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Markmann JF, Rickels MR, Eggerman TL, Bridges ND, Lafontant DE, Qidwai J, Foster E, Clarke WR, Kamoun M, Alejandro R, Bellin MD, Chaloner K, Czarniecki CW, Goldstein JS, Hering BJ, Hunsicker LG, Kaufman DB, Korsgren O, Larsen CP, Luo X, Naji A, Oberholzer J, Posselt AM, Ricordi C, Senior PA, Shapiro AMJ, Stock PG, Turgeon NA. Phase 3 trial of human islet-after-kidney transplantation in type 1 diabetes. Am J Transplant 2021; 21:1477-1492. [PMID: 32627352 PMCID: PMC9074710 DOI: 10.1111/ajt.16174] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 01/25/2023]
Abstract
Allogeneic islet transplant offers a minimally invasive option for β cell replacement in the treatment of type 1 diabetes (T1D). The CIT consortium trial of purified human pancreatic islets (PHPI) in patients with T1D after kidney transplant (CIT06), a National Institutes of Health-sponsored phase 3, prospective, open-label, single-arm pivotal trial of PHPI, was conducted in 24 patients with impaired awareness of hypoglycemia while receiving intensive insulin therapy. PHPI were manufactured using standardized processes. PHPI transplantation was effective with 62.5% of patients achieving the primary endpoint of freedom from severe hypoglycemic events and HbA1c ≤ 6.5% or reduced by ≥ 1 percentage point at 1 year posttransplant. Median HbA1c declined from 8.1% before to 6.0% at 1 year and 6.3% at 2 and 3 years following transplant (P < .001 for all vs baseline), with related improvements in hypoglycemia awareness and glucose variability. The improved metabolic control was associated with better health-related and diabetes-related quality of life. The procedure was safe and kidney allograft function remained stable after 3 years. These results add to evidence establishing allogeneic islet transplant as a safe and effective treatment for patients with T1D and unstable glucose control despite intensive insulin treatment, supporting the indication for PHPI in the post-renal transplant setting.
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Affiliation(s)
- James F. Markmann
- Division of Transplant Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Michael R. Rickels
- Division of Endocrinology, Diabetes & Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Thomas L. Eggerman
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Nancy D. Bridges
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - David E. Lafontant
- Clinical Trials Statistical and Data Management Center, University of Iowa, Iowa City, Iowa
| | - Julie Qidwai
- Clinical Trials Statistical and Data Management Center, University of Iowa, Iowa City, Iowa
| | - Eric Foster
- Ferring Pharmaceuticals, Parsippany, New Jersey
| | - William R. Clarke
- Clinical Trials Statistical and Data Management Center, University of Iowa, Iowa City, Iowa
| | - Malek Kamoun
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rodolfo Alejandro
- Diabetes Research Institute and Clinical Cell Transplant Program, University of Miami Miller School of Medicine, Miami, Florida
| | - Melena D. Bellin
- Department of Endocrinology, University of Minnesota, Minneapolis, Minnesota
| | - Kathryn Chaloner
- Clinical Trials Statistical and Data Management Center, University of Iowa, Iowa City, Iowa
| | - Christine W. Czarniecki
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Julia S. Goldstein
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Bernhard J. Hering
- Schulze Diabetes Institute and Department of Surgery, University of Minnesota, Minneapolis, Minnesota
| | - Lawrence G. Hunsicker
- Clinical Trials Statistical and Data Management Center, University of Iowa, Iowa City, Iowa
| | - Dixon B. Kaufman
- Division of Transplantation, Department of Surgery, University of Wisconsin, Madison, Wisconsin
| | - Olle Korsgren
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | | | - Xunrong Luo
- Department of Medicine, Duke University, Durham, North Carolina
| | - Ali Naji
- Division of Transplantation, Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - José Oberholzer
- Department of Surgery, University of Illinois, Chicago, Illinois
| | - Andrew M. Posselt
- Department of Surgery, University of California, San Francisco, California
| | - Camillo Ricordi
- Diabetes Research Institute and Clinical Cell Transplant Program, University of Miami Miller School of Medicine, Miami, Florida
| | - Peter A. Senior
- Clinical Islet Transplant Program and Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - A. M. James Shapiro
- Clinical Islet Transplant Program and Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Peter G. Stock
- Department of Surgery, University of California, San Francisco, California
| | - Nicole A. Turgeon
- Department of Surgery, University of Texas Dell Medical School, Austin, Texas
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2
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Ansite J, Balamurugan AN, Barbaro B, Battle J, Brandhorst D, Cano J, Chen X, Deng S, Feddersen D, Friberg A, Gilmore T, Goldstein JS, Holbrook E, Khan A, Kin T, Lei J, Linetsky E, Liu C, Luo X, McElvaney K, Min Z, Moreno J, O'Gorman D, Papas KK, Putz G, Ricordi C, Szot G, Templeton T, Wang L, Wilhelm JJ, Willits J, Wilson T, Zhang X, Avila J, Begley B, Cano J, Carpentier S, Holbrook E, Hutchinson J, Larsen CP, Moreno J, Sears M, Turgeon NA, Webster D, Deng S, Lei J, Markmann JF, Bridges ND, Czarniecki CW, Goldstein JS, Putz G, Templeton T, Wilson T, Eggerman TL, Al-Saden P, Battle J, Chen X, Hecyk A, Kissler H, Luo X, Molitch M, Monson N, Stuart E, Wallia A, Wang L, Wang S, Zhang X, Bigam D, Campbell P, Dinyari P, Kin T, Kneteman N, Lyon J, Malcolm A, O'Gorman D, Onderka C, Owen R, Pawlick R, Richer B, Rosichuk S, Sarman D, Schroeder A, Senior PA, Shapiro AMJ, Toth L, Toth V, Zhai W, Johnson K, McElroy J, Posselt AM, Ramos M, Rojas T, Stock PG, Szot G, Barbaro B, Martellotto J, Oberholzer J, Qi M, Wang Y, Bayman L, Chaloner K, Clarke W, Dillon JS, Diltz C, Doelle GC, Ecklund D, Feddersen D, Foster E, Hunsicker LG, Jasperson C, Lafontant DE, McElvaney K, Neill-Hudson T, Nollen D, Qidwai J, Riss H, Schwieger T, Willits J, Yankey J, Alejandro R, Corrales AC, Faradji R, Froud T, Garcia AA, Herrada E, Ichii H, Inverardi L, Kenyon N, Khan A, Linetsky E, Montelongo J, Peixoto E, Peterson K, Ricordi C, Szust J, Wang X, Abdulla MH, Ansite J, Balamurugan AN, Bellin MD, Brandenburg M, Gilmore T, Harmon JV, Hering BJ, Kandaswamy R, Loganathan G, Mueller K, Papas KK, Pedersen J, Wilhelm JJ, Witson J, Dalton-Bakes C, Fu H, Kamoun M, Kearns J, Li Y, Liu C, Luning-Prak E, Luo Y, Markmann E, Min Z, Naji A, Palanjian M, Rickels M, Shlansky-Goldberg R, Vivek K, Ziaie AS, Fernandez L, Kaufman DB, Zitur L, Brandhorst D, Friberg A, Korsgren O. Purified Human Pancreatic Islets, CIT Culture Media with Lisofylline or Exenatide. CellR4 Repair Replace Regen Reprogram 2017; 5:e2377. [PMID: 30613755 PMCID: PMC6319648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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3
