Mallory D. Witt

Inflammatory Markers Associated With Subclinical Coronary Artery Disease: The Multicenter AIDS Cohort Study

Background Despite evidence for higher risk of coronary artery disease among HIV+ individuals, the underlying mechanisms are not well understood. We investigated associations of inflammatory markers with subclinical coronary artery disease in 923 participants of the Multicenter AIDS Cohort Study (575 HIV+ and 348 HIV− men) who underwent noncontrast computed tomography scans for coronary artery calcification, the majority (n=692) also undergoing coronary computed tomography angiography. Methods and Results Outcomes included presence and extent of coronary artery calcification, plus computed tomography angiography analysis of presence, composition, and extent of coronary plaques and severity of coronary stenosis. HIV+ men had significantly higher levels of interleukin‐6 (IL‐6), intercellular adhesion molecule‐1, C‐reactive protein, and soluble‐tumor necrosis factor‐α receptor (sTNFαR) I and II (all P<0.01) and a higher prevalence of noncalcified plaque (63% versus 54%, P=0.02) on computed tomography angiography. Among HIV+ men, for every SD increase in log‐interleukin‐6 and log intercellular adhesion molecule‐1, there was a 30% and 60% increase, respectively, in the prevalence of coronary stenosis ≥50% (all P<0.05). Similarly, sTNFαR I and II in HIV+ participants were associated with an increase in prevalence of coronary stenosis ≥70% (P<0.05). Higher levels of interleukin‐6, sTNFαR I, and sTNFαR II were also associated with greater coronary artery calcification score in HIV+ men (P<0.01). Conclusions Higher inflammatory marker levels are associated with greater prevalence of coronary stenosis in HIV+ men. Our findings underscore the need for further study to elucidate the relationships of inflammatory pathways with coronary artery disease in HIV+ individuals.

Interaction between RANTES Promoter Variant and CCR5Δ32 Favors Recovery from Hepatitis B

Recovery from acute hepatitis B virus (HBV) infection occurs in 95% of adult-acquired infections. A 32-bp deletion in CCR5 (CCR5Δ32), which encodes for a nonfunctional receptor, increases the likelihood of recovery. Using 181 subjects with persistent HBV infection and 316 who had recovered, we tested the hypothesis that an epistatic interaction between functional polymorphisms in RANTES (a CCR5 ligand) and CCR5 impacts recovery. Specific models designed to assess individual contributions of compound genotypes demonstrated that the only combination associated with recovery from an HBV infection was RANTES −403A with CCR5Δ32 (odds ratio 0.36, p = 0.02). Because the phenotypic consequence of −403A is reported to be higher levels of RANTES, we propose a model in which excess RANTES in combination with low CCR5 favors recovery from an HBV infection, which will require validation through functional testing.

Morning free and total testosterone in HIV-infected men: implications for the assessment of hypogonadism

BackgroundHypogonadism is common among HIV-infected men, even among men receiving antiretroviral therapy (ART). Our objective in this study was to determine the prevalence of biochemical hypogonadism among HIV-infected men compared with HIV-uninfected controls. We also examined the use of free testosterone (FT) and total testosterone (TT) measurements in the assessment of biochemical hypogonadism in HIV-infected and –uninfected men.MethodsThis was a cross-sectional analysis from the Multicenter AIDS Cohort Study (MACS). TT levels were measured from archived serum using liquid chromatography-tandem mass spectrometry. FT was calculated from TT and sex hormone-binding globulin (SHBG) (measured by radioimmunoassay) using the Vermeulen equation. Biochemical hypogonadism was defined as having low TT, low FT, or both.ResultsOf 945 men in the MACS Cardiovascular Substudy, T assays were not performed in 89 because of insufficient/no stored serum (n = 18) or use of T replacement therapy (TRT) (n = 71). 530 men had morning (AM) T measurements; 364 (68.7%) were HIV-infected. The prevalence of biochemical hypogonadism was similar in HIV-infected (34/364 = 9.3%) and HIV-uninfected (12/166 = 7.2%) men. Prevalence of hypogonadism, when men on TRT (n = 71) were included in the group of hypogonadal men, was higher in HIV-infected (104/434 = 24.0%) compared with HIV-uninfected (13/167 = 7.8%) men (p < 0.0001). Of 34 HIV-infected men with biochemical hypogonadism not on TRT, 11 (32.4%) had normal TT, but low FT. Of 12 HIV-uninfected men with biochemical hypogonadism not on TRT, none were in this category (p = 0.04) – all had low TT.ConclusionsThe prevalence of biochemical hypogonadism in our sample of HIV-infected men was approximately 10%, with a substantial proportion of these men having a normal TT, but low FT. The measurement of AM FT, rather than TT, in the assessment of hypogonadism in HIV-infected men will likely increase diagnostic sensitivity and should be recommended.

