GeneXpert Essay for BCR-ABL Compared to RT-PCR for Clinical Management of CML

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4416-4416
Author(s):  
G. Pica ◽  
G. Catania ◽  
F. Castelli ◽  
C Repetto ◽  
A. M. Carella ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Standard Deviation ◽  
Predictive Value ◽  
Gene Fusion ◽  
Negative Control ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Prolymphocytic Leukemia ◽  
Blood Samples ◽  
Polymerase Chain

Abstract Abstract 4416 Reverse transcriptase-polymerase chain reaction (RT-PCR) is considered the most sensitive method available for detecting low copy numbers of the BCR-ABL gene fusion. The difference between the BCR-ABL Ct (threshold cycle) and ABL Ct is expected to represent the ratio of the two populations of mRNAs and ultimately the percentage of neoplastic cells present. An international scale (IS) has been proposed for BCR-ABL RQ-PCR measurements. To enable testing centers to gain access to the IS, the Adelaide laboratory initiated a process to develop and validate laboratory-specific conversion factors (CFs) that can be used to convert local values to IS values. Recently, Cepheid introduced its GeneXpert-based assay for the identification of the BCR-ABL gene fusion in cells from blood samples. This system comprises a walkaway self-contained instrument that combines cartridge- based microfluidic sample preparation with reverse transcriptase-polymerase chain reaction-based fluorescent signal detection and BCR-ABL and ABL Ct determination. The CF provided by Cepheid for this procedure is 0.47. We tested this BCR-ABL fusion detection system, compared with a classical RT-PCR analysis as a clinical diagnostic tool for CML patients. We tested 19 patient peripheral blood samples by both methods. The negative control group included 3 blood samples, obtained from 3 patients with hematological disorders unrelated to BCR-ABL gene fusion: one with essential thrombocythemia, one with chronic myelomonocytic leukemia, one with T-cell-prolymphocytic leukemia. The remaining 16 clinical samples belonged to 12 patients with an established diagnosis of CML in chronic phase and to one patient with Philadelphia chromosome-positive acute lymphoblastic leukemia (p210). GeneXpert software reported as negative 2 samples with a numerical threshold limit calculated on Ct (i.e. BCR-ABL was not detected at a detection limit of 0.00046%); the 3rd negative control was indicated as BCR-ABL invalid: this result was probably due to the high proportion of ABL detected as consequence of hyperleukocytosis (WBC 559,6 × 109/L) in T-Cell prolymphocytic leukemia patients. Therefore, the performance of GeneXpert test in this series was: Sensitivity 100%, Specificity 0,66%, Positive Predictive Value 100%, Negative Predictive Value 100%. Among the series of 16 true positive samples GeneXpert revealed mean 8,67; mean standard deviation 27,55; median 1,48. Whereas in the same series RT-PCR results were: mean 37,09; mean standard deviation 59,33; median 3,37. In conclusion GeneXpert essay for BCR-ABL could be an important tool for diagnose and monitor CML but require complete clinical data for the correct interpretation of results. Disclosures: No relevant conflicts of interest to declare.

Prognostic Value of Circulating Melanoma Cells Detected by Reverse Transcriptase–Polymerase Chain Reaction

2003 ◽  
Vol 21 (5) ◽  
pp. 767-773 ◽  
Author(s):  
Giuseppe Palmieri ◽  
Paolo A. Ascierto ◽  
Francesco Perrone ◽  
Sabrina M.R. Satriano ◽  
Alessandro Ottaiano ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Subgroup Analysis ◽  
Peripheral Blood ◽  
Predictive Value ◽  
Prognostic Value ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Blood Samples ◽  
Stage Of Disease ◽  
Polymerase Chain

