The dynamics of CD4+ T cell reconstitution and changes in immune activation and inflammation in HIV-1 disease following initiation of antiretroviral therapy (ART) are incompletely defined and their underlying mechanisms poorly understood.
Thirty-nine treatment-naïve patients were treated with raltegravir, tenofovir DF and emtricitabine. Immunologic and inflammatory indices were examined in persons with sustained virologic control during 48 weeks of therapy.
Initiation of ART increased CD4+ T cell numbers and decreased activation and cell cycle entry among CD4+ and CD8+ T cell subsets, and attenuated markers of coagulation (D-dimer levels) and inflammation (IL-6 and TNFr1). These indices decayed at different rates and almost all remained elevated above levels measured in HIV-seronegatives through 48 weeks of viral control. Greater first and second phase CD4+ T cell restoration was related to lower T cell activation and cell cycling at baseline, to their decay with treatment, and to baseline levels of selected inflammatory indices, but less so to their changes on therapy.
ART initiation results in dynamic changes in viral replication, T cell restoration, and indices of immune activation, inflammation, and coagulation. These findings suggest that determinants of T cell activation/cycling and inflammation/coagulation may have distinguishable impact on immune homeostasis.
U.S. state AIDS Drug Assistance Programs (ADAPs) are federally funded to provide antiretroviral therapy (ART) as the payer of last resort to eligible persons with HIV infection. States differ regarding their financial contributions to and ways of implementing these programs, and it remains unclear how this interstate variability affects HIV treatment outcomes.
We analyzed data from HIV-infected individuals who were clinically-eligible for ART between 2001 and 2009 (i.e., a first reported CD4+ <350 cells/uL or AIDS-defining illness) from 14 U.S. cohorts of the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD). Using propensity score matching and Cox regression, we assessed ART initiation (within 6 months following eligibility) and virologic suppression (within 1 year) based on differences in two state ADAP features: the amount of state funding in annual ADAP budgets and the implementation of waiting lists. We performed an a priori subgroup analysis in persons with a history of injection drug use (IDU).
Among 8,874 persons, 56% initiated ART within six months following eligibility. Persons living in states with no additional state contribution to the ADAP budget initiated ART on a less timely basis (hazard ratio [HR] 0.73, 95% CI 0.60–0.88). Living in a state with an ADAP waiting list was not associated with less timely initiation (HR 1.12, 95% CI 0.87–1.45). Neither additional state contributions nor waiting lists were significantly associated with virologic suppression. Persons with an IDU history initiated ART on a less timely basis (HR 0.67, 95% CI 0.47–0.95).
We found that living in states that did not contribute additionally to the ADAP budget was associated with delayed ART initiation when treatment was clinically indicated. Given the changing healthcare environment, continued assessment of the role of ADAPs and their features that facilitate prompt treatment is needed.
Chronic hepatitis C virus (HCV) infection is associated with B cell activation, although underlying mechanisms are unclear. To investigate B cell regulation during HCV infection, we measured bulk B cell CpG and Staphylococcus aureus Cowan-induced IgG Ab-secreting cell (ASC) frequency, HCV and tetanus-specific ASC frequency, BCR- and CD40L-dependent CD80/CD86 expression, and activation of memory CD4 cells. Immature transitional, naive, resting memory, mature activated, tissue-like memory, and plasma B cell subset frequencies, cell cycling, and intrinsic apoptosis were quantified. We observed intact or enhanced tetanus-specific and total IgG ASC frequency, serum IgG, BCR- and CD40L-dependent CD80/CD86 expression, and CD40L-dependent bulk B cell activation of memory CD4 cells in HCV infection. HCV-specific ASCs were observed in HCV-infected but not control subjects, although frequencies were lower compared with tetanus-specific cells. Immature transitional and mature activated B cell subset frequencies were increased in HCV-infected subjects, with immature transitional frequency associated with liver inflammation and serum B cell-activating factor. Mature activated B cells less commonly expressed Ki67, more commonly expressed Bcl2, and were more intrinsically resistant to apoptosis, whereas immature transitional B cells more commonly expressed Ki67, the latter associated with plasma HCV level. Taken together, these results indicate that in the setting of chronic HCV infection, a state of activation results in B cell subset skewing that is likely the result of alterations in homeostasis, cell cycling, and intrinsic resistance to apoptosis and that results in an overall intact or enhanced B cell response to BCR and CD40L.
