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Elén S, Björkman P, Zazzi M, Böhm M, Bernal E, Sönnerborg A, Elvstam O. Low-level HIV viraemia during antiretroviral therapy: Longitudinal patterns and predictors of viral suppression. HIV Med 2024; 25:107-116. [PMID: 37721192 DOI: 10.1111/hiv.13541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023]
Abstract
OBJECTIVES Our objective was to characterize longitudinal patterns of viraemia and factors associated with viral suppression in people with HIV and low-level viraemia (LLV) during antiretroviral therapy (ART). METHODS We included people with HIV in the EuResist Integrated Database with LLV following ART initiation after 2005. LLV was defined as two or more consecutive viral load (VL) measurements of 51-199 copies/mL 30-365 days apart after >12 months of ART. Viraemia patterns were analyzed over 24 months. Factors associated with viral suppression at 12 months after LLV episodes were identified using univariable and multivariable logistic regression. RESULTS Of 25 113 people with HIV, 2474 (9.9%) had LLV. Among 1387 participants with 24 months of follow-up after LLV, 406 (29%) had persistent suppression, 669 (48%) had transient viraemic episodes, 29 (2%) had persistent LLV, and 283 (20%) had virological failure. Following LLV episodes, the proportion with detectable viraemia declined (p for trend <0.001 and 0.034, in the first and second year, respectively). At 12 months, 68% had undetectable VL, which was associated with suppression before LLV (adjusted odds ratio [aOR] 1.7; 95% confidence interval [CI] 1.2-2.4) and ART modification after LLV (aOR 1.6; 95% CI 1.0-2.4). The following factors were negatively associated with undetectable VL at 12 months: higher VL during LLV (aOR 0.57 per log10 copies/mL; 95% CI 0.37-0.89), injecting drug use (aOR 0.67; 95% CI 0.47-0.96), and regimens with protease inhibitors (aOR 0.65; 95% CI 0.49-0.87) or combined anchor drugs (aOR 0.52; 95% CI 0.32-0.85). CONCLUSION Most people with LLV did not experience sustained viral suppression during 24-month follow-up, supporting the association between LLV and inferior treatment outcome.
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Affiliation(s)
- S Elén
- Department of Translational Medicine, Lund University, Malmö, Sweden
| | - P Björkman
- Department of Translational Medicine, Lund University, Malmö, Sweden
- Department of Infectious Diseases, Skåne University Hospital, Malmö, Sweden
| | - M Zazzi
- Department of Medical Biotechnology, University of Siena, Siena, Italy
| | - M Böhm
- Institute of Virology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - E Bernal
- Infectious Disease Unit. Reina Sofia Hospital, Murcia University and IMIB, Murcia, Spain
| | - A Sönnerborg
- Division of Infectious Diseases, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - O Elvstam
- Department of Translational Medicine, Lund University, Malmö, Sweden
- Department of Infectious Diseases, Växjö Central Hospital, Växjö, Sweden
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Payne AT, Lindner BK, Gilbert AJ, Kumar RN, Thomas BS, Timpone JG. Evaluation of cytomegalovirus "Blips" in high risk kidney/kidney-pancreas transplant recipients. Transpl Infect Dis 2022; 24:e13789. [PMID: 35014122 DOI: 10.1111/tid.13789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/13/2021] [Accepted: 12/27/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Cytomegalovirus (CMV) is a significant cause of morbidity and mortality after solid organ transplantation. While guidelines suggest using highly sensitive QNAT assays for CMV detection, there is no defined viral load to guide initiation of preemptive therapy.1,2 This study evaluates the progression to quantifiable CMV (DNAemia) following a CMV "blip" in high risk (D+/R) kidney/kidney-pancreas (KP) transplant recipients. METHODS This is a single center, retrospective study. A CMV "blip" was defined as the first positive QNAT assay below the level of quantification (< 1.37×102 IU/mL or < 200 viral copies). Subsequent CMV QNAT assays were followed to