Purpose: Factors that are predictive of prognosis in patients who are diagnosed with malignant melanoma (MM) are widely awaited. Detection of circulating melanoma cells (CMCs) by reverse transcriptase-polymerase chain reaction (RT-PCR) has recently been postulated as a possible negative prognostic factor. Two main questions were addressed: first, whether the presence of CMCs, defined as the patient being positive for any of the three markers, had a prognostic role; and second, what the predictive value of each individual marker was. Patients and Methods: A consecutive series of 200 melanoma patients observed between January 1997 and December 1997, with stage of disease ranging from I to IV, was analyzed by semiquantitative RT-PCR. Tyrosinase, p97, and MelanA/MART1 were used as markers to CMCs on baseline peripheral blood samples. Progression-free survival (PFS) was used as a unique end point and was described by the product limit method. Multivariable analysis was applied to verify whether the auspicated prognostic value of these markers was independent of the stage of disease, and a subgroup analysis was performed that excluded patients with stage IV disease. Results: Overall, 32% (64 of 200) of patients progressed, and a median PFS of 52 months in the whole series was observed. The presence of CMCs and the markers individually or combined was predictive of prognosis in the univariate analysis but did not provide additional prognostic information to the stage of disease in multivariable models. In the subgroup analysis of stage (ie, I–III subgroup), similar results were observed. Conclusion: Detection of CMCs in peripheral blood samples at the time of MM diagnosis by semiquantitative RT-PCR does not add any significant predictive value to the stage of disease. Thus, this approach should not be used in clinical practice, and further studies are required to determine its usefulness.

scholarly journals A meta-analysis of accuracy and sensitivity of chest CT and RT-PCR in COVID-19 diagnosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fatemeh Khatami ◽  
Mohammad Saatchi ◽  
Seyed Saeed Tamehri Zadeh ◽  
Zahra Sadat Aghamir ◽  
Alireza Namazi Shabestari ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Ct Scan ◽  
Predictive Value ◽  
Meta Analysis ◽  
Chest Ct ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Chest Ct Scan

AbstractNowadays there is an ongoing acute respiratory outbreak caused by the novel highly contagious coronavirus (COVID-19). The diagnostic protocol is based on quantitative reverse-transcription polymerase chain reaction (RT-PCR) and chests CT scan, with uncertain accuracy. This meta-analysis study determines the diagnostic value of an initial chest CT scan in patients with COVID-19 infection in comparison with RT-PCR. Three main databases; PubMed (MEDLINE), Scopus, and EMBASE were systematically searched for all published literature from January 1st, 2019, to the 21st May 2020 with the keywords "COVID19 virus", "2019 novel coronavirus", "Wuhan coronavirus", "2019-nCoV", "X-Ray Computed Tomography", "Polymerase Chain Reaction", "Reverse Transcriptase PCR", and "PCR Reverse Transcriptase". All relevant case-series, cross-sectional, and cohort studies were selected. Data extraction and analysis were performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5. Among 1022 articles, 60 studies were eligible for totalizing 5744 patients. The overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan compared to RT-PCR were 87% (95% CI 85–90%), 46% (95% CI 29–63%), 69% (95% CI 56–72%), and 89% (95% CI 82–96%), respectively. It is important to rely on the repeated RT-PCR three times to give 99% accuracy, especially in negative samples. Regarding the overall diagnostic sensitivity of 87% for chest CT, the RT-PCR testing is essential and should be repeated to escape misdiagnosis.

scholarly journals The utility of real-time polymerase chain reaction in detecting Coccidioides immitis among clinical specimens in the Central California San Joaquin Valley

2018 ◽  
Vol 57 (6) ◽  
pp. 688-693 ◽  
Author(s):  
Dominic Dizon ◽  
Marilyn Mitchell ◽  
Bernadette Dizon ◽  
Robert Libke ◽  
Michael W Peterson
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Pleural Fluid ◽  
Clinical Setting ◽  
Predictive Value ◽  
Coccidioides Immitis ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Acute Pneumonia ◽  
Polymerase Chain