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Hering BJ, Clarke WR, Bridges ND, Eggerman TL, Alejandro R, Bellin MD, Chaloner K, Czarniecki CW, Goldstein JS, Hunsicker LG, Kaufman DB, Korsgren O, Larsen CP, Luo X, Markmann JF, Naji A, Oberholzer J, Posselt AM, Rickels MR, Ricordi C, Robien MA, Senior PA, Shapiro AMJ, Stock PG, Turgeon NA. Phase 3 Trial of Transplantation of Human Islets in Type 1 Diabetes Complicated by Severe Hypoglycemia. Diabetes Care 2016; 39:1230-40. [PMID: 27208344 PMCID: PMC5317236 DOI: 10.2337/dc15-1988] [Citation(s) in RCA: 397] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 02/21/2016] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Impaired awareness of hypoglycemia (IAH) and severe hypoglycemic events (SHEs) cause substantial morbidity and mortality in patients with type 1 diabetes (T1D). Current therapies are effective in preventing SHEs in 50-80% of patients with IAH and SHEs, leaving a substantial number of patients at risk. We evaluated the effectiveness and safety of a standardized human pancreatic islet product in subjects in whom IAH and SHEs persisted despite medical treatment. RESEARCH DESIGN AND METHODS This multicenter, single-arm, phase 3 study of the investigational product purified human pancreatic islets (PHPI) was conducted at eight centers in North America. Forty-eight adults with T1D for >5 years, absent stimulated C-peptide, and documented IAH and SHEs despite expert care were enrolled. Each received immunosuppression and one or more transplants of PHPI, manufactured on-site under good manufacturing practice conditions using a common batch record and standardized lot release criteria and test methods. The primary end point was the achievement of HbA1c <7.0% (53 mmol/mol) at day 365 and freedom from SHEs from day 28 to day 365 after the first transplant. RESULTS The primary end point was successfully met by 87.5% of subjects at 1 year and by 71% at 2 years. The median HbA1c level was 5.6% (38 mmol/mol) at both 1 and 2 years. Hypoglycemia awareness was restored, with highly significant improvements in Clarke and HYPO scores (P > 0.0001). No study-related deaths or disabilities occurred. Five of the enrollees (10.4%) experienced bleeds requiring transfusions (corresponding to 5 of 75 procedures), and two enrollees (4.1%) had infections attributed to immunosuppression. Glomerular filtration rate decreased significantly on immunosuppression, and donor-specific antibodies developed in two patients. CONCLUSIONS Transplanted PHPI provided glycemic control, restoration of hypoglycemia awareness, and protection from SHEs in subjects with intractable IAH and SHEs. Safety events occurred related to the infusion procedure and immunosuppression, including bleeding and decreased renal function. Islet transplantation should be considered for patients with T1D and IAH in whom other, less invasive current treatments have been ineffective in preventing SHEs.
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Affiliation(s)
- Bernhard J Hering
- Schulze Diabetes Institute and Department of Surgery, University of Minnesota, Minneapolis, MN
| | - William R Clarke
- Clinical Trials Statistical and Data Management Center, University of Iowa, Iowa City, IA
| | - Nancy D Bridges
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Thomas L Eggerman
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Rodolfo Alejandro
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
| | - Melena D Bellin
- Schulze Diabetes Institute and Department of Pediatrics, University of Minnesota, Minneapolis, MN
| | - Kathryn Chaloner
- Clinical Trials Statistical and Data Management Center, University of Iowa, Iowa City, IA
| | - Christine W Czarniecki
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Julia S Goldstein
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Lawrence G Hunsicker
- Clinical Trials Statistical and Data Management Center, University of Iowa, Iowa City, IA
| | - Dixon B Kaufman
- Division of Transplantation, Department of Surgery, University of Wisconsin, Madison, WI
| | - Olle Korsgren
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | | | - Xunrong Luo
- Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - James F Markmann
- Division of Transplant Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Ali Naji
- Institute for Diabetes, Obesity and Metabolism and Departments of Surgery and Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Jose Oberholzer
- Division of Transplantation, University of Illinois Hospital and Health Sciences System, Chicago, IL
| | - Andrew M Posselt
- Department of Surgery, University of California, San Francisco, San Francisco, CA
| | - Michael R Rickels
- Institute for Diabetes, Obesity and Metabolism and Departments of Surgery and Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Camillo Ricordi
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
| | - Mark A Robien
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Peter A Senior
- Clinical Islet Transplant Program and Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - A M James Shapiro
- Clinical Islet Transplant Program and Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Peter G Stock
- Department of Surgery, University of California, San Francisco, San Francisco, CA
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Zhang J, Zhang Y, Chaloner K, Stapleton JT. A sequential classification rule based on multiple quantitative tests in the absence of a gold standard. Stat Med 2015; 35:1359-72. [PMID: 26522690 DOI: 10.1002/sim.6780] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 09/20/2015] [Accepted: 10/06/2015] [Indexed: 12/19/2022]
Abstract
In many medical applications, combining information from multiple biomarkers could yield a better diagnosis than any single one on its own. When there is a lack of a gold standard, an algorithm of classifying subjects into the case and non-case status is necessary for combining multiple markers. The aim of this paper is to develop a method to construct a composite test from multiple applicable tests and derive an optimal classification rule under the absence of a gold standard. Rather than combining the tests, we treat the tests as a sequence. This sequential composite test is based on a mixture of two multivariate normal latent models for the distribution of the test results in case and non-case groups, and the optimal classification rule is derived returning the greatest sensitivity at a given specificity. This method is applied to a real-data example and simulation studies have been carried out to assess the statistical properties and predictive accuracy of the proposed composite test. This method is also attainable to implement nonparametrically.
