Hepatitis C and the risk of kidney disease and mortality in veterans with HIV

Utilizing electronic health record data to understand comorbidity burden among people living with HIV: a machine learning approach

OBJECTIVES

An understanding of the predictors of comorbidity among people living with HIV (PLWH) is critical for effective HIV care management. In this study, we identified predictors of comorbidity burden among PLWH based on machine learning models with electronic health record (EHR) data.

METHODS

The study population are individuals with a HIV diagnosis between January 2005 and December 2016 in South Carolina (SC). The change of comorbidity burden, represented by the Charlson Comorbidity Index (CCI) score, was measured by the score difference between pre- and post-HIV diagnosis, and dichotomized into a binary outcome variable. Thirty-five risk predictors from multiple domains were used to predict the increase in comorbidity burden based on the logistic least absolute shrinkage and selection operator (Lasso) regression analysis using 80% data for model development and 20% data for validation.

RESULTS

Of 8253 PLWH, the mean value of the CCI score difference was 0.8 ± 1.9 (range from 0 to 21) with 2328 (28.2%) patients showing an increase in CCI score after HIV diagnosis. Top predictors for an increase in CCI score using the LASSO model included older age at HIV diagnosis, positive family history of chronic conditions, tobacco use, longer duration with retention in care, having PEBA insurance, having low recent CD4+ cell count and duration of viral suppression.

CONCLUSION

The application of machine learning methods to EHR data could identify important predictors of increased comorbidity burden among PLWH with high accuracy. Results may enhance the understanding of comorbidities and provide the evidence based data for integrated HIV and comorbidity care management of PLWH.

Comorbidity patterns among people living with HIV: a hierarchical clustering approach through integrated electronic health records data in South Carolina

Comorbidity among people living with HIV (PLWH) is understudied although identifying its patterns and socio-demographic predictors would be beneficial for comorbidity management. Using electronic health records (EHR) data, 8,490 PLWH diagnosed between January 2005 and December 2016 in South Carolina were included in the current study. An initial list of 86 individual diagnoses of chronic conditions was extracted in the EHR data. After grouping individual diagnoses with a pathophysiological similarity, 24 diagnosis groups were generated. Hierarchical cluster analysis was applied to these 24 diagnosis groups and yielded four comorbidity clusters: "substance use and mental disorder" (e.g., alcohol use, depression, and illicit drug use); "metabolic disorder" (e.g., hypothyroidism, diabetes, hypertension, and chronic kidney disease); "liver disease and cancer" (e.g., hepatitis B, chronic liver disease, and non-AIDS defining cancers); and "cerebrovascular disease" (e.g., stroke and dementia). Multivariable logistic regression was conducted to investigate the association between socio-demographic factors and multimorbidity (defined as concurrence of ≥ 2 comorbidity clusters). The multivariable logistic regression showed that age, gender, transmission risk, race, initial CD4 counts, and viral load were significant factors associated with multimorbidity. The results suggested the importance of integrated clinical care that addresses the complexities of multiple, and potentially interacting comorbidities among PLWH.

Concurrent Hepatitis C and B Virus and Human Immunodeficiency Virus Infections Are Associated With Higher Mortality Risk Illustrating the Impact of Syndemics on Health Outcomes

Background

Hepatitis C virus (HCV), hepatitis B virus (HBV), and human immunodeficiency virus (HIV) infections are associated with significant mortality globally and in North America. However, data on impact of concurrent multiple infections on mortality risk are limited. We evaluated the effect of HCV, HBV, and HIV infections and coinfections and associated factors on all-cause mortality in British Columbia (BC), Canada.

Methods

The BC Hepatitis Testers Cohort includes ~1.7 million individuals tested for HCV or HIV, or reported as a case of HCV, HIV, or HBV from 1990 to 2015, linked to administrative databases. We followed people with HCV, HBV, or HIV monoinfection, coinfections, and triple infections from their negative status to date of death or December 31, 2016. Extended Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for factors associated with all-cause mortality.

Results

Of 658 704 individuals tested for HCV, HBV, and HIV, there were 33 804 (5.13%) deaths. In multivariable Cox regression analysis, individuals with HCV/HBV/HIV (HR, 8.9; 95% CI, 8.2–9.7) infections had the highest risk of mortality followed by HCV/HIV (HR, 4.8; 95% CI, 4.4–5.1), HBV/HIV (HR, 4.1; 95% CI, 3.5–4.8), HCV/HBV (HR, 3.9; 95% CI, 3.7–4.2), HCV (HR, 2.6; 95% CI, 2.6–2.7), HBV (HR, 2.2; 95% CI, 2.0–2.3), and HIV (HR, 1.6; 95% CI, 1.5–1.7). Additional factors associated with mortality included injection drug use, problematic alcohol use, material deprivation, diabetes, chronic kidney disease, heart failure, and hypertension.

Conclusions

Concurrent multiple infections are associated with high mortality risk. Substance use, comorbidities, and material disadvantage were significantly associated with mortality independent of coinfection. Preventive interventions, including harm reduction combined with coinfection treatments, can significantly reduce mortality.

Metabolic Syndrome in HIV/HCV Co-infected Patients

Purpose of review

We review the scope and burden of metabolic syndrome in HIV/HCV co-infected patients, risk factors and potential mechanisms driving the increased cardio-metabolic risk in this population, and discuss relevant clinical considerations for management in the era of highly effective antiretroviral therapy (ART) and curative anti-HCV direct-acting antivirals.

Recent findings

HIV/HCV co-infected patients are at elevated risk of metabolic syndrome, attributed to (1) patient-specific factors, (2) viral-mediated effects, and (3) ART exposure. Risk factors for cardio-metabolic disorders are common in this population and include poor socioeconomic conditions, substance use, cardiovascular comorbidities, and liver/kidney disease. Chronic HIV/HCV infection induces an inflammatory and immune activated state in the host leading to alterations in glucose and lipid metabolism. Selection of life-saving ART must carefully consider the differential metabolic risk associated with each drug class and agent, such as dyslipidemia, hyperglycemia and insulin resistance, weight gain and hypertension. Emerging evidence supports metabolic derangements in chronic HCV may be improved by viral eradication with direct-acting antivirals, however, additional study in HIV/HCV co-infected patients is needed.