A Cross-sectional Study of the Association Between Chronic Hepatitis C Virus Infection and Subclinical Coronary Atherosclerosis Among Participants in the Multicenter AIDS Cohort Study

BACKGROUND Hepatitis C virus (HCV) infection may increase the risk of cardiovascular disease (CVD). We evaluated the association of chronic HCV infection and coronary atherosclerosis among participants in the Multicenter AIDS Cohort Study. METHODS We assessed 994 men with or without human immunodeficiency virus (HIV) infection (87 of whom had chronic HCV infection) for coronary plaque, using noncontrast coronary computed tomography (CT); 755 also underwent CT angiography. We then evaluated the associations of chronic HCV infection and HIV infection with measures of plaque prevalence, extent, and stenosis. RESULTS After adjustment for demographic characteristics, HIV serostatus, behaviors, and CVD risk factors, chronic HCV infection was significantly associated with a higher prevalence of coronary artery calcium (prevalence ratio, 1.29; 95% confidence interval [CI], 1.02-1.63), any plaque (prevalence ratio, 1.26; 95% CI, 1.09-1.45), and noncalcified plaque (prevalence ratio, 1.42; 95% CI, 1.16-1.75). Chronic HCV infection and HIV infection were independently associated with the prevalence of any plaque and of noncalcified plaque, but there was no evidence of a synergistic effect due to HIV/HCV coinfection. The prevalences of coronary artery calcium, any plaque, noncalcified plaque, a mixture of noncalcified and calcified plaque, and calcified plaque were significantly higher among men with an HCV RNA load of ≥2 × 10(6) IU/mL, compared with findings among men without chronic HCV infection. CONCLUSIONS Chronic HCV infection is associated with subclinical CVD, suggesting that vigilant assessments of cardiovascular risk are warranted for HCV-infected individuals. Future research should determine whether HCV infection duration or HCV treatment influence coronary plaque development.

Maraviroc intensification in patients with suppressed HIV viremia has limited effects on CD4+ T cell recovery and gene expression

Addition of the CCR5 inhibitor Maraviroc (MVC) to ongoing antiretroviral therapy increases CD4+ T cell counts in some virologically suppressed patients with suboptimal CD4+ T cell recovery. To understand the mechanisms by which MVC elicits increases in CD4+ T cell counts, the present study was undertaken to identify host factors (i.e. genes) that are modulated and are correlated with CD4+ T cell recovery during the 24weeks of MVC intensification in 32 subjects. Median changes of CD4+ T cell counts over 24weeks of MVC compared to baseline were 38cells/mm(3) (p<0.001). The median slope of CD4+ T cell recovery was 39cells/mm(3) per year before initiation of MVC and 76cells/mm(3) per year during MVC intensification, however, this increase was not statistically significant (p=0.33). Microarray analysis (N=31,426 genes) identified a single differentially expressed gene, tumor necrosis factor alpha (TNF), which was modestly (1.44-fold, p<0.001) downregulated by MVC at week 24 compared to baseline. TNF differential expression was evaluated using an independent method of droplet digital PCR, but the difference was not significant (p=0.6). Changes in gene expression did not correlate with CD4+ T cell recovery or any changes in the CD4+ T cell maturation, proliferation and activation phenotypes. In summary, our data suggest that modest improvements of CD4+ T cell counts during MVC intensification cannot be explained by changes in gene expression elicited by MVC. However, the modest changes in T cell composition, including reduction of the percentages of Tregs, proliferating CD4+ T cells and senescent CD8+ T cells, suggest immunologically favorable effects of MVC.

Lower adiponectin is associated with subclinical cardiovascular disease among HIV-infected men

Objective:To examine whether altered levels of adipokines, adipose-derived peptides associated with myocardial infarction in the general population, may contribute to subclinical coronary atherosclerosis in HIV-infected persons. Design:Nested cohort study. Methods:We studied HIV-infected (HIV+) and HIV-uninfected (HIV−) men in the Multicenter AIDS Cohort Study with noncontrast computed tomography (CT) to measure coronary artery calcium and regional adiposity; 75% additionally underwent coronary CT angiography to measure plaque composition and stenosis. Adiponectin and leptin levels were assessed. Multiple regression models were used to assess associations between adipokine levels and HIV disease parameters, regional adiposity, and plaque adjusted for age, race, HIV serostatus, and cardiovascular disease (CVD) risk factors. Results:Significant findings were limited to adiponectin. HIV-positive men (n = 493) had lower adiponectin levels than HIV-negative men (n = 250) after adjusting for CVD risk factors (P <0.0001), which became nonsignificant after adjustment for abdominal visceral and thigh subcutaneous adipose tissue. Among HIV-positive men, lower adiponectin levels were associated with higher CD4+ T-cell counts (P = 0.004), longer duration of antiretroviral therapy (P = 0.006), and undetectable HIV RNA levels (P = 0.04) after adjusting for age, race, and CVD risk factors; only CD4+ cell count remained significant after further adjustment for adipose tissue. In both groups, lower adiponectin levels were associated with increased odds of coronary stenosis more than 50% (P <0.007). Lower adiponectin levels were associated with increased extent of plaque in HIV-positive and of mixed plaque in HIV-negative men. Conclusion:Adiponectin levels were lower in HIV-infected men and related to the severity of subclinical atherosclerosis, independent of traditional CVD risk factors.

