Undiagnosed SARS-CoV-2 seropositivity during the first 6 months of the COVID-19 pandemic in the United States.

Asymptomatic SARS-CoV-2 infection and delayed implementation of diagnostics have led to poorly defined viral prevalence rates in the United States and elsewhere. To address this, we analyzed seropositivity in 9089 adults in the United States who had not been diagnosed previously with COVID-19. Individuals with characteristics that reflected the U.S. population (n = 27,716) were selected by quota sampling from 462,949 volunteers. Enrolled participants (n = 11,382) provided medical, geographic, demographic, and socioeconomic information and dried blood samples. Survey questions coincident with the Behavioral Risk Factor Surveillance System survey, a large probability-based national survey, were used to adjust for selection bias. Most blood samples (88.7%) were collected between 10 May and 31 July 2020 and were processed using ELISA to measure seropositivity (IgG and IgM antibodies against SARS-CoV-2 spike protein and the spike protein receptor binding domain). The overall weighted undiagnosed seropositivity estimate was 4.6% (95% CI, 2.6 to 6.5%), with race, age, sex, ethnicity, and urban/rural subgroup estimates ranging from 1.1% to 14.2%. The highest seropositivity estimates were in African American participants; younger, female, and Hispanic participants; and residents of urban centers. These data indicate that there were 4.8 undiagnosed SARS-CoV-2 infections for every diagnosed case of COVID-19, and an estimated 16.8 million infections were undiagnosed by mid-July 2020 in the United States.

Mapping a Pandemic: SARS-CoV-2 Seropositivity in the United States.

Asymptomatic SARS-CoV-2 infection and delayed implementation of diagnostics have led to poorly defined viral prevalence rates. To address this, we analyzed seropositivity in US adults who have not previously been diagnosed with COVID-19. Individuals with characteristics that reflect the US population (n = 11,382) and who had not previously been diagnosed with COVID-19 were selected by quota sampling from 241,424 volunteers (ClinicalTrials.gov NCT04334954). Enrolled participants provided medical, geographic, demographic, and socioeconomic information and 9,028 blood samples. The majority (88.7%) of samples were collected between May 10th and July 31st, 2020. Samples were analyzed via ELISA for anti-Spike and anti-RBD antibodies. Estimation of seroprevalence was performed by using a weighted analysis to reflect the US population. We detected an undiagnosed seropositivity rate of 4.6% (95% CI: 2.6 - 6.5%). There was distinct regional variability, with heightened seropositivity in locations of early outbreaks. Subgroup analysis demonstrated that the highest estimated undiagnosed seropositivity within groups was detected in younger participants (ages 18-45, 5.9%), females (5.5%), Black/African American (14.2%), Hispanic (6.1%), and Urban residents (5.3%), and lower undiagnosed seropositivity in those with chronic diseases. During the first wave of infection over the spring/summer of 2020 an estimate of 4.6% of adults had a prior undiagnosed SARS-CoV-2 infection. These data indicate that there were 4.8 (95% CI: 2.8-6.8) undiagnosed cases for every diagnosed case of COVID-19 during this same time period in the United States, and an estimated 16.8 million undiagnosed cases by mid-July 2020.

Metabolic Changes in Chronic Hepatitis C Patients Who Carry IFNL4-ΔG and Achieve Sustained Virologic Response With Direct-Acting Antiviral Therapy.

BACKGROUND: Clearance of hepatitis C virus (HCV) results in rapid changes in metabolic parameters early in direct-acting antiviral (DAA) therapy. Long-term changes after sustained virologic response (SVR) remain unknown. METHODS: We investigated longitudinal changes in metabolic and inflammatory outcomes in chronic hepatitis C (CHC) patients: low-density lipoprotein (LDL), high-density lipoprotein, triglycerides, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) using a general linear model for repeated measurements at 5 clinical time points and by human immunodeficiency virus (HIV) coinfection and IFNL4 genotype. RESULTS: The mean LDL increased markedly during DAA therapy (pre-DAA, 86.6 to DAA, 107.4 mg/dL; P < .0001), but then it decreased to 97.7 mg/dL by post-SVR year 1 (P < .001 compared with DAA; P = .0013 compared with SVR). In patients who carry the IFNL4-ΔG allele, mean LDL increased during treatment, then decreased at post-SVR year 1; however, in patients with TT/TT, genotype did not change during and after DAA treatment. The mean ALT and AST normalized rapidly between pre-DAA and DAA, whereas only mean ALT continued to decrease until post-SVR. Metabolic and inflammatory outcomes were similar by HIV-coinfection status. CONCLUSIONS: Changes in LDL among CHC patients who achieved SVR differed by IFNL4 genotype, which implicates the interferon-λ4 protein in metabolic changes observed in HCV-infected patients.