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Affiliation(s)
- Jingyang Zhang
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, U.S.A
| | - Ying Zhang
- Department of Biostatistics, Indiana University Fairbanks School of Public Health and School of Medicine, Indianapolis, IN 46202, U.S.A.,Department of Mathematics, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Kathryn Chaloner
- Department of Biostatistics, University of Iowa, Iowa City, IA 52242, U.S.A.,Department of Statistics and Actuarial Sciences, University of Iowa, Iowa City, IA 52242, U.S.A
| | - Jack T Stapleton
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, U.S.A
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5
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Diwakar A, Adam RJ, Michalski AS, Tamegnon MM, Fischer AJ, Launspach JL, Horan RA, Kao SC, Chaloner K, Meyerholz DK, Stoltz DA. Sonographic evidence of abnormal tracheal cartilage ring structure in cystic fibrosis. Laryngoscope 2015; 125:2398-404. [PMID: 25827636 DOI: 10.1002/lary.25255] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/13/2015] [Accepted: 02/18/2015] [Indexed: 11/10/2022]
Abstract
OBJECTIVES/HYPOTHESIS Tracheal cartilage ring structural abnormalities have been reported in cystic fibrosis (CF) mice and pigs. Whether similar findings are present in humans with CF is unknown. We hypothesized that tracheal cartilage ring shape and size would be different in people with CF. STUDY DESIGN Tracheal cartilage ring size and shape were measured in adults with (n = 21) and without CF (n = 18). METHODS Ultrasonography was used in human subjects to noninvasively assess tracheal cartilage ring structure in both the sagittal and the transverse planes. Tracheal cartilage ring thickness was also determined from histological sections obtained from newborn non-CF and CF pigs. These values were compared with human data. RESULTS Human CF tracheas had a greater width and were less circular in shape compared to non-CF subjects. CF tracheal cartilage rings had a greater midline cross-sectional area and were thicker compared to non-CF rings. Maximal tracheal cartilage ring thickness was also greater in both newborn CF pigs and human adults with CF, compared to non-CF controls. CONCLUSIONS Our findings demonstrate that structural differences exist in tracheal cartilage rings in adults with CF. Comparison with newborn CF pig data suggests that some of these changes may be congenital in nature. LEVEL OF EVIDENCE 3b
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Affiliation(s)
- Amit Diwakar
- Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa
| | - Ryan J Adam
- Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa.,Department of Biomedical Engineering, College of Engineering, University of Iowa, Iowa City, Iowa
| | - Andrew S Michalski
- Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa
| | - Monelle M Tamegnon
- Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, Iowa, U.S.A
| | - Anthony J Fischer
- Department of Pediatrics, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa
| | - Jan L Launspach
- Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa
| | - Rebecca A Horan
- Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa
| | - Simon C Kao
- Department of Radiology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa
| | - Kathryn Chaloner
- Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, Iowa, U.S.A
| | - David K Meyerholz
- Department of Pathology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa
| | - David A Stoltz
- Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa.,Department of Molecular Physiology and Biophysics, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa.,Department of Biomedical Engineering, College of Engineering, University of Iowa, Iowa City, Iowa
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Price MP, Gong H, Parsons MG, Kundert JR, Reznikov LR, Bernardinelli L, Chaloner K, Buchanan GF, Wemmie JA, Richerson GB, Cassell MD, Welsh MJ. Localization and behaviors in null mice suggest that ASIC1 and ASIC2 modulate responses to aversive stimuli. Genes Brain Behav 2013; 13:179-94. [PMID: 24256442 DOI: 10.1111/gbb.12108] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/25/2013] [Accepted: 11/18/2013] [Indexed: 12/21/2022]
Abstract
Acid-sensing ion channels (ASICs) generate H(+) -gated Na(+) currents that contribute to neuronal function and animal behavior. Like ASIC1, ASIC2 subunits are expressed in the brain and multimerize with ASIC1 to influence acid-evoked currents and facilitate ASIC1 localization to dendritic spines. To better understand how ASIC2 contributes to brain function, we localized the protein and tested the behavioral consequences of ASIC2 gene disruption. For comparison, we also localized ASIC1 and studied ASIC1(-/-) mice. ASIC2 was prominently expressed in areas of high synaptic density, and with a few exceptions, ASIC1 and ASIC2 localization exhibited substantial overlap. Loss of ASIC1 or ASIC2 decreased freezing behavior in contextual and auditory cue fear conditioning assays, in response to predator odor and in response to CO2 inhalation. In addition, loss of ASIC1 or ASIC2 increased activity in a forced swim assay. These data suggest that ASIC2, like ASIC1, plays a key role in determining the defensive response to aversive stimuli. They also raise the question of whether gene variations in both ASIC1 and ASIC2 might affect fear and panic in humans.
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Affiliation(s)
- M P Price
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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Winokur PL, Chaloner K, Doern GV, Ferreira J, Apicella MA. Safety and immunological outcomes following human inoculation with nontypeable Haemophilus influenzae. J Infect Dis 2013; 208:728-38. [PMID: 23715660 PMCID: PMC3733507 DOI: 10.1093/infdis/jit238] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 03/13/2013] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Nontypeable Haemophilus influenzae (NTHi) exclusively infects humans, causing significant numbers of upper respiratory tract infections. The goal of this study was to develop a safe experimental human model of NTHi nasopharyngeal colonization. METHODS A novel streptomycin-resistant strain of NTHi was developed, and 15 subjects were inoculated in an adaptive-design phase I trial to rapidly identify colonizing doses of NTHi. Bayesian analysis was used to estimate the human colonizing dose 50 and 90 (HCD50 and HCD90, respectively). Side effects and immunological responses to whole-cell sialylated NTHi were measured. RESULTS Nine subjects were colonized and tolerated colonization well. Immunological analyses demonstrated that 7 colonized subjects and 0 noncolonized subjects had a 4-fold rise in serum levels of immunoglobulin A, immunoglobulin M, or immunoglobulin G. Preexisting immunity to whole-cell NTHi did not predict success or failure of colonization. CONCLUSIONS The statistical design incorporated a slow escalation to higher dose levels. HCD50 and HCD90 Bayesian estimates were identified as approximately 2000 and 150 000 colony-forming units, respectively; credible interval estimates were broad. This study provides a potential platform for early proof of concept studies for NTHi vaccines, as well as a way to evaluate bacterial factors associated with colonization.
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Affiliation(s)
- Patricia L Winokur
- Department of Internal Medicine, Division of Infectious Diseases, University of Iowa, 200 Hawkins Dr, Iowa City,IA 52242, USA.
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Poole J, Foster E, Chaloner K, Hunt J, Jennings MP, Bair T, Knudtson K, Christensen E, Munson RS, Winokur PL, Apicella MA. Analysis of nontypeable haemophilus influenzae phase-variable genes during experimental human nasopharyngeal colonization. J Infect Dis 2013; 208:720-7. [PMID: 23715658 DOI: 10.1093/infdis/jit240] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Studies of nontypeable Haemophilus influenzae (NTHi) have demonstrated that a number of genes associated with infectivity have long repeat regions associated with phase variation in expression of the respective gene. The purpose of this study was to determine the genes that underwent phase variation during a 6-day period of experimental human nasopharyngeal colonization. METHODS Strain NTHi 2019Str(R)1 was used to colonize the nasopharynx of human subjects in a study of experimental colonization. Thirteen phase-variable genes were analyzed in NTHi 2019Str(R)1. Samples of NTHi 2019Str(R)1 were cultured from subjects during the 6-day colonization period. We used capillary electrophoresis and Roche 454 pyrosequencing to determine the number of repeats in each gene from each sample. RESULTS A significant number of samples switched licA and igaB from phase off in the inoculated strain to phase on during the 4-day period of observation. lex2A also showed variability as compared to baseline, but the differences were not significant. The remaining genes showed no evidence of phase variation. CONCLUSIONS Our studies suggest that the phase-on genotypes of licA and igaB are important for early human nasopharynx colonization. lex2A showed a trend from phase off to phase on, suggesting a potentially important role in the colonization process.