Differences in hepatitis C virus prevalence and clearance by mode of acquisition among men who have sex with men

We examined the characteristics associated with hepatitis C virus (HCV) antibody (anti‐HCV) prevalence and HCV clearance between injection drug using (IDU) and non‐IDU men who have sex with men (MSM). Stored serum and plasma samples were tested for anti‐HCV and HCV RNA to determine the HCV status of 6925 MSM at enrolment into the Multicentre AIDS Cohort Study (MACS). Prevalence and clearance ratios were calculated to determine the characteristics associated with HCV prevalence and clearance. Multivariable analyses were performed using Poisson regression methods with robust variance estimation. Anti‐HCV prevalence was significantly higher among IDU than among non‐IDU MSM (42.9% vs 4.0%), while clearance was significantly lower among IDU MSM (11.5% vs 34.5% among non‐IDU MSM). HIV infection, Black race, and older age were independently associated with higher prevalence in both groups, while smoking, transfusion history, and syphilis were significantly associated with prevalence only among non‐IDU MSM. The rs12979860‐C/C genotype was the only characteristic independently associated with HCV clearance in both groups, but the effects of both rs12979860‐C/C genotype [clearance ratio (CR) = 4.16 IDUs vs 1.71 non‐IDUs; P = 0.03] and HBsAg positivity (CR = 5.06 IDUs vs 1.62 non‐IDUs; P = 0.03) were significantly larger among IDU MSM. HIV infection was independently associated with lower HCV clearance only among non‐IDU MSM (CR = 0.59, 95% CI = 0.40–0.87). IDU MSM have higher anti‐HCV prevalence and lower HCV clearance than non‐IDU MSM. Differences in the factors associated with HCV clearance suggest that the mechanisms driving the response to HCV may differ according to the mode of acquisition.

HIV Infection, Tenofovir, and Urine α1-Microglobulin: A Cross-sectional Analysis in the Multicenter AIDS Cohort Study

BACKGROUND Tenofovir disoproxil fumarate (TDF) can cause proximal tubular damage and chronic kidney disease in human immunodeficiency virus (HIV)-infected individuals. Urine α1-microglobulin (A1M), a low-molecular-weight protein indicative of proximal tubular dysfunction, may enable earlier detection of TDF-associated tubular toxicity. STUDY DESIGN Cross-sectional. SETTING & PARTICIPANTS 883 HIV-infected and 350 -uninfected men enrolled in the Multicenter AIDS Cohort Study. PREDICTORS HIV infection and TDF exposure. OUTCOME Urine A1M level. RESULTS Urine A1M was detectable in 737 (83%) HIV-infected and 202 (58%) -uninfected men (P<0.001). Among HIV-infected participants, 573 (65%) were current TDF users and 112 (13%) were past TDF users. After multivariable adjustment including demographics, traditional kidney disease risk factors, and estimated glomerular filtration rate, HIV infection was associated with 136% (95% CI, 104%-173%) higher urine A1M levels and 1.5-fold (95% CI, 1.3- to 1.6-fold) prevalence of detectable A1M. When participants were stratified by TDF exposure, HIV infection was associated with higher adjusted A1M levels, by 164% (95% CI, 127%-208%) among current users, 124% (95% CI, 78%-183%) among past users, and 76% (95% CI, 45%-115%) among never users. Among HIV-infected participants, each year of cumulative TDF exposure was associated with 7.6% (95% CI, 5.4%-9.9%) higher A1M levels in fully adjusted models, a 4-fold effect size relative to advancing age (1.8% [95% CI, 0.9%-2.7%] per year). Each year since TDF treatment discontinuation was associated with 4.9% (95% CI, -9.4%--0.2%) lower A1M levels among past users. LIMITATIONS Results may not be generalizable to women. CONCLUSIONS HIV-infected men had higher urine A1M levels compared with HIV-uninfected men. Among HIV-infected men, cumulative TDF exposure was associated with incrementally higher A1M levels, whereas time since TDF treatment discontinuation was associated with progressively lower A1M levels. Urine A1M appears to be a promising biomarker for detecting and monitoring TDF-associated tubular toxicity.

