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2.
BMC Anesthesiol ; 22(1): 62, 2022 03 07.
Article in English | MEDLINE | ID: covidwho-1728877

ABSTRACT

BACKGROUND: The application of a surgical face mask over oxygen delivery devices is now a widespread recommendation in the setting of the Coronavirus disease pandemic. This addition is designed to reduce droplet spread, but this also changes the nature of these devices, and may alter the amount of oxygen delivered to a patient. This research investigated how placing a surgical face mask over both a simple plastic mask ("Hudson mask") and nasal cannula altered the concentration of available oxygen measured at the nares. METHODS: We measured the inspired and end-tidal oxygen concentrations of five healthy non-smoking volunteers. Oxygen was delivered via nasal cannula and also a simple plastic face mask, at flow rates of 2, 4, 6 and 8 l per minute, with and without an overlying surgical face mask. RESULTS: Adding a surgical mask over nasal cannula caused an appreciable rise in the end-tidal oxygen concentrations at all the measured oxygen flow rates 2, 4, 6, 8 L/minute. With the Hudson mask, there was a rise in oxygen concentration at 4 and 6 L/minute. For example, at a flow rate of 4 l/min via nasal cannula, available oxygen concentration increased from 24 to 36%, and via the Hudson mask the concentration rose from 27 to 38%. CONCLUSIONS: The addition of a surgical face mask over both nasal cannula and a Hudson mask resulted in an increased available oxygen concentration. This may be valuable where more advanced oxygen devices are not available, or alternatively providing adequate supplemental oxygen at lower flow rates and thus making critical savings in oxygen usage.


Subject(s)
Masks , Oxygen Inhalation Therapy/instrumentation , Oxygen Inhalation Therapy/methods , Oxygen/administration & dosage , Oxygen/metabolism , Adult , Cannula , Cross-Over Studies , Female , Healthy Volunteers , Humans , Male , Nasal Cavity , Reference Values
3.
BMC Med Genomics ; 14(Suppl 6): 289, 2021 12 14.
Article in English | MEDLINE | ID: covidwho-1571758

ABSTRACT

BACKGROUND: Virus screening and viral genome reconstruction are urgent and crucial for the rapid identification of viral pathogens, i.e., tracing the source and understanding the pathogenesis when a viral outbreak occurs. Next-generation sequencing (NGS) provides an efficient and unbiased way to identify viral pathogens in host-associated and environmental samples without prior knowledge. Despite the availability of software, data analysis still requires human operations. A mature pipeline is urgently needed when thousands of viral pathogen and viral genome reconstruction samples need to be rapidly identified. RESULTS: In this paper, we present a rapid and accurate workflow to screen metagenomics sequencing data for viral pathogens and other compositions, as well as enable a reference-based assembler to reconstruct viral genomes. Moreover, we tested our workflow on several metagenomics datasets, including a SARS-CoV-2 patient sample with NGS data, pangolins tissues with NGS data, Middle East Respiratory Syndrome (MERS)-infected cells with NGS data, etc. Our workflow demonstrated high accuracy and efficiency when identifying target viruses from large scale NGS metagenomics data. Our workflow was flexible when working with a broad range of NGS datasets from small (kb) to large (100 Gb). This took from a few minutes to a few hours to complete each task. At the same time, our workflow automatically generates reports that incorporate visualized feedback (e.g., metagenomics data quality statistics, host and viral sequence compositions, details about each of the identified viral pathogens and their coverages, and reassembled viral pathogen sequences based on their closest references). CONCLUSIONS: Overall, our system enabled the rapid screening and identification of viral pathogens from metagenomics data, providing an important piece to support viral pathogen research during a pandemic. The visualized report contains information from raw sequence quality to a reconstructed viral sequence, which allows non-professional people to screen their samples for viruses by themselves (Additional file 1).


