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Dive into the research topics where Perica Davitkov is active.

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Featured researches published by Perica Davitkov.


Journal of Acquired Immune Deficiency Syndromes | 2013

Plasma proteome analysis reveals overlapping, yet distinct mechanisms of immune activation in chronic HCV and HIV infections.

Daniela Schlatzer; Julia M. Sugalski; Yanwen Chen; Jill S. Barnholtz-Sloan; Perica Davitkov; Fred E. Hazlett; Nicholas T. Funderburg; Benigno Rodriguez; Michael M. Lederman; Scott F. Sieg; Mark R. Chance; Donald D. Anthony

Background:HIV infection contributes to accelerated rates of progression of liver fibrosis during hepatitis C virus (HCV) infection, and HCV liver disease contributes to mortality during HIV infection. Although mechanisms underlying these interactions are not well known, soluble and cellular markers of immune activation associate with disease progression during both infections. Methods:We identified proteins varying in expression across the plasma proteomes of subjects with untreated HIV infection, untreated HCV infection with low aspartate transaminase/platelet ratio index, untreated HCV infection with high aspartate transaminase/platelet ratio index, HIV–HCV coinfection, and controls. We examined correlations between dysregulated proteins and markers of immune activation to uncover biomarkers specific to disease states. Results:We observed the anticipated higher frequencies of HLA-DR+CD38+CD4 and CD8 T cells, higher serum soluble CD14 levels, and higher serum interleukin-6 levels for HCV- and HIV-infected groups compared with controls. Plasma proteome analysis identified 2297 peptides mapping to 227 proteins, and quantitative analysis of peptide intensity identified significant changes in 85 proteins across the 5 groups. Abundance for 7 of these proteins was validated by enzyme-linked immunosorbent assay. Forty-three of these proteins correlated with markers of immune activation, including at least 2 proteins that may directly drive T-cell activation. As a functional validation, we tested the enzymatic pathway product (lysophosphatidic acid, LPA) of one such protein, ecotonucleotide pyrophosphatase/phosphodiesterase-2, for ability to activate T cells in vitro. LPA activated T cells to express CD38 and HLA-DR. Conclusions:These data indicate that elevated levels of ecotonucleotide pyrophosphatase/phosphodiesterase-2 and LPA during advanced HCV disease may play a role in exacerbating immune activation during HCV–HIV coinfection.


Frontiers in Oncology | 2012

Family History of Cancer in Benign Brain Tumor Subtypes Versus Gliomas

Quinn T. Ostrom; Christopher McCulloh; Yanwen Chen; Karen Devine; Yingli Wolinsky; Perica Davitkov; Sarah Robbins; Rajesh Cherukuri; Ashokkumar Patel; Rajnish Gupta; Mark L. Cohen; Jaime Vengoechea Barrios; Cathy Brewer; Cathy Schilero; Kathy N. Smolenski; Mary McGraw; Barbara Denk; Theresa Naska; Frances Laube; Ruth Steele; Dale Greene; Alison Kastl; Susan Bell; Dina Aziz; E. A. Chiocca; Christopher McPherson; Ronald E. Warnick; Gene H. Barnett; Andrew E. Sloan; Jill S. Barnholtz-Sloan

Purpose: Family history is associated with gliomas, but this association has not been established for benign brain tumors. Using information from newly diagnosed primary brain tumor patients, we describe patterns of family cancer histories in patients with benign brain tumors and compare those to patients with gliomas. Methods: Newly diagnosed primary brain tumor patients were identified as part of the Ohio Brain Tumor Study. Each patient was asked to participate in a telephone interview about personal medical history, family history of cancer, and other exposures. Information was available from 33 acoustic neuroma (65%), 78 meningioma (65%), 49 pituitary adenoma (73.1%), and 152 glioma patients (58.2%). The association between family history of cancer and each subtype was compared with gliomas using unconditional logistic regression models generating odds ratios (ORs) and 95% confidence intervals. Results: There was no significant difference in family history of cancer between patients with glioma and benign subtypes. Conclusion: The results suggest that benign brain tumor may have an association with family history of cancer. More studies are warranted to disentangle the potential genetic and/or environmental causes for these diseases.


The Journal of Infectious Diseases | 2012

Genetically Associated CD16+56− Natural Killer Cell Interferon (IFN)–αR Expression Regulates Signaling and Is Implicated in IFN-α–Induced Hepatitis C Virus Decline

Sara J. Conry; Qinglai Meng; Gareth Hardy; Nicole L. Yonkers; Julia M. Sugalski; Amy Hirsch; Perica Davitkov; Anita Compan; Yngve Falck-Ytter; Ronald E. Blanton; Benigno Rodriguez; Clifford V. Harding; Donald D. Anthony

BACKGROUND Natural killer (NK) cells likely contribute to outcome of acute hepatitis C virus (HCV) infection and interferon (IFN)-induced control of chronic HCV infection. We previously observed IFN-αR and NKp30 expression associated with IFN-α-dependent NK cell activity. METHODS Here, we examined CD16(+)56(-), CD16(+)56(+), and CD16(-)56(+) NK cell subset IFN-αR and NKp30 expression in relation to magnitude of HCV genotype 1 decrease during pegylated IFN-α plus ribavirin therapy. RESULTS We observed greater baseline IFN-αR and NKp30 expression on CD16(+)56(+) and CD16(-)56(+) NK subsets in HCV-infected patients than in healthy control subjects. Baseline CD16(+)56(-) NK IFN-αR expression was associated with IFN-α-induced pSTAT1, and both were associated with magnitude of HCV decrease during pegylated IFN-α plus ribavirin therapy. Baseline CD16(+)56(-) NK IFN-αR expression was associated with race and interleukin 28B genotype, negatively associated with aspartate aminotransferase-to platelet ratio index, and positively associated with increase in NKp30 expression after in vivo IFN-α exposure. Finally, in vitro IFN-α2a-activated NK cytolysis of HCV-infected target cells was in part dependent on NKp30, and CD16(+)56(-) NK cell IFN-αR expression correlated with cytolytic activity. CONCLUSIONS IFN-αR expression on CD16(+)56(-) NK cells during chronic HCV infection may in part be genetically determined, and level of expression regulates IFN-α signaling, which in turn may contribute to control of HCV infection.