Genetic relatedness of human immunodeficiency virus type 1 sequences was used to assess variables associated with transmission and characteristics of transmission networks in a large, diverse cohort. Such assessments may be useful in identifying risks for expanding epidemics and targeting effective public health responses.
Background. Clinically, human immunodeficiency virus type 1 (HIV-1) pol sequences are used to evaluate for drug resistance. These data can also be used to evaluate transmission networks and help describe factors associated with transmission risk.
Methods. HIV-1 pol sequences from participants at 5 sites in the CFAR Network of Integrated Clinical Systems (CNICS) cohort from 2000–2009 were analyzed for genetic relatedness. Only the first available sequence per participant was included. Inferred transmission networks (“clusters”) were defined as ≥2 sequences with ≤1.5% genetic distance. Clusters including ≥3 patients (“networks”) were evaluated for clinical and demographic associations.
Results. Of 3697 sequences, 24% fell into inferred clusters: 155 clusters of 2 individuals (“dyads”), 54 clusters that included 3–14 individuals (“networks”), and 1 large cluster that included 336 individuals across all study sites. In multivariable analyses, factors associated with being in a cluster included not using antiretroviral (ARV) drugs at time of sampling (P < .001), sequence collected after 2004 (P < .001), CD4 cell count >350 cells/mL (P < .01), and viral load 10 000–100 000 copies/mL (P < .001) or >100 000 copies/mL (P < .001). In networks, women were more likely to cluster with other women (P < .001), and African Americans with other African Americans (P < .001).
Conclusions. Molecular epidemiology can be applied to study HIV transmission networks in geographically and demographically diverse cohorts. Clustering was associated with lack of ARV use and higher viral load, implying transmission may be interrupted by earlier diagnosis and treatment. Observed female and African American networks reinforce the importance of diagnosis and prevention efforts targeted by sex and race.
The contribution of HIV-infection to periodontal disease (PD) is poorly understood. We proposed that immunological markers would be associated with improved clinical measures of PD.
We performed a longitudinal cohort study of HIV-infected adults who had started highly active antiretroviral therapy (HAART) <2 years. PD was characterized clinically as the percent of teeth with ≥1 site with periodontal probing depth (PPD) ≥5.0mm, recession (REC) >0mm, clinical attachment level (CAL) ≥4.0mm, and bleeding on probing (BOP) at ≥4 sites/tooth and microbiologically as specific periodontopathogen concentration. Linear mixed-effects models were used to assess the associations between immune function and PD.
Forty (40) subjects with median 2.7 months on HAART and median nadir CD4+ T-cell count of 212 cells/μl completed a median 3 visits. Over 24 months, CD4+ T-cell count increased by a mean 173 cells/µl (p<0.001) and HIV RNA decreased by 0.5 log10 copies/ml (p<0.001); concurrently, PPD, CAL and BOP decreased by a mean 11.7%, 12.1%, and 14.7% respectively (all p<0.001). Lower nadir CD4+ T-cell count was associated with worse baseline REC (-6.72%; p=0.04) and CAL (9.06%; p<0.001). Further, lower nadir CD4+ T-cell count was associated with a greater relative longitudinal improvement in PPD in subjects with higher baseline levels of Porphyromonas gingivalis (p=0.027), and BOP in subjects with higher baseline levels of Porphyromonas gingivalis or Treponema denticola (p=0.001 and p=0.006 respectively). Longitudinal changes from baseline in CD4+ T-cell count and level of HIV RNA were not independently associated with longitudinal changes in any clinical markers of PD.