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , Computational Biology/methods , Genome, Viral , Genomics , Metagenomics , SARS-CoV-2/genetics , Algorithms , Animals , Automation , Coronavirus Infections/genetics , High-Throughput Nucleotide Sequencing , Humans , Mass Screening/methods , Pandemics , Pangolins , Reference Values , Software , Transcriptome , Workflow
4.
Transplant Proc ; 53(4): 1126-1131, 2021 May.
Article in English | MEDLINE | ID: covidwho-1525970

ABSTRACT

Coronavirus disease 2019 drastically impacted solid organ transplantation. Lacking scientific evidence, a very stringent but safer policy was imposed on liver transplantation (LT) early in the pandemic. Restrictive transplant guidelines must be reevaluated and adjusted as data become available. Before LT, the prevailing policy requires a negative severe acute respiratory syndrome coronavirus 2 real-time polymerase chain reaction (RT-PCR) of donors and recipients. Unfortunately, prolonged viral RNA shedding frequently hinders transplantation. Recent data reveal that positive test results for viral genome are frequently due to noninfectious and prolonged convalescent shedding of viral genome. Moreover, studies demonstrated that the cycle threshold of quantitative RT-PCR could be leveraged to inform clinical transplant decision-making. We present an evidence-adjusted and significantly less restrictive policy for LT, where risk tolerance is tiered to recipient acuity. In addition, we delineate the pretransplant clinical decision-making, intra- and postoperative management, and early outcome of 2 recipients of a liver graft performed while their RT-PCR of airway swabs remained positive. Convalescent positive RT-PCR results are common in the transplant arena, and the proposed policy permits reasonably safe LT in many circumstances.


Subject(s)
COVID-19 Nucleic Acid Testing/standards , COVID-19/diagnosis , Health Policy , Liver Transplantation/legislation & jurisprudence , SARS-CoV-2/genetics , COVID-19/prevention & control , COVID-19 Nucleic Acid Testing/methods , Female , Humans , Infection Control/legislation & jurisprudence , Infection Control/methods , Liver Transplantation/adverse effects , Male , Middle Aged , Postoperative Complications/prevention & control , Postoperative Complications/virology , Preoperative Care/legislation & jurisprudence , Preoperative Care/methods , Reference Values , Tissue Donors , Virus Shedding
5.
Int J Cardiol ; 346: 105-106, 2022 01 01.
Article in English | MEDLINE | ID: covidwho-1516243

ABSTRACT

BACKGROUND: Short-term sequelae of Multisystem Inflammatory Syndrome in Children (MIS-C), recently published by our institution, showed rapid improvement of the cardiac abnormalities within a few weeks after the onset of the disease. However, subtle residual abnormalities, affecting mainly the myocardial interstitium, were shown in some of the patients. The current study aimed to assess myocardial deformation with CMR shortly after MIS-C. METHODS: Sixty children were included into the study; 30 following MIS-C (onset-to-scan mean 27 days, SD 11) and 30 controls. Strain values were compared between patients and controls and additionally to published paediatric normal CMR values. U-Mann Whitney test was used for comparison of the myocardial deformation between patients and controls. RESULTS: Median age of the patients was 9.0 years (range 0.99-14.4) and controls 9.8 years (range 4.7-14.9). All conventional CMR parameters in patients were in normal range. Strain values were significantly lower in patients than in controls. When compared to published centile graphs, radial and circumferential global strain was within 2.5th and 97.5th centile in all patients. Eleven patients had global longitudinal strain between 2.5th centile and 50th centile, 1 patient was below 2.5th centile and all the others above 50th centile. Only 3 controls had global longitudinal strain between 2.5th centile and 50th centile, all other had higher strain. CONCLUSIONS: This study demonstrates that myocardial deformation indices measured by CMR are within normal range in the vast majority of the patients within a few weeks after the onset of MIS-C. However, when compared to healthy controls, all strain parameters were lower in patients.


