Alan Landay

Rush University Medical Center, Chicago, Illinois, United States

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Publications (429)2517.9 Total impact

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    ABSTRACT: Whether initiation of antiretroviral therapy (ART) regimens aimed at achieving greater concentrations within gut associated lymphoid tissue (GALT) impacts the level of mucosal immune reconstitution, inflammatory markers and the viral reservoir remains unknown. We included 12 HIV- controls and 32 ART-naïve HIV patients who were randomized to efavirenz, maraviroc or maraviroc+raltegravir, each with fixed-dose tenofovir disoproxil fumarate/emtricitabine. Rectal and duodenal biopsies were obtained at baseline and at 9 months of ART. We performed a comprehensive assay of T-cell subsets by flow cytometry, T-cell density in intestinal biopsies, plasma and tissue concentrations of antiretroviral drugs by high-performance liquid chromatography/mass spectroscopy, and plasma interleukin-6 (IL-6), lipoteichoic acid (LTA), soluble CD14 (sCD14) and zonulin-1 each measured by ELISA. Total cell-associated HIV DNA was measured in PBMC and rectal and duodenal mononuclear cells. Twenty-six HIV-infected patients completed the follow-up. In the duodenum, the quadruple regimen resulted in greater CD8+ T-cell density decline, greater normalization of mucosal CCR5+CD4+ T-cells and increase of the naïve/memory CD8+ T-cell ratio, and a greater decline of sCD14 levels and duodenal HIV DNA levels (P = 0.004 and P = 0.067, respectively), with no changes in HIV RNA in plasma or tissue. Maraviroc showed the highest drug distribution to the gut tissue, and duodenal concentrations correlated well with other T-cell markers in duodenum, i.e., the CD4/CD8 ratio, %CD4+ and %CD8+ HLA-DR+CD38+ T-cells. Maraviroc use elicited greater activation of the mucosal naïve CD8+ T-cell subset, ameliorated the distribution of the CD8+ T-cell maturational subsets and induced higher improvement of zonulin-1 levels. These data suggest that combined CCR5 and integrase inhibitor based combination therapy in ART treatment naïve patients might more effectively reconstitute duodenal immunity, decrease inflammatory markers and impact on HIV persistence by cell-dependent mechanisms, and show unique effects of MVC in duodenal immunity driven by higher drug tissue penetration and possibly by class-dependent effects.
    Full-text · Article · Jan 2016 · PLoS Pathogens
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    ABSTRACT: Background: Chronic rhinosinusitis (CRS) is a common inflammatory disease of the upper airways that is often categorized into subtypes including "with" and "without" nasal polyps. However, the influence of multiple important epidemiologic factors, including race, on CRS has not been investigated. Objective: The present study assessed various phenotypic characteristics of CRS in patients, living in the United States, with different racial backgrounds. Methods: We performed a large retrospective cohort study of patients with CRS treated at a large urban tertiary care referral center in Chicago. Results: African American (AA) patients with CRS living in Chicago were more likely to report hyposmia as a symptom of CRS. Furthermore, AA patients with CRS who failed medical therapy and required surgical intervention had a significantly higher frequency of nasal polyposis and aspirin-exacerbated respiratory disease, and a higher disease severity index on computed tomography imaging than did white patients with CRS. The increased polyposis in AAs was associated with increased hospitalization for asthma. There were no differences in the prevalence of atopy, asthma, atopic dermatitis, food allergy, duration of disease, or number of surgeries between different races. Conclusions: AAs with refractory CRS are at increased risk for nasal polyposis, smell loss, aspirin-exacerbated respiratory disease, and a greater severity of disease based on imaging, resulting in increased health care utilization.
