The contribution of HLA class II-restricted CD4+ T cell responses to HIV immune control is poorly defined. Here, we delineated novel peptide-DRB1 restrictions in functional assays and analyzed the host genetic effects of HLA-DRB1 alleles on HIV viremia in a large cohort of HIV controllers and progressors (n=1085). We found distinct stratifications in the effect of HLA-DRB1 alleles on HIV viremia, with DRB1*15:02 significantly associated with low viremia (P=0.003, q=0.04) and DRB1*03:01 significantly associated with high viremia (P=0.004, q=0.04). Interestingly, a sub-group of HLA-DRB1 alleles linked with low viremia showed the ability to promiscuously present a larger breadth of peptides with lower functional avidity when compared to HLA-DRB1 alleles linked with high viremia (p=0.018). Our data provide systematic evidence that HLA-DRB1 allele expression significantly impacts the durable control of HIV replication, an effect that appears to be mediated primarily by the protein-specificity of HIV-specific CD4+ T cell responses to Gag and Nef.
We compared the plasma viromes of HIV-infected subjects with low versus high CD4+ T cell counts from the United States and Uganda by using deep sequencing and detected HIV, hepatitis C virus, hepatitis B virus, GB virus C, anellovirus, and human endogenous retrovirus (HERV) reads. An increase in the proportion of reads for anelloviruses, a family of highly prevalent and genetically diverse human viruses, was seen in subjects with AIDS from both countries. The proportion of endogenous human retrovirus reads was increased in AIDS subjects from Uganda but not the United States. Progression to AIDS is therefore associated with changes in the plasma concentration of commensal viruses.
Cardiovascular complications are more common in human immunodeficiency virus–infected individuals than in age-matched uninfected individuals. Antiretroviral therapy reduces the risk of cardiovascular complications, suggesting that viral replication directly or indirectly causes vascular disease. Long-term effective antiretroviral therapy does not fully restore vascular health, and treated adults continue to have higher-than-expected rates of disease progression. Although this excess risk during therapy is likely due to multiple factors, a growing body of evidence suggests that chronic inflammation, which persists during effective antiretroviral therapy, is directly and causally associated with vascular dysfunction and the accelerated development of atherosclerosis.
Abacavir use has been associated with cardiovascular risk, but it is unknown whether this association may be partly explained by patients with kidney disease being preferentially treated with abacavir to avoid tenofovir. Our objective was to compare associations of abacavir and tenofovir with cardiovascular risks in HIV-infected veterans.
Cohort study of 10 931 HIV-infected patients initiating antiretroviral therapy in the Veterans Health Administration from 1997 to 2007, using proportional hazards survival regression.
Primary predictors were exposure to abacavir or tenofovir within the past 6 months, compared with no exposure to these drugs, respectively. Outcomes were time to first atherosclerotic cardiovascular event, defined as coronary, cerebrovascular, or peripheral arterial disease; and time to incident heart failure.
Over 60 588 person-years of observation, there were 501 cardiovascular and 194 heart failure events. Age-standardized event rates among abacavir and tenofovir users were 12.5 versus 8.2 per 1000 person-years for cardiovascular disease, and 3.9 and 3.7 per 1000 person-years for heart failure, respectively. In multivariate-adjusted models, including time-updated measurements of kidney function, recent abacavir use was significantly associated with incident cardiovascular disease [hazard ratio 1.48, 95% confidence interval (CI) 1.08–2.04]; the association was similar but nonsignificant for heart failure (1.45, 0.85–2.47). In contrast, recent tenofovir use was significantly associated with heart failure (1.82, 1.02–3.24), but not with cardiovascular events (0.78, 0.52–1.16).