Summary

Future research programs should aim to better characterize metabolic syndrome in HIV/HCV co-infected patients with the goal of improved screening, treatment and prevention.

Death after diagnosis of noncommunicable disease comorbid conditions, stratified by injection drug use

OBJECTIVE

Describe all-cause mortality associated with history of injection drug use (IDU) after a validated diagnosis of four noncommunicable disease (NCD) diagnoses: end-stage liver disease (ESLD); end-stage renal disease (ESRD); cancer; or myocardial infarction (MI) or stroke.

DESIGN

We followed four cohorts of persons in continuity HIV care in the Johns Hopkins HIV Clinic with a validated diagnosis of ESLD (n = 67), ESRD (n = 187), cancer (n = 424), and MI or stroke (n = 213) from 1996 through approximately 2014.

METHODS

Crude and adjusted Cox proportional hazards models to estimate hazard ratios for death after a validated diagnosis of one of four NCD diagnoses associated with history of IDU as an HIV acquisition risk factor.

RESULTS

History of IDU was not associated with death after ESRD (adjusted hazard ratio 0.98, 95% confidence interval (CI) 0.57-1.68). Associations between history of IDU and death after ESLD and MI or stroke were weak, imprecise and not statistically significant (hazard ratio 1.17, 95% CI 0.63-2.19; hazard ratio 1.21, 95% CI 0.80-1.83). History of IDU was not associated with death after cancer in the first 6 months, but subsequently, the adjusted hazard ratio was 2.03 (95% CI 1.26-3.27).

CONCLUSION

Persons with a history of injection drug use and non-IDU had strikingly similar risk and hazard of mortality after several major NCD diagnoses. Mortality after cancer diagnosis in this cohort was higher for persons with a history of IDU than those without; this may be because of being diagnosed with a different mix of specific sites and stages of cancers.

Chronic kidney disease, cardiovascular disease, and osteoporotic fractures in patients with and without HIV in the US Veteran's Affairs Administration System

Objective: To evaluate the risk of chronic kidney disease (CKD), cardiovascular disease (CVD), and osteoporotic fractures in human immunodeficiency virus (HIV) patients utilizing data within the Veteran's Affairs (VA) Administration system.Methods: A retrospective cohort study utilizing VA system claims (January 2000-December 2016) were extracted from the VA Informatics and Computing Infrastructure (VINCI). Cases included Veterans with an ICD-9/10 for HIV who had at least one prescription for a complete antiretroviral therapy (ART) regimen. Two non-HIV controls were exactly matched on race, sex, month, and year of birth. All patients were followed until the earliest of the following: first incidence of the outcome (identified based on diagnosis codes or laboratory data), last date of VA activity, death, or December 31, 2016. Relative risks (RR) and odds ratios (ORs) were estimated from multivariable Poisson regression models (CVD and osteoporotic fractures) and multivariable logistic regression models (CKD), respectively. Models were adjusted for demographic factors/comorbidities.Results: A total of 79,578 patients (26,526 HIV and 53,052 non-HIV) met all study criteria. The average age was 49.3 years, 38% were black, 32% were white, and 97% were male for both the HIV and control cohorts. The adjusted models demonstrated that HIV was associated with a 78% increased rate of CKD (OR = 1.78, 95% CI = 1.68-1.89), a 32% increased risk of CVD (RR = 1.32, 95% CI = 1.28-1.37), and a 38% increased risk of fractures (RR = 1.38, 95% CI = 1.23-1.56) compared to non-HIV controls.Conclusions: The risk/rate of the three outcomes were significantly higher in HIV patients compared to controls.

Hepatitis C Virus Infection in the Older Patient

Hepatitis C virus (HCV) is the most common blood-borne infection in the United States and is of concern in older adults. HCV infection is associated with not only hepatic but also extrahepatic comorbidities common to the aging patient including diabetes, kidney and cardiovascular diseases, and neurocognitive impairment. The effect of direct-acting antiviral agents to treat HCV on these outcomes is limited. This article summarizes the literature regarding the epidemiology and natural history of HCV infection; the impact of age on clinical outcomes in HCV-infected persons; and current knowledge regarding safety and efficacy of HCV treatment regimens in the older patient.

Chronic kidney disease in the global adult HIV-infected population: A systematic review and meta-analysis

INTRODUCTION

The widespread use of antiretroviral therapies (ART) has increased life expectancy in HIV patients, predisposing them to chronic non-communicable diseases including Chronic Kidney Disease (CKD). We performed a systematic review and meta-analysis (PROSPERO registration number CRD42016036246) to determine the global and regional prevalence of CKD in HIV patients.

METHODS

We searched PubMed, Web of Science, EBSCO and AJOL for articles published between January 1982 and May 2016. CKD was defined as estimated glomerular filtration rate (eGFR) <60ml/min using the MDRD, Cockcroft-Gault or CKD-EPI equations. Random effects model was used to combine prevalence estimates from across studies after variance stabilization via Freeman-Tukey transformation.

RESULT

Sixty-one eligible articles (n = 209,078 HIV patients) in 60 countries were selected. The overall CKD prevalence was 6.4% (95%CI 5.2-7.7%) with MDRD, 4.8% (95%CI 2.9-7.1%) with CKD-EPI and 12.3% (95%CI 8.4-16.7%) with Cockcroft-Gault; p = 0.003 for difference across estimators. Sub-group analysis identified differences in prevalence by WHO region with Africa having the highest MDRD-based prevalence at 7.9% (95%CI 5.2-11.1%). Within Africa, the pooled MDRD-based prevalence was highest in West Africa [14.6% (95%CI 9.9-20.0%)] and lowest in Southern Africa (3.2%, 95%CI 3.0-3.4%). The heterogeneity observed could be explained by WHO region, comorbid hypertension and diabetes mellitus, but not by gender, hepatitis B or C coinfection, CD4 count or antiretroviral status.