The Association of Inflammatory Markers With Nonalcoholic Fatty Liver Disease Differs by Human Immunodeficiency Virus Serostatus

Abstract Background We aimed to determine the relationship of circulating adipokines and inflammatory biomarkers with fatty liver among men in the Multicenter AIDS Cohort Study. Methods Noncontrast computed tomography was used to assess fatty liver and measure abdominal visceral adipose tissue (VAT) area in 526 participants without history of cardiovascular disease, heavy alcohol use, or viral hepatitis infection. Multivariable logistic regression was used to assess associations of circulating biomarker levels with fatty liver. Results Three hundred twenty-nine human immunodeficiency virus (HIV)-infected men had higher levels of several inflammatory biomarkers compared with 197 HIV-uninfected men. Among HIV-uninfected men, increased adiponectin was associated with lower odds of fatty liver (odds ratio [OR] = 0.51 per doubling, P = .02), whereas higher odds of fatty liver was observed with increased levels of the proinflammatory markers intercellular adhesion molecule (ICAM)-1 (OR = 5.30, P = .004), C-reactive protein (OR = 1.66, P = .002), interleukin (IL)-6 (OR = 1.67, P = .03), and tumor necrosis factor α receptor 2 (OR = 6.55, P = .003). Among HIV-infected men, ICAM-1 was the only proinflammatory marker associated with greater odds of fatty liver (OR = 2.67, P = .02), whereas higher adiponectin (OR = 0.57, P = .003), and osteoprotegerin levels (OR = 0.48, P = .03) were associated with lower odds. These associations were all independent of VAT. Conclusions Fatty liver is associated with a heightened inflammatory state independent of visceral adiposity in HIV-uninfected men but not in HIV-infected men. However, a heightened anti-inflammatory state may protect against fatty liver regardless of HIV serostatus.

Association of Urinary Biomarkers of Kidney Injury with Estimated GFR Decline in HIV-Infected Individuals following Tenofovir Disoproxil Fumarate Initiation

BACKGROUND AND OBJECTIVES Tenofovir disoproxil fumarate (tenofovir) is associated with elevated concentrations of biomarkers of kidney damage and dysfunction in individuals with HIV. The relationship of these kidney biomarkers with longitudinal kidney function decline is unknown. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We evaluated associations of 14 urinary biomarkers of kidney injury with changes in eGFR among 198 men and women with HIV who initiated tenofovir between 2009 and 2015 in the Multicenter AIDS Cohort Study and Womens Interagency HIV Study. Urinary biomarkers included albumin-to-creatinine ratio, α-1-microglobulin, β-2-microglobulin, cystatin C, kidney injury molecule-1 (KIM-1), IL-18, neutrophil gelatinase-associated lipocalin (NGAL), clusterin, osteopontin, uromodulin, monocyte chemoattractant protein-1, EGF, trefoil factor 3, and chitinase 3-like protein 1. We used multivariable linear mixed-effect models controlling for demographics, traditional kidney disease risk factors, and HIV-related risk factors to evaluate associations of baseline biomarkers with first-year changes in eGFR, and associations of year 1 and first-year change in biomarkers with changes in eGFR from year 1 to year 3. We used the least absolute shrinkage and selection operator method to identify a parsimonious set of biomarkers jointly associated with changes in eGFR. RESULTS Median eGFR before tenofovir initiation was 103 (interquartile range, 88-116) ml/min per 1.73 m2. During the first year of tenofovir use, eGFR decreased on average by 9.2 (95% confidence interval, 6.5 to 11.9) ml/min per 1.73 m2 and was stable afterward (decrease of 0.62; 95% confidence interval, -0.85 to 2.1 ml/min per 1.73 m2 per year). After multivariable adjustment, higher baseline β-2-microglobulin, KIM-1, and clusterin were associated with larger first-year eGFR declines, whereas higher baseline uromodulin was associated with a smaller eGFR decline. First-year increase in urinary cystatin C and higher year 1 IL-18 were associated with larger annual eGFR declines from year 1 to year 3. The parsimonious models identified higher pre-tenofovir clusterin and KIM-1, lower pre-tenofovir uromodulin, and higher year 1 IL-18 as jointly associated with larger eGFR declines. CONCLUSIONS Urinary biomarkers of kidney injury measured before and after tenofovir initiation are associated with subsequent changes in eGFR in individuals with HIV. PODCAST This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_08_28_CJASNPodcast_18_9_S.mp3.