Subject(s)
Magnetic Resonance Imaging, Cine , Ventricular Function, Left , Adolescent , Child , Child, Preschool , Humans , Infant , Myocardium , Reference Values
6.
J Infect Dis ; 224(8): 1287-1293, 2021 10 28.
Article in English | MEDLINE | ID: covidwho-1505875

ABSTRACT

BACKGROUND: Previous studies demonstrated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA can be detected for weeks after infection. The significance of this finding is unclear and, in most patients, does not represent active infection. Detection of subgenomic RNA has been proposed to represent productive infection and may be a useful marker for monitoring infectivity. METHODS: We used quantitative reverse-transcription polymerase chain reaction (RT-qPCR) to quantify total and subgenomic nucleocapsid (sgN) and envelope (sgE) transcripts in 185 SARS-CoV-2-positive nasopharyngeal swab samples collected on hospital admission and to relate to symptom duration. RESULTS: We find that all transcripts decline at the same rate; however, sgE becomes undetectable before other transcripts. The median duration of symptoms to a negative test is 14 days for sgE and 25 days for sgN. There is a linear decline in subgenomic compared to total RNA, suggesting that subgenomic transcript copy number is dependent on copy number of total transcripts. The mean difference between total and sgN is 16-fold and the mean difference between total and sgE is 137-fold. This relationship is constant over duration of symptoms, allowing prediction of subgenomic copy number from total copy number. CONCLUSIONS: Subgenomic RNA may be no more useful in determining infectivity than a copy number threshold determined for total RNA.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , RNA, Viral/isolation & purification , SARS-CoV-2/isolation & purification , Viral Load , Aged , COVID-19/transmission , COVID-19/virology , COVID-19 Nucleic Acid Testing/standards , COVID-19 Nucleic Acid Testing/statistics & numerical data , Coronavirus Envelope Proteins/genetics , Coronavirus Nucleocapsid Proteins/genetics , Feasibility Studies , Female , Humans , Male , Middle Aged , Nasopharynx/pathology , Nasopharynx/virology , Phosphoproteins/genetics , Real-Time Polymerase Chain Reaction/statistics & numerical data , Reference Values , Retrospective Studies , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity
7.
Magnes Res ; 34(3): 93-102, 2021 Aug 01.
Article in English | MEDLINE | ID: covidwho-1496707

ABSTRACT

Magnesium (Mg) is the second most abundant intracellular cation and plays a significant role in immune system and cardiac protection. Mg deficiency contributes to chronic low-grade inflammation leading to cardiovascular diseases, and low Mg level exacerbates virus-induced inflammation. The aim of the study was to investigate whether serum magnesium level is associated with myocardial damage and prognosis of COVID-19. This was a single-center, observational retrospective study of patients with COVID-19. The study population was divided into two groups according to in-hospital mortality: a survivor group (SG) and a non-survivor group (NSG). Myocardial damage was defined as blood levels of cardiac troponin I (cTnI) above the 99th percentile upper reference limit. Magnesium, variables regarding inflammation, and myocardial damage were compared between the groups. A total of 629 patients with COVID-19 were included. Mortality rate was 11.85% (n = 82). There were 61 (74.4%) and 294 male patients (53.7%) in NSG and SG, respectively (p = 0.001). The median age of NSG was 64.5 years (min-max: 37-93) and the median age of SG was 56.0 years (min-max: 22-92) (p < 0.001). Median serum magnesium levels of NSG and SG were 1.94 mg/dL (min-max: 1.04-2.87) and 2.03 mg/dL (min-max: 1.18-2.88), respectively (p = 0.027). Median cTnI levels of NSG and SG were 25.20 pg/mL (min-max: 2.10-2240.80) and 4.50 pg/mL (min-max: 0.50-984.3), respectively (p < 0.001). The cTnI levels were lower in those patients whose serum Mg levels were higher than 1.94. Although serum magnesium level was not a predictor for in-hospital mortality, there was a significant negative correlation between magnesemia and myocardial damage.