CONCLUSION

CKD is common in HIV-infected people, particularly in Africa. HIV treatment programs need to intensify screening for CKD with added need to introduce global guidelines for CKD identification and treatment in HIV positive patients.

Comparison of the Hepatitis C Continua of Care Between Hepatitis C Virus/HIV Coinfected and Hepatitis C Virus Mono-Infected Patients in Two Treatment Eras During 2008-2015

Treatment of chronic hepatitis C virus (HCV) infection included use of pegylated interferon-based regimens before 2014 and direct-acting agents (DAA) since 2014 at the VA Medical Center in Washington, DC. We compared the continua of care between our HCV/HIV coinfected and HCV mono-infected patients during 2008-2015. A review of summary data from our local HCV Clinical Case Registry was conducted for the interferon treatment era (2008-2013) and the DAA era (2014-2015). Data were analyzed on a modified HCV Continuum of Care based on these stages: HCV diagnosis, engagement in medical care, HCV treatment, and HCV sustained virologic response (SVR) for differences between HCV/HIV coinfected and HCV mono-infected patients. All patients had 88% engagement in primary care during 2008-2013. HCV mono-infected and HCV/HIV coinfected patients had similar treatment (6% vs. 5%, p = .6622) and HCV SVR (1% vs. 0.5%, p = .1737) rates in the interferon era. However, more HCV/HIV coinfected patients were engaged in care (93% vs. 87%, p = .0044), accessed HCV treatment (36% vs. 23%, p < .0001), and achieved HCV SVR (31% vs. 21% p = .0002) compared to mono-infected patients in the DAA era. Both HCV/HIV coinfected and HCV mono-infected patients achieved higher SVR of ≥86% after DAA treatment. Although improvements were seen for treatment and SVR among HCV mono-infected patients, better rates for care engagement, HCV treatment, and SVR were realized for HCV/HIV coinfected patients in the DAA era.

Racial/ethnic differences in the association between alcohol use and mortality among men living with HIV

BACKGROUND

Increasing alcohol use is associated with increased risk of mortality among patients living with HIV (PLWH). This association varies by race/ethnicity among general outpatients, but racial/ethnic variation has not been investigated among PLWH, among whom racial/ethnic minorities are disproportionately represented.

METHODS

VA electronic health record data from the Veterans Aging Cohort Study (2008-2012) were used to describe and compare mortality rates across race/ethnicity and levels of alcohol use defined by the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) questionnaire. Within each racial/ethnic group, Cox proportional hazards models, adjusted for age, disease severity, and comorbidities, compared mortality risk for moderate-risk (AUDIT-C = 4-7) and high-risk (AUDIT-C ≥ 8) relative to lower-risk (AUDIT-C = 1-3) alcohol use.

RESULTS

Mean follow-up time among black (n = 8518), Hispanic (n = 1353), and white (n = 7368) male PLWH with documented AUDIT-C screening (n = 17,239) was 4.3 years. Black PLWH had the highest mortality rate among patients reporting lower-risk alcohol use (2.9/100 person-years) relative to Hispanic and white PLWH (1.8 and 2.3, respectively) (p value for overall comparison = 0.011). Mortality risk was increased for patients reporting high-risk relative to lower-risk alcohol use in all racial/ethnic groups [black adjusted hazard ratio (AHR) = 1.36, 95% confidence interval (CI) 1.12-1.66; Hispanic AHR = 2.18, 95% CI 1.30-3.64; and white AHR = 2.04, 95% CI 1.61-2.58]. For only white PLWH, mortality risk was increased for patients reporting moderate-relative to lower-risk alcohol use (black AHR = 1.09, 95% CI 0.93-1.27; Hispanic AHR = 1.36, 95% CI 0.89-2.09; white AHR = 1.51, 95% CI 1.28-1.77).

CONCLUSION

Among all PLWH, mortality risk was increased among patients reporting high-risk alcohol use across all racial/ethnic groups, but mortality risk was only increased among patients reporting moderate-risk relative to lower-risk alcohol use among white PLWH, and black patients appeared to have higher mortality risk relative to white patients at lower-risk levels of alcohol use. Findings of the present study further underscore the need to address unhealthy alcohol use among PLWH, and future research is needed to understand mechanisms underlying observed differences.

Metabolic and Cardiovascular Complications in HIV/HCV-Co-infected Patients

PURPOSE OF REVIEW

Fifteen to thirty percent of HIV-infected persons in North America and Europe are co-infected with chronic hepatitis C (HCV). The latter is associated with a significant number of extra-hepatic metabolic complications that could compound HIV-associated increased cardiovascular risk. This article reviews the basic science and epidemiologic and clinical evidence for increased cardio-metabolic risk among HIV/HCV-co-infected patients and discusses potential underlying mechanisms. We will finally review the impact of control of HCV viremia on the cardio-metabolic morbidity and mortality of HIV/HCV-co-infected patients.

RECENT FINDINGS

HCV infection is associated with a number of immune-related complications such as cryoglobulinemia but also metabolic complications including dyslipidemias, hepatic steatosis, insulin resistance, diabetes, and chronic kidney disease. The incidence of these complications is higher among HIV-co-infected patients and might contribute to increased mortality. The potential mechanisms of increased cardiovascular risk among HIV/HCV-co-infected subjects include endothelial dysfunction, chronic inflammation and immune activation, the cardio-metabolic effects of HCV-induced hepatic steatosis and fibrosis or insulin resistance, and chronic kidney disease. However, epidemiologic studies show discordant findings as to whether HCV co-infection further increases the risk of atherosclerotic cardiovascular diseases (acute myocardial infarctions and strokes) among HIV-infected patients. Nonetheless, successful treatment of HCV is associated with significant improvements in cardio-metabolic risk factors including diabetes mellitus. HCV co-infection is associated with a higher incidence of metabolic complications-and likely increased risk of cardiovascular events-that might contribute to increased mortality in HIV. These appear to improve with successful HCV therapy.

