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Featured researches published by Janet Lo.


The Journal of Infectious Diseases | 2011

Soluble CD163, a Novel Marker of Activated Macrophages, Is Elevated and Associated With Noncalcified Coronary Plaque in HIV-Infected Patients

Tricia H. Burdo; Janet Lo; Suhny Abbara; Jeffrey Wei; Michelle E. DeLelys; Fred Preffer; Eric S. Rosenberg; Kenneth C. Williams; Steven Grinspoon

BACKGROUND Pro-inflammatory monocytes/macrophages may contribute to increased atherosclerosis in human immunodeficiency virus (HIV)-infected patients. We investigate--to our knowledge, for the first time--sCD163 and other markers of monocyte activation in relationship to atherosclerotic plaque in HIV-infected patients. METHODS One hundred two HIV-infected and 41 HIV-seronegative men with equivalent cardiovascular risk factors and without history of coronary artery disease were prospectively recruited and underwent computed tomography coronary angiography. RESULTS sCD163 levels and presence of plaque were significantly higher among antiretroviral-treated subjects with undetectable HIV RNA levels, compared with seronegative controls (1172 ± 646 vs. 883 ± 561 ng/mL [P = .02] for sCD163 and 61% vs. 39% [P = .03] for presence of plaque). After adjusting for age, race, lipids, blood pressure, glucose, smoking, sCD14, and HIV infection, sCD163 remained independently associated with noncalcified plaque (P = .008). Among HIV-infected patients, sCD163 was associated with coronary segments with noncalcified plaque (r = 0.21; P = .04), but not with calcium score. In contrast, markers of generalized inflammation, including C-reactive protein level, and D-dimer were not associated with sCD163 or plaque among HIV-infected patients. CONCLUSIONS sCD163, a monocyte/macrophage activation marker, is increased in association with noncalcified coronary plaque in men with chronic HIV infection and low or undetectable viremia. These data suggest a potentially important role of chronic monocyte/macrophage activation in the development of noncalcified vulnerable plaque. CLINICAL TRIAL REGISTRATION NCT00455793.


JAMA | 2012

Arterial inflammation in patients with HIV

Sharath Subramanian; Ahmed Tawakol; Tricia H. Burdo; Suhny Abbara; Jeffrey Wei; Jayanthi Vijayakumar; Erin Corsini; Amr Abdelbaky; Markella V. Zanni; Udo Hoffmann; Kenneth C. Williams; Janet Lo; Steven Grinspoon

CONTEXT Cardiovascular disease is increased in patients with human immunodeficiency virus (HIV), but the specific mechanisms are unknown. OBJECTIVE To assess arterial wall inflammation in HIV, using 18fluorine-2-deoxy-D-glucose positron emission tomography (18F-FDG-PET), in relationship to traditional and nontraditional risk markers, including soluble CD163 (sCD163), a marker of monocyte and macrophage activation. DESIGN, SETTING, AND PARTICIPANTS A cross-sectional study of 81 participants investigated between November 2009 and July 2011 at the Massachusetts General Hospital. Twenty-seven participants with HIV without known cardiac disease underwent cardiac 18F-FDG-PET for assessment of arterial wall inflammation and coronary computed tomography scanning for coronary artery calcium. The HIV group was compared with 2 separate non-HIV control groups. One control group (n = 27) was matched to the HIV group for age, sex, and Framingham risk score (FRS) and had no known atherosclerotic disease (non-HIV FRS-matched controls). The second control group (n = 27) was matched on sex and selected based on the presence of known atherosclerotic disease (non-HIV atherosclerotic controls). MAIN OUTCOME MEASURE Arterial inflammation was prospectively determined as the ratio of FDG uptake in the arterial wall of the ascending aorta to venous background as the target-to-background ratio (TBR). RESULTS Participants with HIV demonstrated well-controlled HIV disease (mean [SD] CD4 cell count, 641 [288] cells/μL; median [interquartile range] HIV-RNA level, <48 [<48 to <48] copies/mL). All were receiving antiretroviral therapy (mean [SD] duration, 12.3 [4.3] years). The mean FRS was low in both HIV and non-HIV FRS-matched control participants (6.4; 95% CI, 4.8-8.0 vs 6.6; 95% CI, 4.9-8.2; P = .87). Arterial inflammation in the aorta (aortic TBR) was higher in the HIV group vs the non-HIV FRS-matched control group (2.23; 95% CI, 2.07-2.40 vs 1.89; 95% CI, 1.80-1.97; P < .001), but was similar compared with the non-HIV atherosclerotic control group (2.23; 95% CI, 2.07-2.40 vs 2.13; 95% CI, 2.03-2.23; P = .29). Aortic TBR remained significantly higher in the HIV group vs the non-HIV FRS-matched control group after adjusting for traditional cardiovascular risk factors (P = .002) and in stratified analyses among participants with undetectable viral load, zero calcium, FRS of less than 10, a low-density lipoprotein cholesterol level of less than 100 mg/dL (<2.59 mmol/L), no statin use, and no smoking (all P ≤ .01). Aortic TBR was associated with sCD163 level (P = .04) but not with C-reactive protein (P = .65) or D-dimer (P = .08) among patients with HIV. CONCLUSION Participants infected with HIV vs noninfected control participants with similar cardiac risk factors had signs of increased arterial inflammation, which was associated with a circulating marker of monocyte and macrophage activation.


