Value of combined detection of PCA, ANCA, ASCA, AGA and ANA in early diagnosis of Gastrointestinal Diseases

Objectives: To investigate the positive detection rate and clinical application value of anti-parietal cell antibody (PCA), anti-neutrophil cytoplasmic antibody (ANCA), anti-Saccharomyces cerevisiae antibody (ASCA), anti-gliadin antibody (AGA) and anti-nuclear antibody (ANA) in patients visiting the Department of Gastroenterology. Methods: From January 2015 to June 2018, 1,083 patients receiving detection of PCA and other autoantibodies were selected from the Department of Gastroenterology of Baoding First Central Hospital. The positive detection rate of autoantibodies was statistically analyzed. The enumeration data were expressed as rate or constituent ratio, and the rates were compared between groups using the x2 test. Results: Among the 1,083 patients, the positive detection rate of ANA, ASCA, AGA, PCA and ANCA was 33.52%, 16.71%, 15.51%, 13.66% and 7.66%, respectively. The total positive detection rate was 62.8% (n = 680). Conclusion: The population with abdominal distension, chronic abdominal pain, diarrhea and other digestive system symptoms should be timely treated with combined detection of PCA, ANCA, ASCA, AGA and ANA, which is of important clinical application value for early diagnosis of gastrointestinal diseases and prevention of missed diagnosis and misdiagnosis. doi: https://doi.org/10.12669/pjms.38.1.4682 How to cite this:Liu X, Guo D, Li X, Guo Y, Song W. Value of combined detection of PCA, ANCA, ASCA, AGA and ANA in early diagnosis of Gastrointestinal Diseases. Pak J Med Sci. 2022;38(1):---------. doi: https://doi.org/10.12669/pjms.38.1.4682 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Investigating Erythrocytosis: Changing Practice Patterns in the Era of Molecular Diagnostics

Background: Since the identification of JAK2 mutations in polycythemia vera (PV) in 2005 (Kralovics et al., NEJM 2005), molecular testing of JAK2 in patients with erythrocytosis has become part of routine clinical practice. We hypothesized that changes in the World Health Organization (WHO) diagnostic criteria for PV in 2016, which lowered the hemoglobin threshold to >165 g/L for men and >160 g/L for women, may have resulted in increased molecular testing. This study examines changing patterns of utilization of molecular diagnostics in patients referred for erythrocytosis at a tertiary care center. Methods: We examined all patients with erythrocytosis who underwent JAK2 testing, which included testing for JAK2 V617F with PCR between 2015 and 2017, and JAK2 V617F and exon 12 mutations with Next-Generation Sequencing (NGS) between 2018 and 2020 at London Health Sciences Centre in Ontario, Canada. We performed a retrospective chart review to extract laboratory and clinical data, including information on medical comorbidities and medications, with a focus on known secondary causes of erythrocytosis. Results: A total of 668 patients with erythrocytosis underwent JAK2 testing at our institution between August 1, 2015 and December 31, 2020. There was an overall increase in testing over the five-year study period, with a decline in the positive detection rate: 8/29 (28%) in 2015, 15/94 (16%) in 2016, 15/100 (15%) in 2017, 19/136 (14%) in 2018, 17/162 (10%) in 2019, and 14/147 (10%) in 2020 (Figure 1). The average hemoglobin levels in patients with erythrocytosis who underwent testing remained similar across all years (range 170-173 g/L for women, 179-181 g/L for men). In our cohort, there was a high proportion of patients with known or suspected secondary causes of erythrocytosis who underwent molecular testing. Between 2018 and 2020, 324/445 (73%) of patients who underwent molecular testing had either chronic obstructive pulmonary disease, obstructive sleep apnea, other hypoxic lung disease, smoking history, erythropoietin-secreting tumor, or potential drug-induced erythrocytosis. Specifically, we observed an increase in proportion of patients who underwent molecular testing on sodium-glucose cotransporter-2 (SGLT-2) inhibitors, a known secondary cause of erythrocytosis, with 15/136 (11%) in 2018, 17/162 (10%) in 2019, and 25/147 (17%) in 2020. In contrast, the proportion of patients on testosterone was relatively constant at 15/136 (11%) in 2018, 11/162 (6.8%) in 2019, and 11/147 (7.5%) in 2020. Conclusion: This study revealed that a high proportion of patients with known or suspected secondary causes of erythrocytosis underwent JAK2 testing, resulting in increase in molecular testing over time and a decline in positive detection rate. In particular, we observed a number of patients on SGLT-2 inhibitors who had investigation, suggesting that this class of medications may be an underrecognized cause of drug-induced erythrocytosis (Chin-Yee et al., CMAJ 2020). Our findings underscore the importance of careful medical history and medication review to support more judicious use of molecular testing. Similarity in average hemoglobin levels across the five-year study period suggests that other factors, such as increased availability of 'routine' molecular testing, rather than changes in the WHO diagnostic criteria may explain increases in JAK2 testing. Our study indicates a need to develop an effective clinical prediction rule for JAK2 positivity to better risk stratify patients with suspected PV based on clinical and laboratory parameters to optimize utilization of molecular diagnostics. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