Recent abacavir exposure was independently associated with increased risk for cardiovascular events. We also observed an association between recent tenofovir exposure and heart failure, which needs to be confirmed in future studies.
antiretroviral therapy; cardiovascular disease; heart failure; HIV
Even in the setting of maximally suppressive antiretroviral therapy (ART), HIV persists indefinitely. Several mechanisms might contribute to this persistence, including chronic inflammation and immune dysfunction. In this study, we have explored a preclinical model for the evaluation of potential interventions that might serve to eradicate or to minimize the level of persistent virus. Given data that metabolic products of the inducible enzyme indoleamine 2,3-dioxygeanse (IDO) might foster inflammation and viral persistence, chronically simian immunodeficiency virus (SIV)-infected, ART-treated rhesus macaques were treated with the IDO inhibitor 1-methyl tryptophan (1mT). Orally administered 1mT achieved targeted plasma levels, but did not impact tryptophan metabolism or decrease viral RNA or DNA in plasma or in intestinal tissues beyond levels achieved by ART alone. Animals treated with 1mT showed no difference in the levels of T cell activation or differentiation, or in the kinetics or magnitude of viral rebound following cessation of ART. Notwithstanding these negative results, our observations suggest that the chronically SIV-infected rhesus macaque on suppressive ART can serve as a tractable model in which to test and to prioritize the selection of other potential interventions designed to eradicate HIV in vivo. In addition, this model might be used to optimize the route and dose by which such interventions are administered and the methods by which their effects are monitored.
Human Endogenous Retroviruses (HERVs) comprise about 8% of the human genome and have lost their ability to replicate or to produce infectious particles after having accumulated mutations over time. We assessed the kinetics of expression of HERV-K (HML-2) Envelope mRNA transcript and surface unit (SU) and transmembrane (TM) subunit proteins during HIV-1 infection. We also mapped the specificity of the humoral response to HERV-K (HML-2) Envelope protein in HIV-1 infected subjects at different stages of disease, and correlated the response with plasma viral load.
We found that HIV-1 modified HERV-K (HML-2) Env mRNA expression, resulting in the expression of a fully N-glycosylated HERV-K (HML-2) envelope protein on the cell surface. Serological mapping of HERV-K (HML-2) envelope protein linear epitopes revealed two major immunogenic domains, one on SU and another on the ectodomain of TM. The titers of HERV-K (HML-2) TM antibodies were dramatically increased in HIV-1 infected subjects (p < 0.0001). HIV-1 infected adults who control HIV-1 in the absence of therapy (“elite” controllers) had a higher titer response against TM compared to antiretroviral-treated adults (p < 0.0001) and uninfected adults (p < 0.0001).
These data collectively suggest that HIV-1 infection induces fully glycosylated HERV-K (HML-2) envelope TM protein to which antibodies are induced. These anti-HERV-K (HML-2) TM antibodies are a potential marker of HIV-1 infection, and are at higher titer in elite controllers. HERV-K (HML-2) envelope TM protein may be a new therapeutic target in HIV-1 infection.
HIV; Antibody; HERV; Endogenous retroviruses; Transmembrane; Envelope; Elite controllers; Alternative transcripts
HIV; pulmonary hypertension; Doppler echocardiography; right heart catheterization
Background. Antiretroviral therapy (ART)–mediated immune reconstitution fails to restore the capacity of the immune system to spontaneously control human immunodeficiency virus (HIV) replication.
Methods. A total of 23 HIV type 1 (HIV-1)–infected, virologically suppressed subjects receiving ART (CD4+ T-cell count, >450 cells/μL) were randomly assigned to have 180 μg/week (for arm A) or 90 μg/week (for arm B) of pegylated (Peg) interferon alfa-2a added to their current ART regimen. After 5 weeks, ART was interrupted, and Peg–interferon alfa-2a was continued for up to 12 weeks (the primary end point), with an option to continue to 24 weeks. End points included virologic failure (viral load, ≥400 copies/mL) and adverse events. Residual viral load and HIV-1 DNA integration were also assessed.
Results. At week 12 of Peg–interferon alfa-2a monotherapy, viral suppression was observed in 9 of 20 subjects (45%), a significantly greater proportion than expected (arm A, P = .0088; arm B, P = .0010; combined arms, P < .0001). Over 24 weeks, both arms had lower proportions of subjects who had viral load, compared with the proportion of subjects in a historical control group (arm A, P = .0046; arm B, P = .0011). Subjects who had a sustained viral load of <400 copies/mL had decreased levels of integrated HIV DNA (P = .0313) but increased residual viral loads (P = .0078), compared with subjects who experienced end-point failure.
