Search

Because both renal disease and immune activation predict progression to acquired immunodeficiency syndrome (AIDS), we evaluated the associations between proteinuria>or=1+, as determined by dipstick analysis (7 [7%] of 1012 subjects); creatinine clearance of <90 mL/min (195 [18%] of 1071 subjects); and percentages of peripheral activated CD8 cells (CD8+CD38+HLA-DR+ cells) in antiretroviral-naive, human immunodeficiency virus (HIV)-infected subjects who were enrolled in AIDS Clinical Trials Group studies 384 and A5095. Proteinuria, but not creatinine clearance, was associated with higher percentages of CD8+CD38+HLA-DR+ cells (55% vs. 50%; P=.01), with even more pronounced differences noted among men and among blacks and Hispanics. Proteinuria may be a surrogate measurement of greater immune activation in HIV-infected patients initiating antiretroviral therapy. [ABSTRACT FROM AUTHOR]

BACKGROUND: We have attempted to identify factors associated with T cell reconstitution in response to highly active antiretroviral therapy. METHODS: In a prospective, multicenter cohort study, we compared clinical, immune, and viral responses to an initial antiretroviral regimen in older (>or=45 years old) versus younger (18-30 years old) human immunodeficiency virus type 1-infected subjects. Multivariable linear-regression models identified independent factors associated with changes in T cell counts. RESULTS: Older subjects had smaller increases in naive T cells but greater T cell receptor-excision circle DNA content after 48 weeks, despite similar virologic responses and comparable reductions in immune activation. Changes in T cell counts were associated with plasma interleukin (IL)-7 levels in subjects with low thymic scores, whereas first-phase T cell increases (perhaps mediated by redistribution to the circulation of tissue-associated lymphocytes) were associated with reductions in immune activation in subjects with high thymic scores. Reductions in immune activation were associated with reductions in spontaneous lymphocyte apoptosis. CONCLUSIONS: Distinct processes may underlie T cell restoration, according to estimated thymic volumes. IL-7-mediated peripheral expansion may drive T cell restoration in persons with low thymic volume, whereas therapy-associated reversal of immune reactivation may drive T cell losses and their restoration in persons with larger thymic volume. Copyright © 2005 Infectious Diseases Society of America [ABSTRACT FROM AUTHOR]

Ferroptosis is implicated in viral neuropathogenesis and may underlie HIV-associated neurocognitive impairment (NCI). Emerging data also suggest differences in brain iron transport by sex. We hypothesized that circulating ferritins that inhibit ferroptosis associate with neurocognitive function and NCI in people with HIV (PWH) in a sex-biased manner. Serum ferritin heavy-chain-1 (FTH1), ferritin light-chain (FTL), and urinary F 2 -isoprostanes (uF 2 -isoPs, specific lipid peroxidation marker) were quantified in 324 PWH (including 61 women) with serial global (NPZ-4) and domain-specific neurocognitive testing. Biomarker associations with neurocognitive test scores and NCIs were evaluated by multivariable regression; correlations with uF 2 -isoPs were also assessed. Higher FTL and FTH1 levels were associated with less NCI in all PWH (adjusted odds ratios 0.53, 95% confidence interval (95% CI) 0.36-0.79 and 0.66, 95% CI 0.45-0.97, respectively). In women, higher FTL and FTH1 were also associated with better NPZ-4 (FTL adjusted beta (β) = 0.15, 95% CI 0.02-0.29; FTL-by-sex β interaction = 0.32, p = 0.047) and domain-specific neurocognitive test scores. Effects on neurocognitive performance persisted for up to 5 years. Levels of both ferritins correlated inversely with uF 2 -isoPs in women (FTL: rho = -0.47, p < 0.001). Circulating FTL and FTH1 exert sustained, sex-biased neuroprotective effects in PWH, possibly by protecting against iron-mediated lipid peroxidation (ferroptosis). Larger studies are needed to confirm the observed sex differences and further delineate the underlying mechanisms.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is the most prevalent carbapenem-resistant Enterobacterales in the United States. We evaluated CRKp clustering in patients in US hospitals., Methods: From April 2016 to August 2017, 350 patients with clonal group 258 CRKp were enrolled in the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae, a prospective, multicenter, cohort study. A maximum likelihood tree was constructed using RAxML. Static clusters shared ≤21 single-nucleotide polymorphisms (SNP) and a most recent common ancestor. Dynamic clusters incorporated SNP distance, culture timing, and rates of SNP accumulation and transmission using the R program TransCluster., Results: Most patients were admitted from home (n = 150, 43%) or long-term care facilities (n = 115, 33%). Urine (n = 149, 43%) was the most common isolation site. Overall, 55 static and 47 dynamics clusters were identified involving 210 of 350 (60%) and 194 of 350 (55%) patients, respectively. Approximately half of static clusters were identical to dynamic clusters. Static clusters consisted of 33 (60%) intrasystem and 22 (40%) intersystem clusters. Dynamic clusters consisted of 32 (68%) intrasystem and 15 (32%) intersystem clusters and had fewer SNP differences than static clusters (8 vs 9; P = .045; 95% confidence interval [CI]: -4 to 0). Dynamic intersystem clusters contained more patients than dynamic intrasystem clusters (median [interquartile range], 4 [2, 7] vs 2 [2, 2]; P = .007; 95% CI: -3 to 0)., Conclusions: Widespread intrasystem and intersystem transmission of CRKp was identified in hospitalized US patients. Use of different methods for assessing genetic similarity resulted in only minor differences in interpretation., (© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Antimicrobial resistance is a global threat. As "proof-of-concept," we employed a system-based approach to identify patient, bacterial, and drug variables contributing to mortality in patients with carbapenem-resistant Klebsiella pneumoniae (CR Kp ) bloodstream infections exposed to colistin (COL) and ceftazidime-avibactam (CAZ/AVI) as mono- or combination therapies. Patients ( n  = 49) and CR Kp isolates ( n  = 22) were part of the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE-1), a multicenter, observational, prospective study of patients with carbapenem-resistant Enterobacterales (CRE) conducted between 2011 and 2016. Pharmacodynamic activity of mono- and combination drug concentrations was evaluated over 24 h using in vitro static time-kill assays. Bacterial growth and killing dynamics were estimated with a mechanism-based model. Random Forest was used to rank variables important for predicting 30-day mortality. Isolates exposed to COL+CAZ/AVI had enhanced early bacterial killing compared to CAZ/AVI alone and fewer incidences of regrowth compared to COL and CAZ/AVI. The mean coefficient of determination (R 2 ) for the observed versus predicted bacterial counts was 0.86 (range: 0.75 - 0.95). Bacterial subpopulation susceptibilities and drug mechanistic synergy were essential to describe bacterial killing and growth dynamics. The combination of clinical (hypotension), bacterial (IncR plasmid, aadA2 , and sul3 ) and drug (KC 50 ) variables were most predictive of 30-day mortality. This proof-of-concept study combined clinical, bacterial, and drug variables in a unified model to evaluate clinical outcomes.