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Affiliation(s)
- Jessica Poole
- Department of Microbiology, University of Iowa, Iowa City, IA 52242, USA
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Zhang J, Chaloner K, McLinden JH, Stapleton JT. Bayesian analysis and classification of two enzyme-linked immunosorbent assay tests without a gold standard. Stat Med 2013; 32:4102-17. [DOI: 10.1002/sim.5816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 03/18/2013] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - James H. McLinden
- Department of Internal Medicine; University of Iowa; Iowa City; IA; U.S.A
| | - Jack T. Stapleton
- Department of Internal Medicine; University of Iowa; Iowa City; IA; U.S.A
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Stapleton JT, Chaloner K, Martenson JA, Zhang J, Klinzman D, Xiang J, Sauter W, Desai SN, Landay A. GB virus C infection is associated with altered lymphocyte subset distribution and reduced T cell activation and proliferation in HIV-infected individuals. PLoS One 2012; 7:e50563. [PMID: 23209780 PMCID: PMC3510065 DOI: 10.1371/journal.pone.0050563] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/23/2012] [Indexed: 01/27/2023] Open
Abstract
GBV-C infection is associated with prolonged survival and with reduced T cell activation in HIV-infected subjects not receiving combination antiretroviral therapy (cART). The relationship between GBV-C and T cell activation in HIV-infected subjects was examined. HIV-infected subjects on cART with non-detectable HIV viral load (VL) or cART naïve subjects were studied. GBV-C VL and HIV VL were determined. Cell surface markers of activation (CD38(+)/HLA-DR(+)), proliferation (Ki-67+), and HIV entry co-receptor expression (CCR5+ and CXCR4+) on total CD4+ and CD8+ T cells, and on naïve, central memory (CM), effector memory (EM), and effector CD4+ and CD8+ subpopulations were measured by flow cytometry. In subjects with suppressed HIV VL, GBV-C was consistently associated with reduced activation in naïve, CM, EM, and effector CD4+ cells. GBV-C was associated with reduced CD4+ and CD8+ T cell surface expression of activation and proliferation markers, independent of HIV VL classification. GBV-C was also associated with higher proportions of naïve CD4+ and CD8+ T cells, and with lower proportions of EM CD4+ and CD8+ T cells. In conclusion, GBV-C infection was associated with reduced activation of CD4+ and CD8+ T cells in both HIV viremic and HIV RNA suppressed patients. Those with GBV-C infection demonstrated an increased proportion of naive T cells and a reduction in T cell activation and proliferation independent of HIV VL classification, including those with suppressed HIV VL on cART. Since HIV pathogenesis is thought to be accelerated by T cell activation, these results may contribute to prolonged survival among HIV infected individuals co-infected with GBV-C. Furthermore, since cART therapy does not reduce T cell activation to levels seen in HIV-uninfected people, GBV-C infection may be beneficial for HIV-related diseases in those effectively treated with anti-HIV therapy.
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Affiliation(s)
- Jack T Stapleton
- Research and Medical Services, Iowa City VA Medical Center, Iowa City, Iowa, United States of America.
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Butler JE, Sun X, Wertz N, Lager KM, Chaloner K, Urban J, Francis DL, Nara PL, Tobin GJ. Antibody repertoire development in fetal and neonatal piglets XXI. Usage of most VH genes remains constant during fetal and postnatal development. Mol Immunol 2011; 49:483-94. [PMID: 22018637 DOI: 10.1016/j.molimm.2011.09.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 09/22/2011] [Accepted: 09/24/2011] [Indexed: 01/15/2023]
Abstract
Usage of variable region gene segments during development of the antibody repertoire in mammals is unresolved in part because of the complexity of the locus in mice and humans and the difficulty of distinguishing intrinsic from extrinsic influences in these species. We present the first vertical studies on VH usage that spans the fetal and neonatal period using the piglet model. We tracked VH usage in DNA rearrangements and in VDJ transcripts throughout 75 days of gestation (DG) in outbred fetuses, thereafter in outbred germfree and colonized isolator piglets, isolator piglets infected with swine influenza and in conventionally reared nematode-infected adults. Seven VH genes account for >90% of the pre-immune repertoire which is the same among tissues and in both transcripts and DNA rearrangements. Statistical modeling supports the view that proportional usage of the major genes remains constant during fetal life and that postnatal usage ranking is similar to that during fetal life. Changes in usage ranking are developmental not antigen dependent. In this species exposure to environmental antigens results in diversification of the repertoire by somatic hypermutation of the same small number of VH genes that comprise the pre-immune repertoire, not by using other VH gene available in the germline. Therefore in swine a small number of VH genes shape the antibody repertoire throughout life questioning the need for extensive VH polygeny.
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Affiliation(s)
- John E Butler
- Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
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Bratsch S, Wertz N, Chaloner K, Kunz TH, Butler JE. The little brown bat, M. lucifugus, displays a highly diverse V H, D H and J H repertoire but little evidence of somatic hypermutation. Dev Comp Immunol 2011; 35:421-430. [PMID: 20547175 DOI: 10.1016/j.dci.2010.06.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 06/02/2010] [Accepted: 06/04/2010] [Indexed: 05/29/2023]
Abstract
Myotis lucifugus populations in Northeastern US are being decimated by a fungal disease. Since almost nothing is known about the immune system of bats, we are characterizing the immunoglobulin genes of bats. We show that M. lucifugus has a diverse V(H) gene repertoire comprised of five of the seven human V(H) gene families and an estimated 236V(H)3 genes. 95% of these germline VH3 genes differ in FR3. A comparison of 67 expressed V(H)3 genes with 75 germline V(H)3 genes revealed a mutation frequency similar to fetal piglets never exposed to environmental antigens. Analysis of CDR3 regions identified at least 13 putative J(H) segments and a large D(H) repertoire. The low mutation frequency, highly diverse V(H), D(H), and J(H) germline repertoire suggests that this species may rely more on combinatorial and junctional diversity than on somatic hypermutation raising questions about the ability of M. lucifugus to respond rapidly to emerging pathogens.