Conclusions. Peg–interferon alfa-2a immunotherapy resulted in control of HIV replication and decreased HIV-1 integration, supporting a role for immunomediated approaches in HIV suppression and/or eradication.
Clinical Trials Registration. NCT00594880.
HIV-1; interferon-alpha; viral integration; immunotherapy
Viremic slow progressors (VSP) are a rare subset of HIV-infected persons who exhibit slow immunologic progression despite high viremia. The mechanisms associated with this slow progression remain to be defined. Clinical characteristics of VSP are similar to those of natural hosts for simian immunodeficiency virus (SIV), such as sooty mangabeys (SM) and African green monkeys (AGM), who maintain near-normal CD4 counts despite high-level viremia but maintain low immune activation. Immune activation is a powerful predictor of disease progression, and we hypothesized that low immune activation might also explain the VSP phenotype. Using multiparameter flow cytometry, we assessed levels of T cell activation and regulatory T cells (Treg) in blood and rectal mucosa of VSP, typical progressors, virologic controllers, and seronegative controls. We also assessed Treg function and CD4 T cell proliferative capacity in VSP. Contrary to expectations, we found that VSP subjects have high levels of T cell activation in the gastrointestinal mucosa. The ratio of Treg to CD3+ T cells in the mucosa of VSP was relatively low, potentially contributing to increased immune activation. Nonetheless, CD4+CD25– T cells isolated from these individuals displayed a comparatively weak proliferative response to anti-CD3 stimulation. These data reveal that the VSP phenotype is associated with elevated markers of mucosal immune activation and low numbers of mucosal Treg, suggesting that factors other than immune activation account for this phenotype.
A subset of CD3negCD56negCD16+ Natural Killer (NK) cells is highly expanded during chronic HIV-1 infection. The role of this subset in HIV-1 pathogenesis remains unclear. The lack of NK cell lineage-specific markers has complicated the study of minor NK cell subpopulations.
Using CD7 as an additional NK cell marker, we found that CD3negCD56negCD16+ cells are a heterogeneous population comprised of CD7+ NK cells and CD7neg non-classical myeloid cells. CD7+CD56negCD16+ NK cells are significantly expanded in HIV-1 infection. CD7+CD56negCD16+ NK cells are mature and express KIRs, the C-type lectin-like receptors NKG2A and NKG2C, and natural cytotoxicity receptors similar to CD7+CD56+CD16+ NK cells. CD7+CD56neg NK cells in healthy donors produced minimal IFNγ following K562 target cell or IL-12 plus IL-18 stimulation; however, they degranulated in response to K562 stimulation similar to CD7+CD56+ NK cells. HIV-1 infection resulted in reduced IFNγ secretion following K562 or cytokine stimulation by both NK cell subsets compared to healthy donors. Decreased granzyme B and perforin expression and increased expression of CD107a in the absence of stimulation, particularly in HIV-1-infected subjects, suggest that CD7+CD56negCD16+ NK cells may have recently engaged target cells. Furthermore, CD7+CD56negCD16+ NK cells have significantly increased expression of CD95, a marker of NK cell activation.
Taken together, CD7+CD56negCD16+ NK cells are activated, mature NK cells that may have recently engaged target cells.
Natural killer cells; NK cells; CD7; Human immunodeficiency virus; HIV-1; HIV pathogenesis; CD56neg NK cells
A recommendation by San Francisco General Hospital in January 2010 to initiate antiretroviral therapy in all human immunodeficiency virus (HIV)–infected patients led to a rapid increase in HIV RNA suppression among patients with a CD4 cell count of >500 cells/μL after clinic enrollment.
Background. On 1 January 2010, a large, publicly funded clinic in San Francisco announced a “universal ART” approach to initiate antiretroviral therapy (ART) in all human immunodeficiency virus (HIV)-infected persons. The effect of changing guidance on real-world patient outcomes has not been evaluated.
Methods. We evaluated untreated adult patients (defined as going >90 days without ART use) visiting clinic from 2001 to 2011. The cumulative incidence of HIV RNA suppression (viral load, <500 copies/mL), stratified by CD4 cell count at entry and calendar dates representing guideline issuance, were estimated using a competing risk framework. A multivariate Poisson-based model identified factors associated with HIV RNA suppression 6 months after clinic entry.
