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Abiola Senok,1,* Hanan Alsuwaidi,1,* Yusrah Atrah,2 Ola Al Ayedi,3 Janan Al Zahid,2 Aaron Han,1 Asma Al Marzooqi,3 Saba Al Heialy,1,4 Basel Altrabulsi,5 Laila AbdelWareth,5,6 Youssef Idaghdour,7 Raghib Ali,7 Tom Loney,1 Alawi Alsheikh-Ali1 1College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates; 2Molecular Department, Unilabs UAE, Dubai, United Arab Emirates; 3Al Khawaneej Health Center, Dubai Health Authority, Dubai, United Arab Emirates; 4Meakins-Christie Laboratories, Research Institute of the McGill University Health Center, Montreal, QC, Canada; 5National Reference Laboratory, Abu Dhabi, United Arab Emirates; 6Pathology and Laboratory Medicine Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates; 7Public Health Research Center, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates*These authors contributed equally to this workCorrespondence: Abiola SenokCollege of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Building 14, Dubai Healthcare City, Dubai 505055, United Arab EmiratesTel +97143838717Email abiola.senok@mbru.ac.aePurpose: With the easing of restriction measures, repeated community-based sampling for tracking new COVID-19 infections is anticipated for the next 6 to 12 months. A non-invasive, self-collected specimen like saliva will be useful for such public health surveillance. Investigations on the use of saliva for SARS-CoV-2 RT-PCR have largely been among COVID-19 in-pa\tients and symptomatic ambulatory patients with limited work in a community-based screening setting. This study was carried out to address this paucity of data and reported discrepancies in diagnostic accuracy for saliva samples.Patients and Methods: From 29th June to 14th July 2020, adults presenting for COVID-19 testing at a community-based screening facility in Dubai, United Arab Emirates were recruited. Clinical data, nasopharyngeal swab in universal transport media and drooling saliva in sterile containers were obtained. Reverse transcriptase PCR amplification of SARS-CoV-2 RdRp and N genes was used to detect the presence of the SARS-CoV-2 virus.Results: Of the 401 participants, 35 (8.7%) had viral detection in at least one specimen type and the majority (n=20/35; 57.1%) were asymptomatic. Both swab and saliva were positive in 19 (54.2%) patients, while 7 (20.0%) patients had swab positive/saliva negative results. There were 9 (25.7%) patients with saliva positive/swab negative result and this included 5 asymptomatic COVID-19 patients undergoing repeat screening. Using the swab as the reference gold standard, the sensitivity and specificity of saliva were 73.1% (95% CI 52.2– 88.4%) and 97.6% (95% CI 95.5– 98.9%) while the positive and negative predictive values were 67.9% (95% CI 51.5– 80.8%) and 98.1% (95% CI 96.5– 99.0%), respectively.Conclusion: The findings suggest good diagnostic accuracy for saliva and feasibility of utilization of specimen without transport media for SARS-CoV-2 RT-PCR. Saliva represents a potential specimen of choice in community settings and population-based screening.Keywords: SARS-CoV-2, nasopharyngeal swab, molecular test, population-based screening, saliva

Background: Lipoprotein(a) [Lp(a)] is a genetically determined risk factor for atherosclerotic cardiovascular disease (CVD). Limited data are available on Lp(a) testing from the Middle-East region. Therefore, we aim to evaluate the utilization and yield of Lp(a) testing over time and characterize CVD profiles of patients with abnormal Lp(a) tasting at a single-quaternary-care center in the United Arab Emirates., Methods: Unique Lp(a) tests conducted between 07/2017 and 10-2023 were included. Overtime trends in Lp(a) test utilization and abnormal Lp(a) [defined as Lp(a) > 125 nmol/L] test findings were described. CVD rates in patients with abnormal Lp(a) were compared to those with Lp(a) ≤ 125 nmol/L using appropriate methods., Results: In our center, 0.95% of the patients ( n  = 5,677) had their Lp(a) measured, with a median level of 32 [11-82] nmol/L. Lp(a) was abnormal in 15.9% of the tests. Over the years 2018-2022, there was a 109% increase in Lp(a) testing, with concomitant up-trends in findings of abnormal Lp(a) (11.8% to 16.4%, P  = 0.02). Compared to patients with Lp(a) ≤ 125 nmol/I, those with abnormal Lp(a) had higher rates of any prevalent CVD (34% vs. 25.1%, P  < 0.001), CAD (25.6% vs. 17.7%, P  < 0.001), HF (6.5% vs. 3.8%, P  < 0.001), and stroke (7.1% vs. 4.4%, P  < 0.001)., Conclusion: Almost one in six patients tested for Lp(a) had abnormally elevated Lp(a), and CVD was prevalent in one-third of the patients who tested abnormal for Lp(a). The study highlights the growing awareness of the relevance of Lp(a) for CVD risk stratification and prevention., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (© 2024 Manla, AbdelWareth, Shantouf, Aljabery, St John, Sabbour, Piechowski-Jozwiak and Almahmeed.)

