Introduction Of Molecular Testing Research Articles

A Diagnostic Stewardship Intervention that Optimizes CNS Infection Management

The introduction of molecular testing has led to more rapid diagnosis and optimization of treatment in the field of infectious diseases. In this volume of The Journal, Messacar et al used a diagnostic stewardship approach to address the role of the FilmArray® Meningitis Encephalitis Panel (MEP), a multiplex CSF PCR, in children with suspected central nervous system infection. After the implementation of pre-test criteria and real-time assistance from an infectious diseases specialist, they found that the use of MEP significantly reduced the time to optimal antimicrobial therapy (28 vs.

THE IMPACT OF POSITIVE ANTI-HBC MARKER ON PERMANENT DEFERRAL OF VOLUNTARY BLOOD DONORS IN EASTERN CROATIA AND ESTIMATION OF OCCULT HEPATITIS B VIRUS INFECTION RATE.

SUMMARYRecently an increase has been reported in the number of HBV transmissions from anti-HBc positive blood donors that were repeatedly negative in HBsAg and nucleic acid testing using the most sensitive tests available. The aim of the study was to show the effect of anti-HBc antibody testing performed in 2006 on permanent deferral of voluntary blood donors (VBDs), and to estimate occult hepatitis B infection (OBI) rate in this population after the introduction of mandatory molecular testing in the 2013-2016 period. More than 30,000 blood donations collected during the 2005-2007 period and more than 14,000 VBDs having donated blood during the 2013-2016 period after the introduction of molecular testing from eastern Croatia were included in the study. Serologic testing was performed with HBsAg assay throughout the study period, and anti-HBc assay was only performed in 2006. As part of the confirmatory algorithm testing, all HBsAg positive and unclear results were tested with molecular tests. Anti-HBc prevalence among VBDs in 2006 was 1.5%, with a rate of 1:197, whereas HBsAg prevalence was stable from 2005 to 2007 (0.04%, 0.1% and 0.1%, respectively). The calculated OBI rate from 2013 to 2016 was 1:30,250. Ten of 161 (12.4%) VBDs had serologic anti-HBc-only pattern. Anti-HBc testing in 2006 resulted in statistically more deferrals of VBDs compared to 2005 and 2007, and to the rest of Republic of Croatia. The strategy of universal anti-HBc testing of VBDs in addition to the existing HBsAg and molecular screening could be an additional measure to prevent HBV transmission by blood and blood components.

Parechovirus and enterovirus infections in neonates.

Parechovirus and enterovirus belong to a family of Picornaviridae, non- enveloped, small-sized RNA viruses, responsible for multiple human diseases. Recent introduction of molecular tests enabled the identi cation of parechovirus and enterovirus infections. Our aim was a retrospective analysis of signs and symptoms associated with confirmed parechovirus or enterovirus infections among children treated in the Department of Neonatology, St. Louis Regional Children's Hospital in Kraków, Poland. Based on laboratory records, we identified all cases of parecho- or enterovirus infections confirmed by identification of viral RNA in nasal swab or cerebrospinal fluid samples. Hospital records and laboratory tests results of selected patients were then analyzed, and selected data were summarized, with emphasis on clinical and laboratory findings at admission. We identified 11 cases of parechovirus and three of enterovirus infections. All cases were neonates admitted to hospital with fever and irritability. Except for leukopenia in 50% of patients, no significant abnormalities were noted in blood counts and serum biochemistry, including low C-reactive protein and procalcitonin. In nine cases, cerebrospinal fluid was collected, the fluid protein concentrations and cell counts were moderately increased. Final diagnosis was meningitis in 12 children, and other viral infections in two. Viral infection, including parecho- and enteroviruses, should be considered in the etiology of fever and meningitis in neonates. The available molecular tests allow for detection of viral genetic material even in a scant biological specimen collected from neonates.

Reverse transcription-polymerase chain reaction molecular testing of cytology specimens: Pre-analytic and analytic factors.