Hepatitis B, hepatitis C, and mortality among HIV-positive individuals

OBJECTIVES

To compare rates of all-cause, liver-related, and AIDS-related mortality among individuals who are HIV-monoinfected with those coinfected with HIV and hepatitis B (HBV) and/or hepatitis C (HCV) viruses.

DESIGN

An ongoing observational cohort study collating routinely collected clinical data on HIV-positive individuals attending for care at HIV treatment centres throughout the United Kingdom.

METHODS

Individuals were included if they had been seen for care from 2004 onwards and had tested for HBV and HCV. Crude mortality rates (all cause, liver related, and AIDS related) were calculated among HIV-monoinfected individuals and those coinfected with HIV, HBV, and/or HCV. Poisson regression was used to adjust for confounding factors, identify independent predictors of mortality, and estimate the impact of hepatitis coinfection on mortality in this cohort.

RESULTS

Among 25 486 HIV-positive individuals, with a median follow-up 4.5 years, HBV coinfection was significantly associated with increased all-cause and liver-related mortality in multivariable analyses: adjusted rate ratios (ARR) [95% confidence intervals (95% CI)] were 1.60 (1.28-2.00) and 10.42 (5.78-18.80), respectively. HCV coinfection was significantly associated with increased all-cause (ARR 1.43, 95% CI 1.15-1.76) and liver-related mortality (ARR 6.20, 95% CI 3.31-11.60). Neither HBV nor HCV coinfection were associated with increased AIDS-related mortality: ARRs (95% CI) 1.07 (0.63-1.83) and 0.40 (0.20-0.81), respectively.

CONCLUSION

The increased rate of all-cause and liver-related mortality among hepatitis-coinfected individuals in this HIV-positive cohort highlights the need for primary prevention and access to effective hepatitis treatment for HIV-positive individuals.

Association of HIV infection with biomarkers of kidney injury and fibrosis in the Multicenter AIDS Cohort Study

BACKGROUND

Chronic kidney disease (CKD) is common among HIV-infected individuals but serum creatinine is insensitive for detecting kidney damage at early stages. We hypothesized that HIV infection would be associated with elevations in subclinical markers of kidney injury and fibrosis in a contemporary cohort of men.

METHODS

In this cross-sectional study, we measured urine levels of interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), pro-collagen type III N-terminal pro-peptide (PIIINP) and albumin-creatinine ratio (ACR) in 813 HIV-infected and 331 uninfected men enrolled in the Multicenter AIDS Cohort Study.

RESULTS

Median eGFR was 95 ml/min/1.73 m2 among African-Americans (n=376) and 87 ml/min/1.73 m2 among Caucasians (n=768). Among HIV-infected men, the median CD4 lymphocyte count was 572 cells/mm3 and 76% of men had undetectable HIV RNA levels. After multivariable adjustment for traditional CKD risk factors including eGFR, HIV infection was associated with 52% higher urine IL-18 (95% CI, 33%, 73%), 44% higher KIM-1 (27%, 64%), 30% higher PIIINP (15%, 47%) and 84% higher ACR (54%, 120%), with similar effect sizes among African-Americans and Caucasians (P>0.2 for tests of interaction by race). These associations remained statistically significant in analyses that excluded persons with detectable HIV RNA levels and in models that adjusted for cumulative exposure to tenofovir disoproxil fumarate.

CONCLUSIONS

Compared with uninfected men, HIV-infected men had more extensive glomerular and tubulointerstitial damage, as assessed by urine biomarkers. Future studies should evaluate whether combinations of biomarkers can be used to monitor stages of kidney injury and to predict CKD risk in HIV-infected individuals.

Hepatitis C Virus, Inflammation, and Cellular Aging: Turning Back Time

There is evidence that hepatitis C virus (HCV) infection, like HIV infection, may be associated with chronic inflammation, immune activation, and immune senescence, which contribute to increased risks for cardiometabolic or other diseases outside the liver, as well as to ongoing damage in the liver. These effects may persist after a sustained virologic response (SVR) is achieved with HCV therapy. Such findings support initiation of treatment for HCV-infected individuals before damage to the liver is apparent and monitoring of individuals for complications even after an SVR is achieved. Fibrosis is not always reversible after SVR is achieved, and this should serve as an argument against waiting until fibrosis develops before initiating treatment for HCV-infected individuals. This article summarizes a presentation by Susanna Naggie, MD, MHS, at the IAS-USA continuing education program, Management of Hepatitis C Virus in the New Era: Small Molecules Bring Big Changes, in New York, New York, in September 2015.

HIV AND HEPATITIS C VIRUS COINFECTION. WHO IS THIS PATIENT TODAY?

BACKGROUND

- The increase in the survival following the introduction of highly active antiretroviral therapy (HAART) has seen the emergence of hepatitis C virus (HCV) infection, renal and cardiovascular diseases as important morbidity and mortality causes together with HIV.

OBJECTIVE

- The present study aimed to investigate the differences between HIV/hepatitis C virus coinfected and HIV-monoinfected regarding demographic and clinical aspects from a HIV/AIDS clinic in Porto Alegre, Brazil.

METHODS

- Review of medical records of 1,030 HIV infected individuals aged 18 years or more in an urban HIV/AIDS clinic based in Porto Alegre, Southern Brazil. Clinical and demographical Data were collected from the records of the patients attended between March 2008 and December 2012.