Results. Of 2245 adults, 87% were male, and the median age was 39 years (interquartile range, 33–45 years). In 534 patients entering clinic with a CD4 cell count of >500 cells/µL, the 1-year incidence of HIV RNA suppression was 10.1% (95% confidence interval [CI], 6.6%–14.6%) before 4 April 2005; 9.1% (95% CI, 3.6%–17.4%) from 4 April 2005 to 1 December 2007; 14.1% (95% CI, 7.5%–22.8%) from 1 December 2007 to the universal ART recommendation and 52.8% (95% CI, 38.2%–65.4%) after. After adjustment, the SFGH policy was associated with a 6-fold increase in the probability of HIV RNA suppression 6 months after clinic entry.
Conclusions. Recommendations to initiate ART in all HIV-infected patients increased the rate of HIV RNA suppression for patients enrolling in care with a CD4 cell count of >500 cells/µL and may foreshadow national trends given the March 2012 revision of national treatment guidelines to favor ART initiation for persons with CD4 cell counts of >500 cells/µL.
Although commercial tests are approved for detection of HIV-1 plasma viral loads ≥20 copies per milliliter (ml), only one specialized research assay has been reported to detect plasma viral loads as low as 1 copy/ml. This manuscript describes a method of concentrating HIV-1 virions from up to 30ml of plasma, which can be combined with a commercial viral load test to create a widely-available, reproducible assay for quantifying plasma HIV RNA levels less than 1 copy/ml. Using this pre-analytically modified assay, samples with a known level of 0.5 copy/ml were detected in 8 of 12 replicates (mean 0.47 copy/ml; 95% confidence interval (CI) 0.14-0.81 copy/ml) and samples with a known level of 1.0 copy/ml were detected in 13 of 13 replicates (mean 1.96 copy/ml; 95% CI 1.42-2.50 copy/ml). By concentrating virus from 30ml of plasma, HIV RNA could be measured in 16 of 19 samples (84%) from 12 of 12 subjects (mean 2.77 copy/ml; 95% CI 0.86-4.68 copy/ml). The measured viral load correlated inversely (r= −0.78; p=0.028) with the total duration of viral suppression (viral load<40 copies/ml).
HIV; plasma RNA; viral load; single copy; Abbott
To determine whether intensification with raltegravir improves endothelial function in antiretroviral-treated, HIV-infected individuals.
Randomized, double-blinded, placebo-controlled study.
Fifty-six subjects with treatment-mediated viral suppression for at least one year were randomized to add raltegravir 400 mg twice daily or matching placebo for 24 weeks. The primary endpoint was the difference in rate of change in endothelial function (as assessed by flow-mediated vasodilation of the brachial artery [FMD]) from baseline to week 24 between the raltegravir and placebo groups. Linear mixed models were used to evaluate the association of treatment group with changes in FMD, immune activation, and measures of viral persistence.
At baseline, the median CD4+ T cell count was 498 cells/mm3, nadir CD4+ T cell count was 191 cells/mm3, duration of HIV infection was 18 years, FMD was 3.3%, and hyperemic velocity (a marker of microvascular function) was 68.3 cm. There were no significant differences between treatment groups in rate of change in FMD (raltegravir group +0.032% per week, placebo group +0.023% per week; p=0.60). There were also no differences between treatment groups in rate of change in hyperemic velocity, immune activation, or viral persistence. In multivariable analysis, older age, longer duration of HIV infection, and current abacavir use were associated with lower FMD. Lower CD4+ T cell count and current abacavir use were associated with lower hyperemic velocity.
The addition of raltegravir to suppressive antiretroviral therapy did not have a significant impact on cardiovascular risk, as assessed by endothelial function (ClinicalTrials.gov NCT00843713).
HIV; raltegravir intensification; endothelial function; flow-mediated vasodilation
Dolutegravir (DTG, S/GSK1349572) is an integrase inhibitor with low nanomolar potency. Susceptibility to dolutegravir and raltegravir was determined for raltegravir-resistant clinical isolates.
