Lab practices that improve coronavirus disease 2019 detection accuracy using real-time PCR.

ABSTRACT: The number of coronavirus disease 2019 (COVID-19) cases significantly increased with the emergence of multiple variants of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This has led to an ongoing effort focused on developing the diagnostic detection tests. Among the currently available tests, real-time reverse transcriptase PCR (RT-PCR) has been considered as the 'golden method' for the detection of SARS-COV-2. However, a significant number of inaccurate (false-negative/false-positive) results have been reported in spite of this method's reliability and effectiveness. These unreliable results may arise because of various issues encountered throughout the entire testing process starting with the sampling phase, going through the PCR process, and ending with the result analysis. This article aims to shed light on the errors that occur during the COVID-19 testing process and suggest ways to overcome them effectively. Accurate testing could be optimized by following the correct swabbing technique, using adequate RT-PCR kits and controls, setting clear lab guidelines, and properly interpreting the results.

A rapid and low-cost protocol for the detection of B.1.1.7 lineage of SARS-CoV-2 by using SYBR Green-based RT-qPCR.

BACKGROUND: The new SARS-CoV-2 variant VOC (202012/01), identified recently in the United Kingdom (UK), exhibits a higher transmissibility rate compared to other variants, and a reproductive number 0.4 higher. In the UK, scientists were able to identify the increase of this new variant through the rise of false negative results for the spike (S) target using a three-target RT-PCR assay (TaqPath kit). METHODS: To control and study the current coronavirus pandemic, it is important to develop a rapid and low-cost molecular test to identify the aforementioned variant. In this work, we designed primer sets specific to the VOC (202012/01) to be used by SYBR Green-based RT-PCR. These primers were specifically designed to confirm the deletion mutations Δ69/Δ70 in the spike and the Δ106/Δ107/Δ108 in the NSP6 gene. We studied 20 samples from positive patients, detected by using the Applied Biosystems TaqPath RT-PCR COVID-19 kit (Thermo Fisher Scientific, Waltham, USA) that included the ORF1ab, S, and N gene targets. 16 samples displayed an S-negative profile (negative for S target and positive for N and ORF1ab targets) and four samples with S, N and ORF1ab positive profile. RESULTS: Our results emphasized that all S-negative samples harbored the mutations Δ69/Δ70 and Δ106/Δ107/Δ108. This protocol could be used as a second test to confirm the diagnosis in patients who were already positive to COVID-19 but showed false negative results for S-gene. CONCLUSIONS: This technique may allow to identify patients carrying the VOC (202012/01) or a closely related variant, in case of shortage in sequencing.

Malignant carcinoma and skin melanoma neoplasms concomitantly in the thyroid.

Malignant melanomas metastatic to the thyroid gland are uncommon. Based on microscopy and DNA methylation profile, we report a rare coexistence of neoplasms in the thyroid, presumably in our case, with relapse-free condition on adjuvant therapy.

Dual antiplatelet therapy up to the time of non-elective coronary artery bypass grafting with prophylactic platelet transfusion: is it safe?

BACKGROUND: Guidelines suggest that patients discontinue Clopidogrel at least 5 days prior to coronary artery bypass grafting (CABG). Those with acute coronary syndrome (ACS) are at high risk for myocardial infarction (MI) if not treated with dual antiplatelet therapy (DAPT). We sought to assess pre and post-operative outcomes of patients maintained on Clopidogrel and aspirin up to the time of surgery and compare them with those on aspirin alone. METHODS: From the cardiac surgery database, 240 patients were retrospectively registered between January and May 2017. There were 126 patients with ACS who underwent CABG on DAPT (Clopidogrel group [CG]) and 114 patients who underwent elective CABG on aspirin alone (control). The CG received intraoperative prophylactic platelet transfusion (PPT). Demographics, comorbidities, and laboratory data were prospectively entered at the time of surgery and were subsequently retrieved for analysis. Per and postoperative findings were identified and compared between both groups. RESULTS: The cohort consisted of 240 patients (mean age 61 years, 81.3% were male, SD ± 9.58). Patients in the CG were younger (Median 57 vs. 63, P-value 0.001), and with male predominance (86% versus 75%, P-value 0.028). In addition, they had less prevalence for diabetes and renal failure as compared to control (P-values 0.003, and 0.005, respectively). There were no significant differences between both groups in number of vessels grafts, duration of on-pump and aortic clamp. Hematologic laboratory data had also similar baseline values. The CG had similar bleeding rate, redo surgery and in-hospital death (P-values non-significant), however more infection and total hospital stay as compared to control (p-values 0.048 and 0.001). CONCLUSION: Patients who are at increased risk for MI can be maintained on DAPT up to the time of CABG because surgery is safe when patients are offered PPT.

Fecal microbiota transplantation for severe clostridium difficile infection after left ventricular assist device implantation: a case control study and concise review on the local and regional therapies.

BACKGROUND: We report herein a case of fecal microbiota transplantation (FMT) used for severe Clostridium difficile infection for a 65-year-old Lebanese man who underwent left ventricular assist device implantation. To the best of our knowledge this is the first case report from Lebanon and the region presenting such technique. CASE PRESENTATION: The patient experienced diarrhea and rectal bleeding and was diagnosed of pseudomembranous colitis (PMC). His condition failed to improve on maximal pharmacological therapy. Protocolectomy, an invasive operation consisting in resection of the entire colon and rectum seemed to be the last resort before the patient responded to FMT given through gastroscopy. CONCLUSION: Despite the increasing experience with FMT for C. difficile infection, published evidence in severe related cases from this region is very limited. Hence, we promote adjunctive FMT, an effective noninvasive method, to be considered as a promising early treatment option in severe C. difficile infection.

Multicentric glioma: problems & interpretations. [corrected].

The authors report four patients suffering from multicentric intraparenchymatous malignant glioma lesions located in different regions of the brain. The incidence of multiple, separated, independent, non-connected neuroepithelial tumors in the same patient is rare, although a discrepancy exists in the literature with regard to its real incidence. There is also controversy with respect to the histological composition of these tumors. In some cases, identical histopathological composition has been found, while in others different cellular patterns are present. Several hypotheses have been put forward to try to explain the occurrence of multicentric glioma tumor in the same patient. They consist of disseminations (through white matter tracts, cerebrospinal fluid pathways, or metastatic satellites around the vicinity of the tumor) or simultaneous development of different tumors, independent from each other.