    No preview · Article · Jan 2016
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    ABSTRACT: Increased chronic immune activation and inflammation are hallmarks of HIV/SIV infection and are highly correlated with progression to AIDS and development of non-AIDS comorbidities, such as hypercoagulability and cardiovascular disease. Intestinal dysfunction resulting in microbial translocation has been proposed as a lead cause of systemic immune activation and hypercoagulability in HIV/SIV infection. Our goal was to assess the biological and clinical impact of a therapeutic strategy designed to reduce microbial translocation through reduction of the microbial content of the intestine (Rifaximin-RFX) and of gut inflammation (Sulfasalazine-SFZ). RFX is an intraluminal antibiotic that was successfully used in patients with hepatic encephalopathy. SFZ is an antiinflammatory drug successfully used in patients with mild to moderate inflammatory bowel disease. Both these clinical conditions are associated with increased microbial translocation, similar to HIV-infected patients. Treatment was administered for 90 days to five acutely SIV-infected pigtailed macaques (PTMs) starting at the time of infection; seven untreated SIVsab-infected PTMs were used as controls. RFX+SFZ were also administered for 90 days to three chronically SIVsab-infected PTMs. RFX+SFZ administration during acute SIVsab infection of PTMs resulted in: significantly lower microbial translocation, lower systemic immune activation, lower viral replication, better preservation of mucosal CD4+ T cells and significantly lower levels of hypercoagulation biomarkers. This effect was clear during the first 40 days of treatment and was lost during the last stages of treatment. Administration of RFX+SFZ to chronically SIVsab-infected PTMs had no discernible effect on infection. Our data thus indicate that early RFX+SFZ administration transiently improves the natural history of acute and postacute SIV infection, but has no effect during chronic infection.
    Preview · Article · Jan 2016 · PLoS Pathogens
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    ABSTRACT: Chronic rhinosinusitis (CRS) has been known as a disease with strong infectious and inflammatory components for decades. The recent advancement in methods identifying microbes has helped implicate the airway microbiome in inflammatory respiratory diseases such as asthma and COPD. Such studies support a role of resident microbes in both health and disease of host tissue, especially in the case of inflammatory mucosal diseases. Identifying interactive events between microbes and elements of the immune system can help us to uncover the pathogenic mechanisms underlying chronic rhinosinusitis. Here we provide a review of the findings on the complex upper respiratory microbiome in CRS in comparison to healthy controls. Furthermore, we have reviewed the defects and alterations of the host immune system that interact with microbes and could be associated with dysbiosis in CRS. This article is protected by copyright. All rights reserved.
    No preview · Article · Oct 2015 · Clinical & Experimental Allergy
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    ABSTRACT: Problem: Identification of the types of cells that produce IL-17 and IL-22 in the genital tract can clarify the roles that these cytokines play in responses to pathogens. Method of study: We isolated and stimulated cells from cervical tissue to identify and characterize cytokine-producing cells. Results: Upon stimulation of CD3(+) CD4(+) endocervical cells, 1.6, 3.4, and 1.5% were induced to produce IL-22, IL-17, and both cytokines, respectively. Stimulation of CD3(+) CD4(+) ectocervical cells resulted in 3.3% IL-22(+) , 5.5% IL-17(+) and 2.6% IL-22(+) IL17(+) cells. CD45(+) CD3(-) cells had relatively high endogenous levels of cytokine expression that did not increase upon stimulation. Innate lymphoid cells (ILCs) made up 5.7-8% of CD45(+) cervical cells and stimulation caused increases in IL-17 and IL-22. Conclusion: These studies show that the majority of the CD45(+) leukocytes that can be induced to produce IL-22 and IL-17 in cervix are CD3(+) CD4(+) , but ILCs are also present and can make both cytokines.
    No preview · Article · Oct 2015 · American Journal Of Reproductive Immunology
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    ABSTRACT: Three groups of CMV seropositive women (total n=164) were selected from the Chicago Women's Interagency HIV-1 Study to investigate the association between CMV co-infection and immune activation: 1) HIV-1 viremic; 2) HIV-1 aviremic; and 3) HIV-1 uninfected. Quantitative measures of CMV serum IgG, CMV DNA, and serum biomarkers IL-6, soluble CD163 (sCD163), soluble CD14 (sCD14), and IP-10 were obtained. Levels of CMV IgG, and the serum biomarkers were significantly higher in the HIV-1 viremic group compared to the aviremic and uninfected groups (p<0.001). No significant associations with CMV IgG levels were found for HIV-uninfected women. When each of the HIV-infected groups was analyzed, sCD14 levels in the viremic women were significantly associated with CMV IgG levels with p<0.02 when adjusted for age, CD4 count and HIV viral load. There was also a modest association (p=0.036) with IL-6 from plasma and cervical vaginal lavage specimens both unadjusted and adjusted for CD4 count and HIV viral load. The association of CMV IgG level with sCD14 implicates the monocyte as a potential site for interaction of the two viruses, which eventually may lead to non-AIDS-defining pathological conditions.