Degree of immunosuppression was associated with baseline gingival recession. After HAART initiation, measures of active PD improved most in those with lower nadir CD4+ T-cell counts and higher baseline levels of specific periodontopathogens. Nadir CD4+ T-cell count differentially influences periodontal disease both before and after HAART in HIV-infected adults.
Increased plasma IL-6 levels have been associated with HIV-1 disease progression risk, yet the drivers of IL-6 production in HIV-1 infection are not known. This study was designed to explore the relationship between HIV-1 replication and IL-6 induction.
Correlations between plasma levels of IL-6 and HIV-1 RNA were examined in two clinical studies. To more directly assess the induction of IL-6 by HIV-1, several cell and tissue types that support HIV-1 replication in vivo were infected with HIV-1 and expression of IL-6 was measured.
Spearman’s rank correlations were used to examine the relationship between plasma levels of IL-6 and HIV-1 RNA. Macrophages, and colonic and lymph node histocultures were infected with HIV-1 or stimulated with bacterial products, LPS or flagellin, and IL-6 levels in supernatant were measured by ELISA or multiplex bead assay.
In the clinical studies there was weak or no correlation between plasma levels of IL-6 and HIV-1 RNA but IL-6 levels were correlated with plasma levels of the LPS coreceptor CD14. Macrophages stimulated with LPS or flagellin showed robust production of IL-6, but there was no increase in IL-6 production after HIV-1 infection. IL-6 expression was not increased in lymph node histocultures obtained from HIV-1 infected subjects nor after productive HIV-1 infection of colonic or lymph node histocultures ex vivo.
We find no evidence that HIV-1 replication is an important driver of IL-6 expression in vivo or in in vitro systems.
IL-6; HIV-1 RNA; histocultures; macrophages; LPS; flagellin
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
Disease progression of human immunodeficiency virus type 1 (HIV-1) is associated with immune activation. Activation indices are higher during coinfection of hepatitis C virus (HCV) and HIV. The effect of immune activation on interferon α (IFN-α) therapy response is unknown. We evaluated soluble CD14 (sCD14) and natural killer (NK)–cell subsets at baseline, and during pegIFN-α2a/ribavirin therapy in HCV-HIV coinfection. The sCD14 level increased during therapy. Baseline sCD14 positively correlated with baseline HCV level and CD16+56− NK-cell frequency, and both sCD14 and CD16+56− NK cells correlated negatively with magnitude of HCV decline. IL28B genotype was associated with therapy response but not sCD14 or CD16+56− NK frequency. Markers of innate immune activation predict poor host response to IFN-α–based HCV therapy during HCV-HIV coinfection.
Background. Natural killer (NK) cells likely contribute to outcome of acute hepatitis C virus (HCV) infection and interferon (IFN)–induced control of chronic HCV infection. We previously observed IFN-αR and NKp30 expression associated with IFN-α–dependent NK cell activity.
Methods. Here, we examined CD16+56−, CD16+56+, and CD16−56+ NK cell subset IFN-αR and NKp30 expression in relation to magnitude of HCV genotype 1 decrease during pegylated IFN-α plus ribavirin therapy.
Results. We observed greater baseline IFN-αR and NKp30 expression on CD16+56+ and CD16−56+ NK subsets in HCV-infected patients than in healthy control subjects. Baseline CD16+56− NK IFN-αR expression was associated with IFN-α–induced pSTAT1, and both were associated with magnitude of HCV decrease during pegylated IFN-α plus ribavirin therapy. Baseline CD16+56− NK IFN-αR expression was associated with race and interleukin 28B genotype, negatively associated with aspartate aminotransferase-to platelet ratio index, and positively associated with increase in NKp30 expression after in vivo IFN-α exposure. Finally, in vitro IFN-α2a–activated NK cytolysis of HCV-infected target cells was in part dependent on NKp30, and CD16+56− NK cell IFN-αR expression correlated with cytolytic activity.