RESULTS

- The present study is a cross-sectional study among HIV-infected patients attended at a public HIV/AIDS clinic in Porto Alegre, Brazil. The prevalence of hepatitis C virus in the present study cohort was 11.8% (CI 95%: 9.9%-13.8%). Hypertension and pathological proteinuria were more common in the coinfected compared to monoinfected group. By the other hand, dyslipidemia were more common among monoinfected patients. There was no difference between the groups regarding CD4+ count or HIV-RNA. Variables significant in the univariate analysis with P<0.05 were further analyzed using a Poisson regression model with robust variance. Coinfected were likely to be older, with lower lipid levels and higher prevalence of pathological proteinuria compared to HIV-monoinfected patients. Although coinfected patients had higher prevalence of tenofovir-based regimen, there was a strong association between hepatitis C virus individuals to pathological proteinuria and dyslipidemia.

CONCLUSION

- Clinicians should recognize that coinfected and monoinfected individuals are different groups regarding the traditional and HIV-related risk factors and should be managed and screened individually in order to prevent cardiovascular and renal complications.

Frequent injection cocaine use increases the risk of renal impairment among hepatitis C and HIV coinfected patients

Supplemental Digital Content is available in the text

Objective:

To examine the association between injection cocaine use, hepatitis C virus (HCV) infection, and chronic renal impairment (CRI).

Design:

Prospective observational cohort study of HIV–HCV coinfected patients.

Methods:

Data from 1129 participants in the Canadian Co-Infection Cohort with baseline and follow-up serum creatinine measurements between 2003 and 2014 were analyzed. Prevalent and incident cohorts were created to examine the association between self-reported past, current, and cumulative cocaine use and chronic HCV with CRI. CRI was defined as an estimated glomerular filtration rate below 70 ml/min per 1.73 m². Multivariate logistic regression was used to calculate odds ratios, and discrete-time proportional-hazards models were used to calculate hazard ratios for cocaine use, in the two respective cohorts, adjusted for HCV RNA and important demographic, HIV disease stage, and comorbidity confounders.

Results:

Eighty-seven participants (8%) had prevalent CRI. Past injection cocaine use was associated with a two-fold greater risk of prevalent CRI [odds ratio 2.03, 95% confidence interval (CI) 0.96, 4.32]. During follow-up, 126 of 1061 participants (12%) developed incident CRI (31 per 1000 person-years). Compared to nonusers, heavy (≥ 3 days/week) and frequent injection cocaine users (≥75% of follow-up time) experienced more rapid progression to CRI (hazard ratio 2.65, 95% CI 1.35, 5.21; and hazard ratio 1.82, 95% CI 1.07, 3.07, respectively). There was no association between chronic HCV and CRI in either cohort.

Conclusion:

After accounting for HCV RNA, frequent and cumulative injection cocaine abuse was associated with CRI progression and should be taken into consideration when evaluating impaired renal function in HIV–HCV coinfection.

Kidney disease in antiretroviral-naïve HIV-positive adults with high CD4 counts: prevalence and predictors of kidney disease at enrolment in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

HIV infection has been associated with an increased risk of chronic kidney disease (CKD). Little is known about the prevalence of CKD in individuals with high CD4 cell counts prior to initiation of antiretroviral therapy (ART). We sought to address this knowledge gap.

METHODS

We describe the prevalence of CKD among 4637 ART-naïve adults (mean age 36.8 years) with CD4 cell counts > 500 cells/μL at enrolment in the Strategic Timing of AntiRetroviral Treatment (START) study. CKD was defined by estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2) and/or dipstick urine protein ≥ 1+. Logistic regression was used to identify baseline characteristics associated with CKD.

RESULTS

Among 286 [6.2%; 95% confidence interval (CI) 5.5%, 6.9%] participants with CKD, the majority had isolated proteinuria. A total of 268 participants had urine protein ≥ 1+, including 41 with urine protein ≥ 2+. Only 22 participants (0.5%) had an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) , including four who also had proteinuria. Baseline characteristics independently associated with CKD included diabetes [adjusted odds ratio (aOR) 1.73; 95% CI 1.05, 2.85], hypertension (aOR 1.82; 95% CI 1.38, 2.38), and race/ethnicity (aOR 0.59; 95% CI 0.37, 0.93 for Hispanic vs. white).

CONCLUSIONS

We observed a low prevalence of CKD associated with traditional CKD risk factors among ART-naïve clinical trial participants with CD4 cell counts > 500 cells/μL.

Injection Drug Use and Hepatitis C as Risk Factors for Mortality in HIV-Infected Individuals: The Antiretroviral Therapy Cohort Collaboration

BACKGROUND

HIV-infected individuals with a history of transmission through injection drug use (IDU) have poorer survival than other risk groups. The extent to which higher rates of hepatitis C (HCV) infection in IDU explain survival differences is unclear.

METHODS

Adults who started antiretroviral therapy between 2000 and 2009 in 16 European and North American cohorts with >70% complete data on HCV status were followed for 3 years. We estimated unadjusted and adjusted (for age, sex, baseline CD4 count and HIV-1 RNA, AIDS diagnosis before antiretroviral therapy, and stratified by cohort) mortality hazard ratios for IDU (versus non-IDU) and for HCV-infected (versus HCV uninfected).

RESULTS

Of 32,703 patients, 3374 (10%) were IDU; 4630 (14%) were HCV+; 1116 (3.4%) died. Mortality was higher in IDU compared with non-IDU [adjusted HR 2.71; 95% confidence interval (CI): 2.32 to 3.16] and in HCV+ compared with HCV- (adjusted HR 2.65; 95% CI: 2.31 to 3.04). The effect of IDU was substantially attenuated (adjusted HR 1.57; 95% CI: 1.27 to 1.94) after adjustment for HCV, while attenuation of the effect of HCV was less substantial (adjusted HR 2.04; 95% CI: 1.68 to 2.47) after adjustment for IDU. Both IDU and HCV were strongly associated with liver-related mortality (adjusted HR 10.89; 95% CI: 6.47 to 18.3 for IDU and adjusted HR 14.0; 95% CI: 8.05 to 24.5 for HCV) with greater attenuation of the effect of IDU (adjusted HR 2.43; 95% CI: 1.24 to 4.78) than for HCV (adjusted HR 7.97; 95% CI: 3.83 to 16.6). Rates of CNS, respiratory and violent deaths remained elevated in IDU after adjustment for HCV.