Subject(s)
COVID-19/blood , COVID-19/complications , Cardiomyopathies/blood , Cardiomyopathies/complications , Magnesium Deficiency/blood , Magnesium Deficiency/complications , Adult , Aged , Aged, 80 and over , COVID-19/mortality , Female , Humans , Inflammation , Male , Middle Aged , Myocardium/pathology , Prognosis , Proportional Hazards Models , Reference Values , Retrospective Studies , Treatment Outcome , Troponin I/blood
8.
Crit Care Med ; 49(11): 1974-1982, 2021 11 01.
Article in English | MEDLINE | ID: covidwho-1475880
9.
Magnes Res ; 34(2): 84-89, 2021 May 01.
Article in English | MEDLINE | ID: covidwho-1468227

ABSTRACT

Magnesium deficiency can have serious health consequences. Low magnesium intake or low serum levels are risk factors for e.g. type 2 diabetes and cardiovascular diseases. Despite its scientifically recognized importance, too little attention is paid to magnesium in clinical practice. This may be due to the fact that there is no uniform and evidence-based reference range for serum magnesium as is the case for other electrolytes such as sodium and potassium. The serum magnesium concentration is also of a limited informative value, as it is maintained for a long time by releasing magnesium from body pools. A low serum magnesium is a definite sign of magnesium deficiency; however, values within the reference range do not rule out deficiencies. Nevertheless, serum magnesium should become part of routine diagnostics in order to be able to better detect deficiency states. For serum magnesium, a reference range of 0.75 to 0.95 mmol/L (1.82 to 2.31 mg/dL) can often be found. However, according to the current data situation, serum magnesium values of less than 0.85 mmol/L are associated with increased health risks. Therefore, the lower limit of the reference range should be raised to 0.85 mmol/L (2.07 mg/dL).


Subject(s)
Diabetes Mellitus, Type 2 , Magnesium Deficiency , Humans , Magnesium , Magnesium Deficiency/diagnosis , Potassium , Reference Values
11.
J Clin Lab Anal ; 35(9): e23935, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1355874

ABSTRACT

BACKGROUND: Neutral-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) are associated with coronavirus disease 2019 (COVID-19) and many diseases, but there are few data about the reference interval (RI) of NLR, LMR, and PLR. METHODS: The neutrophil count, lymphocyte count, monocyte count, and platelet count of 404,272 Chinese healthy adults (>18 years old) were measured by Sysmex XE-2100 automatic hematology analyzer, and NLR, LMR, and PLR were calculated. According to CLSI C28-A3, the nonparametric 95% percentile interval is defined as the reference interval. RESULTS: The results of Mann-Whitney U test showed that NLR (p < .001) in male was significantly higher than that in female; LMR (p < .001) and PLR (p < .001) in male were significantly lower than that in female. Kruskal-Wallis H test showed that there were significant differences in NLR, LMR, and PLR among different genders and age groups (p < .001). The linear graph showed that the reference upper limit of NLR and PLR increased with age and the reference upper limit of LMR decreases with age in male population. In female population, the reference upper limit of NLR in 50-59 group, LMR in >80 group, and PLR in 70-79 group appeared a trough; the reference upper limit of NLR in >80 group, LMR in 50-59 group, and PLR in 40-49 group appeared peak. CONCLUSION: The establishment of RI for NLR, LMR, and PLR in Chinese healthy adults according to gender and age will promote the standardization of clinical application.


Subject(s)
Leukocyte Count/statistics & numerical data , Lymphocyte Count/statistics & numerical data , Monocytes , Neutrophils , Platelet Count/statistics & numerical data , Adult , Age Factors , Aged , Aged, 80 and over , COVID-19/blood , China , Female , Humans , Male , Middle Aged , Reference Values , SARS-CoV-2 , Sex Factors
12.
Respir Res ; 21(1): 154, 2020 Jun 18.
Article in English | MEDLINE | ID: covidwho-1331943