Background: Neurocognitive impairment (NCI) is associated with monocyte activation in people with HIV (PWH). Activated monocytes increase glycolysis, reduce oxidative phosphorylation, and accumulate citrate and succinate, tricarboxylic acid (TCA) cycle metabolites that promote inflammation-this metabolic shift may contribute to NCI and slowed gait speed in PWH., Methods: Plasma citrate and succinate were assayed by liquid chromatography-mass spectrometry from 957 participants upon entry to a multicenter, prospective cohort of older PWH. Logistic, linear, and mixed-effects linear regression models were used to examine associations between entry/baseline TCA cycle metabolites and cross-sectional and longitudinal NCI, neuropsychological test scores (NPZ-4), and gait speed., Results: Median age was 51 (range 40-78) years. Each 1 standard deviation (SD) citrate increment was associated with 1.18 higher odds of prevalent NCI at baseline (P = .03), 0.07 SD lower time-updated NPZ-4 score (P = .01), and 0.02 m/s slower time-updated gait speed (P < .0001). Age accentuated these effects. In the oldest age-quartile, higher citrate was associated with 1.64 higher odds of prevalent NCI, 0.17 SD lower NPZ-4, and 0.04 m/s slower gait speed (P ≤ .01 for each). Similar associations were apparent with succinate in the oldest age-quintile, but not with gait speed. In participants without NCI at entry, higher citrate predicted a faster rate of neurocognitive decline., Conclusions: Higher plasma citrate and succinate are associated with worse cross-sectional and longitudinal measures of neurocognitive function and gait speed that are age-dependent, supporting the importance of altered bioenergetic metabolism in the pathogenesis of NCI in older PWH., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: The mechanisms underlying naïve CD4+ lymphopenia during chronic Hepatitis C Virus (HCV) infection are unclear. Whether direct-acting antiviral (DAA) therapy restores peripheral naïve CD4+ T cell numbers and function is unknown., Methods: We enumerated frequencies and counts of peripheral naïve CD4+, CD4+CD31+ and CD4+CD31- T cells by flow cytometry in a cross sectional analysis comparing chronic HCV infected (n=34), DAA-treated(n=29), and age-range matched controls (n=25), as well as in a longitudinal cohort of HCV DAA treated persons (n=16). The cross-sectional cohort was stratified by cirrhosis state. Cell apoptosis/survival (AnnexinV+7AAD+/BCL-2 labeling) and cell cycle entry (Ki67 expression) of CD31+ and CD31- naïve CD4+ T cells was analyzed directly ex vivo and following 3 and 5 days of in vitro culture with media, interleukin (IL) -7 or CD3/CD28 activator., Results: In the cross-sectional cohort, naïve CD4+ proportions were lower in chronic HCV infected persons compared to controls and DAA-treated persons, an effect in part attributed to cirrhosis. Age was associated with naïve cell counts and proportions in HCV infected and treated persons as well. Naïve CD4+ cell proportions negatively correlated with plasma levels of soluble CD14 following therapy in DAA-treated persons. Naïve CD4+ cells from HCV infected persons exhibited greater direct ex vivo apoptosis and cell-cycling compared to cells from DAA-treated persons and controls, and this was localized to the CD4+CD31+ subset. On the other hand, no remarkable differences in expression of BCL-2 or IL-7 Receptor (CD127) at baseline or following in vitro media or IL7 containing culture were observed. In the longitudinal cohort, naïve CD4+CD31+/CD31- ratio tended to increase 24 weeks after DAA therapy initiation., Conclusions: Activation and apoptosis of peripheral naïve CD4+CD31+ T cells appear to contribute to naïve CD4+ lymphopenia in chronic HCV infection, and this defect is partially reversible with HCV DAA therapy. Age and cirrhosis -associated naïve CD4+ lymphopenia is present both before and after HCV DAA therapy. These findings have implications for restoration of host immune function after DAA therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Auma, Shive, Lange, Damjanovska, Kowal, Zebrowski, Pandiyan, Wilson, Kalayjian, Canaday and Anthony.)

Background: Predicting mortality risk in patients is important in research settings. The Pitt bacteremia score (PBS) is commonly used as a predictor of early mortality risk in patients with bloodstream infections (BSIs). We determined whether the PBS predicts 14-day inpatient mortality in nonbacteremia carbapenem-resistant Enterobacteriaceae (CRE) infections., Methods: Patients were selected from the Consortium on Resistance Against Carbapenems in Klebsiella and Other Enterobacteriaceae, a prospective, multicenter, observational study. We estimated risk ratios to analyze the predictive ability of the PBS overall and each of its components individually. We analyzed each component of the PBS in the prediction of mortality, assessed the appropriate cutoff value for the dichotomized score, and compared the predictive ability of the qPitt score to that of the PBS., Results: In a cohort of 475 patients with CRE infections, a PBS ≥4 was associated with mortality in patients with nonbacteremia infections (risk ratio [RR], 21.9; 95% confidence interval [CI], 7.0, 68.8) and with BSIs (RR, 6.0; 95% CI, 2.5, 14.4). In multivariable analysis, the hypotension, mechanical ventilation, mental status, and cardiac arrest parameters of the PBS were independent risk factors for 14-day all-cause inpatient mortality. The temperature parameter as originally calculated for the PBS was not independently associated with mortality. However, a temperature <36.0°C vs ≥36°C was independently associated with mortality. A qPitt score ≥2 had similar discrimination as a PBS ≥4 in nonbacteremia infections., Conclusions: Here, we validated that the PBS and qPitt score can be used as reliable predictors of mortality in nonbacteremia CRE infections., (© The Author(s) 2019. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Objective: To examine associations between plasma cystatin C and neurocognitive impairment (NCI) and its performance as a diagnostic marker before and during initial antiretroviral therapy (ART)., Methods: Multivariable logistic regression and generalized estimating equations examined associations with NCI, determined by neuropsychological measurements, in participants of a 48-week randomized clinical trial of initial ART. Receiver operator characteristic curves examined diagnostic models of NCI., Results: Cystatin C was associated with NCI before ART [odds ratio (OR) 3.4 (95% CI: 1.2 to 9.4) for each 2-fold increase in baseline levels] and during 48 weeks of ART, in models that excluded baseline measurements [OR 3.0 (1.2 to 7.8) for each 2-fold increase in time-updated levels]. The strength of association increased with more severe impairment using HIV-associated neurocognitive disorder criteria [OR 2.2 (0.8 to 6.0) with asymptomatic NCI and OR 4.0 (1.5 to 11.0) with mild neurocognitive disorder or HIV-associated dementia vs. no impairment, for each 2-fold increase in time-updated levels] or by global development score [OR 2.6 (1.1 to 6.3) with mild impairment and OR 4.6 (1.1 to 18.9) with moderate or severe impairment vs. no impairment]. Cystatin C performed poorly as a diagnostic marker for NCI, however, with an area under the receiver operator characteristic curve of 0.58 at baseline and 0.54 at week 48., Conclusions: Higher plasma cystatin C levels were significantly associated with NCI, but these levels did not seem to be useful as a diagnostic marker for this condition.

In the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE), trimethoprim-sulfamethoxazole (TMP-SMX) had a limited role in the treatment of less severe carbapenem-resistant Enterobacteriaceae (CRE) infections, especially urinary tract infections. Of tested CRE, only 29% were susceptible to TMP-SMX. Development of resistance further limits the use of TMP-SMX in CRE infections.