Conclusions. IFN-αR expression on CD16+56− NK cells during chronic HCV infection may in part be genetically determined, and level of expression regulates IFN-α signaling, which in turn may contribute to control of HCV infection.
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.
HIV-1 infected patients have an increased risk for atherothrombosis and cardiovascular disease, but the mechanism behind these risks is poorly understood. We have previously reported that expression of tissue factor (TF) on circulating monocytes is increased in persons with HIV infection and that TF expression is related to immune activation, to levels of HIV in plasma, and to indices of microbial translocation. In this study, we explore the activation state of platelets in HIV disease.
Here, using flow cytometry-based assays, we measured platelet and platelet microparticle (PMP) activation in samples from HIV-1 infected donors and controls.
Platelets and PMPs from HIV-1 infected patients are activated (as reflected by expression of CD62 P-selectin) and also more frequently expressed the procoagulant tissue factor (TF) than did platelets and PMPs obtained from controls. Expression of these proteins was directly related to expression of TF on monocytes, to markers of T cell activation (CD38 and HLA-DR) and to plasma levels of soluble CD14, the coreceptor for bacterial lipopolysaccharride. Platelet and microparticle expression of TF was not related to plasma levels of HIV but expression of P-selectin was; neither TF nor P-selectin expression was related to CD4 T cell count.
Platelets and microparticles are activated in HIV infection and this activated phenotype may contribute to the increased risk for cardiovascular and thrombotic events in this population although a role for other confounding cardiovascular risks cannot be completely excluded.
tissue factor; platelets; HIV-1; immune activation
Type-I interferon (IFN-I) has been increasingly implicated in HIV-1 pathogenesis. Various studies have shown elevated IFN-I and an IFN-I-induced gene and protein expression signature in HIV-1 infection, yet the elevated IFN-I species has not been conclusively identified, its source remains obscure and its role in driving HIV-1 pathogenesis is controversial. We assessed IFN-I species in plasma by ELISAs and bioassay, and we investigated potential sources of IFN-I in blood and lymph node tissue by qRT-PCR. Furthermore, we measured the effect of therapeutic administration of IFNα in HCV-infected subjects to model the effect of IFNα on chronic immune activation. IFN-I bioactivity was significantly increased in plasma of untreated HIV-1-infected subjects relative to uninfected subjects (p = 0.012), and IFNα was the predominant IFN-I subtype correlating with IFN-I bioactivity (r = 0.658, p<0.001). IFNα was not detectable in plasma of subjects receiving anti-retroviral therapy. Elevated expression of IFNα mRNA was limited to lymph node tissue cells, suggesting that peripheral blood leukocytes are not a major source of IFNα in untreated chronic HIV-1 infection. Plasma IFN-I levels correlated inversely with CD4 T cell count (p = 0.003) and positively with levels of plasma HIV-1 RNA and CD38 expression on CD8 T cells (p = 0.009). In hepatitis C virus-infected subjects, treatment with IFN-I and ribavirin increased expression of CD38 on CD8 T cells (p = 0.003). These studies identify IFNα derived from lymph nodes, rather than blood leukocytes, as a possible source of the IFN-I signature that contributes to immune activation in HIV-1 infection.
To examine long-term effects of antiretroviral therapy (ART) on kidney function, we evaluated the incidence and risk factors for chronic kidney disease (CKD) among ART-naive, HIV-infected adults and compared changes in estimated glomerular filtration rates (eGFR) before and after starting ART.
Multicenter observational cohort study of patients with at least one serum creatinine measurement before and after initiating ART. Cox proportional hazard models, and marginal structure models examined CKD risk factors; mixed-effects linear models examined eGFR slopes.