The value of single-molecule real-time technology in the diagnosis of rare thalassemia variants and analysis of phenotype–genotype correlation

To compare single-molecule real-time technology (SMRT) and conventional genetic diagnostic technology of rare types of thalassemia mutations, and to analyze the molecular characteristics and phenotypes of rare thalassemia gene variants, we used 434 cases with positive hematology screening as the cohort, then used SMRT technology and conventional gene diagnosis technology [(Gap-PCR, multiple ligation probe amplification technology (MLPA), PCR-reverse dot blot (RDB)] for thalassemia gene screening. Among the 434 enrolled cases, conventional technology identified 318 patients with variants (73.27%) and 116 patients without variants (26.73%), SMRT identified 361 patients with variants (83.18%), and 73 patients without variants (16.82%). The positive detection rate of SMRT was 9.91% higher than conventional technology. Combination of the two methods identified 485 positive alleles among 49 types of variant. The genotypes of 354 cases were concordant between the two methods, while 80 cases were discordant. Among the 80 cases, 76 cases had variants only identified in SMRT method, 3 cases had variants only identified in conventional method, and 1 false positive result by the traditional PCR detection technology. Except the three variants in HS40 and HBG1-HBG2 loci, which was beyond the design of SMRT method in this study, all the other discordant variants identified by SMRT were validated by further Sanger sequencing or MLPA. The hematological phenotypic parameters of 80 discordant cases were also analyzed. SMRT technology increased the positive detection rate of thalassemia genes, and detected rare thalassemia cases with variable phenotypes, which had great significance for clinical thalassemia gene screening.

SARS-CoV-2 Neutralizing Antibody Levels Post COVID-19 Vaccination Based on ELISA Method—A Small Real-World Sample Exploration

This study investigated the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies following inoculation with the coronavirus disease (COVID-19) vaccine. From June to July 2021, 127 participants who had completed COVID-19 vaccination (inactivated SARS-CoV-2 vaccine, 64; CoronaVac, 61; CanSino, 2) were recruited and tested using SARS-CoV-2 neutralizing antibody kits. The positive detection rate (inhibition of neutralizing antibodies ≥ 30%) was calculated and stratified according to population characteristics and inoculation time. The positive rate of neutralizing antibody was 47.22% (17/36) in men and 53.85% (49/91) in women, and 54.55% (24/44) in BMI ≥ 24 and 50.60% (42/83) in BMI < 24. Age was stratified as 20–29, 30–39, 40–49, and ≥50; positive detection rates of SARS-CoV-2 neutralizing antibodies were observed in 60.00% (24/40), 50.00% (21/42), 48.39% (15/31), and 42.86% (6/14), respectively, but with no significant difference (x2 = 1.724, p = 0.632). Among 127 vaccinated participants, 66 (51.97%) were positive. The positive detection rate was 63.93% (39/61) with CoronaVac and 42.19% (27/64) with the inactivated SARS-CoV-2 vaccine (significance x2 = 5.927, p = 0.015). Multivariate analysis revealed a significant difference in vaccination times, with average vaccination weeks in the positive and negative groups of 11.57 ± 6.48 and 17.87 ± 9.17, respectively (t= −4.501, p < 0.001). The positive neutralizing antibody rate was 100.00%, 60.00%, 58.33%, 55.56%, 43.14%, 28.57%, and 0.00% at 2–4, 5–8, 9–12, 13–16,17–20, 21–24, and >24 weeks, respectively (x2 = 18.030, p = 0.006). Neutralizing antibodies were detected after COVID-19 inoculation, with differences relating to inoculation timing. This study provides a reference for vaccine evaluation and follow-up immunization strengthening.