assess the progression from blip to CMV DNAemia for 1 year following transplant. RESULTS 134 patients were included in the study. Fifty-three (39.6%) patients had their first positive CMV QNAT value below the level of quantification, a "CMV blip". Of these 53 patients, 69.8% (n = 37) progressed to DNAemia while 30.2% (n = 16) did not. The median time from transplant to the first CMV blip was 68 (46-97) days and most patients with viral blips (71.1%) were on prophylaxis. No differences in patient characteristics were found among those who progressed from blip to DNAemia and those who only had a blip. CONCLUSIONS In CMV high risk kidney/KP transplant recipients, CMV blips progressed to CMV DNAemia in the majority of cases. This progression typically occurred 2-3 weeks following the initial blip. CMV blips are common early post-transplant despite prophylaxis and likely represent an early marker of CMV infection. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Alexandra T Payne
- Georgetown University School of Medicine, Washington, DC, 20007, USA
| | - Brian K Lindner
- MedStar Georgetown University Hospital Department of Pharmacy, Washington, DC, 20007, USA
| | - Alexander J Gilbert
- MedStar Georgetown University Hospital Transplant Institute, Washington, DC, 20007, USA
| | - Rebecca N Kumar
- MedStar Georgetown University Hospital Division of Infectious Diseases and Tropical Medicine, Washington, DC, 20007, USA
| | - Beje S Thomas
- MedStar Georgetown University Hospital Transplant Institute, Washington, DC, 20007, USA
| | - Joseph G Timpone
- MedStar Georgetown University Hospital Division of Infectious Diseases and Tropical Medicine, Washington, DC, 20007, USA
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Cumulative viral load as a predictor of CD4+ T-cell response to antiretroviral therapy using Bayesian statistical models. PLoS One 2019; 14:e0224723. [PMID: 31721805 PMCID: PMC6853324 DOI: 10.1371/journal.pone.0224723] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 10/21/2019] [Indexed: 01/10/2023] Open
Abstract
INTRODUCTION There are Challenges in statistically modelling immune responses to longitudinal HIV viral load exposure as a function of covariates. We define Bayesian Markov Chain Monte Carlo mixed effects models to incorporate priors and examine the effect of different distributional assumptions. We prospectively fit these models to an as-yet-unpublished data from the Tshwane District Hospital HIV treatment clinic in South Africa, to determine if cumulative log viral load, an indicator of long-term viral exposure, is a valid predictor of immune response. METHODS Models are defined, to express 'slope', i.e. mean annual increase in CD4 counts, and 'asymptote', i.e. the odds of having a CD4 count ≥500 cells/μL during antiretroviral treatment, as a function of covariates and random-effects. We compare the effect of using informative versus non-informative prior distributions on model parameters. Models with cubic splines or Skew-normal distributions are also compared using the conditional Deviance Information Criterion. RESULTS The data of 750 patients are analyzed. Overall, models adjusting for cumulative log viral load provide a significantly better fit than those that do not. An increase in cumulative log viral load is associated with a decrease in CD4 count slope (19.6 cells/μL (95% credible interval: 28.26, 10.93)) and a reduction in the odds of achieving a CD4 counts ≥500 cells/μL (0.42 (95% CI: 0.236, 0.730)) during 5 years of therapy. Using informative priors improves the cumulative log viral load estimate, and a skew-normal distribution for the random-intercept and measurement error results is a better fit compared to using classical Gaussian distributions. DISCUSSION We demonstrate in an unpublished South African cohort that cumulative log viral load is a strong and significant predictor of both CD4 count slope and asymptote. We argue that Bayesian methods should be used more frequently for such data, given their flexibility to incorporate prior information and non-Gaussian distributions.