    No preview · Article · Sep 2015 · AIDS research and human retroviruses
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    ABSTRACT: Objectives: In antiretroviral therapy (ART)-treated patients, to determine if AIDS-related non-Hodgkin lymphoma (AIDS-NHL) is preceded by: elevated frequency of potentially malignant abnormal activated/germinal center-like B cells, elevated serum prevalence of B-cell stimulatory Toll-like receptor (TLR) ligands resulting from HIV infection-associated microbial translocation, dysregulated B-cell TLR expression/signaling, and perturbations in the frequency of immunoregulatory cells. Design: A case-control study nested with a cohort study of HIV-infected women. Methods: Prediagnostic AIDS-NHL cases (n = 12, collected 1-12 months before diagnosis) and controls (n = 42) from the Women's Interagency HIV Study cohort, were matched for HIV and ART status, age, race, and CD4 lymphocyte count. Serum levels of TLR ligands, the prevalence of malignancy-associated abnormal activated/germinal center-like (CD19CD10CD71CD86AID) B cells, TLR2 expression on B cells, expression of TLR2-modulating micro-RNA, and the frequency of regulatory T and B cells were assessed. Results: Diagnosis of AIDS-NHL was preceded by a significantly elevated frequency of activated/germinal center-like CD19CD10CD71CD86AID B cells (P = 0.0072), elevated serum prevalence of the TLR2 ligand, and significantly elevated B-cell TLR2 expression (P = 0.0015), positively correlating with the frequency of activated/germinal center-like B cells (rho = 0.7273, P = 0.0144). In cases, a purified subset of activated/germinal center-like B cells exhibited decreased expression of microRNAs that modulate TLR2 signaling, including miR-21, 146a, 146b, and 155. Finally, cases also exhibited significantly elevated frequencies of antitumor immunity inhibitory regulatory B cells (P = 0.0024), but not regulatory T cells. Conclusions: Our findings suggest that increased microbial translocation and dysregulated TLR expression/signaling, coupled with an elevated frequency of regulatory B cells, precede the diagnosis of AIDS-NHL in HIV-infected ART-treated patients.
    No preview · Article · Sep 2015 · AIDS (London, England)
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    ABSTRACT: Plasma HIV RNA is the most significant determinant of cervical HIV shedding. However, shedding is also associated with sexually transmitted infections (STIs) and cervical inflammation. The mechanism by which this occurs is poorly understood. There is evidence that systemic immune activation promotes viral entry, replication and HIV disease progression. We hypothesized that systemic immune activation would be associated with an increase in HIV genital shedding. Clinical assessments, HIV RNA in plasma and genital secretions, and markers of immune activation (CD38+DR+ and CD38-DR-) on CD4+ and CD8+ T cells in blood were evaluated in 226 HIV+ women enrolled in the Women's Interagency HIV Study. There were 569 genital evaluations of which 159 (28%) exhibited HIV RNA shedding, defined as HIV viral load > 80 copies/ml. We tested associations between immune activation and shedding using generalized estimating equations with logit link function. In the univariate model, higher levels of CD4+ and CD8+ T cell activation in blood were significantly associated with genital tract shedding. However, in the multivariate model adjusting for plasma HIV RNA, STIs and genital tract infections, only higher levels of resting CD8+ T cells (CD38-DR- ) were significantly inversely associated with HIV shedding in the genital tract (OR=0.44, 95% CI= 0.21-0.9, P= 0.02). The association of systemic immune activation with genital HIV shedding is multifactorial. Systemic T cell activation is associated with genital tract shedding in univariate analysis but not when adjusting for plasma HIV RNA, STIs and genital tract infections. In addition, women with high percentage of resting T cells are less likely to have HIV shedding compared to those with lower percentages. These findings suggest that a higher percentage of resting cells, as a result of maximal viral suppression with treatment, may decrease local genital activation, HIV shedding, and transmission.
    No preview · Article · Aug 2015 · JAIDS Journal of Acquired Immune Deficiency Syndromes
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    ABSTRACT: Background: Therapeutic vaccination is being studied in eradication and "functional cure" strategies for HIV-1. The Profectus Biosciences multiantigen (MAG) HIV-1 DNA vaccine encodes HIV-1 Gag/Pol, Nef/Tat/Vif, and Envelope, and interleukin-12 (IL-12) and is delivered by electroporation combined with intramuscular injection (IM-EP). Methods: Sixty-two HIV-1-infected patients on antiretroviral therapy (plasma HIV-1 RNA levels ≤200 copies/mL; CD4 T-cell counts ≥500 cells/mm) were randomly allocated 5:1 to receive vaccine or placebo. At weeks 0, 4, and 12, 4 consecutive cohorts received 3000 μg HIV MAG pDNA with 0, 50, 250, or 1000 μg of IL-12 pDNA by IM-EP. A fifth cohort received HIV MAG pDNA and 1000 μg of IL-12 pDNA by standard IM injection. Results: CD4 T cells expressing IL-2 in response to Gag and Pol and interferon-γ responses to Gag, Pol, and Env increased from baseline to week 14 in the low-dose (50-μg) IL-12 arm vs. placebo (P < 0.05; intracellular cytokine staining). The total increase in the IL-2-expressing CD4 T-cell responses to any antigen was also higher in the low-dose IL-12 arm vs. placebo (P = 0.04). Cytokine responses by CD8 T cells to HIV antigens were not increased in any vaccine arm relative to placebo. Conclusions: HIV-1 MAG/low-dose IL-12 DNA vaccine delivered by IM-EP augmented CD4 but not CD8 T-cell responses to multiple HIV-1 antigens.
