoxicity; vorinostat
IL-17A stimulates cardiac fibroblasts to produce inflammatory mediators critical for the recruitment and differentiation of myeloid cells during inflammatory dilated cardiomyopathy.
Inflammatory dilated cardiomyopathy (DCMi) is a major cause of heart failure in individuals below the age of 40. We recently reported that IL-17A is required for the development of DCMi. We show a novel pathway connecting IL-17A, cardiac fibroblasts (CFs), GM-CSF, and heart-infiltrating myeloid cells with the pathogenesis of DCMi. Il17ra−/− mice were protected from DCMi, and this was associated with significantly diminished neutrophil and Ly6Chi monocyte/macrophage (MO/MΦ) cardiac infiltrates. Depletion of Ly6Chi MO/MΦ also protected mice from DCMi. Mechanistically, IL-17A stimulated CFs to produce key chemokines and cytokines that are critical downstream effectors in the recruitment and differentiation of myeloid cells. Moreover, IL-17A directs Ly6Chi MO/MΦ in trans toward a more proinflammatory phenotype via CF-derived GM-CSF. Collectively, this IL-17A–fibroblast–GM-CSF–MO/MΦ axis could provide a novel target for the treatment of DCMi and related inflammatory cardiac diseases.
Body fat changes in HIV-infected persons are associated with increased systemic inflammation and increased mortality. It is unknown whether lipodystrophy is also associated with declines in physical function. Between 2001 and 2003, 33 HIV-infected men with evidence of lipodystrophy (LIPO+), 23 HIV-infected men without lipodystrophy (LIPO−), and 33 seronegative men were recruited from the Multicenter AIDS Cohort Study (MACS) for the Body Composition substudy. Visceral adipose tissue (VAT) was assessed by quantitative computed tomography. Lean body mass (LBM) and extremity fat were measured by dual-energy x-ray absorptiometry. Insulin resistance was estimated by Homeostatic Model Assessment (HOMA). Serum interleukin (IL)-6, soluble tumor necrosis factor (TNF)-α receptors I and II (sTNFRI and sTNFRII), and highly sensitive C-reactive protein (hs-CRP) concentrations were quantified from archived serum samples. These measurements were correlated with grip strength measured in 2007 using linear regression. At the substudy visit, the LIPO+ group had higher HOMA, sTNFRI, sTNFRII, and IL-6 levels than the LIPO− group. In 2007, the LIPO+ group had lower median grip strength than the LIPO− group (34.4 vs. 42.7 kg, p=0.002). Multivariable analysis of HIV+ men showed older age, lower LBM, higher sTNFRII concentrations, and LIPO+ status [adjusted mean difference −4.9 kg (p=0.045)] at the substudy visit were independently associated with lower subsequent grip strength. Inflammation, lower LBM, and lipodystrophy in HIV-infected men were associated with lower subsequent grip strength. These findings suggest that inflammation may contribute to declines in functional performance, independent of age.
The continuous improvement and evolution of immune cell phenotyping requires periodic upgrading of laboratory methods and technology. Flow cytometry laboratories that are participating in research protocols sponsored by the NIAID are required to perform “switch” studies to validate performance before methods for T-cell subset analysis can be changed.
Switch studies were conducted among the four flow cytometry laboratories of the Multicenter AIDS Cohort Study (MACS), comparing a 2-color, lyse-wash method and a newer, 3-color, lyse no-wash method. Two of the laboratories twice failed to satisfy the criteria for acceptable differences from the previous method. Rather than repeating more switch studies, these laboratories were allowed to adopt the 3-color, lyse no-wash method. To evaluate the impact of the switch to the new method at these two sites, their results with the new method were evaluated within the context of all laboratories participating in the NIH-NIAID-Division of AIDS Immunology Quality Assurance (IQA) proficiency-testing program.
Laboratory performance at these two sites substantially improved relative to the IQA standard test results. Variation across the four MACS sites and across replicate samples was also reduced.
Although switch studies are the conventional method for assessing comparability of laboratory methods, two alternatives to the requirement of repeating failed switch studies should be considered: (1) test the new method and assess performance on the proficiency testing reference panel, and (2) prior to adoption of the new methods, use both the old and the new method on the reference panel samples and demonstrate that performance with the new method is better according to standard statistical procedures. These alternatives may help some laboratories’ transition to a new and superior methodology more quickly than if they are required to attempt multiple, serial switch studies.