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Sovershaeva E, Shamu T, Wilsgaard T, Bandason T, Flægstad T, Katzenstein D, Ferrand RA, Odland J. Patterns of detectable viraemia among children and adults with HIV infection taking antiretroviral therapy in Zimbabwe. Int J Infect Dis 2019; 78:65-71. [PMID: 30391420 PMCID: PMC7614873 DOI: 10.1016/j.ijid.2018.10.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/24/2018] [Accepted: 10/25/2018] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE To investigate the incidence and predictors of viraemia among individuals on antiretroviral therapy (ART) in Harare, Zimbabwe. METHODS Children (0-19 years) and adults (>19 years) starting ART between 2013 and 2015 were followed for a median of 2.8 and 2.7 years, respectively. The incidence rates of virological failure (VF), low-level viraemia (LLV), and viral blips were assessed and the predictors of viraemia were determined using logistic and parametric survival regression analyses. RESULTS A total of 630 individuals initiated ART, and 19.7% of children and 5.6% of adults did not achieve viral suppression by 12 months. Younger age and CD4 count ≤200 cells/mm3 at baseline were associated with not being virally suppressed at 12 months in adults. Among those who achieved viral suppression during the follow-up period, the incidence of VF was higher in children (4.0/100 person-years vs. 0.4/100 person-years in adults; p<0.001), as was the incidence of LLV (1.9/100 person-years vs. 0.3/100 person-years in adults; p=0.03). The incidence rate of blips was 10.9 per 100 person-years in children and 4.0 per 100 person-years in adults. CONCLUSIONS Children are less likely to reach viral suppression and are at higher risk of viraemia while on ART than adults. The significance of LLV and blips needs further study.
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Affiliation(s)
- Evgeniya Sovershaeva
- Department of Community Medicine, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway.
| | | | - Tom Wilsgaard
- Department of Community Medicine, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Tsitsi Bandason
- Biomedical Research and Training Institute, Harare, Zimbabwe
| | - Trond Flægstad
- Department of Paediatrics, University Hospital of North Norway, Tromsø, Norway
| | - David Katzenstein
- Division of Infectious Diseases, Stanford University, California, USA
| | - Rashida A Ferrand
- Biomedical Research and Training Institute, Harare, Zimbabwe; Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Jon Odland
- Department of Community Medicine, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway; Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, NTNU The Norwegian University of Science and Technology, Trondheim, Norway
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Discordance of Self-report and Laboratory Measures of HIV Viral Load Among Young Men Who Have Sex with Men and Transgender Women in Chicago: Implications for Epidemiology, Care, and Prevention. AIDS Behav 2018; 22:2360-2367. [PMID: 29637386 DOI: 10.1007/s10461-018-2112-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Suppressing HIV viral load through daily antiretroviral therapy (ART) substantially reduces the risk of HIV transmission, however, the potential population impact of treatment as prevention (TasP) is mitigated due to challenges with sustained care engagement and ART adherence. For an undetectable viral load (VL) to inform decision making about transmission risk, individuals must be able to accurately classify their VL as detectable or undetectable. Participants were 205 HIV-infected young men who have sex with men (YMSM) and transgender women (TGW) from a large cohort study in the Chicago area. Analyses examined correspondence among self-reported undetectable VL, study-specific VL, and most recent medical record VL. Among HIV-positive YMSM/TGW, 54% had an undetectable VL (< 200 copies/mL) via study-specific laboratory testing. Concordance between self-report and medical record VL values was 80% and between self-report and study-specific laboratory testing was 73%; 34% of participants with a detectable study-specific VL self-reported an undetectable VL at last medical visit, and another 28% reported not knowing their VL status. Periods of lapsed viral suppression between medical visits may represent a particular risk for the TasP strategy among YMSM/TGW. Strategies for frequent viral load monitoring, that are not burdensome to patients, may be necessary to optimize TasP.