    No preview · Article · Aug 2015 · JAIDS Journal of Acquired Immune Deficiency Syndromes
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    ABSTRACT: Objectives: Hepatitis C virus (HCV) infection causes an alteration in T-cell maturation and activation in patients coinfected with human immunodeficiency virus (HIV). Because interleukin 7 (IL-7) is a major cytokine controlling T-cell homeostasis, we analyzed the potential influence of HCV coinfection on circulating IL-7 levels in HIV-infected women before and after highly active antiretroviral therapy (HAART). Design and methods: This prospective study included 56 HIV monoinfected, 55 HIV/HCV coinfected without HCV viremia, 132 HIV/HCV coinfected with HCV viremia, and 61 HIV/HCV-uninfected women for whom plasma levels of IL-7 were determined by enzyme-linked immunosorbent assay at 1 or more follow-up visits before and after HAART. Cross-sectional analyses of the associations between plasma IL-7 levels and HCV infection, demographic, clinical, and immunologic characteristics were evaluated using univariate and multivariate linear regression models before and after HAART. Results: In multivariate models, IL-7 levels were significantly higher in coinfected HCV viremic women than in HIV monoinfected women (multiplicative effect = 1.48; 95% confidence interval: 1.01 to 2.16; P = 0.04) before HAART, but were similar between these two groups among women after HAART. In addition to HCV viremia, higher IL-7 levels were associated with older age (P = 0.02), lower CD4 T-cell count (P = 0.0007), and higher natural killer T-cell count (P = 0.02) in women before HAART. Among HAART-treated women, only lower CD4 T-cell count was significantly associated with IL-7 level (P = 0.006). Conclusions: Our data demonstrate that in HIV-infected women, circulating levels of IL-7 are strongly associated with CD4 T-cell depletion both before and after HAART. Our data also demonstrate that HCV viremia increases circulating IL-7 levels before HAART but not after HAART in coinfected women. This suggests that the effect of HCV on lymphopenia is abrogated by HAART.
    No preview · Article · Aug 2015 · JAIDS Journal of Acquired Immune Deficiency Syndromes
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    ABSTRACT: Glycogen expressed by the lower genital tract epithelium is believed to support Lactobacillus growth in vivo, although most genital isolates of Lactobacillus are not able to use glycogen as an energy source in vitro. We recently reported that α-amylase is present in the genital fluid of women and that it breaks down glycogen into small carbohydrates that support growth of lactobacilli. Since the pH of the lower genital tract can be very low, we determined how low pH affects glycogen processing by α-amylase. α-amylase in saliva degraded glycogen similarly at pH 6 and 7, but activity was reduced by 52% at pH 4. The glycogen degrading activity in nine genital samples from seven women showed a similar profile with an average reduction of more than 50% at pH 4. However, two samples collected from one woman at different times had a strikingly different pH profile with increased glycogen degradation at pH 4, 5 and 6 compared to pH 7. This second pH profile did not correlate with levels of human α-acid glucosidase or human intestinal maltase glucoamylase. High-performance anion-exchange chromatography showed that mostly maltose was produced from glycogen by samples with the second pH profile in contrast to genital α-amylase that yielded maltose, maltotriose and maltotetraose. These studies show that at low pH, α-amylase activity is reduced to low but detectable levels, which we speculate helps maintain Lactobacillus growth at a limited but sustained rate. Additionally, some women have a genital enzyme distinct from α-amylase with higher activity at low pH. Further studies are needed to determine the identity and distribution of this second enzyme, and whether its presence influences the makeup of genital microbiota.
