Higher HIV RNA Viral Load in Recent Patients with Symptomatic Acute HIV Infection in Lyon University Hospitals

Introduction

Increased human immunodeficiency virus (HIV) virulence at infection has been suggested by a meta-analysis based on viral load and CD4 T lymphocytes (CD4) count during acute infection. This result was obtained after secondary analyses of large databases, facilitating the detection of differences. Similar finding in cohorts of more modest sample size would indicate that the effect could be more substantial.

Methods

Change from initial CD4 count and HIV viral load after acute HIV infection by calendar year was explored in patients treated at Lyon University hospitals. All patients admitted to our hospitals with acute HIV infection between 1996 and 2013 were included in our study. Initial CD4 count and viral load before the start of anti-retroviral treatment were analyzed. Trends over time were assessed in linear models.

Results

Initial CD4 count remained similar over time. However, in 2006–2013, initial viral load rose significantly (+1.12 log₁₀/ml/year, p = 0.01).

Conclusion

Our data, obtained from a single hospital cohort, confirmed findings from a large meta-analysis, showed increased initial viremia at acute HIV infection since 2006 and suggesting potentially higher HIV virulence in recent years.     

An HIV Epidemic Model Based on Viral Load Dynamics: Value in Assessing Empirical Trends in HIV Virulence and Community Viral Load

Trends in HIV virulence have been monitored since the start of the AIDS pandemic, as studying HIV virulence informs our understanding of HIV epidemiology and pathogenesis. Here, we model changes in HIV virulence as a strictly evolutionary process, using set point viral load (SPVL) as a proxy, to make inferences about empirical SPVL trends from longitudinal HIV cohorts. We develop an agent-based epidemic model based on HIV viral load dynamics. The model contains functions for viral load and transmission, SPVL and disease progression, viral load trajectories in multiple stages of infection, and the heritability of SPVL across transmissions. We find that HIV virulence evolves to an intermediate level that balances infectiousness with longer infected lifespans, resulting in an optimal SPVL∼4.75 log₁₀ viral RNA copies/mL. Adaptive viral evolution may explain observed HIV virulence trends: our model produces SPVL trends with magnitudes that are broadly similar to empirical trends. With regard to variation among studies in empirical SPVL trends, results from our model suggest that variation may be explained by the specific epidemic context, e.g. the mean SPVL of the founding lineage or the age of the epidemic; or improvements in HIV screening and diagnosis that results in sampling biases. We also use our model to examine trends in community viral load, a population-level measure of HIV viral load that is thought to reflect a population''s overall transmission potential. We find that community viral load evolves in association with SPVL, in the absence of prevention programs such as antiretroviral therapy, and that the mean community viral load is not necessarily a strong predictor of HIV incidence.     

Behavioral and Other Characteristics Associated with HIV Viral Load in an Outpatient Clinic

Persons living with HIV (PLWH) who are engaged in care, yet not virally suppressed, represent a risk for transmission and opportunity for risk reduction interventions. This study describes characteristics of an outpatient clinic cohort of PLWH by laboratory confirmed viral suppression status and examines associations with demographics and sexual and drug use behaviors gathered through questionnaire. From a sample of 500 clinic patients, 438 were prescribed antiretroviral treatment (ART) and 62 were not. Among the 438 on ART, 72 (16.4%) were not virally suppressed at the most recent lab draw. Compared to individuals with a suppressed viral load, those that were unsuppressed were more likely to: be black (79.2% vs. 64.2%; p = 0.014); earn below $25,000/year (88.9% vs. 65.0%; p < 0.001); be of a younger age (47.8 vs. 50.0 mean years; p = 0.009); be on opiate substitution (14.1% vs. 6.3%; p = 0.023); and acknowledge poly-substance (38.9% vs. 24.4%; p = 0.012) and excessive alcohol use (13.9% vs. 6.0%; p = 0.019). Conversely, a smaller proportion of those with an unsuppressed viral load had multiple sex partners in the previous 30 days (39.8% vs. 58.5%; p = 0.003). In multivariable regression of those on ART, the prevalence of an unsuppressed viral load was 3% lower with each increasing year of age (aPR: 0.97; 95% CI: 0.95, 0.99) and 47% lower with income over $25,000/year (aPR: 0.33; 95% CI: 0.16, 0.70). In a separate analysis of all 500 subjects, ART was less frequently prescribed to blacks compared to whites, heterosexuals, those with lower education and income, and persons with active substance use. Findings confirm that a large proportion of PLWH and engaged in care were not virally suppressed and continued behaviors that risk transmission, indicating the need for screening, prevention counseling and access to ancillary services to lower the incidence of HIV infections.     