The introduction of molecular testing into cytopathology laboratory practice has expanded the types of samples considered feasible for identifying genetic alterations that play an essential role in cancer diagnosis and treatment. Reverse transcription-polymerase chain reaction (RT-PCR), a sensitive and specific technical approach for amplifying a defined segment of RNA after it has been reverse-transcribed into its DNA complement, is commonly used in clinical practice for the identification of recurrent or tumor-specific fusion gene events. Real-time RT-PCR (quantitative RT-PCR), a technical variation, also permits the quantitation of products generated during each cycle of the polymerase chain reaction process. This review addresses qualitative and quantitative pre-analytic and analytic considerations of RT-PCR as they relate to various cytologic specimens. An understanding of these aspects of genetic testing is central to attaining optimal results in the face of the challenges that cytology specimens may present. Cancer Cytopathol 2017;125:11-19. © 2016 American Cancer Society.

Two years' experience of implementing molecular screening of hepatitis B virus, hepatitis C virus and human immunodeficiency virus 1, 2 in Riyadh blood donors

Molecular screening technologies have improved blood safety by reducing the number of window-period transmissions relative to serological screening. In the two years following the introduction of molecular testing in King Khalid University Hospital, Saudi Arabia, 25,920 donor samples were screened in parallel by both serological and molecular techniques for hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV). No HCV or HIV NAT yields were detected. However, molecular screening enabled the interdiction of two confirmed HBV NAT yields. This is only the second report of confirmed HBV NAT yield in the Kingdom of Saudi Arabia, and amongst the few reports in the wider Middle East and North Africa region.

The fascinating story of urine examination: From uroscopy to the era of microscopy and beyond.

The purpose of this study was to present the evolution of ideas on the examination of urine from antiquity till our days. A thorough study of texts, medical books from antiquity till twentieth century along with a thorough review of the available literature in PubMed was conducted. The first observation on urine examination can be traced back to the Babylonian and Sumerian texts. Almost all physicians in antiquity including Hippocrates referred to the value of urine examination in the diagnosis and prognosis of diseases. The construction of first compound microscope lead to the examination of urine sediment and the development of Urine Cytology which was revolutionized during the twentieth century with the studies of important cytologists such as George Papanicolaou, Geoffrey Krabbe, and Leopold Koss. The introduction of molecular tests in the diagnosis of urothelial cancer inaugurated a new era in the study of urine cytology. The history of urine examination spans a period of 6,000 years. The application of microscope in the examination of urine sediment during the nineteenth century established urine analysis as an important diagnostic tool in clinical practice.

Absence of routine molecular testing and prevalence of HIV-2 infection in regions hardest-hit by HIV infection

Investigating the incidence and dynamics of HIV-2 and false-negative HIV test results in a highly sexually active population where frequent opportunities exist for acquiring and transmitting infections provides additional understanding of the epidemiology of the virus in Africa. The HIV status of 900 active female sex workers (FSWs) was determined using two lateral flow rapid assays in series. The second rapid test device incorporates type-specific recombinant peptides that discriminate between HIV-1 and HIV-2 infection. HIV sero-negative samples were re-tested for HIV infection and their viral loads determined using the NucliSENS real-time nucleic acid sequence-based amplification (NASBA) platform. In total, 335 FSWs were determined to be HIV positive, the majority (227; 67.8%) of whom were between the ages of 20 and 30 years. Eighteen (5.4%) were found to have evidence of HIV-2 infection, 17 of whom were co-infected with HIV-1. Only one HIV-2 mono-infection was observed. Out of 565 HIV-negative individuals determined by serology, 11(1.9%; p > 0.05) were found to be HIV-1 positive when tested via the NASBA platform. False negative test results, HIV-2 infection, and complex transmission networks among FSWs may aid in fueling the HIV epidemic in the Nigerian population. These findings demonstrate the need to reevaluate the quality of HIV serological diagnostics, control services, and stress the need for widespread introduction of molecular testing among high-risk populations in the country.

What are the keys to successful thyroid FNA interpretation?