    Full-text · Article · Jul 2015 · PLoS ONE
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    ABSTRACT: Trichomonas vaginalis infection is associated with an increased risk of HIV infection in exposed-seronegative women (ESN) despite their unique immune quiescent profile. It is important to understand possible mechanisms, such as recruitment of activated T cells, by which T. vaginalis could facilitate HIV infection in this population. We conducted a cross-sectional study exploring the relationships between T. vaginalis infection, inflammatory markers and T cell activation in the cervix of ESN. During scheduled study visits, participants completed a behavioral questionnaire and physical exam, including sexually transmitted infection (STI) screening and collection of endocervical sponge and cytobrush specimens. T cell and monocyte phenotypes were measured in cervical cytobrush specimens using multi-parameter flow cytometry. Cervical sponge specimens were used to measure cytokines (IL-6, IL-8,IL-10, IP-10, RANTES) using Luminex immunoassays and the immune activation marker soluble TNF receptor 1 using ELISA. Specimens of 65 women were tested. Twenty-one of these women were infected with T. vaginalis. T. vaginalis infection was associated with significantly increased concentrations of IL-8 (1275pg/ml vs. 566pg/ml, p=.02) and sTNFr1 (430 pg/ml vs. 264 pg/ml, p=.005). However, T. vaginalis infection was not associated with increased percent expression of CCR5+ T cells nor increased CD38 and HLADR activation compared to uninfected women. It was also not associated with increased expression of CCR5+ monocytes. Among ESN T. vaginalis infection is associated with increased levels of genital pro-inflammatory/immune activation markers IL-8 and TNFr1, but was not associated with an increased percentage of activated endocervical T cells along the CD38 and HLADR pathways. Thus, while T.vaginalis infection may result in some reversal of the immune quiescent profile of ESN, enhanced recruitment of activated CD38 and HLADR expressing CD4+ cells into the endocervix may not be part of the mechanism by which Trichomonas infection alters HIV susceptibility in this unique subset of women.
    Full-text · Article · Jun 2015 · PLoS ONE
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    ABSTRACT: Background: There is a need to prevent or minimize bone loss associated with antiretroviral treatment (ART) initiation. We compared maraviroc (MVC)- to tenofovir disoproxil fumarate (TDF)-containing ART. Methods: This was a double-blind, placebo-controlled trial. ART-naive subjects with human immunodeficiency virus type 1 RNA load (viral load [VL]) >1000 copies/mL and R5 tropism were randomized to MVC 150 mg or TDF 300 mg once daily (1:1), stratified by VL <100 000 or ≥100 000 copies/mL and age <30 or ≥30 years. All subjects received darunavir 800 mg, ritonavir 100 mg, and emtricitabine 200 mg daily. Dual-energy X-ray absorptiometry scanning was done at baseline and week 48. The primary endpoint was percentage change in total hip bone mineral density (BMD) from baseline to week 48 in the as-treated population. Results: We enrolled 262 subjects. A total of 259 subjects (130 MVC, 129 TDF) contributed to the analyses (91% male; median age, 33 years; 45% white, 30% black, 22% Hispanic). Baseline median VL was 4.5 log10 copies/mL and CD4 count was 390 cells/µL. The decline in hip BMD (n = 115 for MVC, n = 109 for TDF) at week 48 was less with MVC (median [Q1, Q3] of -1.51% [-2.93%, -0.11%] vs -2.40% [-4.30%, -1.32%] for TDF (P < .001). Lumbar spine BMD decline was also less with MVC (median -0.88% vs -2.35%; P < .001). Similar proportions of subjects in both arms achieved VL ≤50 copies/mL in as-treated and ITT analyses. Conclusions: MVC was associated with less bone loss at the hip and lumbar spine compared with TDF. MVC may be an option to attenuate ART-associated bone loss. Clinical trials registration: NCT01400412.
    No preview · Article · Jun 2015 · Clinical Infectious Diseases
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    ABSTRACT: HIV-1-associated disruption of intestinal homeostasis is a major factor contributing to chronic immune activation and inflammation. Dendritic cells (DCs) are crucial in maintaining intestinal homeostasis, but the impact of HIV-1 infection on intestinal DC number and function has not been extensively studied. We compared the frequency and activation/maturation status of colonic myeloid DC (mDC) subsets (CD1c(+) and CD1c(neg)) and plasmacytoid DCs in untreated HIV-1-infected subjects with uninfected controls. Colonic mDCs in HIV-1-infected subjects had increased CD40 but decreased CD83 expression, and CD40 expression on CD1c(+) mDCs positively correlated with mucosal HIV-1 viral load, with mucosal and systemic cytokine production, and with frequencies of activated colon and blood T cells. Percentage of CD83(+)CD1c(+) mDCs negatively correlated with frequencies of interferon-γ-producing colon CD4(+) and CD8(+) T cells. CD40 expression on CD1c(+) mDCs positively associated with abundance of high prevalence mucosal Prevotella copri and Prevotella stercorea but negatively associated with a number of low prevalence mucosal species, including Rumminococcus bromii. CD1c(+) mDC cytokine production was greater in response to in vitro stimulation with Prevotella species relative to R. bromii. These findings suggest that, during HIV infection, colonic mDCs become activated upon exposure to mucosal pathobiont bacteria leading to mucosal and systemic immune activation.Mucosal Immunology advance online publication, 29 April 2015; doi:10.1038/mi.2015.33.