Objective: We compared bone mineral density (BMD) changes and their correlates, between men and women participating in two randomized trials of initial [antiretroviral therapy (ART)] regimens, with or without tenofovir disoproxil fumarate (TDF)., Methods: Covariates in linear regression models of 48-week hip and spine %BMD changes, by dual energy X-ray absorptiometry, included baseline and 48-week changes in plasma viral load, CD4 cells, plasma C-terminal telopeptide, procollagen 1 N-terminal propeptide and glomerular filtration rates, and the 48-week area under the curve of fractional excretion of phosphate., Results: Despite overall hip and spine BMD declines of 2.8 and 2.9%, respectively, plasma viral load suppression to less than 50 vs. at least 50 copies/ml was associated 1.0% (P = 0.02) and 0.8% (P = 0.01) less BMD decline. Women had lower baseline spine (P = 0.04; n = 59 women, 418 men) and hip BMD (P = 0.01) in adjusted models, with 1.7% more hip decline on ART than men (P = 0.001). Serum phosphate was positively associated with baseline spine BMD in women (P = 0.03) but not men, and area under the curve of fractional excretion of phosphate was negatively associated with spine BMD changes, particularly in women randomized to TDF regimens (P = 0.03 and 0.054 for interactions by sex, and randomization to TDF vs. non-TDF regimens, respectively; n = 44 women, 326 men). Women also had 0.6% (P = 0.004) more hip BMD decline than men associated with each 100 CD4 cells/μl increase on ART (P = 0.02; n = 49 women, 379 men)., Conclusion: Women randomized to TDF-containing ART had accentuated spine loss associated with phosphaturia, and accentuated hip loss associated with CD4 restoration, regardless of TDF exposure. Viral load suppression reduced bone loss.

Background: Chronic hepatitis C virus (HCV) and HIV infections are associated with impaired responses to neo-antigens contained in hepatitis A virus (HAV)/hepatitis B virus (HBV) vaccines, yet responsible mechanisms are unclear., Methods: ACTG 5232 and CFAR0910 were clinical trials where pre-vaccine levels of plasma IP10, IL-6, sCD163 and sCD14 were measured in viremic HCV- (n = 15) or HIV-infected participants (n = 24) and uninfected controls (n = 10). Accelerated dosing HAV/HBV vaccine and tetanus booster were administered and antibody response was measured at 0, 1, 3, 8, and 24 weeks., Results: Pre-vaccine plasma IP10, IL-6, and sCD14 levels were elevated in both HCV and HIV-infected participants, while sCD163 was also elevated in HCV-infected participants. Pre-immunization tetanus antibody levels were lower in HIV-infected than in uninfected participants, while vaccine induced antibody responses were intact in HCV and HIV-infected participants. After HAV/HBV vaccination, HCV and HIV-infected participants had lower and less durable HAV and HBV antibody responses than uninfected controls. Among HCV-infected participants, pre-vaccine plasma IP10, IL-6, sCD14, and sCD163 levels inversely correlated with HAV, HBV and tetanus antibody responses after vaccine. Low HAV/HBV vaccine responses in HIV-infected participants prohibited assessment of immune correlates., Conclusions: During HCV and HIV infection markers of systemic inflammation reflect immune dysfunction as demonstrated by poor response to HAV/HBV neo-antigen vaccine., (Published by Elsevier Ltd.)

Background: The efficacy of ceftazidime-avibactam-a cephalosporin-β-lactamase inhibitor combination with in vitro activity against Klebsiella pneumoniae carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CRE)-compared with colistin remains unknown., Methods: Patients initially treated with either ceftazidime-avibactam or colistin for CRE infections were selected from the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE), a prospective, multicenter, observational study. Efficacy, safety, and benefit-risk analyses were performed using intent-to-treat analyses with partial credit and the desirability of outcome ranking approaches. The ordinal efficacy outcome was based on disposition at day 30 after starting treatment (home vs not home but not observed to die in the hospital vs hospital death). All analyses were adjusted for confounding using inverse probability of treatment weighting (IPTW)., Results: Thirty-eight patients were treated first with ceftazidime-avibactam and 99 with colistin. Most patients received additional anti-CRE agents as part of their treatment. Bloodstream (n = 63; 46%) and respiratory (n = 30; 22%) infections were most common. In patients treated with ceftazidime-avibactam versus colistin, IPTW-adjusted all-cause hospital mortality 30 days after starting treatment was 9% versus 32%, respectively (difference, 23%; 95% bootstrap confidence interval, 9%-35%; P = .001). In an analysis of disposition at 30 days, patients treated with ceftazidime-avibactam, compared with those treated within colistin, had an IPTW-adjusted probability of a better outcome of 64% (95% confidence interval, 57%-71%). Partial credit analyses indicated uniform superiority of ceftazidime-avibactam to colistin., Conclusions: Ceftazidime-avibactam may be a reasonable alternative to colistin in the treatment of K. pneumoniae carbapenemase-producing CRE infections. These findings require confirmation in a randomized controlled trial., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Persons living with HIV (PLWH) have accentuated risks for age-associated comorbidities. Compared to the general population, PLWH have a 2-fold higher risk of cardiovascular disease, a 3-fold increased risk of fracture, and a risk of kidney disease that is comparable to that in diabetes. Some comorbidities may present at younger ages than among the general population, suggesting the possibility of accelerated aging with HIV infection., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Although statins, angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) are generally well tolerated, the impact of these therapies individually or in combination on the change in neurocognitive function in persons with human immunodeficiency virus infection is unknown., Methods: The study included participants in the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials cohort participants not receiving a statin or ACEI/ARB within 30 days of first neurologic assessment (baseline), with assessments by NPZ-3 (z score of averaged Trailmaking A and B tests and digit symbol test [DST]) from ≥2 measurements. Marginal structural models estimated the causal effect of statin or ACEI/ARB initiation on neurocognitive function; initial constant slope was assumed during the first year of treatment and a second constant slope thereafter., Results: Of 3949 eligible participants, 16% started therapy with a statin, 11% with an ACEI/ARB, and 5% with both. Statin therapy had no significant effect on the composite NPZ-3 (primary outcome), Trailmaking B test, or DST. A small, nonsignificant positive effect on the Trailmaking A test was seen during year 1 (estimate, 0.088; 95% confidence interval, -.010 to .187; P = .08) and a small but significant negative effect (-0.033; -.058 to -.009; P = .007) in each subsequent year. ACEI/ARB therapy had a significant negative effect on the DST (-0.117; 95% confidence interval, -.217 to .016; P = .02) during year 1 but minimal effect in subsequent years or on other neurocognitive domains., Conclusions: In summary, although modest declines in neurocognitive performance were seen in single domains with statin or ACEI/ARB therapy, we did not find consistent evidence that statins or ACEI/ARB have an effect on global neurocognitive function. Future studies should focus on long-term neurocognitive effects., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Patients on chronic intermittent renal replacement therapy (RRT) are at risk for infection with carbapenem-resistant Enterobacteriaceae (CRE). However, the impact of RRT on outcomes after CRE infections remains to be defined. Here we perform a comparison of outcomes for CRE-infected patients with preserved renal function compared with CRE-infected patients on RRT., Methods: Cases and controls were defined from a prospective cohort of CRE-infected patients from the Consortium on Resistance against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE). Cases were defined as CRE-infected patients on RRT at hospital admission, while controls were defined as CRE-infected patients with serum creatinine <2 mg/dL and not receiving RRT at admission. Risk factors for 28-day in-hospital mortality were assessed using multivariable logistic regression. An ordinal ranking of outcomes by desirability analysis was performed., Results: Patients on RRT were more likely to have diabetes mellitus and cardiac disease than controls. Urinary sources of infection were less common in the RRT group. In RRT patients, 28-day in-hospital mortality was increased as compared with controls: 22/71 (31%) vs 33/295 (11%). RRT remained significantly associated with 28-day in-hospital mortality after adjustment for source of infection, prehospitalization origin, and severity of illness (adjusted odds ratio, 2.27; 95% confidence interval [CI], 1.09-4.68; P = .03). Using univariable desirability of outcome ranking analysis, RRT status was associated with a 68% (95% CI, 61%-74%) chance of a worse disposition outcome., Conclusions: Chronic RRT in CRE-infected patients is associated with increased in-hospital mortality and worse disposition outcomes at 28 days.