HIV; immunophenotyping; flow cytometry; quality assessment; multicenter studies
We investigated the association of HIV infection and highly active antiretroviral therapy (HAART) with sleep disordered breathing (SDB), fatigue, and sleepiness.
HIV-uninfected men (HIV−; n = 60), HIV-infected men using HAART (HIV+/HAART+; n = 58), and HIV-infected men not using HAART (HIV+/HAART−; n = 41) recruited from two sites of the Multicenter AIDS cohort study (MACS) underwent a nocturnal sleep study, anthropometric assessment, and questionnaires for fatigue and the Epworth Sleepiness Scale. The prevalence of SDB in HIV- men was compared to that in men matched from the Sleep Heart Health Study (SHHS).
The prevalence of SDB was unexpectedly high in all groups: 86.7% for HIV−, 70.7% for HIV+/HAART+, and 73.2% for HIV+/HAART−, despite lower body-mass indices (BMI) in HIV+ groups. The higher prevalence in the HIV− men was significant in univariate analyses but not after adjustment for BMI and other variables. SDB was significantly more common in HIV− men in this study than those in SHHS, and was common in participants with BMIs <25 kg/m2. HIV+ men reported fatigue more frequently than HIV− men (25.5% vs. 6.7%; p = 0.003), but self-reported sleepiness did not differ among the three groups. Sleepiness, but not fatigue, was significantly associated with SDB.
SDB was highly prevalent in HIV− and HIV+ men, despite a normal or slightly elevated BMI. The high rate of SDB in men who have sex with men deserves further investigation. Sleepiness, but not fatigue, was related to the presence of SDB. Clinicians caring for HIV-infected patients should distinguish between fatigue and sleepiness when considering those at risk for SDB, especially in non-obese men.
Multiassay algorithms (MAAs) can be used to estimate cross-sectional HIV incidence. We previously identified a robust MAA that includes the BED capture enzyme immunoassay (BED-CEIA), the Bio-Rad Avidity assay, viral load, and CD4 cell count. In this report, we evaluated MAAs that include a high-resolution melting (HRM) diversity assay that does not require sequencing. HRM scores were determined for eight regions of the HIV genome (2 in gag, 1 in pol, and 5 in env). The MAAs that were evaluated included the BED-CEIA, the Bio-Rad Avidity assay, viral load, and the HRM diversity assay, using HRM scores from different regions and a range of region-specific HRM diversity assay cutoffs. The performance characteristics based on the proportion of samples that were classified as MAA positive by duration of infection were determined for each MAA, including the mean window period. The cross-sectional incidence estimates obtained using optimized MAAs were compared to longitudinal incidence estimates for three cohorts in the United States. The performance of the HRM-based MAA was nearly identical to that of the MAA that included CD4 cell count. The HRM-based MAA had a mean window period of 154 days and provided cross-sectional incidence estimates that were similar to those based on cohort follow-up. HIV diversity is a useful biomarker for estimating HIV incidence. MAAs that include the HRM diversity assay can provide accurate HIV incidence estimates using stored blood plasma or serum samples without a requirement for CD4 cell count data.
Multi-assay algorithms (MAAs) can be used to estimate HIV incidence in cross-sectional surveys. We compared the performance of two MAAs that use HIV diversity as one of four biomarkers for analysis of HIV incidence.
Both MAAs included two serologic assays (LAg-Avidity assay and BioRad-Avidity assay), HIV viral load, and an HIV diversity assay. HIV diversity was quantified using either a high resolution melting (HRM) diversity assay that does not require HIV sequencing (HRM score for a 239 base pair env region) or sequence ambiguity (the percentage of ambiguous bases in a 1,302 base pair pol region). Samples were classified as MAA positive (likely from individuals with recent HIV infection) if they met the criteria for all of the assays in the MAA. The following performance characteristics were assessed: (1) the proportion of samples classified as MAA positive as a function of duration of infection, (2) the mean window period, (3) the shadow (the time period before sample collection that is being assessed by the MAA), and (4) the accuracy of cross-sectional incidence estimates for three cohort studies.
