The Expression of Retinal miRNA Evoked by Hyperglycemia and After Adiponectin Treatment in Human Retinal Endothelial Cells

Background: Diabetes mellitus is a chronic metabolic disease resulting in microvascular complications including diabetic retinopathy (DR). Adiponectin (ApN) is an adipokine hormone, and recent studies demonstrated that ApN could ameliorate critical biological process involved in the pathogenesis of DR. Micro-Ribonucleic acids (miRNAs) have been documented as novel biomarkers and are increasingly considered as molecules with significant modulatory action. Aim: To characterize the miRNA profile and expression in human retinal endothelial cells (HRECs) exposed to hyperglycemic conditions (HG) and illustrate the effect of adiponectin on miRNA expression and related pathways in HRECs exposed to HG. Methods: HRECs were treated with high glucose (30mM) for 96 hours duration followed by adiponectin (30μg/ml) for 24 h. Total RNA was extracted from HRECs. The gene panel array for both adhesion and angiogenesis molecules were performed using commercial RT2 Profiler PCR arrays. Furthermore, we utilized the small RNA sequencing for microRNA expression profiling of the HRECs. Results: HG treatment increases the expression of different well-known adhesion and angiogenesis genes as well as predicted miRNAs involved in these pathways, which was counteracted by ApN. RNA-Seq for miRNA profiling revealed 13 differentially expressed miRNAs in HRECs exposed to HG. miR-146a-5p was differentially expressed in HRECs treated with ApN. Analysis pathway linked the significantly changed miRNAs induced by HG to essential pathways such as hypoxia signaling, inflammation, and oxidative stress. Conclusion: HG induces expression of various adhesion and angiogenesis genes. Using RNA-Seq technology can accurately identify dysregulated miRNA profiles in HG retinal cells. MiR-146a was upregulated by adiponectin which targets different pathways involved in DR genesis

The Spectrum of Mutations of Homocystinuria in the MENA Region

Homocystinuria is an inborn error of metabolism due to the deficiency in cystathionine beta-synthase (CBS) enzyme activity. It leads to the elevation of both homocysteine and methionine levels in the blood and urine. Consequently, this build-up could lead to several complications such as nearsightedness, dislocated eye lenses, a variety of psychiatric and behavioral disorders, as well as vascular system complications. The prevalence of homocystinuria is around 1/200,000 births worldwide. However, its prevalence in the Gulf region, notably Qatar, is exceptionally high and reached 1:1800. To date, more than 191 pathogenic CBS mutations have been documented. The majority of these mutations were identified in Caucasians of European ancestry, whereas only a few mutations from African-Americans or Asians were reported. Approximately 87% of all CBS mutations are missense and do not target the CBS catalytic site, but rather result in unstable misfolded proteins lacking the normal biological function, designating them for degradation. The early detection of homocystinuria along with low protein and methionine-restricted diet is the best treatment approach for all types of homocystinuria patients. Yet, less than 50% of affected individuals show a significant reduction in plasma homocysteine levels after treatment. Patients who fail to lower the elevated homocysteine levels, through high protein-restricted diet or by B6 and folic acid supplements, are at higher risk for cardiovascular diseases, neurodegenerative diseases, neural tube defects, and other severe clinical complications. This review aims to examine the mutations spectrum of the CBS gene, the disease management, as well as the current and potential treatment approaches with a greater emphasis on studies reported in the Middle East and North Africa (MENA) region

The Current Status of Cytomegalovirus (CMV) Prevalence in the MENA region: a systematic review

Human cytomegalovirus (CMV) is a highly prevalent herpesvirus worldwide. According to the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO), CMV infects people of all ages, and by the age of five, approximately one-third of children in the United States are infected. Although the infection is generally asymptomatic, it can cause severe disease in immunocompromised patients, transplant and transfusion recipients, as well as newborn neonates. The objective of this study is to systematically review published literature on CMV in the MENA region to estimate its incidence in the region and describe its epidemiological and clinical significance. The literature was searched through four scientific databases: PubMed, Scopus, Science Direct, and Web of Science. A total of 72 studies from 11 countries satisfied the inclusion criteria, covering a period from 1988–2019. The CMV IgG seroprevalence ranged from 8.7–99.2% (SD = 38.95%). CMV incidence in these countries ranged between 1.22% and 77% in transplant and transfusion recipients, with an increase in incidence with advanced age. However, the incidence rate was unclear for congenital CMV due to the variability of the reporting. This review highlights the need for more robust and well-designed studies to better estimate CMV incidence in the MENA region, standardize diagnostic criteria, and consider prophylactic and pre-emptive treatments to limit the morbidity and mortality of the disease