Background: This study was performed to characterize the epidemiology, management, and outcomes of skin and soft tissue infection (SSTI) and colonization due to carbapenem-resistant Enterobacteriaceae (CRE)., Methods: Patients from the Consortium on Resistance Against Carbapenem in Klebsiella and Other Enterobacteriaceae (CRACKLE-1) from December 24, 2011 to October 1, 2014 with wound cultures positive for CRE were included in the study. Predictors of surgical intervention were analyzed. Molecular typing of isolates was performed using repetitive extragenic palindromic polymerase chain reaction (PCR). Carbapenemase genes were detected using PCR., Results: One hundred forty-two patients were included: 62 had SSTI (44%) and 56% were colonized. Mean age was 61 years, and 48% were male: median Charlson score was 3 (interquartile range, 1-5). Forty-eight percent of patients were admitted from long-term care facilities (LTCFs), and 31% were from the community. Two strain types (ST258A and ST258B) were identified (73% of 45 tested). Carbapenemase genes were detected in 40 of 45 isolates ( bla KPC-3 [47%], bla KPC-2 [42%]). Sixty-eight patients (48%) underwent surgical intervention, 63% of whom had SSTI. Patients admitted from LTCFs were less likely to undergo surgical intervention (odds ratio [OR], 0.36; 95% confidence interval [CI], 0.18-0.71). In multivariable analysis, among patients with SSTI, those admitted from LTCFs were less likely to undergo debridement (OR, 0.18; 95% CI, 0.04-0.93)., Conclusions: Patients admitted from LTCFs with CRE SSTI were less likely to undergo surgical intervention. Sixteen percent of the patients died, and approximately 50% of survivors required more intensive care upon discharge. These findings suggest a unique, impactful syndrome within the CRE infection spectrum. Further studies are needed to assess the role of surgical debridement in management of CRE-SSTI, particularly among LTCF residents.

Background: Older human immunodeficiency virus (HIV)-infected adults may experience higher rates of frailty and disability than the general population. Improved understanding of the prevalence, risk factors, and types of impairment can better inform providers and the healthcare system., Methods: HIV-infected participants within the AIDS Clinical Trials Group A5322 HAILO study self-reported disability by the Lawton-Brody Instrumental Activities of Daily Living (IADL) Questionnaire. Frailty was measured by 4-m walk time, grip strength, self-reported weight loss, exhaustion, and low activity. Logistic regression models identified characteristics associated with any IADL impairment. Agreement between IADL impairment and frailty was assessed using the weighted kappa statistic., Results: Of 1015 participants, the median age was 51 years, 15% were aged ≥60 years, 19% were female, 29% black, and 20% Hispanic. At least 1 IADL impairment was reported in 18% of participants, most commonly with housekeeping (48%) and transportation (36%) and least commonly with medication management (5%). In multivariable models, greater disability was significantly associated with neurocognitive impairment, lower education, Medicare/Medicaid insurance (vs private/other coverage), smoking, and low physical activity. Although a greater proportion of frail participants had IADL impairment (52%) compared to non-frail (11%) persons, agreement was poor (weighted kappa <0.18, 95% confidence interval, 0.13, 0.23)., Conclusion: IADL disability occurs frequently among middle-aged and older HIV-infected adults on effective antiretroviral therapy. Potentially modifiable risk factors (smoking, physical activity) provide targets for interventions to maintain independent living. Systematic recognition of persons at greater risk for disability can facilitate connection to resources that may help preserve independence., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

The impact of antiretroviral therapy (ART) on frailty among human immunodeficiency virus (HIV)-infected adults has not been well described. HIV-infected participants aged ≥40 years with initial ART receipt through a randomized, controlled AIDS Clinical Trials Group trial completed a frailty assessment. Ordinal logistic regression models examined factors associated with frailty. Of 1016 participants, 6% were frail, and 38% were prefrail. Frailty was associated with lower education, older age, Medicare/Medicaid, initial efavirenz, smoking, obesity, and neurocognitive impairment; physical activity and alcohol use were protective. The associations with ART require further investigation, and associations between frailty and modifiable factors provide targets for future interventions., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Polymyxins including colistin are an important "last-line" treatment for infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKp). Increasing use of colistin has led to resistance to this cationic antimicrobial peptide., Methods: A cohort nested within the Consortium on Resistance against Carbapenems in Klebsiella pneumoniae (CRACKLE) was constructed of patients with infection, or colonization with CRKp isolates tested for colistin susceptibility during the study period of December, 2011 to October, 2014. Reference colistin resistance determination as performed by broth macrodilution was compared to results from clinical microbiology laboratories (Etest) and to polymyxin resistance testing. Each patient was included once, at the time of their first colistin-tested CRKp positive culture. Time to 30-day in-hospital all-cause mortality was evaluated by Kaplan-Meier curves and Cox proportional hazard modeling., Results: In 246 patients with CRKp, 13% possessed ColR CRKp. ColR was underestimated by Etest (very major error rate = 35%, major error rate = 0.4%). A variety of rep-PCR strain types were encountered in both the ColS and the ColR groups. Carbapenem resistance was mediated primarily by blaKPC-2 (46%) and blaKPC-3 (50%). ColR was associated with increased hazard for in-hospital mortality (aHR 3.48; 95% confidence interval, 1.73-6.57; P < .001). The plasmid-associated ColR genes, mcr-1 and mcr-2 were not detected in any of the ColR CRKp., Conclusions: In this cohort, 13% of patients with CRKp presented with ColR CRKp. The apparent polyclonal nature of the isolates suggests de novo emergence of ColR in this cohort as the primary factor driving ColR. Importantly, mortality was increased in patients with ColR isolates., (© The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com)