Three thousand, three hundred and twenty-nine patients met entry criteria, contributing 10 099 person-years of observation on ART. ART was associated with a significantly slower rate of eGFR decline (from −2.18 to −1.37 ml/min per 1.73 m2 per year; P = 0.02). The incidence of CKD defined by eGFR thresholds of 60, 45 and 30 ml/min per 1.73 m2 was 10.5, 3.4 and 1.6 per 1000 person-years, respectively. In adjusted analyses black race, hepatitis C coinfection, lower time-varying CD4 cell count and higher time-varying viral load on ART were associated with higher CKD risk, and the magnitude of these risks increased with more severe CKD. Tenofovir and a ritonavir-boosted protease inhibitor (rPI) was also associated with higher CKD risk [hazard odds ratio for an eGFR threshold <60 ml/min per 1.73 m2: 3.35 (95% confidence interval (CI) = 1.40–8.02)], which developed in 5.7% of patients after 4 years of exposure to this regimen-type.
ART was associated with reduced CKD risk in association with CD4 cell restoration and plasma viral load suppression, despite an increased CKD risk that was associated with initial regimens that included tenofovir and rPI.
antiretroviral therapy; chronic kidney disease; tenofovir
The determinants of HIV-associated cardiovascular disease (CVD) are not well understood. Periodontal disease (PD) has been linked to CVD but this connection has not been examined in HIV infection. We followed a cohort of HIV-infected adults to ascertain whether PD was associated with carotid artery intima media thickness (IMT) and brachial artery flow-mediated dilation (FMD). We performed a longitudinal observational study of HIV-infected adults on HAART for <2 years with no known heart disease. PD was characterized clinically and microbiologically. Cardiovascular disease was assessed by IMT/FMD. Linear mixed models assessed cross-sectional and longitudinal associations between PD and FMD/IMT. Forty three HIV+ adults completed a median of 24 (6–44) months on the study. Defining delta to be the change in a variable between baseline and a follow-up time, longitudinally, on average and after adjusting for change in time, CVD-specific and HIV-specific potential confounding covariates, a 1-log10 increase in delta Porphyromonas gingivalis was associated with a 0.013 mm increase in delta IMT (95% CI: 0.0006–0.0262; p=0.04). After adjusting for the same potential confounding covariates, a 10% increase in delta gingival recession was associated with a 2.3% increase in delta FMD (95% CI: 0.4–4.2; p=0.03). In a cohort of HIV-infected adults, an increase in subgingival Porphyromonas gingivalis, a known periodontal pathogen, was significantly associated with longitudinal increases in IMT, while increased gingival recession, which herein may represent PD resolution, was significantly associated with longitudinal improvement in FMD. In the context of HIV infection, PD may contribute to CVD risk. Intervention studies treating PD may help clarify this association.
Background. Failure to normalize CD4+ T-cell numbers despite effective antiretroviral therapy is an important problem in human immunodeficiency virus (HIV) infection.
Methods. To evaluate potential determinants of immune failure in this setting, we performed a comprehensive immunophenotypic characterization of patients with immune failure despite HIV suppression, persons who experienced CD4+ T-cell restoration with therapy, and healthy controls.
Results. Profound depletion of all CD4+ T-cell maturation subsets and depletion of naive CD8+ T cells was found in immune failure, implying failure of T-cell production/expansion. In immune failure, both CD4+ and CD8+ cells were activated but only memory CD4+ cells were cycling at increased frequency. This may be the consequence of inflammation induced by in vivo exposure to microbial products, as soluble levels of the endotoxin receptor CD14+ and interleukin 6 were elevated in immune failure. In multivariate analyses, naive T-cell depletion, phenotypic activation (CD38+ and HLA-DR expression), cycling of memory CD4+ T cells, and levels of soluble CD14 (sCD14) distinguished immune failure from immune success, even when adjusted for CD4+ T-cell nadir, age at treatment initiation, and other clinical indices.