Validation of Selected Commercial Serological Assays for Diagnosis of COVID-19

As researchers around the globe rush to put the available antibody tests to use, concerns have been raised about their precision. This study aimed to evaluate and compare the performance of selected commercial & automated serological assays, that are widely used in different clinical settings in Qatar. We validated the performance of five commercial IgG and IgM ELISA kits, three fully automated immunoassays, and two commercial rapid tests. The sensitivity of all assays was compared to RT-PCR and a surrogate virus neutralization test (sVNT). In addition, cross-reactivity was investigated. Among the evaluated kits, Lionex IgG assaydemonstrated the best performance (~88% sensitivity and ~99 specificity). All automated assays showed an excellent correlation with the neutralization test with an overall agreement of 93.6-98.5%. The rapid assays demonstrated a very good performance in detecting IgG antibodies (86.0-88.0% sensitivity and 98.0-100% specificity)

Challenges in Laboratory Diagnosis of the Novel Coronavirus SARS-CoV-2

The recent outbreak of the Coronavirus disease 2019 (COVID-19) has quickly spread worldwide since its discovery in Wuhan city, China in December 2019. A comprehensive strategy, including surveillance, diagnostics, research, clinical treatment, and development of vaccines, is urgently needed to win the battle against COVID-19. The past three unprecedented outbreaks of emerging human coronavirus infections at the beginning of the 21st century have highlighted the importance of readily available, accurate, and rapid diagnostic technologies to contain emerging and re-emerging pandemics. Real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) based assays performed on respiratory specimens remain the gold standard for COVID-19 diagnostics. However, point-of-care technologies and serologic immunoassays are rapidly emerging with high sensitivity and specificity as well. Even though excellent techniques are available for the diagnosis of symptomatic patients with COVID-19 in well-equipped laboratories; critical gaps still remain in screening asymptomatic people who are in the incubation phase of the virus, as well as in the accurate determination of live viral shedding during convalescence to inform decisions for ending isolation. This review article aims to discuss the currently available laboratory methods and surveillance technologies available for the detection of COVID-19, their performance characteristics and highlight the gaps in current diagnostic capacity, and finally, propose potential solutions. We also summarize the specifications of the majority of the available commercial kits (PCR, EIA, and POC) for laboratory diagnosis of COVID-19

Performance evaluation of novel fluorescent-based lateral immune flow assay (LIFA) for rapid detection and quantification of total anti-SARS-CoV-2 S-RBD binding antibodies in infected individuals.

The vast majority of the commercially available LFIA is used to detect SARS-CoV-2 antibodies qualitatively. Recently, a novel fluorescence-based LIFA test was developed for quantitative measurement of the total binding antibody units (BAU/mL) against the receptor-binding domain of the SARS-CoV-2 spike protein (S-RBD). To evaluate the performance of the fluorescence LIFA Finecare 2019-nCoV S-RBD test along with its reader (Model No.: FS-113). Plasma from 150 RT-PCR confirmed-positive individuals and 100 pre-pandemic samples were tested by FinCare to access sensitivity and specificity. For qualitative and quantitative validation of the FinCar measurements, the BAU/mL results of FinCare were compared with results of two reference assays: the surrogate virus-neutralizing test (sVNT, GenScript, USA), and the VIDAS®3 automated assay (BioMérieux, France). Finecare showed 92% sensitivity and 100% specificity compared to PCR. Cohen's Kappa statistic denoted moderate and excellent agreement with sVNT and VIDAS®3, ranging from 0.557 (95% CI: 0.32-0.78) to 0.731 (95% CI: 0.51-0.95), respectively. A strong correlation was observed between Finecare/sVNT (r=0.7, p<0.0001) and Finecare/VIDAS®3 (r=0.8, p<0.0001). Finecare is a reliable assay and can be used as a surrogate to assess binding and neutralizing antibody response post-infection or vaccination, particularly in none or small laboratory settings

Low risk of serological cross-reactivity between the dengue virus and SARS-CoV-2 IgG antibodies using advanced detection assays.

Several studies have reported serological cross-reactivity of the immune responses between SARS-CoV-2 and DENV. Most of the available studies are based on the point of care (POC) rapid testing kits. However, some rapid test kits have low specificity and can generate false positives. Hence, we aimed to investigate the potential serological cross-reactivity between SARS-CoV-2 and DENV IgG antibodies using advanced assays including chemiluminescence immunoassay (CLIA) and ELISA test. A total of 90 DENV-IgG-ELISA positive and 90 negative pre-pandemic sera were tested for anti-SARS-CoV-2-IgG using the automated CL-900i CLIA assay. Furthermore, a total of 91 SARS-CoV-2-IgG-CLIA positive and 91 negative post-pandemic sera were tested for anti-DENV-IgG using the Novalisa ELISA assay. The DENV-IgG positive sera resulted in five positives and 85 negatives for SARS-CoV-2-IgG. Similarly, the DENV-IgG negative sera also resulted in five positives and 85 negatives for SARS-CoV-2-IgG. No statistically significant difference in specificity between the DENV-IgG positive and DENV-IgG negative sera was found (p-value=1.00). The SARS-CoV-2-IgG positive sera displayed 43 positives, 47 negatives, and one equivocal for DENV-IgG. Whereas the SARS-CoV-2-IgG negative sera resulted in 50 positives, 40 negatives, and one equivocal for DENV-IgG. No statistically significant difference in the proportion that is DENV-IgG positive between the SARS-CoV-2-IgG positive and SARS-CoV-2-IgG negative sera (p-value=0.58). In conclusion, there is a low risk of serological cross-reactivity between the DENV, and SARS-CoV-2 IgG antibodies when using advanced detection assays.  .L.J.A. acknowledges the support of the Biomedical Research Program and the Biostatistics, Epidemiology, and Biomathematics Research Core, both at Weill Cornell Medicine-Qatar. This work was made possible by Grant Nos. RRC-2-032 and UREP19-013-3-001 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. In addition, G.K.N. would also like to acknowledge funds from Qatar University’s internal Grant QUERG-CMED-2020-2