Patients infected or colonized with carbapenem-resistant Klebsiella pneumoniae (CRKp) are often chronically and acutely ill, which results in substantial mortality unrelated to infection. Therefore, estimating excess mortality due to CRKp infections is challenging. The Consortium on Resistance against Carbapenems in K. pneumoniae (CRACKLE) is a prospective multicenter study. Here, patients in CRACKLE were evaluated at the time of their first CRKp bloodstream infection (BSI), pneumonia or urinary tract infection (UTI). A control cohort of patients with CRKp urinary colonization without CRKp infection was constructed. Excess hospital mortality was defined as mortality in cases after subtracting mortality in controls. In addition, the adjusted hazard ratios (aHR) for time-to-hospital-mortality at 30 days associated with infection compared with colonization were calculated in Cox proportional hazard models. In the study period, 260 patients with CRKp infections were included in the BSI (90 patients), pneumonia (49 patients) and UTI (121 patients) groups, who were compared with 223 controls. All-cause hospital mortality in controls was 12%. Excess hospital mortality was 27% in both patients with BSI and those with pneumonia. Excess hospital mortality was not observed in patients with UTI. In multivariable analyses, BSI and pneumonia compared with controls were associated with aHR of 2.59 (95% CI 1.52-4.50, p <0.001) and 3.44 (95% CI 1.80-6.48, p <0.001), respectively. In conclusion, in patients with CRKp infection, pneumonia is associated with the highest excess hospital mortality. Patients with BSI have slightly lower excess hospital mortality rates, whereas excess hospital mortality was not observed in hospitalized patients with UTI., (Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Background: Various transmission routes contribute to spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) in hospitalized patients. Patients with readmissions during which CRKP is again isolated ("CRKP readmission") potentially contribute to transmission of CRKP., Objective: To evaluate CRKP readmissions in the Consortium on Resistance against Carbapenems in K. pneumoniae (CRaCKLe)., Design: Cohort study from December 24, 2011, through July 1, 2013., Setting: Multicenter consortium of acute care hospitals in the Great Lakes region., Patients: All patients who were discharged alive during the study period were included. Each patient was included only once at the time of the first CRKP-positive culture., Methods: All readmissions within 90 days of discharge from the index hospitalization during which CRKP was again found were analyzed. Risk factors for CRKP readmission were evaluated in multivariable models., Results: Fifty-six (20%) of 287 patients who were discharged alive had a CRKP readmission. History of malignancy was associated with CRKP readmission (adjusted odds ratio [adjusted OR], 3.00 [95% CI, 1.32-6.65], P<.01). During the index hospitalization, 160 patients (56%) received antibiotic treatment against CRKP; the choice of regimen was associated with CRKP readmission (P=.02). Receipt of tigecycline-based therapy (adjusted OR, 5.13 [95% CI, 1.72-17.44], using aminoglycoside-based therapy as a reference in those treated with anti-CRKP antibiotics) was associated with CRKP readmission., Conclusion: Hospitalized patients with CRKP-specifically those with a history of malignancy-are at high risk of readmission with recurrent CRKP infection or colonization. Treatment during the index hospitalization with a tigecycline-based regimen increases this risk.

Objective: To determine the rates of and risk factors for tigecycline nonsusceptibility among carbapenem-resistant Klebsiella pneumoniae (CRKPs) isolated from hospitalized patients., Design: Multicenter prospective observational study., Setting: Acute care hospitals participating in the Consortium on Resistance against Carbapenems in Klebsiella pneumoniae (CRaCKle)., Patients: A cohort of 287 patients who had CRKPs isolated from clinical cultures during hospitalization., Methods: For the period from December 24, 2011 to October 1, 2013, the first hospitalization of each patient with a CRKP during which tigecycline susceptibility for the CRKP isolate was determined was included. Clinical data were entered into a centralized database, including data regarding pre-hospital origin. Breakpoints established by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) were used to interpret tigecycline susceptibility testing., Results: Of 287 patients included in the final cohort, 155 (54%) had tigecycline-susceptible CRKPs. Of all index isolates, 81 (28%) were tigecycline-intermediate and 51 (18%) were tigecycline resistant. In multivariate modeling, independent risk factors for tigecycline nonsusceptibility were (1) admission from a skilled nursing facility (OR, 2.51; 95% CI, 1.51-4.21; P=.0004), (2) positive culture within 2 days of admission (OR, 1.82; 95% CI, 1.06-3.15; P=.03), and (3) receipt of tigecycline within 14 days (OR, 4.38, 95% CI, 1.37-17.01, P=.02)., Conclusions: In hospitalized patients with CRKPs, tigecycline nonsusceptibility was more frequently observed in those admitted from skilled nursing facilities and occurred earlier during hospitalization. Skilled nursing facilities are an important target for interventions to decrease antibacterial resistance to antibiotics of last resort for treatment of CRKPs.

Carbapenem-resistant Enterobacteriaceae (CRE) usually infect patients with significant comorbidities and health care exposures. We present a case of a pregnant woman who developed community-acquired pyelonephritis caused by KPC-producing Klebsiella pneumoniae. Despite antibiotic treatment, she experienced spontaneous prolonged rupture of membranes, with eventual delivery of a healthy infant. This report demonstrates the challenge that CRE may pose to the effective treatment of common infections in obstetric patients, with potentially harmful consequences to maternal and neonatal health., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Objectives: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an important healthcare-associated pathogen. We evaluated the impact of CRKP strain type and treatment on outcomes of patients with CRKP bacteriuria., Patients and Methods: Physician-diagnosed CRKP urinary tract infection (UTI)-defined as those patients who received directed treatment for CRKP bacteriuria-was studied in the multicentre, prospective Consortium on Resistance against Carbapenems in Klebsiella pneumoniae (CRaCKle) cohort. Strain typing by repetitive extragenic palindromic PCR (rep-PCR) was performed. Outcomes were classified as failure, indeterminate or success. Univariate and multivariate ordinal analyses to evaluate the associations between outcome, treatment and strain type were followed by binomial analyses., Results: One-hundred-and-fifty-seven patients with physician-diagnosed CRKP UTI were included. After adjustment for CDC/National Healthcare Safety Network (NHSN)-defined UTI, critical illness and receipt of more than one active antibiotic, patients treated with aminoglycosides were less likely to fail therapy [adjusted OR (aOR) for failure 0.34, 95% CI 0.15-0.73, P=0.0049]. In contrast, patients treated with tigecycline were more likely to fail therapy (aOR for failure 2.29, 95% CI 1.03-5.13, P=0.0425). Strain type data were analysed for 55 patients. The predominant clades were ST258A (n=18, 33%) and ST258B (n=26, 47%). After adjustment for CDC/NHSN-defined UTI and use of tigecycline and aminoglycosides, infection with strain type ST258A was associated with clinical outcome in ordinal analysis (P=0.0343). In multivariate binomial models, strain type ST258A was associated with clinical failure (aOR for failure 5.82, 95% CI 1.47-28.50, P=0.0113)., Conclusions: In this nested cohort study of physician-diagnosed CRKP UTI, both choice of treatment and CRKP strain type appeared to impact on clinical outcomes., (© The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an increasing global threat. Here, we describe the prevalence and impact of tigecycline use in a cohort of patients with CRKP bacteriuria nested within a multicentre, prospective study. In the 21-month study period, 260 unique patients were included. Tigecycline was given to 80 (31%) patients. The use of tigecycline during the index hospitalization was significantly associated with the subsequent development of tigecycline resistance in the same patient (OR, 6.13; 95% CI, 1.15-48.65; p 0.03). In conclusion, the use of tigecycline with CRKP bacteriuria is common, and is associated with the subsequent development of tigecycline resistance., (© 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.)