Conclusions. Immune activation that appears related to exposure to microbial elements distinguishes immune failure from immune success in treated HIV infection.
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.
Determination of the prevalence of accumulated antiretroviral drug resistance among persons infected with human immunodeficiency virus (HIV) is complicated by the lack of routine measurement in clinical care. By using data from 8 clinic-based cohorts from the North American AIDS Cohort Collaboration on Research and Design, drug-resistance mutations from those with genotype tests were determined and scored using the Genotypic Resistance Interpretation Algorithm developed at Stanford University. For each year from 2000 through 2005, the prevalence was calculated using data from the tested subset, assumptions that incorporated clinical knowledge, and multiple imputation methods to yield a complete data set. A total of 9,289 patients contributed data to the analysis; 3,959 had at least 1 viral load above 1,000 copies/mL, of whom 2,962 (75%) had undergone at least 1 genotype test. Using these methods, the authors estimated that the prevalence of accumulated resistance to 2 or more antiretroviral drug classes had increased from 14% in 2000 to 17% in 2005 (P < 0.001). In contrast, the prevalence of resistance in the tested subset declined from 57% to 36% for 2 or more classes. The authors’ use of clinical knowledge and multiple imputation methods revealed trends in HIV drug resistance among patients in care that were markedly different from those observed using only data from patients who had undergone genotype tests.
antiretroviral therapy, highly active; drug resistance; genotype; HIV
Beta defensins are antimicrobial peptides that serve to protect the host from microbial invasion at skin and mucosal surfaces. Here we explore the relationships among beta defensin levels, total bacterial colonization, and colonization by bacterial vaginosis (BV)-related bacteria and lactobacilli in the female genital tract in HIV infected women and healthy controls. Cervicovaginal lavage (CVL) samples were obtained from 30 HIV-infected women and 36 uninfected controls. Quantitative PCR assays were used to measure DNA levels of bacterial 16S ribosomal DNA (reflective of total bacterial load), and levels of three BV-related bacteria, three Lactobacillus species (L. crispatus, L. iners and L. jensenii), and total Lactobacillus levels in CVL. Levels of human beta defensins (hBD-2 and hBD-3) were quantified by ELISA. In viremic HIV+ donors, we found that CVL levels of bacterial 16S rDNA were significantly increased, and inversely correlated with peripheral CD4+ T cell counts in HIV+ women, and inversely correlated with age in both HIV+ women and controls. Although CVL DNA levels of BV-associated bacteria tended to be increased, and CVL levels of lactobacillus DNAs tended to be decreased in HIV+ donors, none of these differences was significant. CVL levels of hBD-2 and hBD-3 were correlated and were not different in HIV+ women and controls. However, significant positive correlations between hBD-3 levels and total bacterial DNA levels in controls were not demonstrable in HIV+ women; the significant positive correlations of hBD2 or hBD-3 and three Lactobacillus species in controls were also not demonstrable in HIV+ women. These results suggest that HIV infection is associated with impaired regulation of innate defenses at mucosal sites.
HIV; Bacterial 16S rDNA; beta defensins; Cervicovaginal lavage
Background. In patients receiving highly active antiretroviral therapy (HAART), antiretroviral drug–metabolizing enzyme and transporter gene polymorphisms, as well as chemokine receptor gene polymorphisms, may influence response to treatment.
Methods. In a North American, treated, adherent human immunodeficiency virus (HIV)–positive cohort (self-identified whites, n = 175; blacks, n = 218), we investigated whether CYP2B6 (516G>T, 983T>C), UGT2B7 (IVS1+985A>G, 802C>T), MDR1 3435C>T, chemokine (C-C motif) receptor 2 (CCR2) 190G>A, and CCR5 (−2459G>A, Δ32) polymorphisms influenced the time to achieve virologic success (TVLS).