There is much concern expressed in the literature regarding the lack of predictive power of the thyroid fine needle aspiration/biopsy (TFNAB) approach to defining the nature of clinically detected thyroid nodules. This has been exacerbated in the past decade or more by the routine use of ultrasonography (US) in examining the thyroid as well as the introduction of molecular testing in the realm of thyroid pathology. Some have even gone so far as to suggest replacing the TFNAB with molecular signature testing to reduce the degree of uncertainty for a specific cytological diagnosis. This review addresses those concerns with a re-emphasis on understanding the basic keys to successfully evaluating a patient with a thyroid nodule by routine TFNAB examination. These keys include bringing to bear an experienced group of physicians in an integrated team approach, a sharpened focus on the TFNAB cytological categories and a grounded understanding of the predictive ability of molecular testing in a given patient when the cytological interpretation creates too much uncertainty in the minds of the patients and clinicians in attempting to reach a decision on how to manage a thyroid nodule. With this practical approach in mind, the false-negative and false-positive rates of "negative (benign)" and "positive (malignant)" thyroid aspirates should be no more than 1%; and the prevalence of an "indeterminate" aspirate - the area in TFNAB attracting the most attention for improvement with novel biomarkers - should be 10% or less. Thus, physicians should be capable of managing at least 90% of patients undergoing TFNAB in a confident manner without further testing beyond the routine, future re-examination of the patient's nodule to re-assess for any change in its nature or its impact on the patient's quality of life. The other 10% can then be considered for molecular testing in a manner tailored to those individuals truly in need of a more sophisticated - and expensive - approach to the characterization of their thyroid nodules. As the era of US has matured - just as with the era of serum PSA testing for prostate cancer in men - we have experienced a paradigm shift: Given the incidence of thyroid nodules in the U.S. adult population in comparison with the risk of dying of thyroid malignancy, the main role of TFNAB is to reduce the need for surgical intervention.

Overdiagnosis and Overtreatment of Breast Cancer

Breast cancer is the most common cancer in women. Through greater awareness, mammographic screening, and aggressive biopsy of calcifications, the proportion of low-grade, early stage cancers and in situ lesions among all breast cancers has risen substantially. The introduction of molecular testing has increased the recognition of lower risk subtypes, and less aggressive treatments are more commonly recommended for these subtypes. Mammographically detected breast cancers are much more likely to have low-risk biology than symptomatic tumors found between screenings (interval cancers) or that present as clinical masses. Recognizing the lower risk associated with these lesions and the ability to confirm the risk with molecular tests should safely enable the use of less aggressive treatments. Importantly, ductal carcinoma in situ (DCIS) lesions, or what have been called stage I cancers, in and of themselves are not life-threatening. In situ lesions have been treated in a manner similar to that of invasive cancer, but there is little evidence to support that this practice has improved mortality. It is also being recognized that DCIS lesions are heterogeneous, and a substantial proportion of them may in fact be precursors of more indolent invasive cancers. Increasing evidence suggests that these lesions are being overtreated. The introduction of molecular tests should be able to help usher in a change in approach to these lesions. Reclassifying these lesions as part of the spectrum of high-risk lesions enables the use of a prevention approach. Learning from the experience with active surveillance in prostate cancer should empower the introduction of new approaches, with a focus on preventing invasive cancer, especially given that there are effective, United States Food and Drug Administration (FDA)-approved breast cancer preventive interventions.