AIDS | 2010

Increased prevalence of subclinical coronary atherosclerosis detected by coronary computed tomography angiography in HIV-infected men.

Janet Lo; Suhny Abbara; Leon Shturman; Anand Soni; Jeffrey Wei; Jose A. Rocha-Filho; Khurram Nasir; Steven Grinspoon

Objective: The degree of subclinical coronary atherosclerosis in HIV-infected patients is unknown. We investigated the degree of subclinical atherosclerosis and the relationship of traditional and nontraditional risk factors to early atherosclerotic disease using coronary computed tomography angiography. Design and methods: Seventy-eight HIV-infected men (age 46.5 ± 6.5 years and duration of HIV 13.5 ± 6.1 years, CD4 T lymphocytes 523 ± 282; 81% undetectable viral load), and 32 HIV-negative men (age 45.4 ± 7.2 years) with similar demographic and coronary artery disease (CAD) risk factors, without history or symptoms of CAD, were prospectively recruited. 64-slice multidetector row computed tomography coronary angiography was performed to determine prevalence of coronary atherosclerosis, coronary stenosis, and quantitative plaque burden. Results: HIV-infected men demonstrated higher prevalence of coronary atherosclerosis than non-HIV-infected men (59 vs. 34%; P = 0.02), higher coronary plaque volume [55.9 (0–207.7); median (IQR) vs. 0 (0–80.5) μl; P = 0.02], greater number of coronary segments with plaque [1 (0–3) vs. 0 (0–1) segments; P = 0.03], and higher prevalence of Agatston calcium score more than 0 (46 vs. 25%, P = 0.04), despite similar Framingham 10-year risk for myocardial infarction, family history of CAD, and smoking status. Among HIV-infected patients, Framingham score, total cholesterol, low-density lipoprotein, CD4/CD8 ratio, and monocyte chemoattractant protein 1 were significantly associated with plaque burden. Duration of HIV infection was significantly associated with plaque volume (P = 0.002) and segments with plaque (P = 0.0009) and these relationships remained significant after adjustment for age, traditional risk factors, or duration of antiretroviral therapy. A total of 6.5% (95% confidence interval 2–15%) of our study population demonstrated angiographic evidence of obstructive CAD (>70% luminal narrowing) as compared with 0% in controls. Conclusion: Young, asymptomatic, HIV-infected men with long-standing HIV disease demonstrate an increased prevalence and degree of coronary atherosclerosis compared with non-HIV-infected patients. Both traditional and nontraditional risk factors contribute to atherosclerotic disease in HIV-infected patients.


AIDS | 2012

Increased coronary atherosclerosis and immune activation in HIV-1 elite controllers.

Florencia Pereyra; Janet Lo; Virginia A. Triant; Jeffrey Wei; Maria J. Buzon; Kathleen V. Fitch; Janice Hwang; Jennifer H. Campbell; Tricia H. Burdo; Kenneth C. Williams; Suhny Abbara; Steven Grinspoon

HIV-1 elite controllers spontaneously maintain suppressed levels of viremia, but exhibit significant immune activation. We investigated coronary atherosclerosis by coronary computed tomography angiography (CTA) in elite controllers, nonelite controller, chronically HIV-1 infected, antiretroviral therapy (ART)-treated patients with undetectable viral load (‘chronic HIV’), and HIV-negative controls. Prevalence of atherosclerosis (78 vs. 42%, P < 0.05) and markers of immune activation were increased in elite controllers compared with HIV-negative controls. sCD163, a monocyte activation marker, was increased in elite controllers compared with chronic HIV-1 (P < 0.05) and compared with HIV-negative controls (P < 0.05). These data suggest a significant degree of coronary atherosclerosis and monocyte activation among elite controllers.