Adoptive lymphocyte transfer to an HIV-infected progressor from an elite controller.

BACKGROUNDHIV-infected patients with poor virologic control and multidrug-resistant virus have limited therapeutic options. The current study was undertaken to evaluate the safety, immunologic effects, and antiviral activity of peripheral lymphocytes transferred from an elite controller, whose immune system is able to control viral replication without antiretroviral medications, to an HLA-B*2705-matched progressor.METHODSApproximately 22 billion cells were collected from an elite controller by lymphapheresis and infused within 6 hours into a recipient with a preinfusion CD4+ T cell count of 10 cells/µL (1%) and HIV plasma viral load of 114,993 copies/mL.RESULTSDonor cells were cleared from the recipient's peripheral blood by day 8. A transient decrease in viral load to 58,421 (day 3) was followed by a rebound to 702,972 (day 6) before returning to baseline values by day 8. The decreased viral load was temporally associated with peak levels of donor T cells, including CD8+ T cells that had high levels of expression of Ki67, perforin, and granzyme B. Notably, recipient CD8+ T cells also showed increased expression of these markers, especially in HIV-specific tetramer-positive cells.CONCLUSIONThese results suggest that the adoptive transfer of lymphocytes from an HIV-infected elite controller to an HIV-infected patient with progressive disease may be able to perturb the immune system of the recipient in both positive and negative ways.TRIAL REGISTRATIONClinicalTrials.gov NCT00559416.FUNDINGIntramural Research Programs of the US NIH Clinical Center and the National Institute of Allergy and Infectious Diseases (NIAID); the National Cancer Institute.

Long-term changes in hepatic fibrosis following hepatitis C viral clearance in patients with and without HIV.

BACKGROUND: While acute changes in hepatic fibrosis are recognized shortly after achieving sustained virological response (SVR) using direct-acting antiviral therapies, long-term outcomes for the growing population of successfully treated patients with HCV remain uncertain. The aim of this study is to characterize long-term changes in fibrosis following SVR in patients with and without HIV and to identify potential factors associated with progression or regression of fibrosis. METHODS: We completed a prospective longitudinal study of 162 subjects with HCV (34% HIV-coinfected) with pre-treatment fibrosis stage determined by liver biopsy and post-SVR transient elastography. Progression of fibrosis was defined as a two-stage or greater increase in fibrosis, while regression was defined as a two-stage or greater decrease at last follow-up. The median duration of follow-up was 4.1 years. RESULTS: Fibrosis progression occurred in 4% of subjects while regression occurred in 7% and 89% were stable and did not differ by HIV coinfection. Fibrosis progression was associated with increased body mass index (BMI), hepatic steatosis and smoking pack-years. In a multivariable logistic regression, HIV coinfection (P=0.009), lower steatosis score (P<0.05) and lower smoking pack-years (P=0.0007) were associated with a lower fibrosis score at last follow-up. CONCLUSIONS: We identify potentially important relationships between BMI, hepatic steatosis and smoking, and changes in hepatic fibrosis post-SVR in patients with and without HIV coinfection. Attention to modifiable risk factors such as body weight and smoking may reduce the risk of liver disease progression in the growing population of successfully treated chronic HCV patients.

Immunological recovery in T-cell activation after sustained virologic response among HIV positive and HIV negative chronic Hepatitis C patients.