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances., (© The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Older HIV infected subjects were previously found to have significant B cell expansion during initial antiretroviral therapy in a prospective age-differentiated cohort of older and younger (≥45 vs. ≤30 years) HIV-infected subjects initiating antiretroviral therapy (ART) through the AIDS Clinical Trials Group. Here to further describe this expansion, using a subset of subjects from the same cohort, we characterized B cell phenotypes at baseline and after 192 weeks of ART in both older and younger HIV-infected groups and compared them to uninfected age-matched controls. We also examined whether phenotypes at baseline associated with response to tetanus and hepatitis A vaccine at 12 weeks. Forty six subjects were analyzed in the HIV infected group (21 older, 25 younger) and 30 in the control group (15 per age group). We observed naïve B cells to normalize in younger subjects after 192 weeks of ART, while in older subjects naïve B cells increased to greater levels than those of controls (p = 0.045). Absolute resting memory (RM) cell count was significantly lower in the older HIV infected group at baseline compared to controls and numbers normalized after 192 weeks of ART (p<0.001). Baseline RM cell count positively correlated with week 12 increase in antibody to tetanus vaccine among both younger and older HIV-infected subjects combined (p = 0.01), but not in controls. The age-associated naïve B cell expansion is a novel finding and we discuss several possible explanations for this observation. Relationship between RM cells at baseline and tetanus responses may lead to insights about the effects of HIV infection on B cell memory function and vaccine responses.

Background: Proteinuria is a marker of vascular dysfunction that predicted increased cardiovascular mortality and is associated with neurocognitive impairment (NCI) in population-based studies. We examined associations between proteinuria and HIV-associated NCI., Methods: Multivariable logistic regression was used to examine associations between NCI at the first neurocognitive assessment (baseline) and simultaneous, clinically significant proteinuria [as random spot urine protein-to-creatinine ratios (UP/Cr) ≥200 mg/g] in a prospective multicenter observational cohort study. Generalized estimating equations were used to examine associations between baseline proteinuria and subsequent NCI among subjects without NCI at baseline. NCI was defined as a Z-score, derived from the combination of normalized scores from the Trailmaking A and B and the Wechsler Adult Intelligence Scale-Revised Digit Symbol tests., Results: A total of 1972 subjects were included in this analysis. Baseline proteinuria was associated with increased odds of NCI [odds ratio (OR): 1.41, 95% confidence interval (CI): 1.08 to 1.85; P = 0.01] and with subsequent NCI among subjects without NCI at baseline (OR: 1.39, 95% CI: 1.01 to 1.93; P = 0.046) in multivariable models adjusted for risk factors and potential confounders. Similar associations were evident when these analyses were limited to visits at which time study subjects maintained plasma HIV RNA levels <200 copies per milliliter., Conclusions: The association between proteinuria and NCI observed in this study adds to a growing body of evidence implicating contributions by vascular disease to NCI in antiretroviral treated individuals. Studies examining interventions that improve vascular function are warranted.

Carbapenem resistance in Gram-negative bacteria is on the rise in the United States. A regional network was established to study microbiological and genetic determinants of clinical outcomes in hospitalized patients with carbapenem-resistant (CR) Klebsiella pneumoniae in a prospective, multicenter, observational study. To this end, predefined clinical characteristics and outcomes were recorded and K. pneumoniae isolates were analyzed for strain typing and resistance mechanism determination. In a 14-month period, 251 patients were included. While most of the patients were admitted from long-term care settings, 28% of them were admitted from home. Hospitalizations were prolonged and complicated. Nonsusceptibility to colistin and tigecycline occurred in isolates from 7 and 45% of the patients, respectively. Most of the CR K. pneumoniae isolates belonged to repetitive extragenic palindromic PCR (rep-PCR) types A and B (both sequence type 258) and carried either blaKPC-2 (48%) or blaKPC-3 (51%). One isolate tested positive for blaNDM-1, a sentinel discovery in this region. Important differences between strain types were noted; rep-PCR type B strains were associated with blaKPC-3 (odds ratio [OR], 294; 95% confidence interval [CI], 58 to 2,552; P < 0.001), gentamicin nonsusceptibility (OR, 24; 95% CI, 8.39 to 79.38; P < 0.001), amikacin susceptibility (OR, 11.0; 95% CI, 3.21 to 42.42; P < 0.001), tigecycline nonsusceptibility (OR, 5.34; 95% CI, 1.30 to 36.41; P = 0.018), a shorter length of stay (OR, 0.98; 95% CI, 0.95 to 1.00; P = 0.043), and admission from a skilled-nursing facility (OR, 3.09; 95% CI, 1.26 to 8.08; P = 0.013). Our analysis shows that (i) CR K. pneumoniae is seen primarily in the elderly long-term care population and that (ii) regional monitoring of CR K. pneumoniae reveals insights into molecular characteristics. This work highlights the crucial role of ongoing surveillance of carbapenem resistance determinants., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

Objective: The predictors of Fanconi syndrome (FS) accompanied by renal function decline with use of the antiretroviral tenofovir disoproxil fumarate (TDF) have not been assessed. In addition, the natural history of renal recovery from FS after TDF discontinuation is not well-described., Design: We prospectively enrolled HIV-infected patients receiving TDF with newly identified FS (defined as at least two markers of proximal tubulopathy and either a >25% decline in creatinine clearance (CrCl) from pre-TDF values or a CrCl <60 mL/min in those without a known pre-TDF CrCl) in a multicenter observational study. These case participants were matched 1:2 to controls; characteristics between the two groups were compared. Case participants with known pre-TDF CrCl values were then followed over 48 weeks to assess renal recovery., Results: Nineteen cases and 37 controls were enrolled. In multivariable analysis, previous or concurrent use of lopinavir/ritonavir [OR 16.37, 95% CI (2.28, 117.68); P = 0.006] and reduced creatinine clearance prior to initiation of TDF [OR 1.44 for every 5 mL/min reduction, 95% CI (1.09, 1.92); P = 0.012; OR 19.77 for pre-TDF CrCl lower than 83 mL/min, 95% CI (2.24, 174.67); P = 0.007] were significantly associated with FS. Of the 14 cases followed for resolution, 7 (50%) achieved at least partial resolution (defined as recovering CrCl >70% of pre-TDF values) although most participants had full normalization of proximal tubulopathy markers within two months of TDF discontinuation., Conclusions: FS, defined by specific CrCl decreases and markers of tubulopathy, is more likely in those who have received or are currently receiving concomitant lopinavir/ritonavir or who had lower CrCl prior to TDF initiation. Half of those with protocol-defined FS had CrCl recover to near pre-TDF values during the first year after TDF discontinuation.

Polymorphisms in APOL1 are associated with CKD, including HIV-related CKD, in individuals of African ancestry. The apolipoprotein L1 (APOL1) protein circulates and is localized in kidney cells, but the contribution of APOL1 location to CKD pathogenesis is unclear. We examined associations of plasma APOL1 levels with plasma cytokine levels, dyslipidemia, and APOL1 genotype in a nested case-control study (n=270) of HIV-infected African Americans enrolled in a multicenter prospective observational study. Patients were designated as having CKD when estimated GFR (eGFR) decreased to <60 ml/min per 1.73 m(2) (eGFR<60 cohort) or protein-to-creatinine ratios became >3.5 g/g (nephrotic proteinuria cohort). Circulating APOL1 levels did not associate with APOL1 genotype, CKD status, or levels of proinflammatory cytokines, but did correlate with fasting cholesterol, LDL cholesterol, and triglyceride levels. At ascertainment, CKD-associated polymorphisms (risk variants) in APOL1 associated with the eGFR<60 cohort, but not the nephrotic-range proteinuria cohort. Of note, in both the eGFR<60 and nephrotic proteinuria cohorts, CKD cases with two APOL1 risk variants had significant declines in eGFR over a median of 4 years compared with individuals with one or no risk variants. APOL1 risk genotype was not associated with changes in proteinuria. Higher circulating proinflammatory cytokine levels were independently associated with CKD but not APOL1 genotype. In conclusion, the function of variant APOL1 proteins derived from circulation or synthesized in the kidney, but not the level of circulating APOL1, probably mediates APOL1-associated kidney disease in HIV-infected African Americans.