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Impact of CMV PCR Blips in Recipients of Solid Organ and Hematopoietic Stem Cell Transplantation. Transplant Direct 2018; 4:e355. [PMID: 30123828 PMCID: PMC6089517 DOI: 10.1097/txd.0000000000000787] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 03/11/2018] [Indexed: 11/26/2022] Open
Abstract
Background Viral blips reflecting polymerase chain reaction (PCR) artefacts or transient low-level replication are well described in the human immunodeficiency virus setting. However, the epidemiology of such blips in transplant recipients screened for cytomegalovirus (CMV) with PCR remains uncertain and was investigated in a cohort of solid organ and hematopoietic stem cell recipients. Methods Eligible recipients had known donor/recipient CMV IgG serostatus, and 3 CMV PCRs ≥. The CMV PCR triplicates (3 consecutive CMV PCRs) were defined; the first CMV PCR was always negative, and the time between the second and third samples was 7 days ≤. A positive second but negative third sample represented a blip. Odds ratio (OR) for factors associated with a triplicate being a blip was estimated by binomial regression adjusted for repeated measurements. Whether blips affected the hazard ratio (HR) for subsequent CMV infection was determined with a Cox model. Results 851 recipients generated 3883 CMV PCR triplicates. The OR of a triplicate representing a blip decreased with increasing viral load of the second sample (vs 273 IU/mL; >273-910 IU/mL: odds ratio [OR], 0.2; 95% confidence interval [CI], 0.1-0.5; >910 IU/mL: OR, 0.08; 95% CI, 0.02-0.2; P ≤ 0.0002) and increased with intermediary-/low-risk serostatus (vs high risk) (OR, 2.8; 95% CI, 1.2-5.5; P = 0.01). Cumulative exposure to DNAemia in the CMV blips greater than 910 IU/mL indicated increased HR of subsequent CMV infection (HR, 4.6; 95% CI, 1.2-17.2; P = 0.02). Conclusions Cytomegalovirus blips are frequent; particularly when the viral load of the first positive PCR is < 910 IU/mL, and serostatus risk is intermediary/low. Accumulating blips suggest intermittent low-level replication. If blips are suspected, confirmation of ongoing replication before initiation of treatment is prudent.
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Sempa JB, Ujeneza EL, Nieuwoudt M. Systematic review of statistically-derived models of immunological response in HIV-infected adults on antiretroviral therapy in Sub-Saharan Africa. PLoS One 2017; 12:e0171658. [PMID: 28199360 PMCID: PMC5310790 DOI: 10.1371/journal.pone.0171658] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 01/24/2017] [Indexed: 12/31/2022] Open
Abstract
Introduction In Sub-Saharan African (SSA) resource limited settings, Cluster of Differentiation 4 (CD4) counts continue to be used for clinical decision making in antiretroviral therapy (ART). Here, HIV-infected people often remain with CD4 counts <350 cells/μL even after 5 years of viral load suppression. Ongoing immunological monitoring is necessary. Due to varying statistical modeling methods comparing immune response to ART across different cohorts is difficult. We systematically review such models and detail the similarities, differences and problems. Methods ‘Preferred Reporting Items for Systematic Review and Meta-Analyses’ guidelines were used. Only studies of immune-response after ART initiation from SSA in adults were included. Data was extracted from each study and tabulated. Outcomes were categorized into 3 groups: ‘slope’, ‘survival’, and ‘asymptote’ models. Wordclouds were drawn wherein the frequency of variables occurring in the reviewed models is indicated by their size and color. Results 69 covariates were identified in the final models of 35 studies. Effect sizes of covariates were not directly quantitatively comparable in view of the combination of differing variables and scale transformation methods across models. Wordclouds enabled the identification of qualitative and semi-quantitative covariate sets for each outcome category. Comparison across categories identified sex, baseline age, baseline log viral load, baseline CD4, ART initiation regimen and ART duration as a minimal consensus set. Conclusion Most models were different with respect to covariates included, variable transformations and scales, model assumptions, modelling strategies and reporting methods, even for the same outcomes. To enable comparison across cohorts, statistical models would benefit from the application of more uniform modelling techniques. Historic efforts have produced results that are anecdotal to individual cohorts only. This study was able to define ‘prior’ knowledge in the Bayesian sense. Such information has value for prospective modelling efforts.