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Affiliation(s)
- Sara Bratsch
- Department of Biology, University of Wisconsin-River Falls, River Falls, WI, USA
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Chen JH, Stoltz DA, Karp PH, Ernst SE, Pezzulo AA, Moninger TO, Rector MV, Reznikov LR, Launspach JL, Chaloner K, Zabner J, Welsh MJ. Loss of anion transport without increased sodium absorption characterizes newborn porcine cystic fibrosis airway epithelia. Cell 2011; 143:911-23. [PMID: 21145458 DOI: 10.1016/j.cell.2010.11.029] [Citation(s) in RCA: 176] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Revised: 08/31/2010] [Accepted: 11/02/2010] [Indexed: 10/18/2022]
Abstract
Defective transepithelial electrolyte transport is thought to initiate cystic fibrosis (CF) lung disease. Yet, how loss of CFTR affects electrolyte transport remains uncertain. CFTR⁻(/)⁻ pigs spontaneously develop lung disease resembling human CF. At birth, their airways exhibit a bacterial host defense defect, but are not inflamed. Therefore, we studied ion transport in newborn nasal and tracheal/bronchial epithelia in tissues, cultures, and in vivo. CFTR⁻(/)⁻ epithelia showed markedly reduced Cl⁻ and HCO₃⁻ transport. However, in contrast to a widely held view, lack of CFTR did not increase transepithelial Na(+) or liquid absorption or reduce periciliary liquid depth. Like human CF, CFTR⁻(/)⁻ pigs showed increased amiloride-sensitive voltage and current, but lack of apical Cl⁻ conductance caused the change, not increased Na(+) transport. These results indicate that CFTR provides the predominant transcellular pathway for Cl⁻ and HCO₃⁻ in porcine airway epithelia, and reduced anion permeability may initiate CF airway disease.
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Affiliation(s)
- Jeng-Haur Chen
- Department of Internal Medicine, University of Iowa, Iowa City, 52242, USA
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Apicella MA, Post DMB, Fowler AC, Jones BD, Rasmussen JA, Hunt JR, Imagawa S, Choudhury B, Inzana TJ, Maier TM, Frank DW, Zahrt TC, Chaloner K, Jennings MP, McLendon MK, Gibson BW. Identification, characterization and immunogenicity of an O-antigen capsular polysaccharide of Francisella tularensis. PLoS One 2010; 5:e11060. [PMID: 20625403 PMCID: PMC2897883 DOI: 10.1371/journal.pone.0011060] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Accepted: 05/14/2010] [Indexed: 11/18/2022] Open
Abstract
Capsular polysaccharides are important factors in bacterial pathogenesis and have been the target of a number of successful vaccines. Francisella tularensis has been considered to express a capsular antigen but none has been isolated or characterized. We have developed a monoclonal antibody, 11B7, which recognizes the capsular polysaccharide of F. tularensis migrating on Western blot as a diffuse band between 100 kDa and 250 kDa. The capsule stains poorly on SDS-PAGE with silver stain but can be visualized using ProQ Emerald glycoprotein stain. The capsule appears to be highly conserved among strains of F. tularensis as antibody 11B7 bound to the capsule of 14 of 14 F. tularensis type A and B strains on Western blot. The capsular material can be isolated essentially free of LPS, is phenol and proteinase K resistant, ethanol precipitable and does not dissociate in sodium dodecyl sulfate. Immunoelectron microscopy with colloidal gold demonstrates 11B7 circumferentially staining the surface of F. tularensis which is typical of a polysaccharide capsule. Mass spectrometry, compositional analysis and NMR indicate that the capsule is composed of a polymer of the tetrasaccharide repeat, 4)-alpha-D-GalNAcAN-(1->4)-alpha-D-GalNAcAN-(1->3)-beta-D-QuiNAc-(1->2)-beta-D-Qui4NFm-(1-, which is identical to the previously described F. tularensis O-antigen subunit. This indicates that the F. tularensis capsule can be classified as an O-antigen capsular polysaccharide. Our studies indicate that F. tularensis O-antigen glycosyltransferase mutants do not make a capsule. An F. tularensis acyltransferase and an O-antigen polymerase mutant had no evidence of an O-antigen but expressed a capsular antigen. Passive immunization of BALB/c mice with 75 microg of 11B7 protected against a 150 fold lethal challenge of F. tularensis LVS. Active immunization of BALB/c mice with 10 microg of capsule showed a similar level of protection. These studies demonstrate that F. tularensis produces an O-antigen capsule that may be the basis of a future vaccine.
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Affiliation(s)
- Michael A Apicella
- Department of Microbiology, University of Iowa, Iowa City, Iowa, United States of America.
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Zhang S, Zhang Y, Chaloner K, Stapleton JT. A copula model for bivariate hybrid censored survival data with application to the MACS study. Lifetime Data Anal 2010; 16:231-249. [PMID: 19921432 PMCID: PMC3567926 DOI: 10.1007/s10985-009-9139-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Accepted: 10/31/2009] [Indexed: 05/28/2023]
Abstract
A copula model for bivariate survival data with hybrid censoring is proposed to study the association between survival time of individuals infected with HIV and persistence time of infection with an additional virus. Survival with HIV is right censored and the persistence time of the additional virus is subject to interval censoring case 1. A pseudo-likelihood method is developed to study the association between the two event times under such hybrid censoring. Asymptotic consistency and normality of the pseudo-likelihood estimator are established based on empirical process theory. Simulation studies indicate good performance of the estimator with moderate sample size. The method is applied to a motivating HIV study which investigates the effect of GB virus type C (GBV-C) co-infection on survival time of HIV infected individuals.
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Affiliation(s)
- Suhong Zhang
- Division of Biostatistics, Edwards Lifesciences, One Edwards Way,
Irvine, CA 92612, USA
| | - Ying Zhang
- Department of Biostatistics, University of Iowa, C22 GH, 200
Hawkins Drive, Iowa City, IA 52242, USA
| | - Kathryn Chaloner
- Department of Biostatistics, University of Iowa, C22 GH, 200
Hawkins Drive, Iowa City, IA 52242, USA
| | - Jack T. Stapleton
- Department of Internal Medicine, University of Iowa and Iowa City
VA Medical Center, SW54-15 GH, 200 Hawkins Drive, Iowa City, IA 52242, USA
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Abstract
Differences in treatment effects between centers in a multi-center trial may be important. These differences represent treatment by subgroup interaction. Peto defines qualitative interaction (QI) to occur when the simple treatment effect in one subgroup has a different sign than in another subgroup: this interaction is important. Interaction where the treatment effects are of the same sign in all subgroups is called quantitative and is often not important because the treatment recommendation is identical in all cases. A hierarchical model is used here with exchangeable mean responses to each treatment between subgroups. The posterior probability of QI and the corresponding Bayes factor are proposed as a diagnostic and as a test statistic. The model is motivated by two multi-center trials with binary responses. The frequentist power and size of the test using the Bayes factor are examined and compared with two other commonly used tests. The impact of imbalance between the sample sizes in each subgroup on power is examined, and the test based on the Bayes factor typically has better power for unbalanced designs, especially for small sample sizes. An exact test based on the Bayes factor is also suggested assuming the hierarchical model. The Bayes factor provides a concise summary of the evidence for or against QI. It is shown by example that it is easily adapted to summarize the evidence for 'clinically meaningful QI,' defined as the simple effects being of opposite signs and larger in absolute value than a minimal clinically meaningful effect.