Results. No difference in TVLS was observed between races. In Kaplan-Meier analyses, only 516G>T (log-rank P = .045 for comparison of GG, GT, and TT and P = .02 GG + GT vs TT) and −2459G>A (log-rank P = .04 for GG, GA, and AA and P = .02 for GG + GA vs AA) genotypes were significantly associated with TVLS in black patients but not in white patients. However, in the Cox proportional hazards model that included age, sex, baseline CD4+ T cell count, and baseline viral load, no significant association was observed between 516G>T and TVLS, whereas the association between −2459G>A and TVLS remained significant even after including CCR2 190G>A as well as all the drug-metabolizing enzyme and transporter genotypes.
Conclusions. These findings suggest that CCR5 −2459G>A genotype had a strong, race-specific influence on TVLS in this cohort. Understanding the possible mechanisms underlying this influence requires further studies.
We report a case of disseminated cutaneous Mycobacterium chelonae infection in a patient with head and neck cancer on salvage chemotherapy, including the epidermal growth factor receptor inhibitor cetuximab. Mycobacterium chelonae should be considered in the differential diagnosis of cutaneous infections in cancer patients receiving epidermal growth factor receptor inhibitors.
Background. Chronic hepatitis C virus (HCV) infection is characterized by reduced numbers of functional HCV-specific T cells. In addition, chronically HCV-infected individuals have reduced response to vaccine. Alterations in naive CD4 T cell phenotype or function may contribute to these immune impairments.
Methods. Using flow cytometric analysis and enzyme-linked immunospot assay, we examined peripheral naive CD4 T cell phenotype and function in chronically HCV-infected patients and control subjects.
Results. We observed significantly lower absolute cell numbers of naive CD4 T cells in HCV-infected patients, localized to the CD127+CD25low/- and CD31+ (RTE) subsets. Moreover, we found greater percentages of naive cells expressing CD25 and KI67 in HCV-infected patients, consistent with immune activation, further supported by higher plasma sCD27 levels. Functional analysis revealed an intact interferon-γ response to allogeneic B cell stimulus. However, after direct TCR stimulation, naive CD4 T cells from HCV-infected patients had altered up-regulation of KI67 and CD25 and less CD27 expression. The latter was associated with elevated baseline activation state. In addition, naive CD4 T cells from HCV-infected patients were more susceptible to cell death.
Conclusions. These numerical and functional defects may contribute to inadequate formation of virus and neoantigen-specific T cell responses during chronic HCV infection.
Twenty-six antiretroviral drugs (ARVs), targeting five different steps in the life cycle of the human immunodeficiency virus type 1 (HIV-1), have been approved for the treatment of HIV-1 infection. Accordingly, HIV-1 phenotypic assays based on common cloning technology currently employ three, or possibly four, different recombinant viruses. Here, we describe a system to assess HIV-1 resistance to all drugs targeting the three viral enzymes as well as viral assembly using a single patient-derived, chimeric virus. Patient-derived p2-INT (gag-p2/NCp7/p1/p6/pol-PR/RT/IN) products were PCR amplified as a single fragment (3,428 bp) or two overlapping fragments (1,657 bp and 2,002 bp) and then recombined into a vector containing a near-full-length HIV-1 genome with the Saccharomyces cerevisiae uracil biosynthesis gene (URA3) replacing the 3,428 bp p2-INT segment (Dudley et al., Biotechniques 46:458–467, 2009). P2-INT-recombinant viruses were employed in drug susceptibility assays to test the activity of protease (PI), nucleoside/nucleotide reverse transcriptase (NRTI), nonnucleoside reverse transcriptase (NNRTI), and integrase strand-transfer (INSTI) inhibitors. Using a single standardized test (ViralARTS HIV), this new technology permits the rapid and automated quantification of phenotypic resistance for all known and candidate antiretroviral drugs targeting all viral enzymes (PR, RT, including polymerase and RNase H activities, and IN), some of the current and potential assembly inhibitors, and any drug targeting Pol or Gag precursor cleavage sites (relevant for PI and maturation inhibitors) This novel assay may be instrumental (i) in the development and clinical assessment of novel ARV drugs and (ii) to monitor patients failing prior complex treatment regimens.
