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Featured researches published by Debra Kohn.


Journal of Clinical Microbiology | 2008

Multicenter Comparison of PCR Assays for Detection of Human Herpesvirus 8 DNA in Semen

Louis Flamand; Annie Gravel; David Boutolleau; Roberto Alvarez-Lafuente; Steve Jacobson; Mauro S. Malnati; Debra Kohn; Yi-Wei Tang; Tetsushi Yoshikawa; Dharam V. Ablashi

ABSTRACT Human herpesvirus 6 (HHV-6) is a ubiquitous virus with which infections have been associated with pathologies ranging from delayed bone marrow engraftment to a variety of neurological diseases. The lack of a standardized assay that can be used to detect and estimate HHV-6 DNA contents in various clinical specimens can lead and has led to discordant results among investigators and on the potential association of HHV-6 to diseases. To identify the most reliable and sensitive assays, an identical set of 11 coded serum samples spiked with various quantities of the HHV-6A variant (range, 4 to 400,000 genome copies/ml) was sent to eight independent laboratories around the world. Each laboratory was asked to estimate the HHV-6 DNA content by use of its own protocols and assays. Among the various assays, three TaqMan-based real-time PCR assays yielded quantities that were closest to the quantity of HHV-6 that had been spiked. To provide better homogeneity between the results from the different laboratories working on HHV-6, we propose that investigators interested in quantifying HHV-6 in clinical samples adopt one of these assays.


Journal of Clinical Microbiology | 2005

Comparative Evaluation of Three Commercial Systems for Nucleic Acid Extraction from Urine Specimens

Yi-Wei Tang; Susan E. Sefers; Haijing Li; Debra Kohn; Gary W. Procop

ABSTRACT A nucleic acid extraction system that can handle small numbers of specimens with a short test turnaround time and short hands-on time is desirable for emergent testing. We performed a comparative validation on three systems: the MagNA Pure compact system (Compact), the NucliSens miniMAG extraction instrument (miniMAG), and the BioRobot EZ1 system (EZ1). A total of 75 urine specimens submitted for polyomavirus BK virus detection were used. The human β-actin gene was detected on 75 (100%), 75 (100%), and 72 (96%) nucleic acid extracts prepared by the miniMAG, EZ1, and Compact, respectively. The miniMAG produced the highest quantity of nucleic acids and the best precision among the three systems. The agreement rate was 100% for BKV detection on nucleic acid extracts prepared by the three extraction systems. When a full panel of specimens was run, the hands-on time and test turnaround time were 105.7 and 121.1 min for miniMAG, 6.1 and 22.6 min for EZ1, and 7.4 and 33.7 min for Compact, respectively. The EZ1 and Compact systems processed automatic nucleic acid extraction properly, providing a good solution to the need for sporadic but emergent specimen detection. The miniMAG yielded the highest quantity of nucleic acids, suggesting that this system would be the best for specimens containing a low number of microorganisms of interest.


Journal of Clinical Virology | 2009

Analytical performance of the Investigational Use Only Cervista™ HPV HR test as determined by a multi-center study

Stephen P. Day; Angela Hudson; Andrea L. Mast; Tamara Sander; Michelle L. Curtis; Sarah M. Olson; Luanne Chehak; Neil B. Quigley; Joellen S. Ledford; Belinda Yen-Lieberman; Debra Kohn; Denise I. Quigley; Marilyn C. Olson

BACKGROUND Any HPV test designed to be utilized in cervical cancer screening programs should be highly validated both analytically and clinically. OBJECTIVES The Investigational Use Only (IUO) Cervista HPV HR test is designed to detect 14 high-risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68). The analytical performance of the Cervista HPV HR test was characterized in a multi-center study. RESULTS Analytical sensitivity for the 14 high-risk HPV types that the test is designed to detect ranged from 1,250 copies to 7,500 copies per reaction depending on HPV type. Accuracy compared to PCR with bi-directional sequencing was 91.4% [95% CI: 86.5 95.0%]. The reproducibility, when tested at three different testing centers, resulted in an overall inter-run reproducibility (between day/within site) agreement of 98.8% [1-sided 95% Confidence Lower Limit = 96.9%] and an overall inter-site reproducibility (between site) agreement of 98.7% [1-sided 95% Confidence Lower Limit = 97.9%]. The Cervista HPV HR test showed no cross-reactivity with DNA from seven non-oncogenic HPV types or 17 different infectious agents at up to 10(7) copies per reaction. CONCLUSIONS The analytical performance of the Cervista HPV HR test demonstrates sufficient analytical performance for use in cervical cancer screening. As with any clinical laboratory test, analytical characteristics must be evaluated in light of the clinical performance of this assay.