The proportion of samples classified as MAA positive as a function of duration of infection was nearly identical for the two MAAs. The mean window period was 141 days for the HRM-based MAA and 131 days for the sequence ambiguity-based MAA. The shadows for both MAAs were <1 year. Both MAAs provided cross-sectional HIV incidence estimates that were very similar to longitudinal incidence estimates based on HIV seroconversion.
MAAs that include the LAg-Avidity assay, the BioRad-Avidity assay, HIV viral load, and HIV diversity can provide accurate HIV incidence estimates. Sequence ambiguity measures obtained using a commercially-available HIV genotyping system can be used as an alternative to HRM scores in MAAs for cross-sectional HIV incidence estimation.
To review the incidence of respiratory conditions and their effect on mortality in HIV-infected and uninfected individuals prior to and during the era of highly active antiretroviral therapy (HAART).
Two large observational cohorts of HIV-infected and HIV-uninfected men (Multicenter AIDS Cohort Study [MACS]) and women (Women’s Interagency HIV Study [WIHS]), followed since 1984 and 1994, respectively.
Adjusted odds or hazards ratios for incident respiratory infections or non-infectious respiratory diagnoses, respectively, in HIV-infected compared to HIV-uninfected individuals in both the pre-HAART (MACS only) and HAART eras; and adjusted Cox proportional hazard ratios for mortality in HIV-infected persons with lung disease during the HAART era.
Compared to HIV-uninfected participants, HIV-infected individuals had more incident respiratory infections both pre-HAART (MACS, odds ratio [adjusted-OR], 2.4; 95% confidence interval [CI], 2.2–2.7; p<0.001) and after HAART availability (MACS, adjusted-OR, 1.5; 95%CI 1.3–1.7; p<0.001; WIHS adjusted-OR, 2.2; 95%CI 1.8–2.7; p<0.001). Chronic obstructive pulmonary disease was more common in MACS HIV-infected vs. HIV-uninfected participants pre-HAART (hazard ratio [adjusted-HR] 2.9; 95%CI, 1.02–8.4; p = 0.046). After HAART availability, non-infectious lung diseases were not significantly more common in HIV-infected participants in either MACS or WIHS participants. HIV-infected participants in the HAART era with respiratory infections had an increased risk of death compared to those without infections (MACS adjusted-HR, 1.5; 95%CI, 1.3–1.7; p<0.001; WIHS adjusted-HR, 1.9; 95%CI, 1.5–2.4; p<0.001).
HIV infection remained a significant risk for infectious respiratory diseases after the introduction of HAART, and infectious respiratory diseases were associated with an increased risk of mortality.
To examine the incidence and risk factors for anal cancer in a multicenter cohort of HIV-positive and negative men who have sex with men followed between 1984 and 2006 (MACS).
Prospective analysis using Poisson regression and Cox proportional hazard models, and a nested case-control study using conditional logistic regression.
There were 28 cases of anal cancer among the 6,972 men who were evaluated. The incidence rate was significantly higher in HIV-positive men than in HIV-negative men (IR= 69 vs. 14 per 100,000 person-years). Among HIV-positive men, anal cancer incidence was higher in the HAART era than the pre-HAART era (IR=137 vs. 30 per 100,000 person-years). In multivariate analysis restricted to the HAART era, anal cancer risk increased significantly with HIV infection (RH=4.7, 95%CI=1.3–17), and increasing number of unprotected receptive anal sex partners at the first three study visits (p-trend=0.03). Among HIV-positive men, current HAART use did not decrease anal cancer risk.
HIV-positive men had increased risk of anal cancer. Improved survival of HIV-positive individuals following HAART initiation may allow for sufficient time for human papillomavirus (HPV) associated anal dysplasias to develop into malignancies, thus explaining the increased incidence of anal cancer in the HAART era.
anal; rectal; cancer; incidence; MACS; sexual risk; HAART
To examine if altered levels of adipokines, adipose-derived peptides associated with myocardial infarction in the general population, may contribute to subclinical coronary atherosclerosis in HIV-infected persons.
Nested cohort study.
We studied HIV-infected(HIV+) and HIV-uninfected(HIV−) men in the Multicenter AIDS Cohort Study with noncontrast CT to measure coronary artery calcium and regional adiposity; 75% additionally underwent coronary CT angiography to measure plaque composition and stenosis. Adiponectin and leptin levels were assessed. Multiple regression models were used to assess associations between adipokine levels and HIV disease parameters, regional adiposity, and plaque adjusted for age, race, HIV serostatus and CVD risk factors (RFs).