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Affiliation(s)
- Joseph B. Sempa
- South African Department of Science and Technology/National Research Foundation Centre of Excellence in Epidemiological Modelling and Analysis (SACEMA), Stellenbosch University, Stellenbosch, South Africa
- * E-mail:
| | - Eva L. Ujeneza
- South African Department of Science and Technology/National Research Foundation Centre of Excellence in Epidemiological Modelling and Analysis (SACEMA), Stellenbosch University, Stellenbosch, South Africa
| | - Martin Nieuwoudt
- South African Department of Science and Technology/National Research Foundation Centre of Excellence in Epidemiological Modelling and Analysis (SACEMA), Stellenbosch University, Stellenbosch, South Africa
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Sempa JB, Dushoff J, Daniels MJ, Castelnuovo B, Kiragga AN, Nieuwoudt M, Bellan SE. Reevaluating Cumulative HIV-1 Viral Load as a Prognostic Predictor: Predicting Opportunistic Infection Incidence and Mortality in a Ugandan Cohort. Am J Epidemiol 2016; 184:67-77. [PMID: 27188943 DOI: 10.1093/aje/kwv303] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 10/29/2015] [Indexed: 11/12/2022] Open
Abstract
Recent studies have evaluated cumulative human immunodeficiency virus type 1 (HIV-1) viral load (cVL) for predicting disease outcomes, with discrepant results. We reviewed the disparate methodological approaches taken and evaluated the prognostic utility of cVL in a resource-limited setting. Using data on the Infectious Diseases Institute (Makerere University, Kampala, Uganda) cohort, who initiated antiretroviral therapy in 2004-2005 and were followed up for 9 years, we calculated patients' time-updated cVL by summing the area under their viral load curves on either a linear scale (cVL1) or a logarithmic scale (cVL2). Using Cox proportional hazards models, we evaluated both metrics as predictors of incident opportunistic infections and mortality. Among 489 patients analyzed, neither cVL measure was a statistically significant predictor of opportunistic infection risk. In contrast, cVL2 (but not cVL1) was a statistically significant predictor of mortality, with each log10 increase corresponding to a 1.63-fold (95% confidence interval: 1.02, 2.60) elevation in mortality risk when cVL2 was accumulated from baseline. However, whether cVL is predictive or not hinges on difficult choices surrounding the cVL metric and statistical model employed. Previous studies may have suffered from confounding bias due to their focus on cVL1, which strongly correlates with other variables. Further methodological development is needed to illuminate whether the inconsistent predictive utility of cVL arises from causal relationships or from statistical artifacts.
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Sörstedt E, Nilsson S, Blaxhult A, Gisslén M, Flamholc L, Sönnerborg A, Yilmaz A. Viral blips during suppressive antiretroviral treatment are associated with high baseline HIV-1 RNA levels. BMC Infect Dis 2016; 16:305. [PMID: 27329293 PMCID: PMC4915053 DOI: 10.1186/s12879-016-1628-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/07/2016] [Indexed: 12/01/2022] Open
Abstract
Background Many HIV-1-infected patients on suppressive antiretroviral therapy (ART) have transiently elevated HIV RNA levels. The clinical significance of these viral blips is uncertain. We have determined the incidence of blips and investigated important associations in the Swedish HIV-cohort. Methods HIV-1-infected ART naïve adults who commenced ART 2007–2013 were retrospectively included. Viral blips were defined as a transient viral load between 50 and 500 copies/mL Subjects not suppressed after six months on ART were excluded. Results Viral blips were found in 76/735 included subjects (10.3 %) and in 90/4449 samples (2.0 %). Median blip viral load was 76 copies/mL (range 56–138). Median follow-up time was 170 weeks (range 97–240). Baseline viral load was higher in subjects with viral blips (median log10 4.85 copies/mL) compared with subjects without blips (median log10 4.55 copies/mL) (p < 0.01). There was a significant association between viral blips and risk for subsequent virological failure (p < 0.001). Conclusions The Swedish national HIV-cohort has a low incidence of viral blips (10 %). Blips were associated with high baseline viral load and an increased risk of subsequent virological failure.
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Affiliation(s)
- Erik Sörstedt
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 413 90, Gothenburg, Sweden.