Objectives: There is substantial immunological evidence that vaccination following natural infection increases protection. We compare the humoral immune response developed in initially seropositive individuals (naturally infected) to humoral hybrid immune response (developed after infection and vaccination) in the same population group after one year., Methods: The study included 197 male individuals who were naturally infected with SARS-CoV-2 and then vaccinated with SARS-CoV-2 vaccine. Trimeric spike, nucleocapsid, and ACE2-RBD blocking antibodies for SARS-CoV-2 were measured. Nasal swabs were collected for SARS-CoV-2 PCR testing. Information on vaccination against SARS-CoV-2 and PCR verified infection was retrieved from official databases (Abu Dhabi Health Data Services- SP LLC. ("Malaffi"), including number of vaccine doses received, date of vaccination, and type of the received vaccine., Results: All the study population were tested PCR-Negative at the time of sample collection. Our results showed that there was a significant rise in the mean (SD) and median (IQR) titers of trimeric spike, nucleocapsid and ACE2-RBD blocking antibodies in the post-vaccination stage. The mean (± SD) and median (IQR) concentration of the anti-S antibody rose by 3.3-fold (+230% ± 197% SD) and 2.8-fold (+185%, 220-390%, p<0.001), respectively. There was an observed positive dose-response relationship between number of the received vaccine doses and having higher proportion of study participants with higher than median concentration in the difference between the measured anti-S and ACE2-RBD blocking antibodies in the post-vaccination compared to pre-vaccination., Conclusion: Our study demonstrates that COVID-19 vaccination post natural infection elicits a robust immunological response with an impressive rise of SARS-CoV-2 antibodies, especially the ACE2-RBD blocking antibodies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 AbdelWareth, Alhousani, Abuyadek, Donnelly, Leinberger-Jabari, Atef and Al-Rifai.)