CONCLUSIONS

A substantial proportion of the excess mortality in HIV-infected IDU is explained by HCV coinfection. These findings underscore the potential impact on mortality of new treatments for HCV in HIV-infected people.

The changing epidemiology of HIV-related chronic kidney disease in the era of antiretroviral therapy

The epidemiology of kidney disease in HIV-infected individuals has changed significantly since the introduction of combination antiretroviral therapy (cART) in the mid 1990s. HIV-associated nephropathy (HIVAN), an aggressive form of collapsing focal segmental glomerulosclerosis (FSGS) caused by direct HIV infection of the kidney in a genetically susceptible host, emerged early in the HIV epidemic as a leading cause of end-stage renal disease. With the widespread use of cART, HIVAN is increasingly rare in populations with access to care, and the spectrum of HIV-related chronic kidney disease now reflects the growing burden of comorbid disease in the aging HIV population. Nonetheless, available data suggest that both HIV infection and cART nephrotoxicity continue to contribute to the increased risk of chronic kidney disease in HIV-infected individuals in the United States and Europe. Despite the genetic susceptibility to HIVAN in individuals of West African descent, limited data are available to define the prevalence and spectrum of HIV-related kidney disease in sub-Saharan Africa, which is home to two-thirds of the world's HIV population. In this mini-review, we characterize the changing epidemiology of HIV-related chronic kidney disease in Western nations and in sub-Saharan Africa.

Role of inflammation in HIV-1 disease progression and prognosis

Inflammation and immune activation have been thrust to center stage in the understanding of HIV-1 disease pathogenesis and progression. Early work demonstrated that heightened levels of immune activation correlated with the extent of CD4 + T cell death in lymphoid tissue; however, this concept was not incorporated into the general view of disease pathogenesis. Since these early studies, the extension of life for patients on combination antiretroviral therapies (cART) has heralded a new era of non-AIDS-related diseases and incomplete restoration of immune function. The common link appears to be ongoing inflammation and immune activation. Thus, despite good control of viral loads, persons living with HIV (PLWH) remain at increased risk of inflammatory-associated complications such as cardiovascular disease and certain cancers. HIV-specific mechanisms as well as non-specific generalized responses to infection contribute to ongoing activation of the immune system. An early loss of gastrointestinal (GI) tract mucosal integrity, the pro-inflammatory cytokine milieu, co-infections and marked destruction of lymph node architecture are all factors contributing to the ongoing activation of the immune system as well as impaired immune recovery. It is becoming increasingly evident that the CD4 count and viral load do not provide a complete picture of the underlying state of the immune system. Heightened levels of inflammatory markers have been shown to predict increased mortality and other adverse events. Therefore, it will be important to incorporate these markers into management algorithms as soon as possible. This is particularly relevant in resource-poor countries where difficulties in cART roll-out and access are still encountered and, therefore, a mechanism for prioritizing individuals for therapy would be of value. This review will focus on the closely inter-related concepts of immune activation and inflammation. Both are broad concepts involving the interaction of various key players in the immune system. Importantly, immune activation promotes inflammation and thrombosis and similarly, inflammation and thrombosis induce immune activation. These concepts are thus intricately linked. Studies highlighting the potentially harmful effects of ongoing inflammation/immune activation are reviewed and the contributions of the GI tract "damage" and other co-infections such as CMV are explored. The complications resulting from persistent immune activation include enhanced CD4 + T cell death, lymphoid tissue destruction, and various pathologies related to chronic inflammation. Ultimately, we envision that the long-term management of the disease will incorporate both the identification and the amelioration of the potentially harmful effects of ongoing immune activation and inflammation.

Serious Non-AIDS events: Immunopathogenesis and interventional strategies

Despite the major advances in the management of HIV infection, HIV-infected patients still have greater morbidity and mortality than the general population. Serious non-AIDS events (SNAEs), including non-AIDS malignancies, cardiovascular events, renal and hepatic disease, bone disorders and neurocognitive impairment, have become the major causes of morbidity and mortality in the antiretroviral therapy (ART) era. SNAEs occur at the rate of 1 to 2 per 100 person-years of follow-up. The pathogenesis of SNAEs is multifactorial and includes the direct effect of HIV and associated immunodeficiency, underlying co-infections and co-morbidities, immune activation with associated inflammation and coagulopathy as well as ART toxicities. A number of novel strategies such as ART intensification, treatment of co-infection, the use of anti-inflammatory drugs and agents that reduce microbial translocation are currently being examined for their potential effects in reducing immune activation and SNAEs. However, currently, initiation of ART before advanced immunodeficiency, smoking cessation, optimisation of cardiovascular risk factors and treatment of HCV infection are most strongly linked with reduced risk of SNAEs or mortality. Clinicians should therefore focus their attention on addressing these issues prior to the availability of further data.

Validation of an algorithm to identify antiretroviral-naïve status at time of entry into a large, observational cohort of HIV-infected patients

PURPOSE

Large, observational HIV cohorts play an important role in answering questions which are difficult to study in randomized trials; however, they often lack detailed information regarding previous antiretroviral treatment (ART). Knowledge of ART treatment history is important when ascertaining the long-term impact of medications, co-morbidities, or adverse reactions on HIV outcomes.