BACKGROUND: Rapid decreases in activated CD4+ and CD8+ (HLA-DR + and CD38+ co-expressed) T-lymphocytes have been described within 1-2 weeks of initiating direct-acting antiviral (DAA) therapy among chronic Hepatitis C (CHC) patients. However, it is not known whether these changes are maintained past sustained virologic response (SVR), particularly in those who are HIV/HCV-coinfected. METHODS: We investigated the changes in immune parameters of T-lymphocytes from pre-DAA therapy to post-SVR among HIV negative and HIV positive patients with CHC. Repeated measurements of activated CD4+ and CD8+ T cells were analyzed by flow cytometry at pre-DAA therapy, DAA therapy, end of treatment, SVR, and post-SVR. A general linear model for repeated measurements was used to estimate the mean outcome at each timepoint and change between timepoints. RESULTS: HCV-monoinfected (n = 161) and HIV/HCV-coinfected (n = 59) patients who achieved SVR with DAA therapy were predominately middle aged, male, black, and non-cirrhotic. At pre-DAA therapy, HCV-monoinfected patients had significantly higher CD4+ T cells and CD4+:CD8+ T-cell ratio, while significantly lower CD8+ and activated CD4+ and CD8+ T cells compared to HIV/HCV-coinfected patients (p < 0.0001). HCV-monoinfected and HIV/HCV-coinfected patients had a significant mean decrease from pre-DAA therapy to post-SVR year 1 for activated CD4+ (HCV-monoinfected: 4.8-3.9%, p < 0.0001; HIV/HCV-coinfected: 6.6-4.5%, p < 0.0001) and activated CD8+ T cells (HCV-monoinfected V: 13.8-11.8%, p = 0.0002; HIV/HCV-coinfected: 18.0-12.4%, p < 0.0001). CONCLUSION: This longitudinal study showed CHC patients treated with DAA therapy had continued decrease of T-lymphocytes from start of DAA therapy to after achievement of SVR suggesting improvement as HCV clearance normalizes activated T-cell phenotype.

Increased Prevalence of Hepatic Steatosis in Young Adults With Lifelong HIV.

Little is known about the effects of lifelong human immunodeficiency virus (HIV) or antiretroviral therapy on hepatic steatosis and fibrosis. Using transient elastography, we evaluated 46 young adults with lifelong HIV and 20 matched HIV-negative controls. Steatosis was present in 33% of persons with HIV and only 10% of controls (P = .04). Hepatic fibrosis scores were not elevated and did not differ between groups. Metabolic parameters, particularly increased waist circumference, and not HIV-specific factors, were significantly associated with steatosis. While this finding should be examined in larger cohorts, modifiable metabolic disturbances may be important targets to optimize liver health in this population.

Testosterone in Men With Chronic Hepatitis C Infection and After Hepatitis C Viral Clearance.

BACKGROUND: Hepatitis C virus (HCV) and hepatic dysfunction are associated with low total and free testosterone (TT and FT) and high sex hormone-binding globulin (SHBG). However, little is known about changes in testosterone following successful HCV treatment. METHODS: We evaluated testosterone levels and the prevalence of low testosterone in a cohort of 327 men with chronic HCV infection (human immunodeficiency virus [HIV] coinfection = 150) and in a subset of 85 men with testosterone levels obtained pre-HCV treatment and after sustained virologic response (SVR). Median follow-up was 36 months. RESULTS: Participants with active HCV at baseline had higher TT (P < .0001) and SHBG (P < .0001) compared with participants who had achieved SVR, whereas FT did not differ. Low TT (<10.4 nmol/L) was more prevalent in participants with SVR compared with active HCV (P = .002); however, low FT (<0.1735 nmol/L) was common (50% active HCV, 43% SVR) and did not different between groups. For participants with longitudinal determinations, TT and SHBG decreased significantly (P < .0001) while FT remained unchanged post-SVR. Low FT persisted after SVR (pre-treatment 58%, post-SVR 54%, P = .72). HIV status and change in aspartate aminotrasferase-to-platelet ratio were significant independent predictors of change in FT following SVR. CONCLUSIONS: During active HCV infection, testosterone deficiency may be masked due to elevated SHBG. Despite improvements in SHBG following SVR, low FT was common and persisted after HCV clearance, indicating the need for enhanced awareness and screening using estimates of FT following successful treatment of chronic HCV. CLINICAL TRIALS REGISTRATION: NCT01350648.

Carotid magnetic resonance imaging in persons living with HIV and 10-year atherosclerotic cardiovascular disease risk score.