ABSTRACT

Electronic cigarette (e-cig) vaping is increasing rapidly in the United States, as e-cigs are considered less harmful than combustible cigarettes. However, limited research has been conducted to understand the possible mechanisms that mediate toxicity and pulmonary health effects of e-cigs. We hypothesized that sub-chronic e-cig exposure induces inflammatory response and dysregulated repair/extracellular matrix (ECM) remodeling, which occur through the α7 nicotinic acetylcholine receptor (nAChRα7). Adult wild-type (WT), nAChRα7 knockout (KO), and lung epithelial cell-specific KO (nAChRα7 CreCC10) mice were exposed to e-cig aerosol containing propylene glycol (PG) with or without nicotine. Bronchoalveolar lavage fluids (BALF) and lung tissues were collected to determine e-cig induced inflammatory response and ECM remodeling, respectively. Sub-chronic e-cig exposure with nicotine increased inflammatory cellular influx of macrophages and T-lymphocytes including increased pro-inflammatory cytokines in BALF and increased SARS-Cov-2 Covid-19 ACE2 receptor, whereas nAChRα7 KO mice show reduced inflammatory responses associated with decreased ACE2 receptor. Interestingly, matrix metalloproteinases (MMPs), such as MMP2, MMP8 and MMP9, were altered both at the protein and mRNA transcript levels in female and male KO mice, but WT mice exposed to PG alone showed a sex-dependent phenotype. Moreover, MMP12 was increased significantly in male mice exposed to PG with or without nicotine in a nAChRα7-dependent manner. Additionally, sub-chronic e-cig exposure with or without nicotine altered the abundance of ECM proteins, such as collagen and fibronectin, significantly in a sex-dependent manner, but without the direct role of nAChRα7 gene. Overall, sub-chronic e-cig exposure with or without nicotine affected lung inflammation and repair responses/ECM remodeling, which were mediated by nAChRα7 in a sex-dependent manner.


Subject(s)
Coronavirus Infections/epidemiology , Electronic Nicotine Delivery Systems , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/epidemiology , Pneumonia/metabolism , Vaping/adverse effects , alpha7 Nicotinic Acetylcholine Receptor/genetics , Angiotensin-Converting Enzyme 2 , Animals , Blood Gas Analysis , Blotting, Western , Bronchoalveolar Lavage Fluid , COVID-19 , Cytokines/analysis , Disease Models, Animal , Female , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Pandemics , Pneumonia/physiopathology , Random Allocation , Reference Values , Role , Severe Acute Respiratory Syndrome/epidemiology , Signal Transduction/genetics
13.
Mol Diagn Ther ; 25(5): 617-628, 2021 09.
Article in English | MEDLINE | ID: covidwho-1328680

ABSTRACT

BACKGROUND AND OBJECTIVE: Since the initial coronavirus disease outbreak in late 2019 (COVID-19), reverse-transcription real-time polymerase chain reaction (RT-qPCR) has become the gold standard test to detect severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). However, a more sensitive and accurate diagnostic tool was required. Therefore, droplet digital polymerase chain reaction (ddPCR) was suggested as an alternative method. Here, we evaluated the performance of ddPCR to detect SARS-CoV-2 and compared it to the performance of RT-qPCR. METHODS: The analytical performances, including limit of blank and limit of detection, were established using positive and negative SARS-CoV-2 reference materials. A total of 366 RNA extracts (173 positive and 193 negative by RT-qPCR) were collected from four institutions and tested with a Bio-Rad SARS-CoV-2 ddPCR kit that detects the SARS-CoV-2 genome using primers for N1 and N2. RESULTS: Limit of blank was set at 0, and the limits of detection of N1 and N2 were 1.99 copies/µL and 5.18 copies/µL, respectively. Linearity was evaluated using serial dilution samples, which demonstrated good results (R2: 0.999, linear range: 5.88-6825.25 copies/µL for N1 and R2: 0.999, 5.53-5855.47 copies/µL for N2). The results of ddPCR and RT-qPCR revealed substantial agreement (Cohen's kappa: 0.639, p < 0.01). The 63 samples with positive ddPCR but negative RT-qPCR showed low copy numbers, and 55% of them had COVID-19-related symptoms. CONCLUSIONS: Droplet digital polymerase chain reaction demonstrated excellent sensitivity for SARS-Cov-2 detection and consistently agreed with the results from conventional RT-qPCR. Furthermore, ddPCR provided quantitative data that can be used to monitor changes in the viral load of patients with COVID-19.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , RNA, Viral/genetics , SARS-CoV-2/genetics , COVID-19/virology , COVID-19 Nucleic Acid Testing/standards , Calibration , Humans , Limit of Detection , Nasopharynx/virology , Reference Values
14.
BMJ Open Gastroenterol ; 8(1)2021 05.
Article in English | MEDLINE | ID: covidwho-1219408