Genotypic and phenotypic susceptibility to integrase inhibitors was examined using 39 clinical isolate samples obtained from 18 adults who had exhibited incomplete viral suppression on a raltegravir-based regimen.
Of 39 samples evaluated, 30 had genotypic and phenotypic resistance to raltegravir. All samples lacking raltegravir resistance retained complete susceptibility to dolutegravir. Of the 30 samples with genotypic evidence of raltegravir resistance, the median level of phenotypic resistance to raltegravir was high (median fold change in inhibitory concentration at 50%, >81; range, 3.7 to >87) while the level of resistance to dolutegravir was close to that of wild-type variants (median fold change, 1.5; range, 0.9–19.0). Longitudinal samples from 5 subjects collected during long-term failure of raltegravir revealed time-dependent general decreases in phenotypic susceptibility to raltegravir, with minimal changes in phenotypic susceptibility to dolutegravir. The median fold change to dolutegravir for isolates containing changes at G140S + Q148H; G140S + Q148R; T97A + Y143R; and N155H (thus including raltegravir signature resistance codons) were 3.75, 13.3, 1.05, and 1.37, respectively.
Dolutegravir retained in vitro activity against clinical isolates obtained from subjects who failed raltegravir-based therapy at near wild-type levels for variants containing the Y143 and N155 resistance mutations. Isolates with Q148 plus additional integrase mutations possessed a broader range of and more reduced susceptibility to dolutegravir.
Dolutegravir; DTG; S/GSK1349572; integrase inhibitor; raltegravir resistance; UCSF SCOPE cohort
Both protective T cell genotypes and NK cell genotypes have been associated with delayed progression to AIDS and shown to be co-inherited in HIV-1 infected subjects who limit viral replication in absence of antiretroviral therapy (“controllers”). However, a comparative analysis of the genotype and function of the innate and adaptive immune compartments in HIV-1 infected controller subjects has been understudied to date.
Here, we simultaneously tested NK and T cell function in controllers to investigate the mechanism(s) that might account for host-immune control over viral replication.
We measured CD8 T cell responses against HIV-1 utilizing overlapping 15-mer peptides spanning the HIV-1 Consensus Clade B Gag protein and tested NK cell degranulation and cytokine secretion against tumor target cells following IFN-alpha stimulation.
Among a cohort of 37 controllers, the presence of protective MHC-Class I HLA alleles (such as HLA-B*57) was not correlated with HIV-specific CD8 responses. In contrast, the inheritance of a protective KIR3DL1*h/*y receptor genotype along with the corresponding HLA-Bw4*80I ligand was associated with significantly heightened target cell-induced NK degranulation and cytokine secretion following IFN-alpha stimulation (p=0.0201, n=13). Interestingly, we observed a significant inverse association between the IFN-alpha stimulated NK response to K562 cells and the HIV-specific CD8 T cell response to Gag among elite controllers. (rho=−0.8321, p=0.0010, n=12).
Together, these results suggest that heightened NK responses can be evidenced independently of HIV-specific T cell responses in HIV-1 infected elite controllers.
HIV-1; AIDS; T Cells; NK Cells; HLA; KIR; Elite Controllers
A small proportion of human immunodeficiency virus-1 (HIV-1) infected individuals, termed HIV-1 controllers, suppress viral replication to very low levels in the absence of therapy. Genetic investigations of this phenotype have strongly implicated variation in the class I major histocompatibility complex (MHC) region as key to HIV-1 control. We collected sequence-based classical class I HLA genotypes at 4-digit resolution in HIV-1-infected African American controllers and progressors (n = 1107), and tested them for association with host control using genome-wide single nucleotide polymorphism data to account for population structure. Several classical alleles at HLA-B were associated with host control, including B*57:03 [odds ratio (OR) = 5.1; P= 3.4 × 10–18] and B*81:01 (OR = 4.8; P= 1.3 × 10−9). Analysis of variable amino acid positions demonstrates that HLA-B position 97 is the most significant association with host control in African Americans (omnibus P = 1.2 × 10−21) and explains the signal of several HLA-B alleles, including B*57:03. Within HLA-B, we also identified independent effects at position 116 (omnibus P= 2.8 × 10−15) in the canonical F pocket, position 63 in the B pocket (P= 1.5 × 10−3) and the non-pocket position 245 (P= 8.8 × 10−10), which is thought to influence CD8-binding kinetics. Adjusting for these HLA-B effects, there is evidence for residual association in the MHC region. These results underscore the key role of HLA-B in affecting HIV-1 replication, likely through the molecular interaction between HLA-B and viral peptides presented by infected cells, and suggest that sites outside the peptide-binding pocket also influence HIV-1 control.