Overdiagnosis and Overtreatment of Breast Cancer

Overview: Breast cancer is the most common cancer in women. Through greater awareness, mammographic screening, and aggressive biopsy of calcifications, the proportion of low-grade, early stage cancers and in situ lesions among all breast cancers has risen substantially. The introduction of molecular testing has increased the recognition of lower risk subtypes, and less aggressive treatments are more commonly recommended for these subtypes. Mammographically detected breast cancers are much more likely to have low-risk biology than symptomatic tumors found between screenings (interval cancers) or that present as clinical masses. Recognizing the lower risk associated with these lesions and the ability to confirm the risk with molecular tests should safely enable the use of less aggressive treatments. Importantly, ductal carcinoma in situ (DCIS) lesions, or what have been called stage I cancers, in and of themselves are not life-threatening. In situ lesions have been treated in a manner similar to that of invasive cancer, but there is little evidence to support that this practice has improved mortality. It is also being recognized that DCIS lesions are heterogeneous, and a substantial proportion of them may in fact be precursors of more indolent invasive cancers. Increasing evidence suggests that these lesions are being overtreated. The introduction of molecular tests should be able to help usher in a change in approach to these lesions. Reclassifying these lesions as part of the spectrum of high-risk lesions enables the use of a prevention approach. Learning from the experience with active surveillance in prostate cancer should empower the introduction of new approaches, with a focus on preventing invasive cancer, especially given that there are effective, United States Food and Drug Administration (FDA)-approved breast cancer preventive interventions.

Les gènes des hémochromatoses

Genetic hemochromatosis (GH) encompass a heterogeneous group of disorders, which is related to hepcidin deficiency (except type 4A of the ferroportin disease), leading to iron overload and eventually organ failure due to inappropriately high intestinal iron absorption. The most frequent entity remains HFE-related hemochromatois associated with the homozygosity for the p.Cys282Tyr mutation in the HFE gene (C282Y mutation), first identified in 1996. Several other genetic causes have been identified since 2000, often referred to as non-HFE hemochromatosis, resulting from mutations in genes involved in the regulation of iron homeostasis, such as transferrin receptor 2 ( TRF2, type 3 GH), hepcidin ( HAMP, type 2 GH), hémojuvelin ( HJV, type 2 GH), ferroportin ( SLC40A1, type 4 GH). Iron excess is due to deficiencies in either hepcidin, regulated by BMP6, or ferroportin (type 4A GH). So, several genes underlie the various forms of the disease, which have similar pathophysiological profiles but distinct clinical presentations. Additional genetic and environmental factors can modify the severity of the disease. The introduction of molecular tests into clinical practice has provided a tool for early diagnosis of these genetic diseases.

The Future of Molecular Approaches to Inflammatory Bowel Disease

Technological advances in genomics and transcriptomics have resulted in the introduction of molecular tests into the clinical arena. Despite established uses of such tests in the oncology field, their integration into the management of complex diseases has not been widely evaluated. Progress in the field of inflammatory bowel disease (IBD) genetics has been rapid in recent years, and these advances have provided more urgent impetus to investigating the role of molecular tests in IBD. This article summarizes the current state of molecular testing available for IBD, and the potential utility of such tests as research in the area widens.

The evolving spectrum of ‘non‐classical’ Diamond‐Blackfan anaemia – a case of eADA positive pancytopenia in a young adult

The evolving spectrum of ‘non‐classical’ Diamond‐Blackfan anaemia – a case of eADA positive pancytopenia in a young adult

Understanding iron homeostasis through genetic analysis of hemochromatosis and related disorders

Genetic analysis of hemochromatosis has led to the discovery of a number of genes whose mutations disrupt iron homeostasis and lead to iron overload. The introduction of molecular tests into clinical practice has provided a tool for early diagnosis of these conditions. It has become clear that hemochromatosis includes a spectrum of disorders that range from simple biochemical abnormalities to chronic asymptomatic tissue damage in midlife to serious life-threatening diseases in young subjects. Molecular studies have identified the systemic loop that controls iron homeostasis and is centered on the hepcidin-ferroportin interaction. The complexity of this regulatory pathway accounts for the genetic heterogeneity of hemochromatosis and related disorders and raises the possibility that genes encoding components of the pathway may be modifiers of the main genotype. Molecular diagnosis has improved the classification of the genetic conditions leading to iron overload and identified novel entities, characterized by both iron loading and variable degrees of anemia. Despite the progress in the diagnosis, classification, and mechanisms of iron overload disorders, the treatment of affected patients continues to rely on regular phlebotomy. Understanding the molecular circuitry of iron control may lead to the identification of potential therapeutic targets for novel treatment strategies to be used in association with or as an alternative to phlebotomy.