AbstractCoccidioidomycosis, the fungal infection caused by dimorphic Coccidioides species, is typically diagnosed by histopathologic identification of spherules, by culture, or by serology. These tests are reliable but time-intensive, delaying diagnosis and treatment. Rapid real-time polymerase chain reaction (RT-PCR) can be performed and was validated to identify Coccidioides immitis using an in-house developed assay for the Becton Dickinson molecular instrument (BD MAXTM). These studies were performed using patient samples that had been shown to be positive on previously set up fungal cultures. To evaluate this new RT-PCR test in the clinical setting, we conducted a retrospective chart review of patients (N = 1160) who underwent Coccidioides PCR (Cocci PCR) on clinical samples between March 1, 2014, and Dec 31, 2016. We abstracted clinical, microbiologic, serologic, radiographic, treatment, and follow-up data. Specimens of cerebrospinal fluid (CSF), bronchioalveolar lavage fluid (BAL), lung tissue biopsy (LTB), sputum, and pleural fluid were evaluated to determine sensitivity and specificity. Of the 113 specimens that tested positive for Cocci PCR, all had clinical disease defined by traditional clinical criteria, yielding 100% specificity. Overall sensitivity was 74% versus 46% for fungal culture and was available in 4 hours rather than 1–2 weeks. Sensitivities varied by source material and clinical setting. CSF had a sensitivity of 59%, BAL for acute pneumonia 91%, sputum for acute pneumonia 94%, pleural fluid 86%, but LTB for lung nodules only 44%. Overall positive predictive value (PPV) was 100%, while negative predictive value (NPV) was 96%, but again this varied by specimen and clinical setting. Our experience with clinical testing of >1160 specimens over 2–3 years shows we can utilize this technology to improve our ability to diagnose disease but that the sensitivity varies by specimen source and clinical setting.

Impact of Molecular Staging Methods in Primary Melanoma: Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) of Ultrasound-Guided Aspirate of the Sentinel Node Does Not Improve Diagnostic Accuracy, But RT-PCR of Peripheral Blood Does Predict Survival

2008 ◽  
Vol 26 (35) ◽  
pp. 5742-5747 ◽  
Author(s):  
Christiane A. Voit ◽  
Gregor Schäfer-Hesterberg ◽  
Martina Kron ◽  
Alexander C.J. van Akkooi ◽  
Juergen Rademaker ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Peripheral Blood ◽  
Primary Melanoma ◽  
Disease Free Survival ◽  
Rt Pcr ◽  
Ultrasound Guided ◽  
Chain Reaction ◽  
Blood Samples ◽  
Polymerase Chain

Purpose This study analyzes (1) the value of tyrosinase reverse-transcriptase polymerase chain reaction (RT-PCR) of aspirates obtained by ultrasound-guided fine-needle aspiration cytology (US-FNAC) of sentinel nodes (SNs) in patients with melanoma before sentinel lymph node biopsy (SLNB) and (2) the value of RT-PCR of blood samples of all SLNB patients. Patients and Methods Between 2001 and 2003, 127 patients with melanoma (median Breslow depth, 2.1 mm) underwent SLNB. FNAC was performed in all SNs of all patients pre- and post-SLNB. The aspirates were partly shock-frozen for RT-PCR and were partly used for standard cytology. Peripheral blood was collected at the time of SLNB and at every outpatient visit thereafter. Results Thirty-four (23%) of 120 SNs were positive for melanoma. SN involvement was predicted by US-FNAC with a sensitivity of 82% and a specificity of 72%. Additional tyrosinase RT-PCR revealed the same sensitivity of 82% and a specificity of 72%. At a median follow-up time of 40 months from first blood sample, peripheral-blood RT-PCR was a significant independent predictor of disease-free survival (DFS) and overall survival (OS; P < .001). Conclusion US-FNAC is highly accurate and eliminates the need for SLNB in 16% of all SLNB patients. RT-PCR of the aspirate or excised SN does not improve sensitivity or specificity. RT-PCR of blood samples predicts DFS and OS.

scholarly journals Is the Portable Chest Radiographic More Reliable to Reveal Covid19 in Highly Suspicion Patient before Real-Time Reverse Transcription Polymerase Chain Reaction (RT-PCR) Test?