Significant findings were limited to adiponectin. HIV+ men (n=493) had lower adiponectin levels than HIV− men (n=250) after adjusting for CVD RFs (p<0.0001), which became non-significant after adjustment for abdominal visceral and thigh subcutaneous adipose tissue. Among HIV+ men, lower adiponectin levels were associated with higher CD4+ T cell counts (p= 0.004), longer duration of antiretroviral therapy (p= 0.006) and undetectable HIV RNA levels (p = 0.04) after adjusting for age, race and CVD RFs; only CD4+ cell count remained significant after further adjustment for adipose tissue. In both groups, lower adiponectin levels were associated with increased odds of coronary stenosis > 50% (p <0.007). Lower adiponectin levels were associated with increased extent of plaque in HIV+ and of mixed plaque in HIV− men.
Adiponectin levels were lower in HIV-infected men and related to the severity of subclinical atherosclerosis, independent of traditional CVD risk factors.
Adipokines; adiponectin; leptin; heart; subclinical coronary atherosclerosis; metabolic side effects of HIV infection; coronary CT angiography; cardiac CT
Cytokine stimulation of B-cell proliferation may be an important etiologic mechanism for acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin lymphoma (NHL). The Epstein-Barr virus may be a co-factor, particularly for primary central nervous system (CNS) tumors, which are uniformly EBV-positive in the setting of AIDS. Thus, we examined associations of genetic variation in IL10 and related cytokine signaling molecules (IL10RA, CXCL12, IL13, IL4, IL4R, CCL5 and BCL6) with AIDS-related NHL risk and evaluated differences between primary CNS and systemic tumors. We compared 160 Multicenter AIDS Cohort Study (MACS) participants with incident lymphomas, of which 90 followed another AIDS diagnosis, to HIV-1-seropositive controls matched on duration of lymphoma-free survival post-HIV-1 infection (N=160) or post-AIDS diagnosis (N=90). We fit conditional logistic regression models to estimate odds ratios (ORs) and 95 percent confidence intervals (95%CIs). Carriage of at least one copy of the T allele for the IL10 rs1800871 (as compared to no copies) was associated with decreased AIDS-NHL risk specific to lymphomas arising from the CNS (CC vs. CT/TT: OR=0.3; 95%CI: 0.1, 0.7) but not systemically (CC vs. CT/TT: OR=1.0; 95%CI: 0.5, 1.9) (Pheterogeneity=0.03). Carriage of two copies of the “low IL10” haplotype rs1800896_A/rs1800871_T/rs1800872_A was associated with decreased lymphoma risk that varied by number of copies (Ptrend=0.02). None of the ORs for the other studied polymorphisms was significantly different from 1.0. Excessive IL10 response to HIV-1 infection may be associated with increased risk of NHL, particularly in the CNS. IL10 dysregulation may be an important etiologic pathway for EBV-related lymphomagenesis.
cytokine; SNPs; AIDS-related lymphoma
Formulae used to estimate glomerular filtration rate (GFR) underestimate higher GFRs and have not been well-studied in HIV-infected (HIV(+)) people; we evaluated the relationships of HIV infection and known or potential risk factors for kidney disease with directly measured GFR and the presence of chronic kidney disease (CKD).
Cross-sectional measurement of iohexol-based GFR (iGFR) in HIV(+) men (n = 455) receiving antiretroviral therapy, and HIV-uninfected (HIV(−)) men (n = 258) in the Multicenter AIDS Cohort Study.
iGFR was calculated from disappearance of infused iohexol from plasma. Determinants of GFR and the presence of CKD were compared using iGFR and GFR estimated by the CKD-Epi equation (eGFR).
Median iGFR was higher among HIV(+) than HIV(−) men (109 vs. 106 ml/min/1.73 m2, respectively, p = .046), and was 7 ml/min higher than median eGFR. Mean iGFR was lower in men who were older, had chronic hepatitis C virus (HCV) infection, or had a history of AIDS. Low iGFR (≤90 ml/min/1.73 m2) was associated with these factors and with black race. Other than age, factors associated with low iGFR were not observed with low eGFR. CKD was more common in HIV(+) than HIV(−) men; predictors of CKD were similar using iGFR and eGFR.
iGFR was higher than eGFR in this population of HIV-infected and -uninfected men who have sex with men. Presence of CKD was predicted equally well by iGFR and eGFR, but associations of chronic HCV infection and history of clinically-defined AIDS with mildly decreased GFR were seen only with iGFR.