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Abstract
In medical research, it is common to have doubly censored survival data: origin time and event time are both subject to censoring. In this paper, we review simple and probability-based methods that are used to impute interval censored origin time and compare the performance of these methods through extensive simulations in the one-sample problem, two-sample problem and Cox regression model problem. The use of a bootstrap procedure for inference is demonstrated.
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Affiliation(s)
- Wei Zhang
- Department of Biometrics, Boehringer Ingelheim Pharmaceuticals, Ridgefield, CT, USA
| | - Ying Zhang
- Department of Biostatistics, University of Iowa, Iowa City, IA, USA
| | - Kathryn Chaloner
- Department of Biostatistics, University of Iowa, Iowa City, IA, USA
| | - Jack T. Stapleton
- Department of Internal Medicine, University of Iowa and Iowa City VA Medical Center, Iowa City, IA, USA
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Abstract
Two common statistical problems in pooling survival data from several studies are addressed. The first problem is that the data are doubly censored in that the origin is interval censored and the endpoint event may be right censored. Two approaches to incorporate the uncertainty of interval-censored origins are developed, and then compared with more usual analyses using imputation of a single fixed value for each origin. The second problem is that the data are collected from multiple studies and it is likely that heterogeneity exists among the study populations. A random-effects hierarchical Cox proportional hazards model is therefore used. The scientific problem motivating this work is a pooled survival analysis of data sets from three studies to examine the effect of GB virus type C (GBV-C) coinfection on survival of HIV-infected individuals. The time of HIV infection is the origin and for each subject this time is unknown, but is known to lie later than the last time at which the subject was known to be HIV negative, and earlier than the first time the subject was known to be HIV positive. The use of an approximate Bayesian approach using the partial likelihood as the likelihood is recommended because it more appropriately incorporates the uncertainty of interval-censored HIV infection times.
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Affiliation(s)
- Wei Zhang
- Department of Biostatistics, University of Iowa, Iowa City, IA, USA.
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Chaloner K. Comments on ‘Bayesians in clinical trials: Asleep at the switch’ by Lemuel A. Moyé,Statistics in Medicine. Stat Med 2008. [DOI: 10.1002/sim.3174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
Continuous monitoring of treatment failures is an important issue in clinical studies of a single experimental treatment for high risk therapy such as hematopoietic stem cell transplantation. The sequential probability ratio test (SPRT) of Wald in 1947 and various alternative stopping rules have been proposed for sequential monitoring of adverse events. It is natural to use prior information to improve stopping rules and statistical analysis. A Bayesian stopping rule is developed and applied to an example of an umbilical cord blood transplant study performed at the University of Minnesota. Two strata, based on the number of nucleated cells per kg recipient body weight (the 'dose') are monitored separately and different rules are constructed for each stratum using different prior distributions. It is believed that patients in the lower dose group have a greater chance of graft failure than those in the higher dose group. A program, written in R, is also presented for calculating the stopping rule using the prior beliefs. The program is an improvement upon existing programs and it can be used for larger studies.
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Affiliation(s)
- C Chen
- School of Statistics, University of Minnesota, Minneapolis, MN, USA.
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Souza IE, Allen JB, Xiang J, Klinzman D, Diaz R, Zhang S, Chaloner K, Zdunek D, Hess G, Williams CF, Benning L, Stapleton JT. Effect of primer selection on estimates of GB virus C (GBV-C) prevalence and response to antiretroviral therapy for optimal testing for GBV-C viremia. J Clin Microbiol 2006; 44:3105-13. [PMID: 16954234 PMCID: PMC1594694 DOI: 10.1128/jcm.02663-05] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
GB virus C (GBV-C; also called hepatitis G virus) is a common cause of infection associated with prolonged survival among HIV-infected individuals. The prevalences of GBV-C viremia vary widely in different studies, and there has been poor agreement among different laboratories performing GBV-C RNA detection in quality control studies. To determine the optimal method of measuring GBV-C RNA in clinical samples, samples obtained from 939 HIV-infected subjects were studied using reverse transcription (RT)-PCR methods amplifying four separate regions of the GBV-C genome. Primers amplifying the E2 coding region were 100% specific; however, their sensitivity was only 76.6%. In contrast, primers amplifying three additional conserved regions of the GBV-C genome (the 5' nontranslated region and the nonstructural protein-coding regions 3 and 5A) were more sensitive but produced higher rates of false-positive results. Using low-specificity primer sets influenced the significance of association between GBV-C viremia and response to antiretroviral therapy. Using a quantitative GBV-C RNA method, the GBV-C RNA concentration did not correlate with baseline or set point HIV RNA levels; however, a correlation between negative, low, and high GBV-C RNA levels and increasing reduction in HIV RNA following antiretroviral therapy was observed. Subjects with both GBV-C E2 antibody and viremia had significantly lower GBV-C RNA levels than did viremic subjects without E2 antibody. These studies demonstrate that accurate detection of GBV-C RNA by nested RT-PCR requires the use of primers representing multiple genome regions. Analyses based on testing with single primers do not lead to reliable conclusions about the association between GBV-C infection and clinical outcomes.
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Affiliation(s)
- I E Souza
- Department of Internal Medicine, SW54-15, GH, University of Iowa, 200 Hawkins Drive, Iowa City, 52242, USA
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Abstract
OBJECTIVES To conduct a meta-analysis to synthesize the evidence regarding the effect of co-infection with GB virus C (GBV-C) on survival of HIV-infected individuals, and to estimate the effect. METHODS A Bayesian meta-analysis was conducted to synthesize evidence from eligible studies. Prospective survival studies of HIV-1-infected individuals, with outcome defined as time from baseline to all-cause death, were included and classified by whether GBV-C status was determined in early or late HIV disease. The primary measure was the hazard ratio (HR) of death for HIV-infected individuals with GBV-C infection versus those without GBV-C infection. RESULTS Eleven studies from eight publications met the inclusion criteria. For studies with GBV-C status measured 2 years or less after HIV seroconversion (912 subjects), the combined HR was 0.88 [95% credible interval (CI) 0.30, 1.50]. For studies with GBV-C status measured more than 2 years after HIV seroconversion (1294 subjects), the combined HR was 0.41 (95% CI 0.23, 0.69). CONCLUSIONS No conclusive evidence was found of an association between survival and GBV-C infection early in HIV disease. However, when GBV-C infection was present later in HIV disease, a significant reduction in the hazard for mortality was observed for those with co-infection. Potential explanations for this difference include a non-proportional benefit of GBV-C over time, possibly related to clearance of GBV-C infection early in HIV disease. The timing of GBV-C infection appears to account for the contradictory results of studies on the effect of GBV-C coinfection on survival of HIV-infected people.