Type I interferons play important roles in innate immune defense. In HIV infection, type I interferons may delay disease progression by inhibiting viral replication while at the same time accelerating disease progression by contributing to chronic immune activation.
To investigate the effects of type I interferons in HIV-infection, we obtained cryopreserved peripheral blood mononuclear cell samples from 10 subjects who participated in AIDS Clinical Trials Group Study 5192, a trial investigating the activity of systemic administration of IFNα for twelve weeks to patients with untreated HIV infection. Using flow cytometry, we examined changes in cell cycle status and expression of activation antigens by circulating T cells and their maturation subsets before, during and after IFNα treatment.
The proportion of CD38+HLA-DR+CD8+ T cells increased from a mean of 11.7% at baseline to 24.1% after twelve weeks of interferon treatment (p = 0.006). These frequencies dropped to an average of 20.1% six weeks after the end of treatment. In contrast to CD8+ T cells, the frequencies of activated CD4+ T cells did not change with administration of type I interferon (mean percentage of CD38+DR+ cells = 2.62% at baseline and 2.17% after 12 weeks of interferon therapy). As plasma HIV levels fell with interferon therapy, this was correlated with a “paradoxical” increase in CD8+ T cell activation (p<0.001).
Administration of type I interferon increased expression of the activation markers CD38 and HLA DR on CD8+ T cells but not on CD4+ T cells of HIV+ persons. These observations suggest that type I interferons may contribute to the high levels of CD8+ T cell activation that occur during HIV infection.
Both clinical experience and a growing medical literature indicate that there are persons who have been exposed to HIV infection who have remained uninfected. While in some instances this may represent good fortune, cohorts of uninfected persons have been reported where risks for infection are thought to be high. In these cohorts a variety of characteristics have been proposed as mediating protection but to date only the 32 base pair deletion in the CCR5 gene that results in complete failure of cell surface expression of this co-receptor has been associated with high level protection from HIV infection. With this in mind, there are likely numerous other factors that may individually or in combination provide some level of protection from acquisition of HIV infection. As some of these factors are likely incompletely protective or inconsistently active, identifying them with confidence will be difficult. Nonetheless, clarifying the determinants of protection against HIV infection is a high priority that will require careful selection of high risk uninfected cohorts to which targeted studies of plausible mediators and broad screening for unexpected determinants of protection should be applied.
HIV infection; Exposed Seronegatives; High Risk Seronegatives; Interferon; Restriction factors; CCR5
Immune reconstitution after HAART is incomplete, but no widely accepted method to quantify subclinical immune deficiency is available. We immunized 9 HIV-negative subjects and 29 HIV-infected patients with CD4 ≥450 cells/μL and undetectable HIV RNA levels with 2 doses of diphtheria/tetanus toxoid (TT) and KLH, a presumed neoantigen. We quantified the response by lymphoproliferative assay, delayed-type hypersensitivity (DTH), and antibody titers up to 59 days after enrollment. We assessed T cell proliferative capacity using anti-Vβ3 and anti-Vβ5 antibody stimulation, which we herein show induces predominant proliferation of naïve T cells. Subjects with detectable responses to KLH tended to exhibit greater proliferative responses to anti-Vβ3/Vβ5 stimulation; no such pattern was seen with response to TT. Several measures of in vitro T cell proliferative capacity correlated significantly with DTH and antibody responses to KLH, but not with TT responses; this association was independent of naïve T cell numbers. Our results indicate that naïve T cell proliferation predicts response to neo-, but not recall antigens, and suggest that it may be a meaningful reflection of in vivo immune competence in HIV-infected persons.
Naïve T cells; HIV; HAART; immune reconstitution; T cell proliferation; neoantigens; vaccine responses