Background. Accurate testing algorithms are needed for estimating human immunodeficiency virus (HIV) incidence from cross-sectional surveys.
Methods. We developed a multiassay algorithm (MAA) for HIV incidence that includes the BED capture enzyme immunoassay (BED-CEIA), an antibody avidity assay, HIV load, and CD4+ T-cell count. We analyzed 1782 samples from 709 individuals in the United States who had a known duration of HIV infection (range, 0 to >8 years). Logistic regression with cubic splines was used to compare the performance of the MAA to the BED-CEIA and to determine the window period of the MAA. We compared the annual incidence estimated with the MAA to the annual incidence based on HIV seroconversion in a longitudinal cohort.
Results. The MAA had a window period of 141 days (95% confidence interval [CI], 94–150) and a very low false-recent misclassification rate (only 0.4% of 1474 samples from subjects infected for >1 year were misclassified as indicative of recent infection). In a cohort study, annual incidence based on HIV seroconversion was 1.04% (95% CI, .70%–1.55%). The incidence estimate obtained using the MAA was essentially identical: 0.97% (95% CI, .51%–1.71%).
Conclusions. The MAA is as sensitive for detecting recent HIV infection as the BED-CEIA and has a very low rate of false-recent misclassification. It provides a powerful tool for cross-sectional HIV incidence determination.
HIV; incidence testing; United States; epidemiology
There is limited research about cochlear function in adults who are human immunodeficiency virus (HIV) positive (+). The aim of the present study was to collect measures of cochlear function in a large sample of adults with, or at risk for, HIV infection, to evaluate associations between HIV status, HIV treatment, and cochlear function.
Distortion product otoacoustic emissions (DPOAEs) were used to evaluate cochlear function in 506 participants; 329 men, 150 of whom were HIV+, and 177 women, 136 of whom were HIV+. DPOAEs were measured at frequencies 1000, 2000, 3000, 4000, and 6000 Hz. A DPOAE nonresponse (NR) was defined as an absolute DPOAE level less than −15 dB SPL or a difference between the absolute DPOAE level and the background noise level less than 6 dB. The total number of NRs was calculated for each ear. The associations of demographic variables, HIV status, and HIV treatment with number of NRs were evaluated with univariate and multivariate ordinal regression models.
There was a statistically significant increase in the odds of higher numbers of NRs with age, being male, and being non-Black, but not with HIV status. Among HIV+ participants, there were no statistically significant associations of the HIV disease status or treatment variables with higher number of NRs.
The authors found no evidence of impaired cochlear function by HIV disease status or highly active antiretroviral therapy–treated HIV infection in this cross-sectional study.
A limiting antigen avidity enzyme immunoassay (HIV-1 LAg-Avidity assay) was recently developed for cross-sectional HIV incidence estimation. We evaluated the performance of the LAg-Avidity assay alone and in multi-assay algorithms (MAAs) that included other biomarkers.
Methods and Findings
Performance of testing algorithms was evaluated using 2,282 samples from individuals in the United States collected 1 month to >8 years after HIV seroconversion. The capacity of selected testing algorithms to accurately estimate incidence was evaluated in three longitudinal cohorts. When used in a single-assay format, the LAg-Avidity assay classified some individuals infected >5 years as assay positive and failed to provide reliable incidence estimates in cohorts that included individuals with long-term infections. We evaluated >500,000 testing algorithms, that included the LAg-Avidity assay alone and MAAs with other biomarkers (BED capture immunoassay [BED-CEIA], BioRad-Avidity assay, HIV viral load, CD4 cell count), varying the assays and assay cutoffs. We identified an optimized 2-assay MAA that included the LAg-Avidity and BioRad-Avidity assays, and an optimized 4-assay MAA that included those assays, as well as HIV viral load and CD4 cell count. The two optimized MAAs classified all 845 samples from individuals infected >5 years as MAA negative and estimated incidence within a year of sample collection. These two MAAs produced incidence estimates that were consistent with those from longitudinal follow-up of cohorts. A comparison of the laboratory assay costs of the MAAs was also performed, and we found that the costs associated with the optimal two assay MAA were substantially less than with the four assay MAA.