Human Leukocyte Antigens and HIV Type 1 Viral Load in Early and Chronic Infection: Predominance of Evolving Relationships

Background

During untreated, chronic HIV-1 infection, plasma viral load (VL) is a relatively stable quantitative trait that has clinical and epidemiological implications. Immunogenetic research has established various human genetic factors, especially human leukocyte antigen (HLA) variants, as independent determinants of VL set-point.

Methodology/Principal Findings

To identify and clarify HLA alleles that are associated with either transient or durable immune control of HIV-1 infection, we evaluated the relationships of HLA class I and class II alleles with VL among 563 seroprevalent Zambians (SPs) who were seropositive at enrollment and 221 seroconverters (SCs) who became seropositive during quarterly follow-up visits. After statistical adjustments for non-genetic factors (sex and age), two unfavorable alleles (A*3601 and DRB1*0102) were independently associated with high VL in SPs (p<0.01) but not in SCs. In contrast, favorable HLA variants, mainly A*74, B*13, B*57 (or Cw*18), and one HLA-A and HLA-C combination (A*30+Cw*03), dominated in SCs; their independent associations with low VL were reflected in regression beta estimates that ranged from −0.47±0.23 to −0.92±0.32 log₁₀ in SCs (p<0.05). Except for Cw*18, all favorable variants had diminishing or vanishing association with VL in SPs (p≤0.86).

Conclusions/Significance

Overall, each of the three HLA class I genes had at least one allele that might contribute to effective immune control, especially during the early course of HIV-1 infection. These observations can provide a useful framework for ongoing analyses of viral mutations induced by protective immune responses.     

Effect of Synaptic Transmission on Viral Fitness in HIV Infection

HIV can spread through its target cell population either via cell-free transmission, or by cell-to-cell transmission, presumably through virological synapses. Synaptic transmission entails the transfer of tens to hundreds of viruses per synapse, a fraction of which successfully integrate into the target cell genome. It is currently not understood how synaptic transmission affects viral fitness. Using a mathematical model, we investigate how different synaptic transmission strategies, defined by the number of viruses passed per synapse, influence the basic reproductive ratio of the virus, R₀, and virus load. In the most basic scenario, the model suggests that R₀ is maximized if a single virus particle is transferred per synapse. R₀ decreases and the infection eventually cannot be maintained for larger numbers of transferred viruses, because multiple infection of the same cell wastes viruses that could otherwise enter uninfected cells. To explain the relatively large number of HIV copies transferred per synapse, we consider additional biological assumptions under which an intermediate number of viruses transferred per synapse could maximize R₀. These include an increased burst size in multiply infected cells, the saturation of anti-viral factors upon infection of cells, and rate limiting steps during the process of synapse formation.     

The Nucleolus and Viral Infection

The nucleolus is a subnuclear structure of eukaryocytes. It was thought that nucleolus only participates in the biogenesis and processing of rRNA. However, more and more evidence shows that it has many other functions, such as tRNA precursor processing, stress sensing and it is also involved in gene silencing, senescence and cell cycle regulation. Here, we summarize the recent understandings about the nucleolar functions, the regulation of nucleolar localization of proteins and the role that the nucleolus p...     