Objectives: We investigated the reinfection rate of vaccinated or convalescent immunized SARS-CoV-2 in 952 expatriate workers with SARS-CoV-2 serological antibody (Ab) patterns and surrogate T cell memory at recruitment and follow-up., Methods: Trimeric spike, nucleocapsid, and neutralizing Abs were measured, along with a T cell stimulation assay, targeting SARS-CoV-2 memory in clusters of differentiation (CD) 4+ and CD8+ T cells. The subjects were then followed up for reinfection for up to 6 months., Results: The seroprevalence positivity at enrollment was greater than 99%. The T cell reactivity in this population was 38.2%. Of the 149 (15.9%) participants that were reinfected during the follow-up period (74.3%) had nonreactive T cells at enrollment. Those who had greater than 100 binding Ab units/ml increase from the median concentration of antispike immunoglobulin G Abs had a 6% reduction in the risk of infection. Those who were below the median concentration had a 78% greater risk of infection., Conclusion: Significant immune protection from reinfection was observed in those who retained T cell activation memory. Additional protection was observed when the antispike was greater than the median value., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Introduction: The induction and speed of production of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) immune biomarkers may vary by type and number of inoculated vaccine doses. This study aimed to explore variations in SARS-CoV-2 anti-spike (anti-S), anti-nucleocapsid (anti-N), and neutralizing immunoglobulin G (IgG) antibodies, and T-cell response by type and number of SARS-CoV-2 vaccine doses received., Methods: In a naturally exposed and SARS-CoV-2-vaccinated population, we quantified the anti-S, anti-N, and neutralizing IgG antibody concentration and assessed T-cell response. Data on socio-demographics, medical history, and history of SARS-CoV-2 infection and vaccination were collected. Furthermore, nasal swabs were collected to test for SARS-CoV-2 infection. Confounder-adjusted association between having equal or more than a median concentration of the three IgG antibodies and T-cell response by number and type of the inoculated vaccines was quantified., Results: We surveyed 952 male participants with a mean age of 35.5 years ± 8.4 standard deviations. Of them, 52.6% were overweight/obese, and 11.7% had at least one chronic comorbidity. Of the participants, 1.4, 0.9, 20.2, 75.2, and 2.2% were never vaccinated, primed with only one dose, primed with two doses, boosted with only one dose, and boosted with two doses, respectively. All were polymerase chain reaction-negative to SARS-CoV-2. BBIBP-CorV (Sinopharm) was the most commonly used vaccine (92.1%), followed by rAd26-S + rAd5-S (Sputnik V Gam-COVID-Vac) (1.5%) and BNT162b2 (Pfizer-BioNTech) (0.3%). Seropositivity to anti-S, anti-N, and neutralizing IgG antibodies was detected in 99.7, 99.9, and 99.3% of the study participants, respectively. The T-cell response was detected in 38.2% of 925 study participants. Every additional vaccine dose was significantly associated with increased odds of having ≥median concentration of anti-S [adjusted odds ratio (aOR), 1.34; 95% confidence interval (CI): 1.02-1.76], anti-N (aOR, 1.35; 95% CI: 1.03-1.75), neutralizing IgG antibodies (aOR, 1.29; 95% CI: 1.00-1.66), and a T-cell response (aOR, 1.48; 95% CI: 1.12-1.95). Compared with boosting with only one dose, boosting with two doses was significantly associated with increased odds of having ≥median concentration of anti-S (aOR, 13.8; 95% CI: 1.78-106.5), neutralizing IgG antibodies (aOR, 13.2; 95% CI: 1.71-101.9), and T-cell response (aOR, 7.22; 95% CI: 1.99-26.5) although not with anti-N (aOR, 0.41; 95% CI: 0.16-1.08). Compared with priming and subsequently boosting with BBIBP-CorV, all participants who were primed with BBIBP-CorV and subsequently boosted with BNT162b2 had ≥median concentration of anti-S and neutralizing IgG antibodies and 14.6-time increased odds of having a T-cell response (aOR, 14.63; 95% CI: 1.78-120.5). Compared with priming with two doses, boosting with the third dose was not associated, whereas boosting with two doses was significantly associated with having ≥median concentration of anti-S (aOR, 14.20; 95% CI: 1.85-109.4), neutralizing IgG (aOR, 13.6; 95% CI: 1.77-104.3), and T-cell response (aOR, 7.62; 95% CI: 2.09-27.8)., Conclusion: Achieving and maintaining a high blood concentration of protective immune biomarkers that predict vaccine effectiveness is very critical to limit transmission and contain outbreaks. In this study, boosting with only one dose or with only BBIBP-CorV after priming with BBIBP-CorV was insufficient, whereas boosting with two doses, particularly boosting with the mRNA-based vaccine, was shown to be associated with having a high concentration of anti-S, anti-N, and neutralizing IgG antibodies and producing an efficient T-cell response., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Al-Rifai, Alhosani, Abuyadek, Atef, Donnelly, Leinberger-Jabari, Ahmed, Altrabulsi, Alatoom, Alsuwaidi and AbdelWareth.)