2021 ◽  
Vol 6 (03) ◽  
pp. 228-236
Author(s):  
Bushra A. A. Albazi ◽  
Dr Noof. Albaz ◽  
Dr Nayef. Alqahtani ◽  
Dr. Angham Salih ◽  
Dr Rafat Mohtasab
Keyword(s):  
Polymerase Chain Reaction ◽  
Retrospective Study ◽  
Predictive Value ◽  
Rt Pcr ◽  
Chain Reaction ◽  
X Ray ◽  
Polymerase Chain ◽  
Rate Type ◽  
Test Result ◽  
Pcr Test

A large number of patients with coronavirus disease 2019 (COVID-19) present at hospitals. There are a limited number of isolation rooms open, and patients must often wait a long time to get a reverse transcription-polymerase chain reaction (RT-PCR) test done. This necessitates the introduction of effective triage plans. A patient with suspicions is referred to an emergency room (ED) depending on their medical record for a simple physical assessment, blood test findings, and chest imaging.A retrospective study design was conduct at Prince Sultan Medical Military City (PSMMC). Ethical approval was obtained from the institutional board to wave the consent forms since it is a retrospective study. Only the primary investigator has had the data access to the patients’ medical records. The collected patient records were under specific categories, including symptoms score starts from 5 and above, RT-PCR test result done after CXRP imaging, the patient admitted to the emergency department (ED). Excluding all CXRP done after RT-PCR TEST, positive Covid 19 admitted to the intensive care unit (ICU), pediatric patients, and patients with score symptoms were less than five. Two experienced radiologists reviewed the images blindly, and the inter-observer reliability of observations noted by the radiologists was calculated. As for the relationship between the x-ray reading and the RT-PCR test result, our results showed a high correlation between the variables (chi-square χ² = 12.44, with df =1, and p<0.001). The sensitivity of x-ray diagnosing covid19 was 65.52 %, while the specificity was 54.51 %, and the accuracy of radiologists reading was 58.17 %. Furthermore, the positive predictive value (PPV) was 41.76 %, and the negative predictive value (NPV) was 76.05%. Finally, the false positive rate (type-i error (alpha) was 45.49%, and the false-negative rate (type-ii error (beta) was 34.48% Our research findings show that CXRP imaging can detect COVID-19 infection in symptomatic patients and can be a valuable addition to RT-PCR testing. In an inpatient ED environment where availability of test kits, laboratory equipment, and laboratory personnel is compromised and risks delaying patient treatment and hospital workflow, serial CXRP could theoretically be used as an adjunct diagnostic function and monitoring in patients suspected of having COVID-19.

scholarly journals Performance comparison of two malaria rapid diagnostic test with real time polymerase chain reaction and gold standard of microscopy detection method

2020 ◽  
Author(s):  
Puspa Wardhani ◽  
Trieva Verawaty Butarbutar ◽  
Christophorus Oetama Adiatmaja ◽  
Amarensi Milka Betaubun ◽  
Nur Hamidah ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Diagnostic Test ◽  
Real Time Pcr ◽  
Predictive Value ◽  
Gold Standard ◽  
Detection Method ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain

Background: The diagnostic test for malaria is mostly based on Rapid Diagnostic Test (RDT) and detection by microscopy. Polymerase Chain Reaction (PCR) is also a sensitive detection method that can be considered as a diagnostic tool. The outcome of malaria microscopy detection depends on the examiner's ability and experience. Some RDT has been distributed in Indonesia, which needs to be evaluated for their results. Objective: This study aimed to compare the performance of RightSign RDT and ScreenPlus RDT for detection of Plasmodium in human blood. We used specific real-time polymerase chain reaction abTESTMMalaria qPCRII) and gold standard of microscopy detection method to measure diagnostic efficiency. Methods: Blood specimens were evaluated using RightSign RDT, ScreenPlus RDT, Microscopy detection, and RT-PCR as the protocol described. The differences on specificity (Sp), sensitivity (Sn), positive predictive value (PPV), and negative predictive value (NPV) were analyzed using McNemar and Kruskal Wallis analysis. Results: A total of 105 subjects were recruited. Based on microscopy test, RightSign RDT had sensitivity, Specificity, PPV, NPV, 100%, 98%, 98.2%, 100%, respectively. ScreenPlus showed 100% sensitivity, 98% specificity, 98.2% PPV, 100% NPV. The sensitivity of both RDTs became lower (75%) and the specificity higher (100 %) when using real-time PCR. Both RDTs showed a 100% agreement. RT-PCR detected higher mix infection when compared to microscopy and RDTs. Conclusion: RightSign and ScreenPlus RDT have excellent performance when using microscopy detection as a gold standard. Real-time PCR method can be considered as a confirmation tool for malaria diagnosis.

scholarly journals The exact place of PCR and chest CT in screening, staging, and diagnosis of Covid-19: A meta-analysis

2020 ◽  
Author(s):  
Fatemeh Khatami ◽  
Mohammad Saatchi ◽  
Seyed Saeed Tamehri Zadeh ◽  
Zahra Sadat Aghamir ◽  
Alireza Namazi Shabestari ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Ct Scan ◽  
Predictive Value ◽  
Meta Analysis ◽  
Chest Ct ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Chest Ct Scan

Abstract Introduction: Nowadays there is an ongoing acute respiratory outbreak causing by the novel highly contagious coronavirus (nCoV). There are two diagnostic protocol based on chest CT scan and quantitative reverse-transcription polymerase chain reaction (RT-PCR) which their diagnostic accuracy is under the debate. We designed this meta-analysis study to determine the diagnostic value of initial chest CT scan in patients with nCoV infection in comparison with RT- PCR.Search strategy and statistical analysis: Three main databases the PubMed (MEDLINE), Scopus, and EMBASE was systematically searched for all published literatures from January 1st, 2019, to the 27th march 2020 with key grouping of “COVID19 virus”, “2019 novel coronavirus”, “Wuhan coronavirus”, “2019-nCoV”, “X-Ray Computed Tomography”, “Polymerase Chain Reaction”, “Reverse Transcriptase PCR”, and “PCR Reverse Transcriptase”. All relevant case- series, cross-sectional, and cohort studies were selected. Data extraction was done in Excel 2007 (Microsoft Corporation, Redmond, CA) and their analysis was performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5.Result: From first recruited 668 articles we end up to the final 47 studies, which comprised a total sample size of 4238 patients. In compare to RT-PCR, the overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan were 86% (95% CI: 83% -90%), 43 % (95% CI: 26% -60%), 67% (95% CI: 57% -78%), and 84% (95% CI: 74% -95%) respectively. However the RT-PCR should be repeated for three times in order to give the 99% accuracy especially in negative samples.Conclusion: According to the acceptable sensitivity of chest CT scan, it can be employed complement to RT-PCR to diagnosis patients who are clinically suspicious for nCoV.

scholarly journals Detecting SARS-CoV-2 at point of care: preliminary data comparing loop-mediated isothermal amplification (LAMP) to polymerase chain reaction (PCR)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Marc F. Österdahl ◽  
Karla A. Lee ◽  
Mary Ni Lochlainn ◽  
Stuart Wilson ◽  
Sam Douthwaite ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcription ◽  
Predictive Value ◽  
Point Of Care ◽  
Isothermal Amplification ◽  
Service Improvement ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Loop Mediated Isothermal Amplification ◽  
Polymerase Chain