Background: The contribution of immune activation to accelerated HIV-disease progression in older individuals has not been delineated., Methods: Prospective multicenter cohort of older (≥45 years) and younger (18-30 years) HIV-infected adults initiating 192 weeks of antiretroviral therapy (ART). Longitudinal models of CD4 cell restoration examined associations with age-group, thymic volume, immune activation, and viral load., Results: Forty-five older and 45 younger adults (median age 50 and 26 years, respectively) were studied. Older patients had fewer naive CD4 cells (P<0.001) and higher HLA-DR/CD38 expression on CD4 (P=0.05) and CD8 cells (P=0.07) than younger patients at any time on ART. The rate of naive and total CD4 cell increase was similar between age groups, but older patients had a faster mean rate of B-cell increase (by +0.7 cells/week; P=0.01), to higher counts than healthy controls after 192 weeks (P=0.003). Naive CD4 increases from baseline were associated with immune activation reductions (as declines from baseline of %CD8 cells expressing HLA-DR/CD38; P<0.0001), but these increases were attenuated in older patients, or in those with small thymuses. A 15% reduction in activation was associated with naive gains of 29.9 and 6.2 cells/μl in younger, versus older patients, or with gains of 25.7, 23.4, and 2.1 cells/μl in patients with the largest, intermediate, and smallest thymuses, respectively (P<0.01 for interactions between activation reduction and age-group or thymic volume)., Conclusion: Older patients had significant B-cell expansion, higher levels of immune activation markers, and significantly attenuated naive CD4 cell gains associated with activation reduction., (© 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins)

Objective: 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., Methods: 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., Results: 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 m per year; P = 0.02). The incidence of CKD defined by eGFR thresholds of 60, 45 and 30 ml/min per 1.73 m 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 m: 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., Conclusion: 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.

Kidney disease is more prevalent among persons living with HIV, and may arise from a combination of comorbidities, co-infections, and medication-associated toxicities. Additional effects of HIV-1 viral replication, immunodeficiency and genetic factors also contribute to kidney disease. As is true in the general population, persons of African descent exhibit a disproportionate risk for severe kidney disease. Antiretroviral therapy (ART) modifies the natural history of HIV-associated nephropathy (HIVAN), and renal benefits of ART may not be limited to persons with HIVAN. Robust associations between proteinuria and cardiovascular disease imply that common mechanisms of vascular endothelial dysfunction may contribute to both processes.

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.

Kidney disease remains a prominent complication of HIV disease, despite beneficial effects of antiretroviral therapy on the natural history of HIV-associated nephropathy, and on kidney function in general populations of HIV infected patients. Persons of African descent continue to bear a disproportionate burden of severe kidney disease, as is true for the general population. Recently identified genetic variants in the apolipoprotein L1 gene may contribute to this burden. As is also true for the general population, markers of kidney disease, including microalbuminuria, are sensitive predictors of cardiovascular disease and mortality among persons living with HIV. The emerging experience with kidney transplantation also suggests this to be a viable option in selected patients.

HIV infection results in depletion and dysfunction of naïve CD4(+) T cells. The mechanisms underlying these deficiencies are not understood. We investigated the frequencies of CD4(+) naïve subsets in HIV disease as defined by expression of CD25 and/or FoxP3 and the relationship of these frequencies to naïve T cell proliferation function. We observed increased proportions of CD25(+)FoxP3(+) and CD25(+)FoxP3(-) cells and decreased proportions of CD25(-)FoxP3(-) cells within the naïve CD4(+) cell compartment from HIV-infected persons compared with findings in healthy donors. These perturbations were related to higher plasma HIV RNA levels but not with higher immune activation, as measured by the proportions of CD38(+) memory CD4(+) T cells. Naïve T cell proliferation responses to mitogen stimulation were inversely related to the frequencies and absolute numbers of FoxP3(+) naïve T cells. MDA, a marker of oxidative stress, and sCD14, a marker of monocyte activation and a surrogate for microbial translocation, were increased in serum samples from HIV(+) donors; however, neither marker was related to naïve T cell function in HIV(+) donors. These observations suggest that alterations in naïve T cell subset frequencies could contribute to naïve T cell dysfunction in HIV disease, but these alterations are not necessarily the result of chronic immune activation.

Background: To identify inflammatory pathways that may contribute to the pathogenesis of human immunodeficiency virus (HIV) disease, we explored associations between AIDS or death and different inflammatory markers, including selected soluble tumor necrosis factor superfamily receptors (sTNFRs) and ligands, interleukin (IL)-6, and CD8 T cell activation, in individuals treated with highly active antiretroviral therapy (HAART)., Methods: A case-control study of subjects in AIDS Clinical Trials Group (ACTG) protocols 384 and 5015, who were matched according to the CD4 cell count and plasma viral load at baseline, was performed using conditional logistic regression., Results: Higher pretreatment concentrations of sTNFR-1, sCD27, sCD40L, and plasma IL-6 were associated with a new AIDS-defining illness or death in separate models adjusted for age, sex, hemoglobin, and the latest CD4 cell counts. In additional models that excluded case patients with opportunistic infections, sTNFR-1, sCD27, and sCD40L were each associated with a new AIDS-defining malignancy or death that developed at a median of 51 weeks after initiation of HAART, by which time the majority of subjects had a CD4 cell count of >200 cells/cm(3) and had achieved a plasma viral load of <50 copies/mL., Conclusion: These data are compatible with a model in which these soluble inflammatory markers identify pathways that may contribute to the pathogenesis of HIV disease progression, pathways that might not be a direct consequence of ongoing HIV type 1 replication.

The advent of highly active antiretroviral therapy in the treatment of HIV disease has substantially extended the lifespan of individuals infected with HIV resulting in a growing population of older HIV-infected individuals. The efficacy and safety of antiretroviral agents in the population are important concerns. There have been relatively few studies assessing antiretroviral pharmacokinetics in older patients. Thirty-seven subjects aged 18-30 years and 40 subjects aged 45-79 years, naive to antiretroviral therapy, received lopinavir/ritonavir (400/100) bid, emtricitibine 200 mg qd, and stavudine 40 mg bid. Trough lopinavir concentrations were available for 44 subjects, collected at 24, 36, and 96 weeks. At week 24, older age was associated with higher lopinavir trough concentrations, and a trend was observed toward older age being associated with higher lopinavir trough concentrations when all time points were evaluated. In the young cohort, among subjects with two or more measurements, there was a trend toward increasing intrasubject trough lopinavir concentrations over time. Using a nonlinear, mixed-effects population pharmacokinetic model, age was negatively associated with lopinavir clearance after adjusting for adherence. Adherence was assessed by patient self-reports; older patients missed fewer doses than younger patients (p = 0.02). No difference in grade 3-4 toxicities was observed between the two age group. Older patients have higher trough lopinavir concentrations and likely decreased lopinavir clearance. Age-related changes in the pharmacokinetics of antiretroviral drugs may be of increasing importance as the HIV-infected population ages and as older individuals comprise an increasing proportion of new diagnoses.