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Affiliation(s)
- W Zhang
- Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
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Abstract
OBJECTIVES GB virus C (GBV-C) infection is associated with delayed mortality in HIV-infected people in most, but not all, studies. Previous investigations of the effect of GBV-C viraemia on response to antiretroviral therapy (ART) were inconclusive. To determine the effect of GBV-C on ART, we retrospectively analysed plasma samples taken from patients in a prospective randomized clinical trial of ART in HIV-positive Brazilians. METHODS GBV-C viraemia was characterized by testing stored serum samples from 175 participants by reverse transcriptase-polymerase chain reaction (RT-PCR). Subjects were randomized to receive indinavir (n=59), zidovudine and lamivudine (n=58), or zidovudine, lamivudine and indinavir (n=58). The effect of GBV-C viraemia on the average change in HIV viral load and CD4 count following initiation of therapy was evaluated in a multiple regression analysis. RESULTS The prevalence of GBV-C viraemia was similar to that observed in previous studies (24%). HIV viral load decreased following ART to a significantly greater extent in patients with GBV-C viraemia (by 0.48 log(10) HIV-1 RNA copies/mL, P=0.009, adjusting for age, ART group, and baseline CD4 count). Although there was no significant difference in change in CD4 count between individuals with and without GBV-C viraemia overall, CD4 counts were higher following 48 weeks of therapy in GBV-C viraemic individuals receiving the least potent ART regimen (zidovudine and lamivudine) compared with those without GBV-C infection. CONCLUSIONS GBV-C viraemia is associated with an enhanced reduction of HIV viral load in response to ART. In this study of treatment-naive individuals during 48 weeks of follow up, patients with GBV-C viraemia had reductions in HIV viral load that were approximately 0.5 log copies/mL greater than those found in patients without GBV-C viraemia. This is similar to reductions observed with nucleoside reverse transcriptase inhibitors.
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Affiliation(s)
- I E Souza
- Department of Internal Medicine, University of Iowa Roy, Iowa City, IA 52242, USA
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Stapleton JT, Chaloner K, Williams CF. GB Virus C Infection and Survival in the Amsterdam Cohort Study. J Infect Dis 2005; 191:2157-8; author reply 2158-60. [PMID: 15898008 DOI: 10.1086/430505] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Abstract
Bayesian experimental design is investigated for Bayesian analysis of nonlinear mixed-effects models. Existence of the posterior risk for parameter estimation is shown. When the same prior distribution is used for both design and inference, existence of the preposterior risk for design is also proven. If the prior distribution used in design is different from that used for inference, sufficient conditions are established for existence of the preposterior risk for design. A case study of design for an experiment in population HIV dynamics is provided.
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Affiliation(s)
- Cong Han
- TAP Pharmaceutical Products Inc., Lake Forest, Illinois 60045, USA.
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Fisher EJ, Chaloner K, Cohn DL, Grant LB, Alston B, Brosgart CL, Schmetter B, El-Sadr WM, Sampson J. The safety and efficacy of adefovir dipivoxil in patients with advanced HIV disease: a randomized, placebo-controlled trial. AIDS 2001; 15:1695-700. [PMID: 11546945 DOI: 10.1097/00002030-200109070-00013] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Efficacy and safety of adefovir dipivoxil (adefovir) added to background antiretroviral therapy in advanced HIV disease. DESIGN Randomized, double-blind, placebo-controlled multicenter trial. SETTING Fifteen clinical trial units providing HIV primary care. PARTICIPANTS Adults with CD4 cell count < or = 100 x 10(6)/l, or 101-200 x 10(6)/l with prior nadir < or = 50 x 10(6)/l. INTERVENTIONS Oral adefovir or placebo 120 mg once daily. MAIN OUTCOME MEASURES Survival, cytomegalovirus (CMV) disease, plasma HIV-RNA, CD4 cell count, grade 4 drug toxicity, permanent drug discontinuation due to toxicity. RESULTS Among the 253 patients assigned adefovir and the 252 assigned placebo, respectively, 17 and 16 died (P = 0.88), and four and eight experienced CMV disease (P = 0.25). Mean change in log(10) plasma HIV-RNA in the adefovir and placebo groups, respectively, was 0.09 and -0.03 copies/ml at 6 months (P = 0.22) and 0.06 and -0.02 at 12 months (P = 0.87). Changes in CD4 cell counts were not different between groups. At 12 months the cumulative percent with proximal renal tubular dysfunction (PRTD) was 17% in the adefovir group and 0.4% in the placebo group (P < 0.0001, log rank test). Median time to resolution of PRTD was 15 weeks among patients assigned adefovir, and 16% of patients did not resolve completely 41 weeks after onset. More drug discontinuations occurred in the adefovir group than in the placebo group. CONCLUSIONS No virologic or immunologic benefit was observed when adefovir was added to background antiretroviral therapy in advanced HIV disease, and adefovir was associated with considerable nephrotoxicity. This study does not support the use of adefovir for treatment of advanced HIV disease in pretreated patients.
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Affiliation(s)
- E J Fisher
- Richmond AIDS Consortium, Richmond, Virginia 23298-0049, USA
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Abstract
Collecting and documenting subjective prior beliefs from knowledgeable clinicians about the potential results of a clinical trial has many advantages. Two large trials of prophylactic treatments in an HIV-positive population are used as examples. The trials recruited patients of primary care physicians and compared treatments which were in use in clinical practice. Opinions about these trials were elicited from 58 practising HIV clinicians. It is shown how the documented opinions can be used to augment the monitoring process; the prior opinions are updated with interim data using approximate Bayesian methods to give posterior opinions incorporating interim results. These posterior opinions can be used by the monitoring board to anticipate the clinicians' reaction to the results. Eliciting prior beliefs is also ethically important for documenting the nature of the uncertainty or equipoise. Important information is provided for the informed consent process and Institutional Review Board (IRB).
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Affiliation(s)
- K Chaloner
- School of Statistics, University of Minnesota, 313 Ford Hall, 224 Church Street S.E., Minneapolis, MN 55455, USA.