Abstract Background A cost effective and efficient diagnostic tool for COVID-19 as near to the point of care (PoC) as possible would be a game changer in the current pandemic. We tested reverse transcription loop mediated isothermal amplification (RT-LAMP), a method which can produce results in under 30 min, alongside standard methods in a real-life clinical setting. Methods This prospective service improvement project piloted an RT-LAMP method on nasal and pharyngeal swabs on 21 residents of a high dependency care home, with two index COVID-19 cases, and compared it to multiplex tandem reverse transcription polymerase chain reaction (RT-PCR). We recorded vital signs of patients to correlate clinical and laboratory information and calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of a single swab using RT-LAMP compared with the current standard, RT-PCR, as per Standards for Reporting Diagnostic Accuracy Studies (STARD) guidelines. Results The novel method accurately detected 8/10 RT-PCR positive cases and identified a further 3 positive cases. Eight further cases were negative using both methods. Using repeated RT-PCR as a “gold standard”, the sensitivity and specificity of a single novel test were 80 and 73% respectively. PPV was 73% and NPV was 83%. Incorporating retesting of low signal RT-LAMP positives improved the specificity to 100%. We also speculate that hypothermia may be a significant early clinical sign of COVID-19. Conclusions RT-LAMP testing for SARS-CoV-2 was found to be promising, fast and to work equivalently to RT-PCR methods. RT-LAMP has the potential to transform COVID-19 detection, bringing rapid and accurate testing to the PoC. RT-LAMP could be deployed in mobile community testing units, care homes and hospitals to detect disease early and prevent spread.

Interlaboratory Evaluation of a New Reverse Transcriptase Polymerase Chain Reaction–Based Enzyme-Linked Immunosorbent Assay for the Detection of Circulating Melanoma Cells: A Multicenter Study of the Dermatologic Cooperative Oncology Group

2001 ◽  
Vol 19 (6) ◽  
pp. 1723-1727 ◽  
Author(s):  
U. Reinhold ◽  
C. Berkin ◽  
A.-K. Bosserhoff ◽  
A. Deutschmann ◽  
C. Garbe ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Tumor Cells ◽  
High Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Blood Samples ◽  
Melanoma Patients ◽  
Polymerase Chain ◽  
Interlaboratory Reproducibility

PURPOSE: Reverse transcription-polymerase chain reaction (RT-PCR)–based detection of tyrosinase mRNA is the most frequently used laboratory method for the detection of circulating tumor cells in melanoma patients. However, previously published results showed considerable variability in the PCR positivity rates. MATERIALS AND METHODS: We designed a collaborative study to assess the sensitivity, specificity, and clinical relevance of a new standardized RT-PCR–based enzyme-linked immunosorbent assay (ELISA) for the detection of circulating melanoma cells. Blood samples of healthy donors mixed with cells of a melanoma cell line were prepared in a blinded fashion, and aliquots were sent to seven participating laboratories experienced in RT-PCR. RESULTS: The results demonstrate a high sensitivity (1 melanoma cell/mL blood) and specificity (no false-negatives and 7.4% [2 of 28] false-positives) of the assay and a satisfactory rate of interlaboratory reproducibility. The analysis of aliquots of blinded samples derived from 60 melanoma patients identified tyrosinase mRNA in 17 of 60 (28.3%): three (20%) of 15 stage I patients, two (13.3%) of 15 stage II patients, five (35.7%) of 14 stage III patients, and seven (43.8%) of 16 stage IV patients. The interlaboratory reproducibility of positive samples, however, was extremely low and indicates the presence of low amounts of target mRNA. CONCLUSION: Reverse transcriptase-PCR ELISA has a high sensitivity and specificity for the detection of tyrosinase mRNA in peripheral blood cells. The low interlaboratory reproducibility for the detection of tumor cells in blood samples of melanoma patients, however, raises the question of relevance of this assay for clinical use.

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