METHODS

We performed a retrospective study to validate a prediction algorithm for identifying ART-naïve patients using the Veterans Aging Cohort Study's Virtual Cohort-an observational cohort of 40 594 HIV-infected veterans nationwide. Medical records for 3070 HIV-infected patients were reviewed to determine history of combination ART treatment. An algorithm using Virtual Cohort laboratory data was used to predict ART treatment status and compared to medical record review.

RESULTS

Among 3070 patients' medical records reviewed, 1223 were eligible for analysis. Of these, 990 (81%) were ART naïve at cohort entry based on medical record review. The prediction algorithm's sensitivity was 86%, specificity 47%, positive predictive value (PPV) 87%, and negative predictive value 45%, using a viral load threshold of <400 copies/ml. Sensitivity analysis revealed that PPV would be maximized by increasing the viral load threshold, whereas sensitivity would be maximized by lowering the viral load threshold.

CONCLUSIONS

A prediction algorithm using available laboratory data can be used to accurately identify ART-naïve patients in large, observational HIV cohorts. Use of this algorithm will allow investigators to accurately limit analyses to ART-naïve patients when studying the contribution of ART to outcomes and adverse events.

Kidney Disease in HIV-Infected Persons

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.

Risk factors for chronic kidney disease in a large cohort of HIV-1 infected individuals initiating antiretroviral therapy in routine care

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.

Comorbid diabetes and the risk of progressive chronic kidney disease in HIV-infected adults: data from the Veterans Aging Cohort Study

INTRODUCTION

Approximately, 15% of HIV-infected individuals have comorbid diabetes. Studies suggest that HIV and diabetes have an additive effect on chronic kidney disease (CKD) progression; however, this observation may be confounded by differences in traditional CKD risk factors.

METHODS

We studied a national cohort of HIV-infected and matched HIV-uninfected individuals who received care through the Veterans Healthcare Administration. Subjects were divided into 4 groups based on baseline HIV and diabetes status, and the rate of progression to an estimated glomerular filtration rate (eGFR) <45 mL/min/1.73m was compared using Cox-proportional hazards modeling to adjust for CKD risk factors.

RESULTS

About 31,072 veterans with baseline eGFR ≥45 mL/min/1.73m (10,626 with HIV only, 5088 with diabetes only, and 1796 with both) were followed for a median of 5 years. Mean baseline eGFR was 94 mL/min/1.73m, and 7% progressed to an eGFR < 45 mL/min/1.73m. Compared with those without HIV or diabetes, the relative rate of progression was increased in individuals with diabetes only [adjusted hazard ratio (HR) 2.48; 95% confidence interval (CI): 2.19 to 2.80], HIV only [HR: 2.80, 95% CI: 2.50 to 3.15], and both HIV and diabetes [HR: 4.47, 95% CI: 3.87 to 5.17].

DISCUSSION

Compared with patients with only HIV or diabetes, patients with both diagnoses are at significantly increased risk of progressive CKD even after adjusting for traditional CKD risk factors. Future studies should evaluate the relative contribution of complex comorbidities and accompanying polypharmacy to the risk of CKD in HIV-infected individuals and prospectively investigate the use of cART, glycemic control, and adjunctive therapy to delay CKD progression.

Hepatitis C virus infection and kidney disease: a meta-analysis

BACKGROUND AND OBJECTIVES

Hepatitis C virus (HCV) infection and kidney disease are both highly prevalent diseases. The association between HCV and GN has been supported by previous research but little is known about the relationship between HCV and kidney disease.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A systematic review of the published medical literature was conducted to determine if HCV is associated with increased likelihood of kidney disease in the general population. A random-effects model was used to generate a summary estimate of the relative risk for kidney disease, defined as an estimated GFR <60 ml/min per 1.73 m(2) or proteinuria, with HCV across the published studies.

RESULTS

Nine clinical studies (817,917 unique individuals) were identified. Pooling of study results demonstrated the absence of a relationship between HCV seropositive status and reduced estimated GFR (adjusted relative risk, 1.12; 95% confidence interval, 0.91, 1.38; P=0.28) according to the random-effects model. HCV seropositive serology was an independent and significant risk factor for proteinuria (defined by urine dipstick test or spot urine albumin/creatinine ratio) in the general population, with a summary estimate for adjusted relative risk of 1.47 (95% confidence interval, 1.12, 1.94; P=0.006). Significant heterogeneity was observed between studies (Ri=0.82; P value by Q test, <0.001).

CONCLUSIONS

This meta-analysis shows that HCV is independently associated with proteinuria but not with reduced GFR in the general population. Substantial heterogeneity occurred.

The New Epidemiology of HIV-Related Kidney Disease

HIV-related kidney disease has been associated with significant morbidity and mortality in the HIV population. It is clear that the epidemiology of HIV-related kidney disease has changed dramatically since the first case reports in 1984. During these early years, the predominant etiology of kidney disease in HIV was recognized as HIV-associated nephropathy (HIVAN), an aggressive form of kidney disease with a high rate of progression to end-stage renal disease (ESRD). Subsequently, with the widespread use of combination antiretroviral therapy (cART), there was a dramatic decrease in the incidence of ESRD attributed to HIV/AIDS. Although the incidence of HIV-related ESRD has plateaued in the last 15 years, the prevalence has continued to increase because of improved survival. Available prevalence estimates do not include HIV-infected individuals with comorbid ESRD, although there is growing evidence that the epidemiology of kidney disease in the HIV-infected population has changed. This article reviews the impact of risk factors such as race, diabetes mellitus, hypertension, hepatitis C virus coinfection, and the chronic use of cART on the changing epidemiology of HIV-related kidney disease. Additionally in this review, we propose potential areas of translational research that will help to further characterize HIV-related kidney disease in the 21^st century.

Renal issues in 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.