To examine the association between early HIV viremia and mortality after HIV-associated lymphoma.
Multicenter observational cohort study.
Center for AIDS Research Network of Integrated Clinical Systems cohort.
HIV-infected patients with lymphoma diagnosed between 1996 and 2011, who were alive 6 months after lymphoma diagnosis and with ≥2 HIV RNA values during the 6 months after lymphoma diagnosis.
Cumulative HIV viremia during the 6 months after lymphoma diagnosis, expressed as viremia copy-6-months.
Main outcome measure
All-cause mortality between 6 months and 5 years after lymphoma diagnosis.
Of 224 included patients, 183 (82%) had non-Hodgkin lymphoma (NHL) and 41 (18%) had Hodgkin lymphoma (HL). At lymphoma diagnosis, 105 (47%) patients were on antiretroviral therapy (ART), median CD4 count was 148 cells/µlL (IQR 54– 322), and 33% had suppressed HIV RNA (<400 copies/mL). In adjusted analyses, mortality was associated with older age [adjusted hazard ratio (AHR) 1.37 per decade increase, 95% CI 1.03–1.83], lymphoma occurrence on ART (AHR 1.63, 95% CI 1.02– 2.63), lower CD4 count (AHR 0.75 per 100 cell/µL increase, 95% CI 0.64–0.89), and higher early cumulative viremia (AHR 1.35 per log10copies × 6-months/mL, 95% CI 1.11–1.65). The detrimental effect of early cumulative viremia was consistent across patient groups defined by ART status, CD4 count, and histology.
Exposure to each additional 1-unit log10 in HIV RNA throughout the 6 months after lymphoma diagnosis, was associated with a 35% increase in subsequent mortality. These results suggest that early and effective ART during chemotherapy may improve survival.
AIDS; Burkitt lymphoma; diffuse large B-cell lymphoma; HIV; Hodgkin lymphoma; lymphoma; non-Hodgkin lymphoma
Although antiretroviral therapy for HIV infection prevents AIDS related complications and prolongs life, it does not fully restore health. Long-term treated patients remain at higher than expect risk for a number of complications typically associated with aging, including cardiovascular disease, cancer, osteoporosis and other end-organ diseases. The potential effect of HIV on health is perhaps most clearly exhibited by a number of immunologic abnormalities that persist despite effect suppression of HIV replication. These changes are consistent with some of the changes to the adaptive immune system that are seen in the very old (“immunosenescence”) and that are likely related in part to persistent inflammation. HIV-associated inflammation and immunosenescence have been implicated as causally related to the premature onset of other end organ diseases. Novel therapeutic strategies aimed at preventing or reversing these immunologic defects may be necessary if HIV infected patients are achieve normal life span.
The human gut mucosa is a major site of HIV infection and infection-associated pathogenesis. Increasing evidence shows that natural killer (NK) cells play an important role in control of HIV infection but the mechanism(s) by which they mediate antiviral activity in the gut is unclear. Here we show two distinct subsets of NK cells exist in the gut, one localized to intraepithelial spaces (IEL) and the other to the lamina propria (LP). The frequency of both subsets of NK cells was reduced in chronic infection, whereas IEL NK cells remained stable in spontaneous controllers with protective KIR/HLA genotypes. Both IEL and LP NK cells were significantly expanded in immunologic non-responsive (INR) patients, who incompletely recovered CD4+ T cells on HAART. These data suggest that both IEL and LP NK cells may expand in the gut in an effort to compensate for compromised CD4+ T cell recovery, but that only IEL NK cells may be involved in providing durable control of HIV in the gut,
Despite widespread highly active antiretroviral therapy use, HIV disease remains associated with increased risk of kidney disease. Whether tenofovir use is associated with higher risk of kidney disease is controversial.