BACKGROUND: Both traditional and HIV-specific risk factors contribute to greater incidence of cardiovascular disease in persons living with HIV (PLWH). Using state-of-the-art, high-resolution magnetic resonance (MR) imaging of the common carotid arteries, this study aimed to evaluate the relationship between carotid vessel wall thickness (c-VWT) and atherosclerotic cardiovascular disease (ASCVD) risk score in PLWH. METHODS: Cross-sectional determinations of c-VWT using MR imaging in virally suppressed PLWH without known cardiovascular disease (n=32) and matched controls (n=13) were completed. Clinical data, including ASCVD risk and c-VWT, were compared between groups and regression analyses performed to identify predictors of c-VWT. RESULTS: PLWH had significantly higher c-VWT (1.15 ±0.11 mm versus 1.08 ±0.08 mm; P=0.02) as well as higher diastolic blood pressure compared to controls, but exhibited no differences in 10-year ASCVD risk score, systolic blood pressure or smoking. Ten-year ASCVD risk score (r=0.53, P-value =0.0002), age (r=0.30, P-value <0.05), triglycerides (r=0.33, P-value =0.03) and waist circumference (r=0.36, P-value =0.02) were significantly associated with increased c-VWT. Among PLWH, c-VWT did not differ by protease inhibitor use. In a multivariate regression analysis, ASCVD risk score was the only variable significantly associated with c-VWT (P-value =0.02), whereas, HIV status was not. CONCLUSIONS: In this cross-sectional study MR imaging demonstrated that c-VWT, a known marker for CVD risk, was increased in PLWH relative to controls, and that 10-year ASCVD risk was closely related to c-VWT, independent of HIV infection. Our data suggest that traditional cardiovascular disease risk factors in PLWH are adequately captured in the ASCVD risk score which was closely associated with subclinical carotid disease.

No Improvement in Hemoglobin A1c Following Hepatitis C Viral Clearance in Patients With and Without HIV.

Hepatitis C clearance with directly acting antivirals (DAAs) may be associated with acute decreases in hemoglobin A1c (HbA1c). We prospectively evaluated 251 chronic hepatitis C virus (HCV)-infected subjects (31% human immunodeficiency virus [HIV] positive) pre- and post-DAA therapy (median follow-up 28 months). Changes in HbA1c and glucose were minimal and did not differ by sustained virologic response (SVR), HIV, diabetes, or fibrosis. Following SVR, mean change in HbA1c was -0.022 ± 0.53%; however, total and low-density lipoprotein cholesterol increased significantly. Subjects with HIV had smaller transaminase reductions after SVR. Sustained benefits in glycemia were not identified following HCV clearance irrespective of HIV, diabetes, or fibrosis stage, whereas lipid alterations may warrant further investigation.

Pioglitazone for Hepatic Steatosis in HIV/Hepatitis C Virus Coinfection.

Chronic hepatitis C infection frequently coexists with human immunodeficiency virus (HIV) and together are associated with increased hepatic steatosis. Steatosis is a risk factor for progression of liver disease and may persist despite a sustained virologic response to hepatitis C treatment. Therefore, therapies to target hepatic steatosis are important for individuals with HIV and hepatitis C virus (HCV) coinfection. We completed a 48-week, randomized, double-blind, placebo-controlled trial of pioglitazone (45 mg/day) in 13 subjects with HIV/HCV coinfection. The primary outcome variable was hepatic fat content, measured by magnetic resonance spectroscopy (MRS) imaging. Individuals randomized to pioglitazone had a significant decrease in hepatic fat content measured by MRS from baseline (15.1 ± 7.0%) to week 48 (7.6 ± 3.9%), with a mean difference of -7.4% (p = 0.02, n = 5). There was no significant change in hepatic fat content with placebo. Glycemic control as measured by oral glucose challenge improved significantly with pioglitazone (p = 0.047). Though not statistically significant, there were trends toward improved alanine aminotransferase (ALT) and histopathologic grade of steatosis in subjects who received pioglitazone. Pioglitazone was well tolerated and no one discontinued due to side effects. This study demonstrates that 48 weeks of pioglitazone therapy, and not placebo, results in significant reductions in hepatic fat content as measured by MRS in subjects with HIV and HCV coinfection and hepatic steatosis. This small study shows that pioglitazone helps ameliorate steatosis in the context of HIV/HCV coinfection.

Influence of Panax ginseng on the steady state pharmacokinetic profile of lopinavir-ritonavir in healthy volunteers.