Diagnostic Molecular Pathology | 2004

Detection of Polyoma Virus in Brain Tissue of Patients with Progressive Multifocal Leukoencephalopathy by Real-Time PCR and Pyrosequencing

Rose C. Beck; Debra Kohn; Marion J. Tuohy; Richard A. Prayson; Belinda Yen-Lieberman; Gary W. Procop

We evaluated 2 methods, a LightCycler PCR assay and pyrosequencing for the detection of the JC polyoma virus (JCV) in fixed brain tissue of 10 patients with and 3 control patients without progressive multifocal leukoencephalopathy (PML). Nucleic acid extraction was performed after deparaffinization and proteinase K digestion. The LightCycler assay differentiates the BK virus (BKV), JCV, and SV40 using melt curve analysis. Conventional PCR was used with the same primers to generate products for pyrosequencing. Two sequencing primers were used that differentiate the polyoma viruses. Seven of 11 biopsies (1 patient had 2 biopsies) with PML were positive for JCV by real-time PCR and/or PCR/pyrosequencing. Three of 4 remaining biopsies were positive by real-time PCR but had melting points between JCV and SV40. The 4 specimens that were negative or atypical by LightCycler PCR were positive by traditional PCR, but 1 had an amplicon of lower molecular weight by gel electrophoresis. These were shown to represent JCV by at least 1 of the 2 pyrosequencing primers. The biopsies from patients without PML were PCR negative. Both the LightCycler and pyrosequencing assays are useful for confirming JCV in brain biopsies from patients with PML, but variant JCVs may require supplementary methods to confirm JCV infection.


Journal of Clinical Microbiology | 2005

BK and JC Polyomaviruses Are Not Associated with Idiopathic Pulmonary Fibrosis

Gary W. Procop; Debra Kohn; J. E. Johnson; Haijing Li; J. E. Loyd; Belinda Yen-Lieberman; Yi-Wei Tang

ABSTRACT We sought to determine if the BK and JC polyomaviruses were associated with idiopathic pulmonary fibrosis (IPF). We did not detect the BK or JC polyomaviruses in lung tissue extracts from 33 patients with IPF by using real-time PCR, which suggests that an etiologic association is unlikely.


Diagnostic Molecular Pathology | 2006

JC virus chromogenic in situ hybridization in brain biopsies from patients with and without PML.

Gary W. Procop; Rose C. Beck; James Pettay; Debra Kohn; Marion J. Tuohy; Belinda Yen-Lieberman; Richard A. Prayson; Raymond R. Tubbs

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC polyoma virus. Electron microscopy and immunohistochemistry are the traditional methods of confirming the presence of the virus in brain biopsies from these patients. We studied the brain biopsies from 7 patients with PML and 6 patients without PML with chromogenic in situ hybridization (CISH) for the JC polyoma virus using a commercially available probe. The biopsies from the patients with the PML cases were proven to contain the JC polyoma virus by traditional and molecular methods. The CISH findings were compared with the known state of infection. All (7/7) of the biopsies from patients with PML were positive for the presence of polyoma virus by CISH, whereas the biopsies from patients without PML were uniformly negative. CISH seems to be a useful tool for the detection of the JC virus in brain biopsies from patients with PML, and is more accessible because a commercial probe is available.


Journal of Clinical Microbiology | 2016

Multicenter Evaluation of Meridian Bioscience HSV 1&2 Molecular Assay for Detection of Herpes Simplex Virus 1 and 2 from Clinical Cutaneous and Mucocutaneous Specimens

Matthew L. Faron; Nathan A. Ledeboer; Anami Patel; Safedin H. Beqa; Belinda Yen-Lieberman; Debra Kohn; Amy Leber; Donna Mayne; William I. Northern; Blake W. Buchan