ABSTRACT

OBJECTIVES: Following the disruption of normal paediatric inflammatory bowel disease (IBD) services during the peak of the COVID-19 pandemic, we prospectively audited the first-time use of home faecal calprotectin testing. We aimed to provide an alternative to laboratory tests and to assess the value of home testing as part of our regular services going forward. METHODS: Home test kits as well as accompanying user instructions were made available to our patients with paediatric IBD that required faecal calprotectin test between 17 April and 12 August 2020. Once the user completed the test, results were automatically uploaded to the result portal and clinical staff were alerted. A user feedback questionnaire was sent to users that had completed the home test. RESULTS: Of the 54 patients, 41 (76%) aged between 4.7 and 18.1 years used the home test. A total of 45 home tests were done, one of which produced an invalid result. The decision to modify management was made in 12 (29%) of the patients, while 14 (34%) had no changes made and 15 (37%) required further assessment. Twenty (48.8%) responded to the questionnaire and 85% stated that they preferred the home test to the laboratory testing method. CONCLUSIONS: Home calprotectin tests were useful in guiding clinical management during a time when laboratory testing was less available. They may offer benefits as part of routine paediatric IBD monitoring to help target appointments and reduce unnecessary hospital attendances in the future.


Subject(s)
COVID-19/epidemiology , Feces/chemistry , Inflammatory Bowel Diseases/therapy , Leukocyte L1 Antigen Complex/analysis , Pandemics , Point-of-Care Testing , Adolescent , Biomarkers/analysis , Child , Child, Preschool , Clinical Chemistry Tests/statistics & numerical data , Feedback , Female , Home Care Services , Humans , Male , Patient Portals , Patient Preference/statistics & numerical data , Prospective Studies , Reagent Kits, Diagnostic/statistics & numerical data , Reference Values , Surveys and Questionnaires
15.
Int J Infect Dis ; 105: 312-318, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-1116860

ABSTRACT

BACKGROUND: Cardiac injury is frequently encountered in patients with coronavirus disease 2019 (COVID-19) and is associated with increased risk of mortality. Elevated troponin may signify myocardial damage and is predictive of mortality. This study aimed to assess the prognostic value of troponin above the 99th percentile upper reference limit (URL) for mortality, and factors affecting the relationship. METHODS: A comprehensive literature search of PubMed (MEDLINE), Scopus and Embase was undertaken, from inception of the databases until 16 December 2020. The key exposure was elevated serum troponin, defined as troponin (of any type) above the 99th percentile URL. The outcome was mortality due to any cause. RESULTS: In total, 12,262 patients from 13 studies were included in this systematic review and meta-analysis. The mortality rate was 23% (20-26%). Elevated troponin was observed in 31% (23-38%) of patients. Elevated troponin was associated with increased mortality [odds ratio (OR) 4.75, 95% confidence interval (CI) 4.07-5.53; P < 0.001; I2 = 19.9%]. Meta-regression showed that the association did not vary with age (P = 0.218), male gender (P = 0.707), hypertension (P = 0.182), diabetes (P = 0.906) or coronary artery disease (P = 0864). The association between elevated troponin and mortality had sensitivity of 0.55 (0.44-0.66), specificity of 0.80 (0.71-0.86), positive likelihood ratio of 2.7 (2.2-3.3), negative likelihood ratio of 0.56 (0.49-0.65), diagnosis odds ratio of 5 (4-5) and area under the curve of 0.73 (0.69-0.77). The probability of mortality was 45% in patients with elevated troponin and 14% in patients with non-elevated troponin. CONCLUSION: Elevated troponin was associated with mortality in patients with COVID-19 with 55% sensitivity and 80% specificity.