    No preview · Article · Apr 2015 · Mucosal Immunology
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    ABSTRACT: Background: Individuals infected with human immunodeficiency virus (HIV) live longer as a result of effective treatment, but long-term consequences of infection, treatment, and immunological dysfunction are poorly understood. Methods: We prospectively examined 1011 women (74% HIV-infected) in the Women's Interagency HIV Study and 811 men (65% HIV-infected) in the Multicenter AIDS Cohort Study who underwent repeated B-mode carotid artery ultrasound imaging in 2004-2013. Outcomes included changes in right common carotid artery intima-media thickness (CCA-IMT) and new focal carotid artery plaque formation (IMT >1.5 mm) over median 7 years. We assessed the association between HIV serostatus and progression of subclinical atherosclerosis, adjusting for demographic, behavioral, and cardiometabolic risk factors. Results: Unadjusted mean CCA-IMT increased (725 to 752 µm in women, 757 to 790 µm in men), but CCA-IMT progression did not differ by HIV serostatus, either in combined or sex-specific analyses. Focal plaque prevalence increased from 8% to 15% in women and 25% to 34% in men over 7 years. HIV-infected individuals had 1.6-fold greater risk of new plaque formation compared with HIV-uninfected individuals (relative risk [RR] 1.61, 95% CI, 1.12-2.32), adjusting for cardiometabolic factors; the association was similar by sex. Increased plaque occurred even among persistently virologically suppressed HIV-infected individuals compared with uninfected individuals (RR 1.56, 95% CI, 1.07-2.27). HIV-infected individuals with baseline CD4+ ≥500 cells/µL had plaque risk not statistically different from uninfected individuals. Conclusions: HIV infection is associated with greater increases in focal plaque among women and men, potentially mediated by factors associated with immunodeficiency or HIV replication at levels below current limits of detection.
    No preview · Article · Apr 2015 · Clinical Infectious Diseases
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    ABSTRACT: Tissue factor (TF) is a protein that mediates the initiation of the coagulation cascade. TF expression is increased in patients with poorly-controlled HIV, and may be associated with increased immune activation that leads to cardiovascular morbidity. The role of TF in immune activation in liver disease in hepatitis C virus (HCV)-monoinfection and HIV/HCV-coinfection has not been explored. Fifty-nine patients were stratified: A) HIV-monoinfection (N = 15), B) HCV-monoinfection with chronic hepatitis C (CHC) (N = 15), C) HIV/HCV-coinfection with CHC (N = 14), and D) HIV/HCV-seropositive with cleared-HCV (N = 15). All HIV+ patients had undetectable HIV viremia. Whole blood was collected for CD4/CD8 immune activation markers by flow cytometry and plasma was assayed for microparticle TF (MPTF) activity. Subjects underwent transient elastography (TE) to stage liver fibrosis. Undetectable versus detectable MPTF was compared across strata using Fisher's Exact test. MPTF activity was more frequently detected among patients with HCV-monoinfection (40%), compared to HIV-monoinfection and HIV/HCV-seropositive with cleared HCV (7%) and HIV/HCV-coinfection with CHC (14%)(p = 0.02). Mean TE-derived liver stiffness score in kPa was higher in patients with detectable MPTF (12.4 ± 8.5) than those with undetectable MPTF (6.4 ± 3.0)(p = 0.01). Mean CD4 + HLADR+ and CD4 + CD38-HLADR+ expression were higher in those with detectable MPTF (44 ± 9.8% and 38 ± 8.7%, respectively) than those with undetectable MPTF (36 ± 11% and 31 ± 10.4% respectively)(p = 0.05 and 0.04 respectively). HCV-monoinfection and HIV/HCV-coinfection with CHC were associated with MPTF activity. MPTF activity is also associated with advanced liver fibrosis and with CD4 + HLADR+ immune activation.