ABSTRACT Herpes simplex virus (HSV) causes acute and relapsing symptoms characterized by ulcerative lesions. Laboratory diagnosis of HSV in cutaneous or mucocutaneous lesions has historically been performed with the use of viral cell culture systems; however, these tests are laborious and suffer decreased sensitivity for advanced-stage lesions. The recent availability of FDA-cleared moderately complex assays has resulted in the increased use of molecular diagnostics for the routine detection of HSV in superficial swab specimens. We performed a clinical evaluation of the recently FDA-cleared illumigene HSV 1&2 loop-mediated isothermal amplification (LAMP) assay (Meridian Bioscience, Cincinnati OH) for the detection and differentiation of HSV-1 and HSV-2 in cutaneous and mucocutaneous swab specimens. A total of 1,153 clinical swab specimens were collected and tested at 7 different clinical centers. Each specimen was tested for the presence of HSV-1 and HSV-2 using the illumigene assay, and results were compared to those of the enzyme-linked virus-inducible system (ELVIS) as the reference method. Overall, the illumigene assay demonstrated a sensitivity and specificity of 94.8% and 95.5%, respectively, for the detection of HSV-1. Detection of HSV-2 was similar, with a sensitivity of 98.9% and a specificity of 95.5%. Discrepant analysis was performed using an alternative molecular test (AmpliVue HSV1+2 assay; Quidel Molecular, San Diego, CA) on 91/99 specimens that were recorded as false positive (FP) or false negative (FN) compared to the reference method. In total, 57/78 (73%) FP and 9/13 (69%) FN illumigene results were supported by the AmpliVue result. The illumigene HSV 1&2 assay demonstrated high sensitivity and specificity to detect and differentiate HSV in clinical specimens and identified 57 additional specimens that were positive for HSV compared to culture. The use of LAMP eliminates the need for the cycling of temperatures and provides results in less than 60 min, with approximately 2 min of hands-on time per specimen.


American Journal of Clinical Pathology | 2018

Detection of Herpes Simplex Virus and Varicella-Zoster Virus by Traditional and Multiplex Molecular Methods

Dejan Nikolic; Debra Kohn; Belinda Yen-Lieberman; Gary W. Procop

Objectives To compare multiplex nucleic acid amplification tests (NAATs) that detect and differentiate herpes simplex virus (HSV) and varicella-zoster virus (VZV) with traditional virologic assays. Methods The HSV ELVIS Test System (Quidel, San Diego, CA) and/or Light Diagnostics VZV direct fluorescent antibody (DFA) kit (Millipore Sigma, Billerica, MA), as well as an ARIES HSV 1&2/VZV assay (Luminex, Austin, TX) and the Solana HSV1 + 2/VZV Assay (Quidel), were performed on non-cerebrospinal fluid specimens. Results The sensitivities/specificities for the ELVIS, Aries, and Solana assays for HSV were 71.1%/93.2%, 94.9%/93.2%, and 94.7%/100%, respectively. The sensitivities/specificities for the DFA, Aries, and Solana assays for VZV were 71.4%/100%, 100%/96.0%, and 95.3%/100%, respectively. HSV and VZV were detected but clinically unsuspected in 5.4% and 4.2% of the specimens, respectively. Conclusions Both NAAT assays were comparable and more sensitive than traditional methods. The recovery of unsuspected HSV and VZV from clinical specimens supports the implementation of a combined HSV/VZV assay.


Journal of Medical Virology | 2016

Absence of human herpesvirus 6B detection in association with illness in children undergoing cancer chemotherapy.

Johanna Goldfarb; Nirica Borges; Laura K. Gowans; Debra Kohn; Sarah Worley; Liang Li; Belinda Yen-Lieberman; Donna Lach; Lara Danziger-Isakov; Stephanie Yee-Guardino; Charles Trunick; Philip E. Pellett

The lymphotropic herpesviruses, cytomegalovirus (CMV), Epstein‐Barr virus (EBV), and human herpesvirus 6B (HHV‐6B) can reactivate and cause disease in organ transplant recipients; the contributions of HHV‐6A and HHV‐7 to disease are less certain. Less is known about their pathogenic roles in children undergoing treatment for malignancies. Children with newly diagnosed cancer were followed for 24 months. Clinical information and blood samples were collected during routine visits and during acute visits for fever or possible viral infections. Lymphotropic herpesvirus DNA in blood was measured by polymerase chain reaction (PCR). Although HHV‐6B DNA was detected at least once in about half of the patients; the other viruses were seldom detected. There was no association between HHV‐6B detection and individual acute clinical events, however, HHV‐6B detection was more common in children who experienced more frequent acute clinical events. In children being treated for various malignancies, HHV‐6B detection was common, but was not associated with individual events of acute illness. Thus, if HHV‐6B is not assessed longitudinally, clinical events may be misattributed to the virus. The elevated frequency of detection of HHV‐6B in sicker children is consistent with prior reports of its detection during apparently unrelated acute clinical events. J. Med. Virol. 88:1427–1437, 2016.


Emerging Infectious Diseases | 2008

β-Herpesviruses in Febrile Children with Cancer

Stephanie Yee-Guardino; Kate L. Gowans; Belinda Yen-Lieberman; Pamela Berk; Debra Kohn; Fu-Zhang Wang; Lara Danziger-Isakov; Sarah Worley; Philip E. Pellett; Johanna Goldfarb

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Yi-Wei Tang

Memorial Sloan Kettering Cancer Center

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Lara Danziger-Isakov

Cincinnati Children's Hospital Medical Center

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Rose C. Beck

Case Western Reserve University

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