The LAg-Avidity assay did not perform well in a single-assay format, regardless of the assay cutoff. MAAs that include the LAg-Avidity and BioRad-Avidity assays, with or without viral load and CD4 cell count, provide accurate incidence estimates.
The ability of individual T cells to perform multiple effector functions is crucial
for protective immunity against viruses and cancer. This polyfunctionality is
frequently lost during chronic infections; however, the molecular mechanisms driving
T cell polyfunctionality are poorly understood. We found that human T cells
stimulated by a high concentration of antigen lacked polyfunctionality and expressed
a transcription profile similar to that of exhausted T cells. One specific pathway
implicated by the transcription profile in control of T cell polyfunctionality was
the MAPK/ERK pathway. This pathway was altered in response to different antigen
concentrations, and polyfunctionality correlated with upregulation of phosphorylated
ERK. T cells that were stimulated with a high concentration of antigen upregulated
sprouty-2 (SPRY2), a negative regulator of the MAPK/ERK pathway. The
clinical relevance of SPRY2 was confirmed by examining SPRY2
expression in HIV-specific T cells, where high levels of SPRY2 were seen in
HIV-specific T cells and inhibition of SPRY2 expression enhanced the
HIV-specific polyfunctional response independently of the PD-1 pathway. Our findings
indicate that increased SPRY2 expression during chronic viral
infection reduces T cell polyfunctionality and identify SPRY2 as a potential target
Current assays for quantification of HIV-1 virions rely on real-time reverse transcriptase (RT)-PCR detection of conserved regions of HIV-1 RNA and can be limited by detection of contaminating viral or plasmid DNA. We developed a novel RT-PCR assay using a reverse primer that hybridizes with the poly(A) tail of HIV-1 mRNAs, anchored by conserved viral nucleotides at the most distal region of the transcript. This assay can detect and quantify HIV-1 RNA with high specificity and sensitivity.
Cryopreservation of peripheral blood mononuclear cells (PBMC) allows assays of cellular function and phenotype to be performed in batches at a later time on PBMC at a central laboratory to minimize assay variability. The Multicenter AIDS Cohort Study (MACS) is an ongoing prospective study of the natural and treated history of human immunodeficiency virus (HIV) infection that stores cryopreserved PBMC from participants two times a year at four study sites. In order to ensure consistent recovery of viable PBMC after cryopreservation, a quality assessment program was implemented and conducted in the MACS over a 6-year period. Every 4 months, recently cryopreserved PBMC from HIV-1-infected and HIV-1-uninfected participants at each MACS site were thawed and evaluated. The median recoveries of viable PBMC for HIV-1-infected and -uninfected participants were 80% and 83%, respectively. Thawed PBMC from both HIV-1-infected and -uninfected participants mounted a strong proliferative response to phytohemagglutinin, with median stimulation indices of 84 and 120, respectively. Expression of the lymphocyte surface markers CD3, CD4, and CD8 by thawed PBMC was virtually identical to what was observed on cells measured in real time using whole blood from the same participants. Furthermore, despite overall excellent performance of the four participating laboratories, problems were identified that intermittently compromised the quality of cryopreserved PBMC, which could be corrected and monitored for improvement over time. Ongoing quality assessment helps laboratories improve protocols and performance on a real-time basis to ensure optimal cryopreservation of PBMC for future studies.
Little is known about modifications to highly active antiretroviral therapy (HAART) initiated during acute or early HIV infection.
Reasons for first modifications of HAART regimens were recorded using the AIDS Clinical Trials Group form among 363 subjects who initiated HAART within 1 year of seroconversion from 2005 in the Acute Infection and Early Disease Research Program. Modifications recorded as due to “patient choice” or “physician choice” were clarified by query to the recording site. Times to events were analyzed by Kaplan–Meier methods; significance of differences was assessed by the log-rank test.