呼吸道感染患儿EBV-DNA载量表达及其与肝肾功能损伤的关系研究

摘要 目的：探讨呼吸道感染患儿爱泼斯坦-巴尔病毒（EBV）-脱氧核糖核酸（DNA）载量表达及其与肝肾功能损伤的关系研究。方法：选取2016年1月至2019年6月本院门诊及病房住院治疗经临床确诊的175例呼吸道感染儿童为研究对象,依据EBV-DNA载量水平分为阳性组（n=117）和阴性组（n=58）,比较不同性别、年龄的呼吸道感染患儿EBV-DNA阳性率,根据EBV-DNA载量峰值将阳性组患儿分为EBV-DNA高载量组(n=21)、中载量组（n=35）和低载量组（n=61）,比较不同EBV-DNA载量组患儿肝肾功能异常比例及血清丙氨酸转氨酶（ALT）、天冬氨酸氨基转移酶（AST）、胱抑素 C(CysC)、β₂微球蛋白(β₂-MG)水平,Pearson相关性分析EBV-DNA载量与ALT、AST、CysC、β₂-MG的关系。结果：不同性别患儿间EBV -DNA阳性率差异无统计学意义（P>0.05）,1-3、3-6岁年龄段儿童中EBV -DNA阳性率最高,不同年龄间患儿EBV -DNA阳性率差异有统计学意义（P<0.05）;EBV-DNA低载量组、中载量组、高载量组的肝异常比例为19.67%、48.57%、66.67%,肾异常比例为13.11%、42.86%、52.38%,不同EBV -DNA载量患儿肝肾功能异常比例相比,差异有统计学意义（P<0.05）;血清ALT、AST、CysC、β₂-MG水平随EBV-DNA载量升高而升高（P<0.05）, EBV -DNA载量与ALT、AST、CysC、β₂-MG水平呈正相关性（P＜0.05）。结论：呼吸道感染患儿EBV -DNA载量升高会增加发生肝肾功能损伤的风险,且在1-6岁儿童EBV -DNA阳性率较高,检测EBV -DNA载量有助于呼吸道感染患儿肝肾功能的损伤的评估。     

环状RNA与病毒感染之间相互关系的研究进展

非编码RNA (non-coding RNA,ncRNA)是指一类不具有编码蛋白质功能的RNA,包括转运RNA (transfer RNA,tRNA)、核糖体RNA (ribosomal RNA,rRNA)、微小RNA (micro RNA,miRNA)、长链非编码RNA (long non-coding RNA,lncRNA)以及环状RNA(circular RNA,circRNA)等.近年来circRNA在癌症,肿瘤以及心脑血管疾病等多种疾病中被证实发挥重要作用,此外研究还发现宿主circRNA与病毒来源的cicrRNA均会参与到病毒感染进程,但其中circRNA发挥的功能还有待进一步研究,因此,该文综述了circRNA的发现、分类、主要功能以及宿主circRNA和病毒来源的circRNA与病毒感染之间相互关系的研究进展,将有助于理解circRNA与病毒感染之间的互作机制.     

Plasma HIV Viral Rebound following Protocol-Indicated Cessation of ART Commenced in Primary and Chronic HIV Infection

Objectives

The magnitude of HIV viral rebound following ART cessation has consequences for clinical outcome and onward transmission. We compared plasma viral load (pVL) rebound after stopping ART initiated in primary (PHI) and chronic HIV infection (CHI).

Design

Two populations with protocol-indicated ART cessation from SPARTAC (PHI, n = 182) and SMART (CHI, n = 1450) trials.

Methods

Time for pVL to reach pre-ART levels after stopping ART was assessed in PHI using survival analysis. Differences in pVL between PHI and CHI populations 4 weeks after stopping ART were examined using linear and logistic regression. Differences in pVL slopes up to 48 weeks were examined using linear mixed models and viral burden was estimated through a time-averaged area-under-pVL curve. CHI participants were categorised by nadir CD4 at ART stop.

Results

Of 171 PHI participants, 71 (41.5%) rebounded to pre-ART pVL levels, at a median of 50 (95% CI 48–51) weeks after stopping ART. Four weeks after stopping treatment, although the proportion with pVL≥400 copies/ml was similar (78% PHI versus 79% CHI), levels were 0.45 (95% CI 0.26–0.64) log₁₀ copies/ml lower for PHI versus CHI, and remained lower up to 48 weeks. Lower CD4 nadir in CHI was associated with higher pVL after ART stop. Rebound for CHI participants with CD4 nadir >500 cells/mm³ was comparable to that experienced by PHI participants.