PLOS ONE | 2016

Treatment Selection Choices Should Not Be Based on Benefits or Costs Alone: A Head-to-Head Randomized Controlled Trial of Antiviral Drugs for Hepatitis C

Perica Davitkov; Apoorva K. Chandar; Amy Hirsch; Anita Compan; Marina G. Silveira; Donald D. Anthony; Suzanne R. Smith; Clare Gideon; Robert A. Bonomo; Yngve Falck-Ytter

Background Clinicians often face dilemmas with decisions related to formulary choices when two similar drugs are simultaneously available in the market. We studied the comparative safety, effectiveness, and treatment costs of the two first generation direct-acting antiviral agents (DAA), boceprevir and telaprevir as uncertainty existed regarding the drug of choice between these two seemingly equally Hepatitis-C treatment options. Methods We randomly assigned 50 patients in an open-label, pragmatic randomized controlled trial (RCT) at a VA Medical Center to either boceprevir or telaprevir in combination with peginterferon and ribavirin, stratified by the presence of cirrhosis and prior treatment experience. Tolerability was assessed at each visit and reasons for discontinuation of treatment and severity of adverse events due to PI treatment were adjudicated using a blinded adjudication committee. The primary outcome was difference in tolerability between boceprevir vs. telaprevir. Secondary outcomes included viral response rates and cost-per cure achieved. Results Higher rates of treatment discontinuations and/or severe DAA associated adverse events were seen in 10/25 (40%) patients randomized to telaprevir compared to 2/25 (8%) patients randomized to boceprevir (RR: 5; 95% CI: 1.2, 20; p<0.01). Cure rates did not appear to be significantly different between groups (telaprevir vs. boceprevir: RR 1.23; 95% CI: 0.76, 1.99; p = 0.39). On an intention-to-treat basis, total cost per cure was


Gastroenterology | 2017

No Significant Differences in SVR Rates for African Americans (AA) vs. Non-AA with an 8 Week Treatment Course of Ledipasvir/Sofosbuvir (LDV/SOF) in HCV

Vanessa Marshall; Perica Davitkov; Yasser Alsamman; Amy Hirsch; Kelsey Rife; Christina Vonhaz; Anita Compan; Yngve Falck-Ytter

44,329 for boceprevir vs.


Gastroenterology | 2017

Appropriately Managed Proton Pump Inhibitor (PPI) Use does not Reduce Sustained Virologic Response with Ledipasvir/Sofosbuvir (LDV/SOF)

Yasser Alsamman; Perica Davitkov; Vanessa Marshall; Amy Hirsch; Kelsey Rife; Anita Compan; Christina Vonhaz; Kierra M. Dotson; Yngve Falck-Ytter

57,115 for telaprevir. The significant side effect profile of telaprevir combined with the availability of highly efficacious second generation DAAs led to the early discontinuation of the trial. Conclusion Telaprevir is associated with a significantly higher rate of severe adverse events leading to treatment discontinuations, hospitalizations or severe anemia and a substantially higher cost per SVR when compared to boceprevir. Real-time, point of care, pragmatic randomized controlled trials are necessary for guidance beyond just acquisition costs and to make evidence-based formulary selections when multiple effective treatments are available. (Clinicaltrials.gov registration: NCT02113631).


Gastroenterology | 2014

Tu1001 Intensive Vaccination Strategies vs. Standard of Care in the Hepatitis C Clinic: a Pragmatic Randomized 2×2 Factorial Trial

Amy Hirsch; Yang Liu; Perica Davitkov; Apoorva K. Chandar; Renée H. Lawrence; Brook Watts; Yngve Falck-Ytter


Gastroenterology | 2014

Su1075 Boceprevir -Associated Resource Use Is Less Per SVR Achieved Compared to Telaprevir -A Pragmatic Head-to-Head Randomized Controlled Trial

Perica Davitkov; Amy Hirsch; Apoorva K. Chandar; Anita Compan; Marina G. Silveira; Donald D. Anthony; Robert A. Bonomo; Yngve Falck-Ytter


Gastroenterology | 2013

Su1705 Paracentesis Within 12 Hours of Admission Improves Outcomes in Patients With Cirrhosis

Basel Abusneineh; Samita Garg; Maissaa Janbain; Perica Davitkov; Yngve Falck-Ytter


Cochrane Database of Systematic Reviews | 2013

Protease inhibitors in combination with pegylated interferon and ribavirin for adult patients with chronic hepatitis C virus

Mohammed Eyad Yaseen Alsabbagh; Perica Davitkov; Yngve Falck-Ytter

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Yngve Falck-Ytter

Case Western Reserve University

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Amy Hirsch

United States Department of Veterans Affairs

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Anita Compan

United States Department of Veterans Affairs

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Donald D. Anthony

Case Western Reserve University

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Apoorva K. Chandar

Case Western Reserve University

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Jill S. Barnholtz-Sloan

Case Western Reserve University

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Yanwen Chen

Case Western Reserve University

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Andrew E. Sloan

Case Western Reserve University

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Benigno Rodriguez

Case Western Reserve University

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Julia M. Sugalski

Case Western Reserve University

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