    Preview · Article · Apr 2015 · BMC Infectious Diseases
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    ABSTRACT: Measurement of CD4+ T-lymphocytes (CD4) is a crucial parameter in the management of HIV patients, particularly in determining eligibility to initiate antiretroviral treatment (ART). A number of technologies exist for CD4 enumeration, with considerable variation in cost, complexity, and operational requirements. We conducted a systematic review of the performance of technologies for CD4 enumeration. Studies were identified by searching electronic databases MEDLINE and EMBASE using a pre-defined search strategy. Data on test accuracy and precision included bias and limits of agreement with a reference standard, and misclassification probabilities around CD4 thresholds of 200 and 350 cells/μl over a clinically relevant range. The secondary outcome measure was test imprecision, expressed as % coefficient of variation. Thirty-two studies evaluating 15 CD4 technologies were included, of which less than half presented data on bias and misclassification compared to the same reference technology. At CD4 counts <350 cells/μl, bias ranged from -35.2 to +13.1 cells/μl while at counts >350 cells/μl, bias ranged from -70.7 to +47 cells/μl, compared to the BD FACSCount as a reference technology. Misclassification around the threshold of 350 cells/μl ranged from 1-29% for upward classification, resulting in under-treatment, and 7-68% for downward classification resulting in overtreatment. Less than half of these studies reported within laboratory precision or reproducibility of the CD4 values obtained. A wide range of bias and percent misclassification around treatment thresholds were reported on the CD4 enumeration technologies included in this review, with few studies reporting assay precision. The lack of standardised methodology on test evaluation, including the use of different reference standards, is a barrier to assessing relative assay performance and could hinder the introduction of new point-of-care assays in countries where they are most needed.
    Full-text · Article · Mar 2015 · PLoS ONE
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    ABSTRACT: All-cause mortality and serious non-AIDS events (SNAEs) in individuals with HIV-1 infection receiving antiretroviral therapy are associated with increased production of interleukin-6 which appears to be driven by monocyte/macrophage activation. Plasma levels of other cytokines or chemokines associated with immune activation might also be biomarkers of an increased risk of mortality and/or SNAEs. Baseline plasma samples from 142 participants enrolled into the Strategies for Management of Antiretroviral Therapy study, who subsequently died, and 284 matched controls, were assayed for levels of 15 cytokines and chemokines. Cytokine and chemokine levels were analysed individually and when grouped according to function (innate/proinflammatory response, cell trafficking and cell activation/proliferation) for their association with the risk of subsequent death. Higher plasma levels of proinflammatory cytokines (interleukin-6 and tumour necrosis factor-α) were associated with an increased risk of all-cause mortality but in analyses adjusted for potential confounders, only the association with interleukin-6 persisted. Increased plasma levels of the chemokine CXCL8 were also associated with all-cause mortality independently of hepatitis C virus status but not when analyses were adjusted for all confounders. In contrast, higher plasma levels of cytokines mediating cell activation/proliferation were not associated with a higher mortality risk and exhibited a weak protective effect when analysed as a group. Whereas plasma levels of interleukin-6 are the most informative biomarker of cytokine dysregulation associated with all-cause mortality in individuals with HIV-1 infection, assessment of plasma levels of CXCL8 might provide information about causes of mortality and possibly SNAEs.
    No preview · Article · Feb 2015 · AIDS (London, England)
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    ABSTRACT: Chronic inflammation and immune activation occur in both HIV infection and normal ageing and are associated with inflammatory disease. However, the degree to which HIV influences age-related innate immune changes, and the biomarkers which best reflect them, remains unclear. We measured established innate immune ageing biomarkers in 309 individuals including 88 virologically-suppressed (VS) and 52 viremic (viral load ≤ and >50 copies/ml respectively) HIV+ individuals. Levels of soluble (ie. CXCL10, soluble CD163, neopterin) and cellular (ie. proportions of inflammatory CD16+ monocytes) biomarkers of monocyte activation were increased in HIV+ individuals and were only partially ameliorated by viral suppression. Viremic and VS HIV+ individuals show levels of age-related monocyte activation biomarkers that are similar to uninfected controls aged 12 and 4 years older respectively. Viremic HIV infection was associated with an accelerated rate of change of some monocyte activation markers (eg. neopterin) with age, whilst in VS individuals, subsequent age-related changes occurred at a similar rate as in controls, albeit at a higher absolute level. We further identified CXCL10 as a robust soluble biomarker of monocyte activation, highlighting the potential utility of this chemokine as a prognostic marker. These findings may partially explain the increased prevalence of inflammatory, age-related diseases in HIV+ individuals and potentially indicate the pathological mechanisms underlying these diseases which persist despite viral suppression.