A Microbial World: Could Metagenomic Next-Generation Sequencing Be Involved in Acute Respiratory Failure?

BackgroundThe usefulness of metagenomic next-generation sequencing (mNGS) in identifying pathogens is being investigated. We aimed to compare the power of microbial identification between mNGS and various methods in patients with acute respiratory failure.MethodsWe reviewed 130 patients with respiratory failure, and 184 specimens including blood, bronchoalveolar lavage fluid (BALF), sputum, pleural effusion, ascitic fluid, and urine were tested by mNGS and conventional methods (culture, PCR). We also enrolled 13 patients to evaluate the power of mNGS and pathogen targets NGS (ptNGS) in microbial identifications. Clinical features and microbes detected were analyzed.ResultsmNGS outperformed the conventional method in the positive detection rate of Mycobacterium tuberculosis (MTB) (OR, ∞; 95% CI, 1–∞; P &lt; 0.05), bacteria (OR, 3.7; 95% CI, 2.4–5.8; P &lt; 0.0001), fungi (OR, 4.37; 95% CI, 2.7–7.2; P &lt; 0.0001), mycoplasma (OR, 10.5; 95% CI, 31.8–115; P = 0.005), and virus (OR, ∞; 95% CI, 180.7–∞; P &lt; 0.0001). We showed that 20 patients (28 samples) were detected with Pneumocystis jirovecii (P. jirovecii) by mNGS, but not by the conventional method, and most of those patients were immunocompromised. Read numbers of Klebsiella pneumoniae (K. pneumoniae), Acinetobacter baumannii (A. baumannii), Pseudomonas aeruginosa (P. aeruginosa), P. jirovecii, cytomegalovirus (CMV), and Herpes simplex virus 1 (HSV1) in BALF were higher than those in other sample types, and the read number of Candida albicans (C. albicans) in blood was higher than that in BALF. We found that orotracheal intubation and type 2 diabetes mellitus (T2DM) were associated with a higher detection rate of bacteria and virus by mNGS, immunosuppression was associated with a higher detection rate of fungi and virus by mNGS, and inflammatory markers were associated with mNGS-positive detection rate of bacteria. In addition, we observed preliminary results of ptNGS.ConclusionmNGS outperformed the conventional method in the detection of MTB, bacteria, fungi, mycoplasma, and virus. Orotracheal intubation, T2DM, immunosuppression, and inflammatory markers were associated with a higher detection rate of bacteria, fungi, and virus by mNGS. In addition, ptNGS results were consistent with the detection of abundant bacteria, fungi, and mycoplasma in our specimens.

Effectiveness and cost-effectiveness of four different strategies for SARS-CoV-2 surveillance in the general population (CoV-Surv Study): study protocol for a two-factorial randomized controlled multi-arm trial with cluster sampling

Background To achieve higher effectiveness in population-based SARS-CoV-2 surveillance and to reliably predict the course of an outbreak, screening, and monitoring of infected individuals without major symptoms (about 40% of the population) will be necessary. While current testing capacities are also used to identify such asymptomatic cases, this rather passive approach is not suitable in generating reliable population-based estimates of the prevalence of asymptomatic carriers to allow any dependable predictions on the course of the pandemic. Methods This trial implements a two-factorial, randomized, controlled, multi-arm, prospective, interventional, single-blinded design with cluster sampling and four study arms, each representing a different SARS-CoV-2 testing and surveillance strategy based on individuals’ self-collection of saliva samples which are then sent to and analyzed by a laboratory. The targeted sample size for the trial is 10,000 saliva samples equally allocated to the four study arms (2500 participants per arm). Strategies differ with respect to tested population groups (individuals vs. all household members) and testing approach (without vs. with pre-screening survey). The trial is complemented by an economic evaluation and qualitative assessment of user experiences. Primary outcomes include costs per completely screened person, costs per positive case, positive detection rate, and precision of positive detection rate. Discussion Systems for active surveillance of the general population will gain more importance in the context of pandemics and related disease prevention efforts. The pandemic parameters derived from such active surveillance with routine population monitoring therefore not only enable a prospective assessment of the short-term course of a pandemic, but also a more targeted and thus more effective use of local and short-term countermeasures. Trial registration ClinicalTrials.gov DRKS00023271. Registered November 30, 2020, with the German Clinical Trials Register (Deutsches Register Klinischer Studien)