The Journal of Infectious Diseases | 2013

Noncalcified Coronary Atherosclerotic Plaque and Immune Activation in HIV-Infected Women

Kathleen V. Fitch; Suman Srinivasa; Suhny Abbara; Tricia H. Burdo; Kenneth C. Williams; Peace Eneh; Janet Lo; Steven Grinspoon

BACKGROUND Little is known about coronary plaque in human immunodeficiency virus (HIV)-infected women. METHODS Sixty HIV-infected and 30 non-HIV-infected women without symptoms or history of cardiovascular disease were recruited to assess coronary plaque with coronary computed tomographic angiography and immune activation. Data from 102 HIV-infected men and 41 non-HIV-infected male controls were compared. RESULTS HIV-infected women demonstrated significantly higher percentages of segments with noncalcified plaque (mean ± SD, 74% ± 28% vs 23% ± 39% compared to female control subjects; median [interquartile range], 75% [63%-100%] vs 0% [0%-56%]; P = .007) and more segments with noncalcified plaque (mean ± SD, 0.92 ± 1.48 vs 0.40 ± 1.44; median [interquartile range], 0 [0-2] vs 0 [0-0]; P = .04). Immune activation parameters, including soluble CD163 (sCD163; P = .006), CXCL10 (P = .002), and percentages of CD14(+)CD16(+) monocytes (P = .008), were higher in HIV-infected women than in female control subjects, but no differences were seen in general inflammatory markers. Among HIV-infected women with noncalcified coronary plaque, sCD163 levels were significantly higher than in HIV-infected women without noncalcified plaque (P = .04). In multivariate modeling for sCD163 levels among male and female subjects, significant effects of HIV (P < .0001), age (P = .002), and sex (P = .0002) were seen. CONCLUSIONS Young, asymptomatic, HIV-infected women, demonstrate increased noncalcified coronary plaque and increased immune activation, particularly monocyte activation. Independent effects of sex, HIV status, and aging on immune activation may contribute to cardiovascular disease in this population. CLINICAL TRIALS REGISTRATION NCT00455793.


The Lancet HIV | 2015

Effects of statin therapy on coronary artery plaque volume and high-risk plaque morphology in HIV-infected patients with subclinical atherosclerosis: a randomised, double-blind, placebo-controlled trial.

Janet Lo; Michael T. Lu; Ezinne J. Ihenachor; Jeffrey Wei; Sara E. Looby; Kathleen V. Fitch; Jinhee Oh; Chloe O. Zimmerman; Janice Hwang; Suhny Abbara; Jorge Plutzky; Gregory K. Robbins; Ahmed Tawakol; Udo Hoffmann; Steven Grinspoon

BACKGROUND HIV-infected patients have a high risk of myocardial infarction. We aimed to assess the ability of statin treatment to reduce arterial inflammation and achieve regression of coronary atherosclerosis in this population. METHODS In a randomised, double-blind, placebo-controlled trial, 40 HIV-infected participants with subclinical coronary atherosclerosis, evidence of arterial inflammation in the aorta by fluorodeoxyglucose (FDG)-PET, and LDL-cholesterol concentration of less than 3.37 mmol/L (130 mg/dL) were randomly assigned (1:1) to 1 year of treatment with atorvastatin or placebo. Randomisation was by the Massachusetts General Hospital (MGH) Clinical Research Pharmacy with a permuted-block algorithm, stratified by sex with a fixed block size of four. Study codes were available only to the MGH Research Pharmacy and not to study investigators or participants. The prespecified primary endpoint was arterial inflammation as assessed by FDG-PET of the aorta. Additional prespecified endpoints were non-calcified and calcified plaque measures and high risk plaque features assessed with coronary CT angiography and biochemical measures. Analysis was done by intention to treat with all available data and without imputation for missing data. The trial is registered with ClinicalTrials.gov, number NCT00965185. FINDINGS The study was done from Nov 13, 2009, to Jan 13, 2014. 19 patients were assigned to atorvastatin and 21 to placebo. 37 (93%) of 40 participants completed the study, with equivalent discontinuation rates in both groups. Baseline characteristics were similar between groups. After 12 months, change in FDG-PET uptake of the most diseased segment of the aorta was not different between atorvastatin and placebo, but technically adequate results comparing longitudinal changes in identical regions could be assessed in only 21 patients (atorvastatin Δ -0.03, 95% CI -0.17 to 0.12, vs placebo Δ -0.06, -0.25 to 0.13; p=0.77). Change in plaque could be assessed in all 37 people completing the study. Atorvastatin reduced non-calcified coronary plaque volume relative to placebo: median change -19.4% (IQR -39.2 to 9.3) versus 20.4% (-7.1 to 94.4; p=0.009, n=37). The number of high-risk plaques was significantly reduced in the atorvastatin group compared with the placebo group: change in number of low attenuation plaques -0.2 (95% CI -0.6 to 0.2) versus 0.4 (0.0, 0.7; p=0.03; n=37); and change in number of positively remodelled plaques -0.2 (-0.4 to 0.1) versus 0.4 (-0.1 to 0.8; p=0.04; n=37). Direct LDL-cholesterol (-1.00 mmol/L, 95% CI -1.38 to 0.61 vs 0.30 mmol/L, 0.04 to 0.55, p<0.0001) and lipoprotein-associated phospholipase A2 (-52.2 ng/mL, 95% CI -70.4 to -34.0, vs -13.3 ng/mL, -32.8 to 6.2; p=0.005; n=37) decreased significantly with atorvastatin relative to placebo. Statin therapy was well tolerated, with a low incidence of clinical adverse events. INTERPRETATION No significant effects of statin therapy on arterial inflammation of the aorta were seen as measured by FDG-PET. However, statin therapy reduced non-calcified plaque volume and high-risk coronary plaque features in HIV-infected patients. Further studies should assess whether reduction in high-risk coronary artery disease translates into effective prevention of cardiovascular events in this at-risk population. FUNDING National Institutes of Health, Harvard Clinical and Translational Science Center, National Center for Research Resources.