| | - Staffan Nilsson
- Department of Mathematical Sciences, Chalmers University of Technology, 412 58, Gothenburg, Sweden
| | - Anders Blaxhult
- Department of Infectious Diseases, Venhälsan-Södersjukhuset, 118 83, Stockholm, Sweden
| | - Magnus Gisslén
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 413 90, Gothenburg, Sweden
| | - Leo Flamholc
- Department of Infectious Diseases, Malmö University Hospital, 205 02, Malmö, Sweden
| | - Anders Sönnerborg
- Department of Infectious Diseases, Karolinska Institute, Karolinska University Hospital, 141 86, Stockholm, Sweden.,Department of Clinical Microbiology, Karolinska Institute, Karolinska University Hospital, 141 86, Stockholm, Sweden
| | - Aylin Yilmaz
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 413 90, Gothenburg, Sweden
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Paintsil E, Martin R, Goldenthal A, Bhandari S, Andiman W, Ghebremichael M. Frequent Episodes of Detectable Viremia in HIV Treatment-Experienced Children is Associated with a Decline in CD4+ T-cells Over Time. ACTA ACUST UNITED AC 2016; 7. [PMID: 27379199 DOI: 10.4172/2155-6113.1000565] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The clinical consequences of the magnitude and the duration of detectable viremia in HIV-infected children have not been well characterized. We examined the predictors and immunologic consequences over time of frequent episodes of detectable viremia in HIV-infected children followed at Yale-New Haven Hospital. METHODS We analyzed the CD4+ T-cell and HIV viral load over a 19-year period (1996 to 2013) of 104 HIV-infected children enrolled in the Yale Prospective Longitudinal Pediatric HIV Cohort. Both CD4+ T-lymphocytes and HIV viral load were measured at clinic visits every 3 to 4 months. Longitudinal data analyses using polynomial random coefficients models were conducted to examine overtime changes in CD4+ T-cell counts by frequency of episodes of detectable viremia. Moreover, regression analyses using logistic regression models were used to assess the predictors of frequent episodes of detectable viremia. RESULTS One hundred and four (104) HIV-infected children with more than one HIV viral load measurement between 1996 and November 2013 were included in the analysis. Over 80% (N=86) of the children had detectable viral load (HIV RNA viral load ≥50 copies/ml) during more than 50% of their clinic visits. Children with infrequent episodes of detectable viremia had significantly higher CD4+ T-cell counts overtime compared to those with frequent episodes of detectable viremia (P<0.0001). CONCLUSIONS Both frequency and magnitude of episodes of detectable viremia had effect on CD4+ T-cells. Strict adherence to a treatment goal of undetectable HIV viremia in children is likely to be beneficial.
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Affiliation(s)
- Elijah Paintsil
- Departments of Pediatrics and Pharmacology, Yale University School of Medicine, New Haven, USA
| | | | - Ariel Goldenthal
- Columbia University College of Physicians and Surgeons, New York, USA
| | | | - Warren Andiman
- Department of Pediatrics, Yale University School of Medicine, New Haven, USA
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Zhang W, Wahl LM, Yu P. Backward bifurcations, turning points and rich dynamics in simple disease models. J Math Biol 2016; 73:947-76. [PMID: 26921202 DOI: 10.1007/s00285-016-0976-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 12/03/2015] [Indexed: 12/13/2022]
Abstract
In this paper, dynamical systems theory and bifurcation theory are applied to investigate the rich dynamical behaviours observed in three simple disease models. The 2- and 3-dimensional models we investigate have arisen in previous investigations of epidemiology, in-host disease, and autoimmunity. These closely related models display interesting dynamical behaviors including bistability, recurrence, and regular oscillations, each of which has possible clinical or public health implications. In this contribution we elucidate the key role of backward bifurcations in the parameter regimes leading to the behaviors of interest. We demonstrate that backward bifurcations with varied positions of turning points facilitate the appearance of Hopf bifurcations, and the varied dynamical behaviors are then determined by the properties of the Hopf bifurcation(s), including their location and direction. A Maple program developed earlier is implemented to determine the stability of limit cycles bifurcating from the Hopf bifurcation. Numerical simulations are presented to illustrate phenomena of interest such as bistability, recurrence and oscillation. We also discuss the physical motivations for the models and the clinical implications of the resulting dynamics.