Evaluation of commercially available fully automated and ELISA-based assays for detecting anti-SARS-CoV-2 neutralizing antibodies

Rapid and accurate measurement of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2)-specific neutralizing antibodies (nAbs) is paramount for monitoring immunity in infected and vaccinated subjects. The current gold standard relies on pseudovirus neutralization tests which require sophisticated skills and facilities. Alternatively, recent competitive immunoassays measuring anti-SARS-CoV-2 nAbs are proposed as a quick and commercially available surrogate virus neutralization test (sVNT). Here, we report the performance evaluation of three sVNTs, including two ELISA-based assays and an automated bead-based immunoassay for detecting nAbs against SARS-CoV-2. The performance of three sVNTs, including GenScript cPass, Dynamiker, and Mindray NTAb was assessed in samples collected from SARS-CoV-2 infected patients (n = 160), COVID-19 vaccinated individuals (n = 163), and pre-pandemic controls (n = 70). Samples were collected from infected patients and vaccinated individuals 2–24 weeks after symptoms onset or second dose administration. Correlation analysis with pseudovirus neutralization test (pVNT) and immunoassays detecting anti-SARS-CoV-2 binding antibodies was performed. Receiver operating characteristic (ROC) curve analysis was generated to assess the optimal threshold for detecting nAbs by each assay. All three sVNTs showed an excellent performance in terms of specificity (100%) and sensitivity (100%, 97.0%, and 97.1% for GenScript, Dynamiker, and Mindray, respectively) in samples collected from vaccinated subjects. GenScript demonstrated the strongest correlation with pVNT (r = 0.743, R2 = 0.552), followed by Mindray (r = 0.718, R2 = 0.515) and Dynamiker (r = 0.608, R2 = 0.369). Correlation with anti-SARS-CoV-2 binding antibodies was variable, but the strongest correlations were observed between anti-RBD IgG antibodies and Mindray (r = 0.952, R2 = 0.907). ROC curve analyses demonstrated excellent performance for all three sVNT assays in both groups, with an AUC ranging between 0.99 and 1.0 (p < 0.0001). Also, it was shown that the manufacturer's recommended cutoff values could be modified based on the tested cohort without significantly affecting the sVNT performance. The sVNT provides a rapid, low-cost, and scalable alternative to conventional neutralization assays for measuring and expanding nAbs testing across various research and clinical settings. Also, it could aid in evaluating actual protective immunity at the population level and assessing vaccine effectiveness to lay a foundation for boosters' requirements.Funding was provided by Qatar Foundation (Grant number: UREP28-173-3-057), Shenzhen Mindray Bio-Medical Electronics Co., Ltd., Shenzhen, China, Qatar University (Grant number: RRC-2-032)

Diagnostic Efficiency of Three Fully Automated Serology Assays and Their Correlation with a Novel Surrogate Virus Neutralization Test in Symptomatic and Asymptomatic SARS-COV-2 Individuals

Abstract: To support the deployment of serology assays for population screening during the COVID-19 pandemic, we compared the performance of three fully automated SARS-CoV-2 IgG assays: Mindray CL-900i® (target: spike [S] and nucleocapsid [N]), BioMérieux VIDAS®3 (target: receptor-binding domain [RBD]) and Diasorin LIAISON®XL (target: S1 and S2 subunits). A total of 111 SARS-CoV-2 RT-PCR- positive samples collected at ≥ 21 days post symptom onset, and 127 prepandemic control samples were included. Diagnostic performance was assessed in correlation to RT-PCR and a surrogate virus-neutralizing test (sVNT). Moreover, cross-reactivity with other viral antibodies was investigated. Compared to RT-PCR, LIAISON®XL showed the highest overall specificity (100%), followed by VIDAS®3 (98.4%) and CL-900i® (95.3%). The highest sensitivity was demonstrated by CL-900i® (90.1%), followed by VIDAS®3 (88.3%) and LIAISON®XL (85.6%). The sensitivity of all assays was higher in symptomatic patients (91.1–98.2%) compared to asymptomatic patients (78.4–80.4%). In correlation to sVNT, all assays showed excellent sensitivities (92.2–96.1%). In addition, VIDAS®3 demonstrated the best correlation (r = 0.75) with the sVNT. The present study provides insights on the performance of three fully automated assays, which could help diagnostic laboratories in the choice of a particular assay according to the intended us