JAMA | 2008

Low-Dose Physiological Growth Hormone in Patients With HIV and Abdominal Fat Accumulation: A Randomized Controlled Trial

Janet Lo; Sung Min You; Bridget Canavan; James Liebau; Greg Beltrani; Polyxeni Koutkia; Linda C. Hemphill; Hang Lee; Steven Grinspoon

CONTEXT Antiretroviral therapy can be associated with visceral adiposity and metabolic complications, increasing cardiovascular risk, and reduced growth hormone (GH) secretion may be a contributing factor. OBJECTIVE To investigate the effects of low-dose physiological GH administration on body composition, glucose, and cardiovascular parameters in patients with human immunodeficiency virus (HIV) having abdominal fat accumulation and relative GH deficiency. DESIGN, SETTING, AND PATIENTS A randomized, double-blind, placebo-controlled trial of 56 patients with HIV, abdominal fat accumulation, and reduced GH secretion (peak GH <7.5 ng/mL) conducted at a US academic medical center between November 2003 and October 2007. INTERVENTION Patients were randomly assigned to receive either subcutaneous GH or matching placebo titrated to the upper quartile of normal insulinlike growth factor 1 (IGF-1) range for 18 months. Starting dose was 2 microg/kg/d and increased to maximum dose of 6 microg/kg/d (average dose, 0.33 mg/d). MAIN OUTCOME MEASURES Change in body composition assessed by computed tomographic scan and dual-energy x-ray absorptiometry. Secondary outcomes included glucose, IGF-1, blood pressure (BP), and lipids. Treatment effect was the difference in the change between GH and placebo groups, using all available data. RESULTS Fifty-five patients (26 with GH and 29 with placebo) were included in the safety analyses and 52 patients (25 with GH and 27 with placebo) were included in the efficacy analyses. Visceral adipose tissue area (treatment effect [last-value-carried-forward analysis {n = 56}, -19 cm(2); 95% confidence interval {CI}, -37 to -0.3 cm(2)], -19 cm(2); 95% CI, -38 to -0.5 cm(2); P = .049); trunk fat (-0.8 kg; 95% CI, -1.5 to -0.04 kg; P = .04); diastolic BP (-7 mm Hg; 95% CI, -11 to -2 mm Hg; P = .006); and triglycerides (-7 mg/dL, P = .002) improved but 2-hour glucose levels on glucose tolerance testing increased in the GH group vs the placebo group (treatment effect, 22 mg/dL; 95% CI, 6-37 mg/dL; P = .009). The IGF-1 levels increased (treatment effect, 129 ng/mL; 95% CI, 95-164 ng/mL; P < .001). Adverse events were not increased for GH vs placebo (23%; 95% CI, 9%-44% vs 28%; 95% CI, 13%-47%; P = .70). CONCLUSIONS In HIV-associated abdominal fat accumulation and relative GH deficiency, low-dose GH received for 18 months resulted in significantly reduced visceral fat and truncal obesity, triglycerides, and diastolic BP, but 2-hour glucose levels on glucose tolerance testing were increased. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00100698.


AIDS | 2013

Increased coronary atherosclerotic plaque vulnerability by coronary computed tomography angiography in HIV-infected men.