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Affiliation(s)
- Wenjing Zhang
- Applied Mathematics, Western University, London, ON, N6A 5B7, Canada.
| | - Lindi M Wahl
- Applied Mathematics, Western University, London, ON, N6A 5B7, Canada
| | - Pei Yu
- Applied Mathematics, Western University, London, ON, N6A 5B7, Canada
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Maldonado-Martínez G, Hunter-Mellado RF, Fernández-Santos D, Ríos-Olivares E. Persistent HIV Viremia: Description of a Cohort of HIV Infected Individuals with ART Failure in Puerto Rico. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 13:ijerph13010050. [PMID: 26703691 PMCID: PMC4730441 DOI: 10.3390/ijerph13010050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 11/16/2015] [Accepted: 11/24/2015] [Indexed: 11/16/2022]
Abstract
The introduction of antiretroviral therapy (ART) has allowed human immunodeficiency virus (HIV) suppression in patients. We present data of a cohort of Puerto Rican patients with HIV who were under treatment with a steady regime of ART across a time horizon of eleven years. The time periods were categorized into four year stratums: 2000 to 2002; 2003 to 2005; 2006 to 2008 and 2009 to 2011. Socio-demographic profile, HIV risk factors, co-morbid conditions were included as study variables. One year mortality was defined. The p value was set at ≤0.05. The cohort consisted of 882 patients with 661 subjects presenting with persistent HIV viral load after a self-reported 12 month history of ART use. In this sub-cohort a higher viral load was seen across time (p < 0.05). Illicit drug use, IV drug use, alcohol use, loss of work were associated to having higher viral load means (p < 0.05). HIV viral load mean was lower as BMI increased (p < 0.001). It is imperative to readdress antiretroviral adherence protocols and further study ART tolerance and compliance.
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Affiliation(s)
- Gerónimo Maldonado-Martínez
- Data Management and Statistical Research Support Unit, Universidad Central del Caribe, Bayamón 00960, Puerto Rico.
| | | | - Diana Fernández-Santos
- Data Management and Statistical Research Support Unit, Universidad Central del Caribe, Bayamón 00960, Puerto Rico.
| | - Eddy Ríos-Olivares
- Microbiology Department, Universidad Central del Caribe, Bayamón 00960, Puerto Rico.
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Time above 1500 copies: a viral load measure for assessing transmission risk of HIV-positive patients in care. AIDS 2015; 29:947-54. [PMID: 25768835 DOI: 10.1097/qad.0000000000000640] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE We examined HIV transmission potential of patients in care by analyzing the amount of person-time spent above a viral load threshold that increases risk for transmission. DESIGN Observational cohort and supplemental data. METHODS The cohort included HIV patients who received care at six HIV clinics in the United States, from 1 April 2009 to 31 March 2013, and had two or more viral load tests during this interval. Person-time (in days) above a viral load of 1500 copies/ml out of the total observation time was determined by inspecting consecutive pairs of viral load results and the time intervals between those pairs. The person-time rate ratios comparing demographic and clinical subgroups were estimated with Poisson regression. RESULTS The cohort included 14 532 patients observed for a median of 1073 days with a median of nine viral load records. Ninety percent of the patients had been prescribed antiretroviral therapy. On average, viral load exceeded 1500 copies/ml during 23% of the patients' observation time (average of 84 days per year, per patient). Percentage of person-time above the threshold was higher among patients who had more than a fourth of their viral load pairs exceeding a 6-month interval (34% of observation time), patients not on antiretroviral therapy (58% of time), new/re-engaging patients (34% of time), patients 16-39 years of age (32% of time), and patients of black race (26% of time). CONCLUSION HIV patients in care spent an average of nearly a quarter of their time with viral loads above 1500 copies/ml, higher among some subgroups, placing them at risk for potentially transmitting HIV to others.