Conclusions

Stopping ART initiated in PHI and CHI was associated with viral rebound to levels conferring increased transmission risk, although the level of rebound was significantly lower and sustained in PHI compared to CHI.     

Hepatitis B Infection,Viral Load and Resistance in HIV-Infected Patients in Mozambique and Zambia

Background

Few data on the virological determinants of hepatitis B virus (HBV) infection are available from southern Africa.

Methods

We enrolled consecutive HIV-infected adult patients initiating antiretroviral therapy (ART) at two urban clinics in Zambia and four rural clinics in Northern Mozambique between May 2013 and August 2014. HBsAg screening was performed using the Determine^® rapid test. Quantitative real-time PCR and HBV sequencing were performed in HBsAg-positive patients. Risk factors for HBV infection were evaluated using Chi-square and Mann-Whitney tests and associations between baseline characteristics and high level HBV replication explored in multivariable logistic regression.

Results

Seventy-eight of 1,032 participants in Mozambique (7.6%, 95% confidence interval [CI]: 6.1–9.3) and 90 of 797 in Zambia (11.3%, 95% CI: 9.3–13.4) were HBsAg-positive. HBsAg-positive individuals were less likely to be female compared to HBsAg-negative ones (52.3% vs. 66.1%, p<0.001). Among 156 (92.9%) HBsAg-positive patients with an available measurement, median HBV viral load was 13,645 IU/mL (interquartile range: 192–8,617,488 IU/mL) and 77 (49.4%) had high values (>20,000 UI/mL). HBsAg-positive individuals had higher levels of ALT and AST compared to HBsAg-negative ones (both p<0.001). In multivariable analyses, male sex (adjusted odds ratio: 2.59, 95% CI: 1.22–5.53) and CD4 cell count below 200/μl (2.58, 1.20–5.54) were associated with high HBV DNA. HBV genotypes A1 (58.8%) and E (38.2%) were most prevalent. Four patients had probable resistance to lamivudine and/or entecavir.

Conclusion

One half of HBsAg-positive patients demonstrated high HBV viremia, supporting the early initiation of tenofovir-containing ART in HIV/HBV-coinfected adults.     

Genotype Distribution,Viral Load and Clinical Characteristics of Infants with Postnatal or Congenital Cytomegalovirus Infection

Background

Congenital cytomegalovirus infection is a leading cause of long-term sequelae. Cytomegalovirus is also frequently transmitted to preterm infants postnatally, but these infections are mostly asymptomatic. A correlation between cytomegalovirus genotypes and clinical manifestations has been reported previously in infants with congenital infection, but not in preterm infants with postnatal infection.

Objectives

The main objective of this study was to investigate cytomegalovirus genotype distribution in postnatal and congenital cytomegalovirus infection and its association with disease severity.

Methods

Infants admitted to the neonatal intensive care unit of the University Medical Center Utrecht, The Netherlands between 2003–2010 and diagnosed with postnatal or congenital cytomegalovirus infection were included. Classification of cytomegalovirus isolates in genotypes was performed upon amplification and sequencing of the cytomegalovirus UL55 (gB) and UL144 genes. Clinical data, cerebral abnormalities, neurodevelopmental outcome and viral load were studied in relation to genotype distribution.

Results

Genotyping results were obtained from 58 preterm infants with postnatal cytomegalovirus infection and 13 infants with congenital cytomegalovirus infection. Postnatal disease was mild in all preterm infants and all had favourable outcome. Infants with congenital infection were significantly more severely affected than infants with postnatal infection. Seventy-seven percent of these infants were symptomatic at birth, 2/13 died and 3/13 developed long-term sequelae (median follow-up 6 (range 2–8) years). The distribution of cytomegalovirus genotypes was comparable for postnatal and congenital infection. UL55 genotype 1 and UL144 genotype 3 were predominant genotypes in both groups.