Markella V. Zanni; Suhny Abbara; Janet Lo; Bryan Wai; David Hark; Eleni Marmarelis; Steven Grinspoon

Objective:Among HIV-infected patients, high rates of myocardial infarction (MI) and sudden cardiac death have been observed. Exploring potential underlying mechanisms, we used multidetector spiral coronary computed tomography angiography (coronary CTA) to compare atherosclerotic plaque morphology in HIV-infected patients and non-HIV-infected controls. Methods:Coronary atherosclerotic plaques visualized by CTA in HIV-infected (101) and non-HIV-infected (41) men without clinically apparent heart disease matched on cardiovascular risk factors were analyzed for three vulnerability features: low attenuation, positive remodeling, and spotty calcification. Results:Ninety-five percent of HIV-infected patients were receiving ART (median duration 7.9 years) and had well controlled disease (median CD4 cell count, 473 cells/&mgr;l; median HIV RNA <50 copies/ml). Age and traditional cardiovascular risk factors were similar in HIV-infected patients and controls. Among the HIV-infected (versus control) group, there was a higher prevalence of patients with at least one: low attenuation plaque (22.8 versus 7.3%, P = 0.02), positively remodeled plaque (49.5 versus 31.7%, P = 0.05) and high-risk 3-feature plaque (7.9 versus 0%, P = 0.02). Moreover, patients in the HIV-infected (versus control) group demonstrated a higher number of low attenuation plaques (P = 0.01) and positively remodeled plaques (P = 0.03) per patient. Conclusion:Our data demonstrate an increased prevalence of vulnerable plaque features among relatively young HIV-infected patients. Differences in coronary atherosclerotic plaque morphology – namely, increased vulnerable plaque among HIV-infected patients – are here for the first time reported and may contribute to increased rates of MI and sudden cardiac death in this population.


AIDS | 2007

Dietary fat intake and relationship to serum lipid levels in HIV-infected patients with metabolic abnormalities in the HAART era.

Tisha Joy; Hester M Keogh; Colleen Hadigan; Hang Lee; Sara E. Dolan; Kathleen V. Fitch; James Liebau; Janet Lo; Stine Johnsen; Jane Hubbard; Ellen J. Anderson; Steven Grinspoon

Objective:To evaluate dietary intake and its relationship to lipid parameters in HIV-infected patients with metabolic abnormalities. Method:We prospectively determined dietary intake (4-day food records or 24-h recall) in 356 HIV-infected patients and 162 community-derived HIV-negative controls evaluated for metabolic studies between 1998–2005. Differences in dietary intake between HIV-infected patients and non-HIV-infected controls, in relation to the established 2005 USDA (United States Department of Agriculture) Recommended Dietary Guidelines, were determined. The relationship between dietary fat intake and serum lipid levels among HIV-infected individuals was also evaluated. Results:Assessment of dietary intake in this group of HIV-infected patients demonstrated increased intake of total dietary fat (P < 0.05), saturated fat (P = 0.006), and cholesterol (P = 0.006) as well as a greater percentage of calories from saturated fat (P = 0.002) and from trans fat (P = 0.02), despite similar caloric intake to the control individuals. A significantly higher percentage of HIV-infected patients were above the 2005 USDA Recommended Dietary Guidelines for saturated fat (> 10%/day) (76.0% HIV vs. 60.9% controls, P = 0.003), and cholesterol (> 300 mg/day) (49.7% HIV vs. 37.9% controls, P = 0.04). Saturated fat intake was strongly associated with triglyceride level [triglyceride level increased 8.7 mg/dl (parameter estimate) per gram of increased saturated fat intake, P = 0.005] whereas total fat was inversely associated with triglyceride level [triglyceride level decreased 3.0 mg/dl (parameter estimate) per gram of increased total fat intake, P = 0.02] among HIV-infected individuals. Conclusions:Increased intake of saturated fat is seen and contributes to hypertriglyceridemia among HIV-infected patients who have developed metabolic abnormalities. Increased saturated fat intake should be targeted for dietary modification in this population.


Clinical Endocrinology | 2010

Gender effects on cardiac valvular function in hyperprolactinaemic patients receiving cabergoline: a retrospective study

Lisa B. Nachtigall; Elena Valassi; Janet Lo; David McCarty; Jonathan Passeri; Beverly M. K. Biller; Karen K. Miller; Andrea L. Utz; Steven Grinspoon; Elizabeth A. Lawson; Anne Klibanski

Background  Ergot‐derived dopamine agonists are associated with increased risk of valvular dysfunction in Parkinson’s disease. The risk of valvular disease associated with lower doses of cabergoline used to treat prolactinomas remains controversial.

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Suhny Abbara

University of Texas Southwestern Medical Center

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