We evaluated the association of cumulative and ever exposure to tenofovir on kidney outcomes in 10,841 HIV-infected patients from the Veterans Health Administration who initiated antiretroviral therapy from 1997-2007.
Cox proportional hazards and marginal structural models evaluated associations between tenofovir and time to first occurrence of 1) proteinuria (two consecutive urine dipstick measurements ≥30mg/dL), 2) rapid decline in kidney function (≥3ml/min/1.73m2 annual decline), and 3) CKD (estimated glomerular filtration rate <60ml/min/1.73m2).
Median follow-up ranged from 3.9 years (proteinuria) to 5.5 years (CKD), during which 3400 proteinuria, 3078 rapid decline, and 533 CKD events occurred. After multivariable adjustment, each year of exposure to tenofovir was associated with 34% increased risk of proteinuria (95%CI 25-45%, p<0.0001), 11% increased risk of rapid decline (3-18%, p=0.0033), and 33% increased risk of CKD (18-51%; p<0.0001). Pre-existing renal risk factors did not appear to worsen the effects of tenofovir. Other ARVs showed weaker or inconsistent associations with kidney disease events. Among those who discontinued tenofovir use, risk of kidney disease events did not appear to decrease during follow-up.
Tenofovir exposure was independently associated with increased risk for three types of kidney disease events, and did not appear to be reversible. Because subtle kidney function decline affects long-term morbidity and mortality, the balance between efficacy and probable adverse effects requires further study.
HIV; antiretroviral therapy; kidney disease; tenofovir
Resting CD4+ T cells infected with HIV persist in the presence of suppressive anti-viral therapy (ART) and are barriers to a cure. One potential curative approach, therapeutic vaccination, is fueled by recognition of the ability of a subset of elite controllers (EC) to control virus without therapy due to robust anti-HIV immune responses. Controllers have low levels of integrated HIV DNA and low levels of replication competent virus, suggesting a small reservoir. As our recent data indicates some reservoir cells can produce HIV proteins (termed GPR cells for Gag-positive reservoir cells), we hypothesized that a fraction of HIV-expressing resting CD4+ T cells could be efficiently targeted and cleared in individuals who control HIV via anti-HIV cytotoxic T lymphocytes (CTL). To test this we examined if superinfected resting CD4+ T cells from EC express HIV Gag without producing infectious virus and the susceptibility of these cells to CTL. We found that resting CD4+ T cells expressed HIV Gag and were cleared by autologous CD8+ T cells from EC. Importantly, we found the extent of CTL clearance in our in vitro assay correlates with in vivo reservoir size and that a population of Gag expressing resting CD4+ T cells exists in vivo in patients well controlled on therapy.
The level of T cell activation in untreated HIV disease is strongly and independently associated with risk of immunologic and clinical progression. The factors that influence the level of activation, however, are not fully defined. Since endogenous glucocorticoids are important in regulating inflammation, we sought to determine whether less optimal diurnal cortisol patterns are associated with greater T cell activation.
We studied 128 HIV-infected adults who were not on treatment and had a CD4+ T cell count above 250 cells/µl. We assessed T cell activation by CD38 expression using flow cytometry, and diurnal cortisol was assessed with salivary measurements.
Lower waking cortisol levels correlated with greater T cell immune activation, measured by CD38 mean fluorescent intensity, on CD4+ T cells (r = −0.26, p = 0.006). Participants with lower waking cortisol also showed a trend toward greater activation on CD8+ T cells (r = −0.17, p = 0.08). A greater diurnal decline in cortisol, usually considered a healthy pattern, correlated with less CD4+ (r = 0.24, p = 0.018) and CD8+ (r = 0.24, p = 0.017) activation.
These data suggest that the hypothalamic-pituitary-adrenal (HPA) axis contributes to the regulation of T cell activation in HIV. This may represent an important pathway through which psychological states and the HPA axis influence progression of HIV.