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Abstract
OBJECTIVE To investigate the attitudes of cognitively normal older adults toward various life-sustaining procedures in the face of dementia. METHODS Participants were 84 cognitively normal men and women (70% response rate), 65 years and older, from a variety of urban and suburban settings, including private homes, assisted-living apartments, transitional care facilities, and nursing homes. In-person interviews were conducted with each participant to obtain information about demographic characteristics, life and health, and desire for various life-sustaining procedures for 4 hypothesized levels of dementia. RESULTS Approximately three fourths of participants said they would not want cardiopulmonary resuscitation, use of a respirator, or parenteral or enteral tube nutrition with the milder forms of dementia, and 95% or more of participants would not want these procedures with severe dementia. In addition, only one third or fewer participants thought they would want to be hospitalized or given antibiotics if they were severely demented. Logistic regression analysis showed a relationship between participants' desire for life-sustaining procedures and having less education, greater independence, and a higher perceived quality of life. CONCLUSIONS Most surveyed individuals did not desire life-sustaining treatments with any degree of dementia, and the proportion of individuals not desiring such treatments increased with the projected severity of dementia. These findings indicate a need for including dementia in advance directives planning.
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Affiliation(s)
- D K Gjerdingen
- Department of Family Practice and Community Health, University of Minnesota, St Paul, USA.
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Shlay JC, Chaloner K, Max MB, Flaws B, Reichelderfer P, Wentworth D, Hillman S, Brizz B, Cohn DL. Acupuncture and amitriptyline for pain due to HIV-related peripheral neuropathy: a randomized controlled trial. Terry Beirn Community Programs for Clinical Research on AIDS. JAMA 1998; 280:1590-5. [PMID: 9820261 DOI: 10.1001/jama.280.18.1590] [Citation(s) in RCA: 179] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Peripheral neuropathy is common in persons infected with the human immunodeficiency virus (HIV) but few data on symptomatic treatment are available. OBJECTIVE To evaluate the efficacy of a standardized acupuncture regimen (SAR) and amitriptyline hydrochloride for the relief of pain due to HIV-related peripheral neuropathy in HIV-infected patients. DESIGN Randomized, placebo-controlled, multicenter clinical trial. Each site enrolled patients into 1 of the following 3 options: (1) a modified double-blind 2 x 2 factorial design of SAR, amitriptyline, or the combination compared with placebo, (2) a modified double-blind design of an SAR vs control points, or (3) a double-blind design of amitriptyline vs placebo. SETTING Terry Beirn Community Programs for Clinical Research on AIDS (HIV primary care providers) in 10 US cities. PATIENTS Patients with HIV-associated, symptomatic, lower-extremity peripheral neuropathy. Of 250 patients enrolled, 239 were in the acupuncture comparison (125 in the factorial option and 114 in the SAR option vs control points option), and 136 patients were in the amitriptyline comparison (125 in the factorial option and 11 in amitriptyline option vs placebo option). INTERVENTIONS Standardized acupuncture regimen vs control points, amitriptyline (75 mg/d) vs placebo, or both for 14 weeks. MAIN OUTCOME MEASURE Changes in mean pain scores at 6 and 14 weeks, using a pain scale ranging from 0.0 (no pain) to 1.75 (extremely intense), recorded daily. RESULTS Patients in all 4 groups showed reduction in mean pain scores at 6 and 14 weeks compared with baseline values. For both the acupuncture and amitriptyline comparisons, changes in pain score were not significantly different between the 2 groups. At 6 weeks, the estimated difference in pain reduction for patients in the SAR group compared with those in the control points group (a negative value indicates a greater reduction for the "active" treatment) was 0.01 (95% confidence interval [CI], -0.11 to 0.12; P=.88) and for patients in the amitriptyline group vs those in the placebo group was -0.07 (95% CI, -0.22 to 0.08; P=.38). At 14 weeks, the difference for those in the SAR group compared with those in the control points group was -0.08 (95% CI, -0.21 to 0.06; P=.26) and for amitriptyline compared with placebo was 0.00 (95% CI, -0.18 to 0.19; P=.99). CONCLUSIONS In this study, neither acupuncture nor amitriptyline was more effective than placebo in relieving pain caused by HIV-related peripheral neuropathy.
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Affiliation(s)
- J C Shlay
- Denver Community Programs for Clinical Research on AIDS, Colo, USA.
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Affiliation(s)
- D K Gjerdingen
- Department of Family Practice and Community Health, University of Minnesota, St Paul, USA.
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Ziegel ER, Berry D, Chaloner K, Geweke J. Bayesian Analysis in Statistics and Econometrics. Technometrics 1997. [DOI: 10.2307/1270799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
This prospective, longitudinal study was conducted to investigate the changes in the division of household labor, and in the emotional and practical support received by new mothers during the first postpartum year. Questionnaires were completed by 436 married, recently employed mothers at 1, 3, 6, 9, and 12 months after they had delivered their first child. Results showed that women assumed primary responsibility for the majority of household tasks studied, and that they perceived declines over time in their husbands' participation in household chores, their husbands' and others' expressions of caring, and in the frequency with which friends and relatives "helped out" during the year. Women who had had cesarean sections (versus those with vaginal deliveries) and who returned to work (versus those who stayed home) believed their husbands participated more in traditionally feminine household chores. Women's satisfaction with their husbands' contribution to household activities was significantly related to their own mental health, delivery type (cesarean section), job status (being at home vs. back at work), and family income; and to their husbands' occupation, expressions of caring, and participation in child care and certain household chores (house cleaning, grocery shopping, cooking, washing clothes and dishes, household repairs, car maintenance, and garbage removal). Overall, these findings showed diminishing levels of emotional and practical support for women at a time when the need for support was likely greater: following the birth of their first child.
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Affiliation(s)
- D K Gjerdingen
- Department of Family Practice and Community Health, University of Minnesota
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Atkinson AC, Chaloner K, Herzberg AM, Juritz J. Optimum experimental designs for properties of a compartmental model. Biometrics 1993; 49:325-37. [PMID: 8369370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Three properties of interest in bioavailability studies using compartmental models are the area under the concentration curve, the maximum concentration, and the time to maximum concentration. Methods are described for finding designs that minimize the variance of the estimates of these quantities in such a model. These methods use prior information. Both prior estimates and prior distributions are used. The designs for an open one-compartment model are compared with the corresponding D theta-optimum design for all parameters and also with designs that minimize the sum of the scaled variances of the individual properties.
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Affiliation(s)
- A C Atkinson
- Department of Statistical and Mathematical Sciences, London School of Economics, United Kingdom
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Carlin BP, Chaloner K, Church T, Louis TA, Matts JP. Bayesian Approaches for Monitoring Clinical Trials with an Application to Toxoplasmic Encephalitis Prophylaxis. ACTA ACUST UNITED AC 1993. [DOI: 10.2307/2348470] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chaloner K, Heller B. MACSYMA for Statisticians. J Am Stat Assoc 1992. [DOI: 10.2307/2290234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chaloner K, Lindley DV. Making Decisions. J Am Stat Assoc 1987. [DOI: 10.2307/2289173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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