STUDY OBJECTIVE: Panax ginseng has been shown in preclinical studies to modulate cytochrome P450 enzymes involved in the metabolism of HIV protease inhibitors. Therefore, the purpose of this study was to determine the influence of P. ginseng on the pharmacokinetics of the HIV protease inhibitor combination lopinavir-ritonavir (LPV-r) in healthy volunteers. DESIGN: Single-sequence, open-label, single-center pharmacokinetic investigation. SETTING: Government health care facility. SUBJECTS: Twelve healthy human volunteers. MEASUREMENTS AND MAIN RESULTS: Twelve healthy volunteers received LPV-r (400-100 mg) twice/day for 29.5 days. On day 15 of LPV-r administration, serial blood samples were collected over 12 hours for determination of lopinavir and ritonavir concentrations. On study day 16, subjects began taking P. ginseng 500 mg twice/day, which they continued for 2 weeks in combination with LPV-r. On day 30 of LPV-r administration, serial blood samples were again collected over 12 hours for determination of lopinavir and ritonavir concentrations. Lopinavir and ritonavir pharmacokinetic parameter values were determined using noncompartmental methods, and preadministration and postadministration ginseng values were compared using a Student t test, where p<0.05 was accepted as statistically significant. CONCLUSION: Neither lopinavir nor ritonavir steady-state pharmacokinetics were altered by 2 weeks of P. ginseng administration to healthy human volunteers. Thus, a clinically significant interaction between P. ginseng and LPV-r is unlikely to occur in HIV-infected patients who choose to take these agents concurrently. It is also unlikely that P. ginseng will interact with other ritonavir-boosted protease inhibitor combinations, although confirmatory data are necessary.

CXCR4/IgG-expressing plasma cells are associated with human gastrointestinal tissue inflammation.

BACKGROUND: We previously reported abnormalities in circulating B cells in patients with chronic granulomatous disease (CGD) and those with HIV infection. Gastrointestinal complications are common to both diseases and likely involve perturbation of immune cells, including plasma cells (PCs). IgA is the most abundant immunoglobulin in the human body, with roles in protection and maintenance of intestinal homeostasis. IgA is produced primarily by PCs residing in mucosal tissues that are also thought to circulate in the blood. OBJECTIVE: We sought to characterize and compare PCs in patients with infectious (HIV) and noninfectious (CGD and Crohn disease) diseases that have been associated with intestinal inflammation. METHODS: Phenotypic and transcriptional analyses were performed on cells isolated from the blood and colon. RESULTS: IgA-secreting CCR10-expressing PCs predominated in the guts of healthy subjects, whereas in patients with HIV, CGD, and Crohn disease, there was a significant increase in the proportion of IgG-secreting PCs. Where intestinal inflammation was present, IgG-secreting PCs expressed reduced levels of CCR10 and increased levels of CXCR4. The intensity of CXCR4 expression correlated with the frequency of IgG-expressing PCs and the frequency of CXCR4(+)/IgG(+) PCs was associated with the severity of intestinal inflammatory disease yet distinct from PCs and plasmablasts circulating in the blood. CONCLUSIONS: These findings suggest that regardless of the underlying disease, the presence of CXCR4(+)/IgG(+) PCs in the gut is a strong yet localized indicator of intestinal inflammation. Furthermore, our findings suggest that CXCR4(+)/IgG(+) PCs might play a role in immune cell homeostasis during inflammatory processes of the gut.

Influence of low-dose ritonavir with and without darunavir on the pharmacokinetics and pharmacodynamics of inhaled beclomethasone.

OBJECTIVE: To identify an alternative inhaled corticosteroid to fluticasone propionate that can be safely coadministered with HIV protease inhibitors, the safety and pharmacokinetics of beclomethasone dipropionate (BDP) and its active metabolite, beclomethasone 17-monopropionate (17-BMP), in combination with ritonavir (RTV) and darunavir/ritonavir (DRV/r) were assessed. DESIGN: Open-label, prospective, randomized pharmacokinetic and pharmacodynamic study in healthy volunteers. METHODS: Thirty healthy volunteers received inhaled 160 µg bid BDP for 14 days and were then randomized (1:1:1) into 3 groups: group 1 (control) remained on BDP alone for 28 days, group 2 received 100 mg bid BDP + RTV for 28 days, and group 3 received 600/100 mg bid BDP + DRV/r for 28 days. Pharmacokinetic sampling for 17-BMP was performed on days 14 and 28, and pharmacokinetic parameter values were compared within patients and between groups. Cortisol stimulation testing was also performed on days 1, 14, 28, and 42 and compared within and between groups. RESULTS: Geometric mean ratios (day 28:day 14) (90% confidence interval) for 17-BMP area under the concentration-time curve in groups 1, 2, and 3, respectively, were 0.93 (0.81 to 1.06, P = 0.27), 2.08 (1.52 to 2.65, P = 0.006), and 0.89 (0.68 to 1.09, P = 0.61). There were no significant reductions in serum cortisol levels within or between groups (P > 0.05). CONCLUSIONS: DRV/r did not increase 17-BMP exposure, whereas RTV alone produced a statistically significant but clinically inconsequential 2-fold increase in 17-BMP exposure. Adrenal suppression was not observed in any of the study groups. These data suggest that BDP can be safely coadministered with DRV/r and likely other RTV-boosted protease inhibitors.