Acute human immunodeficiency virus type 1 (HIV-1) infection is characterized by high levels of immune activation. Immunomodulation with cyclosporine combined with antiretroviral therapy (ART) in the setting of acute and early HIV-1 infection has been reported to result in enhanced immune reconstitution. Fifty-four individuals with acute and early infection were randomized to receive ART with 4 weeks of cyclosporine versus ART alone. In 48 subjects who completed the study, there were no significant differences between treatment arms in levels of proviral DNA or CD4(+) T cell counts. Adjunctive therapy with cyclosporine in this setting does not provide apparent virologic or immunologic benefit.

Antiretroviral therapy (ART) preserves kidney function in patients with human immunodeficiency virus (HIV)-associated nephropathy (HIVAN). Emerging data also document substantial renal benefits of ART in the general HIV-infected population, which is associated in part with suppression of HIV-1 viral replication. The extent to which the response to ART differs in persons with HIVAN compared with those with other HIV-associated kidney disorders is unknown. Beneficial effects of corticosteroids and angiotensin-converting enzyme inhibitors on kidney function also are suggested by retrospective cohort studies and uncontrolled trials of patients with HIVAN. Underexposure to ART or inadequate ART dosing in HIV-infected patients with CKD may curtail the optimal benefits that may be derived from this therapy.

Direct effects of HIV-1 infection on the kidney combine with immune and genetic factors, comorbidities, coinfections, and medication toxicities to induce a spectrum of kidney disorders in HIV disease. The most dramatic of these, HIV-associated nephropathy (HIVAN), emerges almost exclusively in persons of African descent and is associated with rapid progression to end-stage renal disease in the absence of antiretroviral therapy (ART). ART modifies the natural history of HIVAN, but the renal benefits of ART may not be limited to HIVAN. ART is often under prescribed or incorrectly dosed in persons with kidney disease. Vigilant attention to renal function and an understanding of the complex associations involving the kidneys are necessary for optimal care of these patients.

T-regulatory cell (T-reg) frequency is increased in HIV infection and with aging. We evaluated the effect of age on total, memory and naïve T-reg percentages in untreated HIV infection. Older HIV(+) subjects had a total T-reg percent that is 2.8% (p=0.02) higher than among younger HIV(+), older HIV(-) and younger HIV(-) subjects. In HIV(+) subjects, the total T-reg percentage is inversely correlated with the lymphocyte proliferative responses to tetanus (r=-0.45, p=0.002) and Candida (r=-0.43, p=0.003) antigens. Similar correlations were seen between memory T-reg percentages and the lymphocyte proliferative response to tetanus and Candida in HIV(+) subjects. T-reg percentages did not correlate consistently with markers of immune activation. T-reg percentages are increased in the older HIV(+) population and may play a role in the accelerated disease progression seen in older HIV-infected persons.

Background: Proteinuria is associated with progressive renal disease and overall mortality in HIV-infected patients; however, the prevalence and correlates of quantitative proteinuria in the highly active antiretroviral therapy era are unknown., Methods: Spot urine protein to creatinine (P/Cr) ratios, an accepted measure of quantitative daily proteinuria, were measured annually since 2002 in participants of the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials cohort. We used linear regression models with general estimating equations to identify factors associated with the abnormal P/Cr thresholds of >/=0.2 and >/=1.0., Results: Of the 2,857 participants (most of whom were receiving antiretroviral therapy) analysed, 16% and 3% had P/Cr levels >/=0.2 and >/=1.0, respectively, at first measurement. P/Cr levels did not change during a median follow-up of 3 years (interquartile range 2-4). Factors associated with P/Cr>/=0.2 at any measurement included greater age, lower glomerular filtration rate, female sex, antiretroviral therapy prior to entry into parent randomized trial, HIV type-1 RNA level >/=400 copies/ml, lower CD4(+) T-cell count and history of hypertension, diabetes or hepatitis C coinfection (all P<0.04). Black race and higher non-high-density lipoprotein cholesterol levels were associated with P/Cr levels >/=1.0, but not with P/Cr levels >/=0.2. Hepatitis B coinfection and current use of adefovir, indinavir and tenofovir were not associated with either of the P/Cr thresholds., Conclusions: Both HIV-1 and non-HIV-1-related factors are associated with abnormal levels of proteinuria and identify those who are at a greater risk of worse clinical outcomes. Several of these factors are differentially associated with lower and higher proteinuria thresholds.

Objective: To examine the association between changes in glomerular filtration rates (GFR) and antiretroviral therapy (ART)-mediated suppression of plasma HIV-1 viremia., Design: : Observational, prospective, multicenter cohort study., Intervention: ART regimens or treatment strategies in HIV-1-infected subjects were implemented through randomized clinical trials; 1776 ambulatory subjects from these trials also enrolled in this cohort study., Method: The association between suppression of viremia and GFR changes from baseline was examined using the abbreviated Modification of Diet and Renal Disease equation in mixed effects linear models., Results: GFR improvement was associated with ART-mediated suppression of plasma viremia in subjects with both chronic kidney disease stage > or = 2 and low baseline CD4 cell counts (< 200 cells/microl). In this subset, viral suppression (by > 1.0 log10 copies/ml or to < 400 copies/ml) was associated with an average increase in GFR of 9.2 ml/min per 1.73 m(2) from baseline (95% confidence interval, 1.6-16.8; P = 0.02) over a median follow-up of 160 weeks. The magnitude of this association increased in subjects who had greater baseline impairment of renal function, and it did not depend on race or sex., Conclusions: Viral suppression was associated with GFR improvements in those with both low CD4 cell counts and impaired baseline renal function, supporting an independent contribution of HIV-1 replication to chronic renal dysfunction in advanced HIV disease. GFR improvement not associated with viral suppression also was observed in subjects with higher CD4 cell counts.

We identified a deletion at codon 70 (Delta70) of HIV-1 reverse transcriptase (RT) occurring together with L74V and Q151M mutations in a sample from a tenofovir (TFV)- and abacavir (ABC)-treated patient with extensive prior antiretroviral treatment. To investigate the characteristics of this mutant, we studied the drug susceptibility, relative infectivity, and fitness of viruses carrying Delta70 and associated RT mutations. The Delta70, L74V, and Q151M mutations were introduced into Hxb2 RT by site-directed mutagenesis and expressed in HIV-1 recombinants. The Delta70 mutation increased resistance to lamivudine and emtricitabine alone and in combination with various resistance mutations and augmented resistance to ABC and didanosine when present together with L74V. A recombinant virus expressing RT from the original clinical viral sample (Delta70-PRT) exhibited greater fitness than one in which the deletion had been repaired (K70-PRT). The Delta70 mutation also increased fitness of Hxb2 wild-type and 74V and Q151M mutants. Recombinants carrying Delta70-PRT showed greater relative infectivity in the presence of ABC (but not TFV) compared with K70-PRT recombinants. These results show that Delta70 enhances resistance to certain purine and pyrimidine analogues and contributes to multinucleoside resistance in the appropriate viral genetic background.