Background and Aim: We have previously shown in a retrospective analysis that the plasma thyroid-stimulating hormone (TSH) rises significantly post-Ramadan in levothyroxine-treated hypothyroid patients, possibly as a result of lifestyle alterations and time restrictions during the nonfasting period from dusk until dawn. The aim of this study is to determine the best time to instruct patients to take levothyroxine during Ramadan so as to minimize changes in thyroid function tests during this period., Methods: In a randomized prospective design, hypothyroid patients taking levothyroxine were randomized to receive instructions to take levothyroxine at one of the following 3 times during Ramadan: (group 1) at dusk 30-min before Iftar meal, (group 2) 3 or more hours after Iftar meal, or (group 3) at dawn 30-min before Suhur meal. Thyroid function tests were performed within 3 months before Ramadan and within 6 weeks post-Ramadan. Data from patients with at least 1 blood test before or after Ramadan were analyzed using mixed-effects regression models., Results: Plasma TSH levels were available at one or more time points for 148 patients, group 1 ( n = 50), group 2 ( n = 46), and group 3 ( n = 52). A statistically significant within-patient increase in plasma TSH was seen in patients at the 25th percentile pre-Ramadan in groups 2 and 3 ( p values <0.001), but not in group 1. A statistically significant within-patient decrease in plasma TSH was found in patients at the 75th percentile in group 1 only. For patients at the 50th percentile pre-Ramadan, no statically significant within-patient changes were found, though descriptively, increases in plasma TSH were observed for groups 2 and 3, while a decrease was observed in group 1., Conclusions: Our data suggest that instructing patients to take levothyroxine at the time of breaking the fast 30 min before the Iftar meal minimizes unfavorable changes in plasma TSH post-Ramadan. In contrast, instructing patients to take levothyroxine 3 h post-Iftar or 30 min before Suhur led to a greater rise in post-Ramadan TSH., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 by European Thyroid Association Published by S. Karger AG, Basel.)

Background: Serology assays have the potential to support RT-PCR in the diagnosis of SARS-CoV-2 infection. We studied three commercially available immunoassays for their diagnostic accuracy from blood specimens collected from 93 patients., Methods: Blood samples from patients with confirmed COVID-19 infection were analysed using three different Immunoassays (Roche total antibody assay, Abbott IgG assay and Euroimmun IgG assay). Sensitivity, specificity, precision and time of seroconversion were evaluated., Results: The sensitivity of Roche, Abbott and Euroimmun assays was 38.7%, 35.5% and 25.0% respectively for specimens collected <10 days and 84.4%, 84.4% and 70.0% respectively for specimens collected ≥10 days after the first positive RT-PCR. The specificity of all the three assays in this study was 100%. The timing of seroconversion occurred at day 1, 7 or 14., Conclusions: The assays evaluated in this study have different sensitivities for detecting antibodies in SARS-CoV-2 infection. Sensitivity for detecting antibodies for all three assays was higher for specimens collected ≥10 days after first positive PCR compared with specimens collected <10 days. Time of seroconversion is variable and assay-dependent., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

(1) Background: There are limited data regarding the efficacy of convalescent plasma (CP) in critically ill patients admitted to the intensive care unit (ICU) due to coronavirus disease 2019 (COVID-19). We aimed to determine whether CP is associated with better clinical outcome among these patients. (2) Methods:&nbsp;A&nbsp;retrospective single-center study including adult patients with laboratory-confirmed SARS-CoV-2 infection admitted to the ICU for acute respiratory failure. The primary outcome was time to clinical improvement, within 28 days, defined as patient discharged alive or reduction of 2 points on a 6-point disease severity scale. (3)&nbsp;Results:&nbsp;Overall, 110 COVID-19 patients were admitted. Thirty-two patients (29%) received CP; among them, 62.5% received at least one CP with high neutralizing antibody titers (≥1:160). Clinical improvement occurred within 28 days in 14 patients (43.7%) of the CP group vs. 48 patients (61.5%) in the non-CP group (hazard ratio (HR): 0.75 (95% CI: 0.41-1.37), p = 0.35). After adjusting for potential confounding factors, CP was not independently associated with time to clinical improvement (HR: 0.53 (95% CI: 0.23-1.22), p = 0.14). Additionally, the average treatment effects of CP, calculated using the inverse probability weights (IPW), was not associated with the primary outcome (-0.14 days (95% CI: -3.19-2.91 days), p = 0.93). Hospital mortality did not differ between CP and non-CP groups (31.2% vs. 19.2%, p = 0.17, respectively). Comparing CP with high neutralizing antibody titers to the other group yielded the same findings. (4) Conclusions: In this study of life-threatening COVID-19 patients, CP was not associated with time to clinical improvement within 28 days, or hospital mortality.