Comprehensive analysis of unique cases with extraordinary control over HIV replication.

True long-term nonprogressors (LTNPs)/elite controllers (ECs) maintain durable control over HIV replication without antiretroviral therapy. Herein we describe 4 unique persons who were distinct from conventional LTNPs/ECs in that they had extraordinarily low HIV burdens and comparatively weak immune responses. As a group, typical LTNPs/ECs have unequivocally reactive HIV-1 Western blots, viral loads below the lower threshold of clinical assays, low levels of persistent viral reservoirs, an over-representation of protective HLA alleles, and robust HIV-specific CD8(+) T-cell responses. The 4 unique cases were distinguished from typical LTNPs/ECs based on weakly reactive Western blots, undetectable plasma viremia by a single copy assay, extremely low to undetectable HIV DNA levels, and difficult to isolate replication-competent virus. All 4 had at least one protective HLA allele and CD8(+) T-cell responses that were disproportionately high for the low antigen levels but comparatively lower than those of typical LTNPs/ECs. These unique persons exhibit extraordinary suppression over HIV replication, therefore, higher-level control than has been demonstrated in previous studies of LTNPs/ECs. Additional insight into the full spectrum of immune-mediated suppression over HIV replication may enhance our understanding of the associated mechanisms, which should inform the design of efficacious HIV vaccines and immunotherapies.

Influence of Panax ginseng on cytochrome P450 (CYP)3A and P-glycoprotein (P-gp) activity in healthy participants.

A number of herbal preparations have been shown to interact with prescription medications secondary to modulation of cytochrome P450 (CYP) and/or P-glycoprotein (P-gp). The purpose of this study was to determine the influence of Panax ginseng on CYP3A and P-gp function using the probe substrates midazolam and fexofenadine, respectively. Twelve healthy participants (8 men) completed this open-label, single-sequence pharmacokinetic study. Healthy volunteers received single oral doses of midazolam 8 mg and fexofenadine 120 mg, before and after 28 days of P ginseng 500 mg twice daily. Midazolam and fexofenadine pharmacokinetic parameter values were calculated and compared before and after P ginseng administration. Geometric mean ratios (postginseng/preginseng) for midazolam area under the concentration-time curve from zero to infinity (AUC(0-∞)), half-life (t(1/2)), and maximum concentration (C(max)) were significantly reduced at 0.66 (0.55-0.78), 0.71 (0.53-0.90), and 0.74 (0.56-0.93), respectively. Conversely, fexofenadine pharmacokinetics were unaltered by P ginseng administration. Based on these results, P ginseng appeared to induce CYP3A activity in the liver and possibly the gastrointestinal tract. Patients taking P ginseng in combination with CYP3A substrates with narrow therapeutic ranges should be monitored closely for adequate therapeutic response to the substrate medication.

Lack of compartmentalization of HIV-1 quasispecies between the gut and peripheral blood compartments.

Compartmental differences in human immunodeficiency virus type 1 (HIV-1) between the gut and peripheral blood and within the gut were examined. Biopsy specimens from the colon and ileum and peripheral blood samples were collected from chronically HIV-1-infected individuals. HIV-1 envelope sequences were examined from cell-associated DNA and RNA and virion RNA. Phylogenetic analysis revealed no evidence of compartmentalization of HIV-1 between the gut and peripheral blood and within the gut (colon and ileum). HIV-1 sequences detected in the gut were transcriptionally active and were also found in peripheral blood from matching time points, providing evidence of ongoing virus production in the gut and equilibrium of HIV-1 between the gut and peripheral blood compartments.

CD4+ T cells, including Th17 and cycling subsets, are intact in the gut mucosa of HIV-1-infected long-term nonprogressors.