    No preview · Article · Feb 2015 · JAIDS Journal of Acquired Immune Deficiency Syndromes
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    ABSTRACT: With the advent of antiretroviral therapy that can control virus replication below the detection levels of conventional assays, a new clinical landscape of AIDS emerged, in which non-AIDS complications prevail over AIDS-defining conditions. These comorbidities are diverse and affect multiple organs, thus resulting in cardiovascular, kidney, neurocognitive and liver disease, osteopenia/osteoporosis, and cancers. A common feature of these conditions is that they are generally associated with accelerated aging. The mechanism behind these comorbidities is chronic excessive inflammation induced by HIV infection, which persists under antiretroviral therapy. Progressive simian immunodeficiency virus (SIV) infection of nonhuman primates (NHPs) closely reproduces these comorbidities and offers a simplified system in which most of the traditional human risk factors for comorbidities (i.e., smoking, hyperlipidemia) are absent. Additionally, experimental conditions can be properly controlled during a shorter course of disease for SIV infection. As such, NHPs can be employed to characterize new paradigms of AIDS pathogenesis and to test the efficacy of interventions aimed at alleviating non-AIDS-related comorbidities.
    Preview · Article · Jan 2015 · Current HIV/AIDS Reports

Publication Stats

18k Citations
2,517.90 Total Impact Points


  • 2001-2016
    • Rush University Medical Center
      • Department of Immunology and Microbiology
      Chicago, Illinois, United States
  • 2013-2015
    • Utrecht University
      • Division of Pharmacology
      Utrecht, Utrecht, Netherlands
  • 2014
    • Drexel University College of Medicine
      • Division of Infectious Diseases & HIV Medicine
      Filadelfia, Pennsylvania, United States
  • 1987-2012
    • University of Illinois at Chicago
      Chicago, Illinois, United States
    • Abbott Laboratories
      North Chicago, Illinois, United States
  • 1986-2010
    • Rush Medical College
      Chicago, Illinois, United States
  • 2009
    • University of California, Los Angeles
      Los Angeles, California, United States
  • 1988-2003
    • Dana-Farber Cancer Institute
      Boston, Massachusetts, United States
  • 2002
    • University of Texas Medical Branch at Galveston
      • Department of Internal Medicine
      Galveston, Texas, United States
    • Treatment Research Institute, Philadelphia PA
      Filadelfia, Pennsylvania, United States
  • 2000
    • University of North Carolina at Chapel Hill
      North Carolina, United States
    • Beth Israel Deaconess Medical Center
      • Division of Viral Pathogenesis
      Boston, MA, United States
    • Johns Hopkins University
      Baltimore, Maryland, United States
    • Case Western Reserve University School of Medicine
      Cleveland, Ohio, United States
    • Ottawa Hospital Research Institute
      Ottawa, Ontario, Canada
  • 1999
    • Harvard University
      Cambridge, Massachusetts, United States
    • Harvard Medical School
      Boston, Massachusetts, United States
  • 1998
    • Case Western Reserve University
      • Center for AIDS Research
      Cleveland, Ohio, United States
    • The University of Chicago Medical Center
      • Department of Microbiology and Immunology
      Chicago, Illinois, United States
  • 1997
    • Baylor College of Medicine
      Houston, Texas, United States
    • Beth Israel Medical Center
      • Division of Infectious Disease
      New York, New York, United States
  • 1991-1997
    • National Institutes of Health
      • Branch of Experimental Immunology
      Bethesda, MD, United States
    • Northwestern University
      Evanston, Illinois, United States
    • University of Wisconsin, Madison
      • Department of Human Oncology
      Madison, MS, United States
  • 1994
    • Cancer Research Institute
      New York, New York, United States
  • 1993
    • Mayo Clinic - Rochester
      Rochester, Minnesota, United States
    • University of Washington Seattle
      • Department of Laboratory Medicine
      Seattle, Washington, United States
  • 1989-1992
    • Aurora St. Luke's Medical Center
      Milwaukee, Wisconsin, United States
  • 1990
    • Pennsylvania State University
      • Department of Medicine
      University Park, Maryland, United States
  • 1983-1986
    • University of Alabama at Birmingham
      • • Comprehensive Cancer Center
      • • Department of Pediatrics
      Birmingham, Alabama, United States