The Asia-Pacific Society of Cardiology (APSC) high-sensitivity troponin T (hs-TnT) consensus recommendations and rapid algorithm were developed to provide guidance for healthcare professionals in the Asia-Pacific region on assessing patients with suspected acute coronary syndrome (ACS) using a hs-TnT assay. Experts from Asia-Pacific convened in 2 meetings to develop evidence-based consensus recommendations and an algorithm for appropriate use of the hs-TnT assay. The Expert Committee defined a cardiac troponin assay as a high-sensitivity assay if the total imprecision is ≤10% at the 99th percentile of the upper reference limit and measurable concentrations below the 99th percentile are attainable with an assay at a concentration value above the assay's limit of detection for at least 50% of healthy individuals. Recommendations for single-measurement rule-out/rule-in cutoff values, as well as for serial measurements, were also developed. The Expert Committee also adopted similar hs-TnT cutoff values for men and women, recommended serial hs-TnT measurements for special populations, and provided guidance on the use of point-of-care troponin T devices in individuals suspected of ACS. These recommendations should be used in conjunction with all available clinical evidence when making the diagnosis of ACS.

Background: The United Arab Emirates is experiencing increasing rates of type 2 diabetes (T2D) and its complications. As soluble levels of the receptor for advanced glycation end products, (sRAGE), and endogenous secretory RAGE (esRAGE), the latter an alternatively spliced form of AGER (the gene encoding RAGE), have been reported to be associated with T2D and its complications, we tested for potential relationships between these factors and T2D status in Emirati subjects., Methods: In a case-control study, we recruited Emirati subjects with T2D and controls from the Sheikh Khalifa Medical City in Abu Dhabi. Anthropomorphic characteristics, levels of plasma sRAGE and esRAGE, and routine chemistry variables were measured., Results: Two hundred and sixteen T2D subjects and 215 control subjects (mean age, 57.4 ± 12.1 vs. 50.7 ± 15.4 years; P  < 0.0001, respectively) were enrolled. Univariate analyses showed that levels of sRAGE were significantly lower in the T2D vs. control subjects (1033.9 ± 545.3 vs. 1169.2 ± 664.1 pg/ml, respectively; P  = 0.02). Multivariate analyses adjusting for age, sex, systolic blood pressure, pulse, body mass index, Waist/Hip circumference ratio, fasting blood glucose, HDL, LDL, insulin, triglycerides, Vitamin D and urea levels revealed that the difference in sRAGE levels between T2D and control subjects remained statistically-significant, P  = 0.03, but not after including estimated glomerular filtration rate in the model, P  = 0.14. There were no significant differences in levels of esRAGE. Levels of plasma insulin were significantly higher in the control vs. the T2D subjects (133.6 ± 149.9 vs. 107.6 ± 93.3 pg/L. respectively; P  = 0.01, after adjustment for age and sex)., Conclusion/discussion: Levels of sRAGE, but not esRAGE, were associated with T2D status in Abu Dhabi, but not after correction for eGFR. Elevated levels of plasma insulin in both control and T2D subjects suggests the presence of metabolic dysfunction, even in subjects without diabetes.