Conclusions

Distribution of UL55 and UL144 genotypes was similar in asymptomatic postnatal and severe congenital CMV infection suggesting that other factors rather than cytomegalovirus UL55 and UL144 genotype are responsible for the development of severe disease.     

T Cell Activation but Not Polyfunctionality after Primary HIV Infection Predicts Control of Viral Load and Length of the Time without Therapy

Objective

Immune changes occurring after primary HIV infection (PHI) have a pivotal relevance. Our objective was to characterize the polyfunctionality of immune response triggered by PHI, and to characterize immune activation and regulatory T cells, correlating such features to disease progression.

Patients and Methods

We followed 11 patients experiencing PHI for 4 years. By polychromatic flow cytometry, we studied every month, for the first 6 months, T lymphocyte polyfunctionality after cell stimulation with peptides derived from HIV-1 gag and nef. Tregs were identified by flow cytometry, and T cell activation studied by CD38 and HLA-DR expression.

Results

An increase of anti-gag and anti-nef CD8+ specific T cells was observed 3 months after PHI; however, truly polyfunctional T cells, also able to produce IL-2, were never found. No gross changes in Tregs were present. T lymphocyte activation was maximal 1 and 2 months after PHI, and significantly decreased in the following period. The level of activation two months after PHI was strictly correlated to the plasma viral load 1 year after infection, and significantly influenced the length of period without therapy. Indeed, 80% of patients with less than the median value of activated CD8+ (15.5%) or CD4+ (0.9%) T cells remained free of therapy for >46 months, while all patients over the median value had to start treatment within 26 months.

Conclusions

T cell activation after PHI, more than T cell polyfunctionality or Tregs, is a predictive marker for the control of viral load and for the time required to start treatment.     

High Heritability Is Compatible with the Broad Distribution of Set Point Viral Load in HIV Carriers

Set point viral load in HIV patients ranges over several orders of magnitude and is a key determinant of disease progression in HIV. A number of recent studies have reported high heritability of set point viral load implying that viral genetic factors contribute substantially to the overall variation in viral load. The high heritability is surprising given the diversity of host factors associated with controlling viral infection. Here we develop an analytical model that describes the temporal changes of the distribution of set point viral load as a function of heritability. This model shows that high heritability is the most parsimonious explanation for the observed variance of set point viral load. Our results thus not only reinforce the credibility of previous estimates of heritability but also shed new light onto mechanisms of viral pathogenesis.     

外体和病毒感染

外体(exosome)是源自细胞内体的小囊泡,可由多种哺乳动物细胞分泌释放,其组分包括蛋白质、脂质、mRNA和microRNA,是细胞间"通讯"交互的工具之一。我们以介绍外体的组成和生物发生为基础,综述了近年来其在病毒感染致病中的研究成果,以期为病毒感染致病机理的研究提供新的切入点。     

Technical and Regulatory Shortcomings of the TaqMan Version 1 HIV Viral Load Assay

Background

The lower limit of detection of the original Roche Amplicor HIV plasma viral load (pVL) assay (50 copies/mL) has defined HIV treatment success. The Amplicor assay, however, has been replaced by the Roche TaqMan assay(s). Changes to the limits of detection and calibration have not been validated for clinical utility. Sudden increases in the number of patients with detectable pVL have been reported following the introduction of the TaqMan version 1 assay.

Methods

Between October 2009 and April 2010 all routine pVL samples from British Columbia, Canada, with 40–250 copies/mL by TaqMan were re-tested by Amplicor (N = 1198). Subsequent short-term virological and resistance outcomes were followed in patients with unchanged therapy (N = 279; median 3.2 months follow-up).

Results

TaqMan and Amplicor values correlated poorly at low pVL values. Low-level pVL by TaqMan was not associated with impending short-term virological failure; only 17% of patients with 40–250 copies/mL by TaqMan had detectable pVL by Amplicor at follow-up. During the follow-up period only 20% of patients had an increase in pVL by TaqMan (median [IQR]: 80 [36–283] copies/mL). In addition, in ∼2.4% of samples pVL was dramatically underestimated by TaqMan due to poor binding of the proprietary TaqMan primers.