The impact of antiviral therapy and the influence of metabolic cofactors on the outcome of chronic HCV infection

NATURAL HISTORY OF HCV RELATED CHRONIC HEPATITIS IS INFLUENCED AND MODIFIED BY MANY FACTORS: virus features, coinfections and host characteristics. In particular, a peculiar genetic background of the host by conditioning the occurrence of intracellular metabolic derangements (i.e., insulin resistance) might contribute to accelerate the rate of progression to cirrhosis and eventually the occurrence of hepatocellular carcinoma (HCC) and death. Likely, direct interplays between virus genotype and host genetic background might be hypothesized at this level. Morbidity and mortality in cirrhosis is primarily associated with complications of liver cirrhosis (ascites, hepatic encephalopathy, jaundice, and gastroesophageal bleeding) and HCC occurrence. Therefore the main goal of therapy is to clear viral infection and decrease liver necro-inflammation that directly relates to development of cirrhosis and HCC. Among patients treated with Interferon-based therapy, those with sustained viral response showed a significant reduction of progression to cirrhosis and development of HCC. However, a residual risk of hepatocellular carcinoma still remains indicating the need for careful follow-up using ultrasonography every six months in cirrhotic patients, even in those showing persistently normal ALT and undetectable HCV RNA levels after antiviral therapy.

Renal disease in HIV-infected individuals

PURPOSE OF REVIEW

Highly active antiretroviral therapy (HAART) has resulted in a marked decrease in AIDS-related conditions and death. With improved survival, cardiovascular disease, hepatic, renal disease, and non-AIDS-related cancers represent an increasing burden for HIV-infected individuals.

RECENT FINDINGS

HIV-associated nephropathy (HIVAN), acute renal injury, HAART, and comorbid conditions such as hepatitis C, hypertension, and diabetes are among the multiple causes of renal disease. In HIVAN there is incomplete understanding of the interaction of the virus with renal cells and the host genetics leading to susceptibility to this form of renal dysfunction. There is agreement that a baseline estimated glomerular filtration should be obtained and that renal function should be monitored during antiretroviral therapy. There is, however, no agreement as to the most accurate method of estimating GFR. Renal transplantation has emerged as a feasible and successful modality of management of end-stage renal disease (ESRD) in HIV-infected individuals.

SUMMARY

Kidney disease represents an increasing concern in the care of HIV-infected persons, although there are questions remaining regarding the pathophysiology of HIVAN. Transplantation, however, can be carried out safely in infected persons with ESRD.

Nephrotoxicity of HAART

Highly active antiretroviral therapy (HAART) and other medical therapies for HIV-related infections have been associated with toxicities. Antiretroviral therapy can contribute to renal dysfunction directly by inducing acute tubular necrosis, acute interstitial nephritis, crystal nephropathy, and renal tubular disorders or indirectly via drug interactions. With the increase in HAART use, clinicians must screen patients for the development of kidney disease especially if the regimen employed increases risk of kidney injury. It is also important that patients with chronic kidney disease (CKD) are not denied the best combinations, especially since most drugs can be adjusted based on the estimated GFR. Early detection of risk factors, systematic screening for chronic causes of CKD, and appropriate referrals for kidney disease management should be advocated for improved patient care. The interaction between immunosuppressive therapy and HAART in patients with kidney transplants and the recent endorsement of tenofovir/emtricitabine by the Centers for Disease Control (CDC) for preexposure prophylaxis bring a new dimension for nephrotoxicity vigilance. This paper summarizes the common antiretroviral drugs associated with nephrotoxicity with particular emphasis on tenofovir and protease inhibitors, their risk factors, and management as well as prevention strategies.

HIV/HCV co-infection: pathogenesis, clinical complications, treatment, and new therapeutic technologies

World-wide, hepatitis C virus (HCV) accounts for approximately 130 million chronic infections, with an overall 3% prevalence. Four to 5 million persons are co-infected with HIV. It is well established that HIV has a negative impact on the natural history of HCV, including a higher rate of viral persistence, increased viral load, and more rapid progression to fibrosis, end-stage liver disease, and death. Whether HCV has a negative impact on HIV disease progression continues to be debated. However, following the introduction of effective combination antiretroviral therapy, the survival of coinfected individuals has significantly improved and HCV-associated diseases have emerged as the most important co-morbidities. In this review, we summarize the newest studies regarding the pathogenesis of HIV/HCV coinfection, including effects of coinfection on HIV disease progression, HCV-associated liver disease, the immune system, kidney and cardiovascular disease, and neurologic status; and effectiveness of current anti-HIV and HCV therapies and proposed new treatment strategies.

Hepatitis C increases the risk of progression of chronic kidney disease in patients with glomerulonephritis

BACKGROUND/AIMS

We have shown that hepatitis C does not increase the risk of developing chronic kidney disease (CKD), but it is not known if hepatitis C worsens progression of existing CKD.

METHODS

We retrospectively identified patients with primary glomerulonephritis on biopsy over 4 years, evaluating the progression of CKD over time.

RESULTS

The cohort consisted of 111 patients: 21% were positive for hepatitis C, 61% were negative for hepatitis C and 18% were not tested. The hepatitis C-positive subjects were more likely to be African American (p = 0.031), followed for fewer days (p = 0.007) and have diabetes and focal segmental glomerulosclerosis on biopsy (p < 0.001). Longitudinal follow-up of CKD progression using multiple creatinine measures analyzed by repeated measures ANCOVA demonstrated that patients with hepatitis C had a worsening creatinine over time compared to the hepatitis C-negative and not tested groups (p < 0.001). By Cox hazards regression analyses, risk of death/end-stage renal disease (ESRD) was decreased in patients who tested negative for hepatitis C compared to testing positive (0.46, CI 0.27-0.88), but this became nonsignificant after adjustment for mean arterial pressure and hemoglobin.

CONCLUSION

Our results support that infection with hepatitis C in patients with glomerulonephritis is associated with an increased risk of progression of CKD. Prospective studies are required to confirm these observations.