During acute human immunodeficiency virus (HIV) infection, there is a massive depletion of CD4(+) T cells in the gut mucosa that can be reversed to various degrees with antiretroviral therapy. Th17 cells have been implicated in mucosal immunity to extracellular bacteria, and preservation of this subset may support gut mucosal immune recovery. However, this possibility has not yet been evaluated in HIV-1-infected long-term nonprogressors (LTNPs), who maintain high CD4(+) T cell counts and suppress viral replication in the absence of antiretroviral therapy. In this study, we evaluated the immunophenotype and function of CD4(+) T cells in peripheral blood and gut mucosa of HIV-uninfected controls, LTNPs, and HIV-1-infected individuals treated with prolonged antiretroviral therapy (ART) (VL [viral load]<50). We found that LTNPs have intact CD4(+) T cell populations, including Th17 and cycling subsets, in the gut mucosa and a preserved T cell population expressing gut homing molecules in the peripheral blood. In addition, we observed no evidence of higher monocyte activation in LTNPs than in HIV-infected (HIV(-)) controls. These data suggest that, similar to nonpathogenic simian immunodeficiency virus (SIV) infection, LTNPs preserve the balance of CD4(+) T cell populations in blood and gut mucosa, which may contribute to the lack of disease progression observed in these patients.

The effect of intermittent IL-2 therapy on CD4 T cells in the gut in HIV-1-infected patients.

We sought to determine the effects of interleukin-2 administered in combination with antiretroviral therapy (ART) on CD4+ T cells in the gut. Lymphocytes from whole blood, colon, and terminal ileum of HIV-infected adults treated with interleukin-2 and ART or ART alone were examined. There were no differences between groups in the proportion of CD4+ T cells or in expression of CD25 or Ki67 by CD4+ T cells in the gut. Although IL-2 administration leads to expansion of peripheral blood CD4+ T cells, there is no alteration in the proportion or activation of CD4+ T cells in the gut mucosa.

Echinacea purpurea significantly induces cytochrome P450 3A activity but does not alter lopinavir-ritonavir exposure in healthy subjects.

STUDY OBJECTIVE: . To determine the influence of Echinacea purpurea on the pharmacokinetics of lopinavir-ritonavir and on cytochrome P450 (CYP) 3A and P-glycoprotein activity by using the probe substrates midazolam and fexofenadine, respectively. DESIGN: Open-label, single-sequence pharmacokinetic study. SETTING: Outpatient clinic in a federal government research center. SUBJECTS: Thirteen healthy volunteers (eight men, five women). INTERVENTION: Subjects received lopinavir 400 mg-ritonavir 100 mg twice/day with meals for 29.5 days. On day 16, subjects received E. purpurea 500 mg 3 times/day for 28 days: 14 days in combination with lopinavir-ritonavir and 14 days of E. purpurea alone. In order to assess CYP3A and P-glycoprotein activity, subjects received single oral doses of midazolam 8 mg and fexofenadine 120 mg, respectively, before and after the 28 days of E. purpurea. MEASUREMENTS AND MAIN RESULTS: On days 15 and 30 of lopinavir-ritonavir administration (before and after E. purpurea administration, respectively), serial blood samples were collected over 12 hours to determine lopinavir and ritonavir concentrations and subsequent pharmacokinetic parameters by using noncompartmental methods. Neither lopinavir nor ritonavir pharmacokinetics were significantly altered by 14 days of E. purpurea coadministration. The post-echinacea: pre-echinacea geometric mean ratios (GMRs) for lopinavir area under the concentration-time curve (AUC) from 0-12 hours and for maximum concentration were 0.96 (90% confidence interval [CI] 0.83-1.10, p=0.82) and 1.00 (90% CI 0.88-1.12, p=0.72), respectively. Conversely, GMRs for midazolam AUC from time zero extrapolated to infinity and oral clearance were 0.73 (90% CI 0.61-0.85, p=0.008) and 1.37 (90% CI 1.10-1.63, p=0.02), respectively. Fexofenadine pharmacokinetics did not significantly differ before and after E. purpurea administration (p>0.05). CONCLUSION: Echinacea purpurea induced CYP3A activity but did not alter lopinavir concentrations, most likely due to the presence of the potent CYP3A inhibitor, ritonavir. Echinacea purpurea is unlikely to alter the pharmacokinetics of ritonavir-boosted protease inhibitors but may cause modest decreases in plasma concentrations of other CYP3A substrates.