Respiratory syncytial virus infection in children and its correlation with climatic and environmental factors

Objective In this study, we aimed to investigate the clinical epidemiology of lower respiratory tract infections with different respiratory syncytial virus (RSV) subtypes in hospitalized children in Suzhou and their correlation with climatic and environmental factors. Method In this retrospective cross-sectional study, we collected nasopharyngeal secretion samples from children hospitalized with acute lower respiratory tract infection. We collected the clinical data of children with RSV infection, and compared and analyzed their epidemiological characteristics. Results RSV-B was the dominant strain in 2016. In 2018, RSV-A was the dominant strain. The positive detection rate of RSV-A was negatively correlated with monthly mean temperature, monthly mean wind speed, total monthly rainfall, and O3 concentration and positively correlated with PM2.5, PM10, and NO2, SO2, and CO concentrations. The positive detection rate of RSV-B was negatively correlated with monthly average temperature, monthly total rainfall, monthly sunshine duration, and O3 concentration and positively correlated with CO concentration. Conclusions RSV-A was the main subtype detected in this study. The positive detection rate of RSV-A was related to temperature, wind speed, rainfall, PM2.5. PM10, and NO2, SO2, CO, and O3 concentrations. The positive detection rate of RSV-B was related to temperature, rainfall, sunshine time, and O3 concentration.

BLUE SCREEN VIDEO FORGERY DETECTION AND LOCALIZATION USING AN ENHANCED 3-STAGE FOREGROUND ALGORITHM

The availability of easy to use video editing software has made it easy for cyber criminals to combine different videos from different sources using blue screen composition technology. This, makes the authenticity of such digital videos questionable and needs to be verified especially in the court of law. Blue Screen Composition is one of the ways to carry out video forgery using simple to use and affordable video editing software. Detecting this type of video forgery aims at revealing and observing the facts about a video so as to conclude whether the contents of the video have undergone any unethical manipulation. In this work, we propose an enhanced 3-stage foreground algorithm to detect Blue Screen manipulation in digital video. The proposed enhanced detection technique contains three (3) phases, extraction, detection and tracking. In the extraction phase, a Gaussian Mixture Model (GMM) is used to extract foreground element from a target video. Entropy function as a descriptive feature of image is extracted and calculated from the target video in the detection phase. The tracking phase seeks to use Minimum Output Sum of Squared Error (MOSSE) object tracking algorithm to fast track forged blocks of small sizes in a digital video. The result of the experiments demonstrates that the proposed detection technique can adequately detect Blue Screen video forgery when the forged region is small with a true positive detection rate of 98.02% and a false positive detection rate of 1.99%. The result of this our research can be used to

SARS-CoV-2 RT-PCR test results across symptomatic COVID-19 cases in Auckland, New Zealand, February–June 2020

During the first wave of COVID-19 transmission in New Zealand, a review of RT-PCR testing in all symptomatic cases reported in the Auckland Region found 74% of test results to have been positive. Detection rate was superior for nasopharyngeal swabs than for oropharyngeal samples, and highest one week after symptom onset. Certain symptom presentations may associate with these cases returning negative results, with dyspnoea reported by a greater proportion of cases who tested negative.

Expanding the Scope of Non-invasive Prenatal Testing to Detect Fetal Chromosomal Copy Number Variations

Non-invasive prenatal testing (NIPT) for common fetal trisomies is effective. However, the usefulness of cell-free DNA testing to detect other chromosomal abnormalities is poorly understood. We analyzed the positive rate at different read depths in next-generation sequencing (NGS) and identified a strategy for fetal copy number variant (CNV) detection in NIPT. Pregnant women who underwent NIPT by NGS at read depths of 4–6 M and fetuses with suspected CNVs were analyzed by amniocentesis and chromosomal microarray analysis (CMA). These fetus samples were re-sequenced at a read depth of 25 M and the positive detection rate was determined. With the increase in read depth, the positive CNV detection rate increased. The positive CNV detection rates at 25 M with small fragments were higher by NGS than by karyotype analysis. Increasing read depth in NGS improves the positive CNV detection rate while lowering the false positive detection rate. NIPT by NGS may be an accurate method of fetal chromosome analysis and reduce the rate of birth defects.