Context.—: Opening a new hospital is a once in a lifetime experience and can be very inspiring for those involved in its activation. However, establishing a safe transfusion practice in a greenfield environment comes with unique challenges and opportunities., Objective.—: To highlight critical activation components such as on-boarding of new personnel, establishing clinical practices, and integrating critical laboratory software., Design.—: Our staff initially faced challenges in standardizing transfusion medicine clinical practice inside the laboratory. Our efforts were mainly focused on the appropriate use of various transfusion orders, creating comprehensive policies for type and screening, cost effective utilization of blood products, and establishment of the maximum surgical blood order schedule. The transfusion service was launched with 2 information technology programs that separately facilitated steps in the transfusion process, but did not provide centralized access to the entire process. In these circumstances, we partnered with the laboratory information system team to create a series of interfaces that streamlined each system's functionality and implemented the existing infrastructure with upgrades that enable remote location and management of blood products., Results.—: The transfusion medicine team spent more than a year training and monitoring workflows to avoid individual variations between technologists and to adopt our own standards of practice. Participation in a structured training plan was also necessary between clinical caregivers to know the safe and efficient use of these standards., Conclusions.—: Although laboratory and clinical staff are knowledgeable in care delivery, it is always a learning experience to establish a new system because of the natural tendency of resorting to previous practices and resistance to new approaches.

In this case, we report an elderly patient with multiple chronic conditions and prolonged intensive care unit (ICU) stays who had recurrent Candida auris (C. auris) in blood despite antifungal therapy. C. auris was misidentified using conventional automated identification system as Candida haemulonii resulting in delayed diagnosis. The isolate showed increasing minimum inhibitory concentrations (MICs) to different antifungal drugs and persisted in the patient's blood before the patient deceased. This is the first case of C. auris reported from the United Arab Emirates (UAE); laboratories should be aware of this Candida species and should confirm suspected cases since it is an emerging multi-drug resistant and health-care associated Candida., (Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: This study compared the activity of ceftolozane-tazobactam and ceftazidime-avibactam against 120 bacterial strains, including extended-spectrum beta-lactamase (ESBL) producers, carbapenem-resistant Enterobacteriaceae (CRE), and Pseudomonas aeruginosa, isolated from patients admitted to Cleveland Clinic Abu Dhabi, United Arab Emirates., Methods: In vitro susceptibility was tested using the Etest strip minimum inhibitory concentration (MIC) method, and PCR was used to characterize the carbapenemase enzymes produced by CRE strains., Results: All 29 ESBL isolates were susceptible to ceftazidime-avibactam (MIC 50 0.125μg/ml), whereas all but one were susceptible to ceftolozane-tazobactam (MIC 50 0.38μg/ml). Twenty-seven (45%) CRE isolates were susceptible to ceftazidime-avibactam (MIC 50 ≥256μg/ml), whereas only six (10%) isolates were susceptible to ceftolozane-tazobactam (MIC 50 ≥256μg/ml). Very few NDM-1 isolates were susceptible to ceftazidime-avibactam, whereas the majority of OXA-48 isolates were susceptible. Twenty-nine (94%) P. aeruginosa isolates were susceptible to ceftazidime-avibactam (MIC 50 1.5μg/ml), whereas 30 (97%) isolates were susceptible to ceftolozane-tazobactam (MIC 50 0.75μg/ml)., Conclusions: Ceftolozane-tazobactam and ceftazidime-avibactam showed comparable activity against ESBL and P. aeruginosa, with ceftazidime-avibactam having lower MICs against ESBL isolates and ceftolozane-tazobactam having lower MICs against P. aeruginosa. Ceftazidime-avibactam showed better activity against all CRE isolates except for those carrying the NDM-1 enzyme., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)