Conclusions

The replacement of Amplicor with the TaqMan assay has altered the previously accepted definition of HIV treatment failure without any evidence to support the clinical relevance of the new definition. Given the systematic differences in measurement in the low pVL range the British Columbia HIV treatment guidelines now use a threshold of >250 copies/mL by TaqMan to define treatment failure.     

A Comparison of Methods for Analyzing Viral Load Data in Studies of HIV Patients

HIV RNA viral load (VL) is a pivotal outcome variable in studies of HIV infected persons. We propose and investigate two frameworks for analyzing VL: (1) a single-measure VL (SMVL) per participant and (2) repeated measures of VL (RMVL) per participant. We compared these frameworks using a cohort of 720 HIV patients in care (4,679 post-enrollment VL measurements). The SMVL framework analyzes a single VL per participant, generally captured within a “window” of time. We analyzed three SMVL methods where the VL binary outcome is defined as suppressed or not suppressed. The omit-participant method uses a 8-month “window” (-6/+2 months) around month 24 to select the participant’s VL closest to month 24 and removes participants from the analysis without a VL in the “window”. The set-to-failure method expands on the omit-participant method by including participants without a VL within the “window” and analyzes them as not suppressed. The closest-VL method analyzes each participant’s VL measurement closest to month 24. We investigated two RMVL methods: (1) repeat-binary classifies each VL measurement as suppressed or not suppressed and estimates the proportion of participants suppressed at month 24, and (2) repeat-continuous analyzes VL as a continuous variable to estimate the change in VL across time, and geometric mean (GM) VL and proportion of participants virally suppressed at month 24. Results indicated the RMVL methods have more precision than the SMVL methods, as evidenced by narrower confidence intervals for estimates of proportion suppressed and risk ratios (RR) comparing demographic strata. The repeat-continuous method had the most precision and provides more information than other considered methods. We generally recommend using the RMVL framework when there are repeated VL measurements per participant because it utilizes all available VL data, provides additional information, has more statistical power, and avoids the subjectivity of defining a “window.”     

Finger Prick Dried Blood Spots for HIV Viral Load Measurement in Field Conditions in Zimbabwe

BackgroundIn the context of a community-randomized trial of antiretrovirals for HIV prevention and treatment among sex workers in Zimbabwe (the SAPPH-IRe trial), we will measure the proportion of women with HIV viral load (VL) above 1000 copies/mL (“VL>1000”) as our primary endpoint. We sought to characterize VL assay performance by comparing results from finger prick dried blood spots (DBS) collected in the field with plasma samples, to determine whether finger prick DBS is an acceptable sample for VL quantification in the setting.MethodsWe collected whole blood from a finger prick onto filter paper and plasma samples using venipuncture from women in two communities. VL quantification was run on samples in parallel using NucliSENS EasyQ HIV-1 v2.0. Our trial outcome is the proportion of women with VL>1000, consistent with WHO guidelines relating to regimen switching. We therefore focused on this cut-off level for assessing sensitivity and specificity. Results were log transformed and the mean difference and standard deviation calculated, and correlation between VL quantification across sample types was evaluated.ResultsA total of 149 HIV-positive women provided DBS and plasma samples; 56 (63%) reported being on antiretroviral therapy. VL ranged from undetectable-6.08 log₁₀ using DBS and undetectable-6.40 log10 using plasma. The mean difference in VL (plasma-DBS) was 0.077 log₁₀ (95%CI = 0.025–0.18 log₁₀; standard deviation = 0.63 log₁₀,). 78 (52%) DBS and 87 (58%) plasma samples had a VL>1000. Based on plasma ‘gold-standard’, DBS sensitivity for detection of VL>1000 was 87.4%, and specificity was 96.8%.ConclusionThere was generally good agreement between DBS and plasma VL for detection of VL>1000. Overall, finger prick DBS appeared to be an acceptable sample for classifying VL as above or below 1000 copies/mL using the NucliSENS assay.