Two hundred five of 363 (56%) subjects modified therapy, at a median of 425 days after initiation, by changing drugs, discontinuing treatment, or removing or adding drugs. Most modifications were attributed to toxicity (n = 105, 51%), most of which was low grade; regimen simplification (n = 18, 5%); and achievement of viral suppression (n = 15, 7%). Time to first modification was shorter for those with shorter time from infection to initiation (P = 0.005) and those having higher CD4 lymphocyte count at initiation (P = 0.06). Modifications occurred sooner in subjects receiving regimens taken more than once daily (P < 0.001) or with more than 2 pills daily (P < 0.001). Most regimens were nonnucleoside reverse transcriptase inhibitor based or protease inhibitor based, and these did not differ significantly in rate and timing of modification.
HAART initiated early in HIV infection was modified in the majority of cases, usually due to minor toxicities whose incidence was similar for protease inhibitor–based and nonnucleoside reverse transcriptase inhibitor–based regimens. Convenience of regimens (lower pill burden and dosing frequency) was associated with a lower rate of modification.
cohort studies; regimen modification; toxicity
Previous studies have reported that the adoption of a single-platform flow cytometry cell counting method resulted in lower interlaboratory variation in absolute T cell counts as compared to predicate dual-platform flow cytometry methods which incorporate independent automated lymphocyte counts (Schnizlein-Bick et al., Clin Diagn Lab Immunol 2000;7:336–343; Reimann et al., Clin Diagn Lab Immunol 2000;7:344–351). In the present study, we asked whether use of a single-platform method could reduce variation in absolute cell counts across the laboratories in the Multicenter AIDS Cohort Study (MACS) (n = 4), as suggested by the studies cited.
Identical study samples were shipped overnight to the MACS laboratories either by the National Institute of Allergy and Infectious Diseases, Division of AIDS Immunology Quality Assessment (NIAID-IQA) proficiency-testing program (n = 14), or by the Los Angeles site of the MACS (n = 10). For each sample, two tubes of blood were received; one was used for an automated complete blood count and differential, and the other for flow cytometry. The latter was performed using both our current dual-platform method (three-color CD45 gating and automated hematology) and the single-platform method (with TruCOUNT® beads to generate the absolute counts).
The median percent coefficients of variation (%CVs) for the dual-platform and single-platform methods were 6.6 and 9.9, respectively, for CD4 T cell counts, and 5.9 and 8.5, respectively, for CD8 T cell counts (n = 24). These differences were not statistically significant. The differences in absolute T-cell counts between the MACS sites and the median of all laboratories participating in the NIAID-IQA were smaller for the dual-platform than for single-platform absolute count method.
In contrast to previous reports, we did not observe lower interlaboratory variation across the MACS sites for single-platform absolute lymphocyte subset counting relative to dual-platform methods. This result may be at least partly explained by the lower interlaboratory variation with the optimized dual-platform method in this study relative to the previous reports.
HIV; absolute CD4 counts; flow cytometry; single platform; dual platform; interlaboratory variation
The presence of antibody to R7V (anti-R7VAb), a seven-amino acid sequence derived from β2-microglobulin incorporated into HIV-1 virions from the surface of infected cells, has been proposed as an early marker of nonprogressive HIV-1 infection. The present study was undertaken because no prospective studies have tested this hypothesis. Stored samples collected prospectively from 361 HIV-1 seroconverting men in the Multicenter AIDS Cohort Study (0.44–1.53 years after seroconversion) were assayed for the presence or absence of anti-R7VAb, using a standardized ELISA. Using Cox proportional hazards models, crude and adjusted relative hazards (RH) were determined for the following outcomes: (a) clinically defined AIDS, (b) clinically defined AIDS or CD4 T cell count of <200 cells/μl, and (c) death. A total of 143 (39.6%) men had early anti-R7VAb and 218 (60.4%) did not; 192 (53.2%) developed AIDS. At the visit tested, men with anti-R7VAb had significantly lower CD4 T cell counts and higher plasma HIV-1 viral loads than those without antibody. After adjustment for CD4 T cell count, HIV-1 viral load, CCR5 polymorphism, and use of combined antiretroviral therapy, the presence of anti-R7VAb was associated with a higher risk of progression for all outcomes, but not significantly so. Absence of anti-R7VAb was significantly associated with expression of HLA-B*5701 and -B*2705, two alleles associated with slower progression of HIV-1 disease. The early presence of anti-R7VAb in HIV-1 seroconverters was not associated with slower progression of HIV-1 disease.