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Calvo-Cidoncha E, González-Bueno J, Almeida-González CV, Morillo-Verdugo R. Influence of treatment complexity on adherence and incidence of blips in HIV/HCV coinfected patients. J Manag Care Spec Pharm 2015; 21:153-7. [PMID: 25615004 PMCID: PMC10397842 DOI: 10.18553/jmcp.2015.21.2.153] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The addition of antihepatitis C therapy to highly active antiretroviral treatment (HAART) in human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfected patients leads to an increase in the treatment complexity that may result in decreased adherence. Blips, defined as intermittent episodes of detectable low-level HIV viremia, may be an indication of poor adherence to HAART. OBJECTIVES To (a) determine the influence of adding anti-HCV therapy to HAART on complexity index, adherence, and incidence of blips and (b) determine complexity index and adherence in patient subgroups based on anti-HCV therapy. METHODS We conducted a prospective 2-center observational study. HIV/HCV coinfected patients under antiretroviral treatment who started anti-HCV bi-therapy or triple therapy between January 2011 and December 2013 were included. Patients were excluded if they were virologically uncontrolled (HIV viral load greater than 50 copies RNA/mL) or if they had changed antiretroviral treatment in the 6 months prior to the introduction of anti-HCV therapy. Data were collected before and after the addition of anti-HCV therapy to HAART. The main variables were complexity index, incidence of blips, and adherence. The complexity index was based on a score that utilized the number of pills per day, dosing schedule, dosage form, and any specific instructions linked to use of the drug. Blips were defined as a detectable HIV-RNA level ( greater than 50 copies/mL but no more than 1,000 copies/mL) occurring between 2 negative assays. Medication adherence was assessed using electronic pharmacy refill records. The threshold for optimal adherence was defined at 95% and above. Differences in the variables collected were assessed before and after the addition of anti-HCV therapy to HAART.R ESULTS: A total of 66 patients were included in the study. Based on the complexity index, the median value before and after the addition of anti-HCV therapy to HAART was 4.2 (interquartile range [IQR] = 3.5-5.5) and 11.5 (IQR = 10.4-13.4), respectively. The median difference between both complexity indices was 6.9 (95% CI = 6.9-7, P less than 0.001). After introducing the anti-HCV therapy into HAART, the number of adherent patients decreased from 50 (75.8%) to 45 (68.2%, P greater than 0.05), and 12 (18.2%) patients presented blips (P less than 0.001). Subgroup analysis based on anti-HCV therapy showed that patients on boceprevir or telaprevir therapy had a higher complexity index, 16.8 (IQR = 6.0-18.4), compared with patients on bi-therapy anti-HCV, 11.3 (IQR = 10.3-12). The median difference was 6.0 (95% CI = 5.0-7.2, P less than 0.001). The number of adherent patients decreased only in patients on bi-therapy from 42 (79.2%) to 37 (69.8%, P greater than 0.05). CONCLUSIONS Adding anti-HCV therapy to antiretroviral treatment significantly increases treatment complexity and the incidence of blips. The introduction of anti-HCV therapy is also associated with a decrease in the number of adherent patients. The regimen complexity calculation may be useful for identifying patients who need more care from health care professionals or are at risk for failure to comply with treatment regimens.
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Is forced migration a barrier to treatment success? Similar HIV treatment outcomes among refugees and a surrounding host community in Kuala Lumpur, Malaysia. AIDS Behav 2014; 18:323-34. [PMID: 23748862 PMCID: PMC3905173 DOI: 10.1007/s10461-013-0494-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In response to an absence of studies among refugees and host communities accessing highly active antiretroviral therapy (HAART) in urban settings, our objective was to compare adherence and virological outcomes among clients attending a public clinic in Kuala Lumpur, Malaysia. A cross-sectional survey was conducted among adult clients (≥18 years). Data sources included a structured questionnaire that measured self-reported adherence, a pharmacy-based measure of HAART prescription refills over the previous 24 months, and HIV viral loads. The primary outcome was unsuppressed viral load (≥40 copies/mL). Among a sample of 153 refugees and 148 host community clients, refugees were younger (median age 35 [interquartile range, IQR 31, 39] vs 40 years [IQR 35, 48], p < 0.001), more likely to be female (36 vs 21 %, p = 0.004), and to have been on HAART for less time (61 [IQR 35, 108] vs 153 weeks [IQR 63, 298]; p < 0.001). Among all clients, similar proportions of refugee and host clients were <95 % adherent to pharmacy refills (26 vs 34 %, p = 0.15). When restricting to clients on treatment for ≥25 weeks, similar proportions from each group were not virologically suppressed (19 % of refugees vs 16 % of host clients, p = 0.54). Refugee status was not independently associated with the outcome (adjusted odds ratio, aOR = 1.28, 95 % CI 0.52, 3.14). Overall, the proportions of refugee and host community clients with unsuppressed viral loads and sub-optimal adherence were similar, supporting the idea that refugees in protracted asylum situations are able to sustain good treatment outcomes and should explicitly be included in the HIV strategic plans of host countries with a view to expanding access in accordance with national guidelines for HAART.
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