Subject(s)
COVID-19/mortality , Myocardium/chemistry , Troponin/blood , Biomarkers/blood , Female , Humans , Male , Prognosis , Reference Values , SARS-CoV-2 , Sensitivity and Specificity
16.
J Glob Health ; 11: 05001, 2021 Jan 16.
Article in English | MEDLINE | ID: covidwho-1090198

ABSTRACT

BACKGROUND: On 12 June 2020, Brazil reached the second position worldwide in the number of COVID-19 cases. Authorities increased the number of tests performed, including the identification of antibodies to SARS-CoV-2 (IgG, IgA, and IgM). There was an overflooding of the market with several tests, and the presence of possible false-positive results became a challenge. The purpose of this study was to describe the seroprevalence and immunoglobulin blood levels in a group of asymptomatic individuals using the reference levels provided by the manufacturer. METHODS: Levels of IgG and IgA antibodies to SARS-CoV-2 were determined in blood serum by the same ELISA (enzyme-linked immunoassay) test. Patients must be free of symptoms. RESULTS: From 20 to 22 May 2020, 938 individuals were tested. There were 441 (47%) men, age 53 years (interquartile range (IQR) = 39-63.2). The sample included 335 (35.7%) subjects aged ≥60 years old. Subjects with a positive test were 54 (5.8%) for IgG and 96 (10.2%) for IgA and 42 (4.5%) for both IgG and IgA. The prevalence of IgG and IgA positive test was not different in men and women and not different in individuals under 60 and over 60 years of age. Conversely, analysing only individuals with positive tests, the levels of IgG in positive subjects were significantly higher than those with an IgA positive test, 3.00 (IQR = 1.68-5.65), and 1.95 (IQR = 1.40-3.38), respectively; P = 0.017. Additionally, individuals with isolated IgA positive tests had significantly lower levels of IgA than those with both IgA and IgG positive tests: 1.95 (IQR = 1.60-2.40) and 3.15 (IQR = 2.20-3.90), respectively, P = 0.005. These latter data suggest that IgA shows a deviation of the distribution to the left in comparison to IgG distribution data. Indeed, many subjects reported as IgA positive had immunoglobulin levels slightly elevated. CONCLUSIONS: In conclusion, we strongly suggest caution in the interpretation of IgA test results. This recommendation is more important for those with positive IgA just above the reference level.


Subject(s)
Antibodies, Viral/blood , COVID-19/diagnosis , False Positive Reactions , Immunoglobulin A/blood , SARS-CoV-2/immunology , Adult , Brazil/epidemiology , COVID-19/epidemiology , Cross-Sectional Studies , Female , Humans , Immunoglobulin G/blood , Male , Middle Aged , Reference Values , Seroepidemiologic Studies
17.
J Pharm Biomed Anal ; 196: 113927, 2021 Mar 20.
Article in English | MEDLINE | ID: covidwho-1051794

ABSTRACT

To administer vitamin C (VC) with precision to patients with the coronavirus disease (COVID-19), we developed an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to assess plasma VC concentrations. 31 patients with COVID-19 and 51 healthy volunteers were enrolled. VC stability was evaluated in blood, plasma, and precipitant-containing stabilizers. A proportion of 7.7 % of VC was degraded in blood at room temperature (RT) (approximately 20-25 °C) at 1.5 h post administration with respect to the proportion degraded at 0.5 h, but without statistical difference. VC was stable in plasma for 0.75 h at RT, 2 h at 4 °C, 5 days at -40 °C, and 4 h in precipitant-containing stabilizer (2 % oxalic acid) at RT. The mean plasma concentration of VC in patients with COVID-19 was 2.00 mg/L (0.5-4.90) (n = 8), which was almost 5-fold lower than that in healthy volunteers (9.23 mg/L (3.09. 35.30)) (n = 51). After high-dose VC treatment, the mean VC concentration increased to 13.46 mg/L (3.93. 34.70) (n = 36), higher than that in healthy volunteers, and was within the normal range (6-20 mg/L). In summary, we developed a simple UPLC-MS/MS method to quantify VC in plasma, and determined the duration for which the sample remained stable. VC levels in patients with COVID-19 were considerably low, and supplementation at 100 mg/kg/day is considered highly essential.


Subject(s)
Ascorbic Acid/blood , Ascorbic Acid/pharmacology , COVID-19/blood , COVID-19/prevention & control , Adult , Aged , Chromatography, High Pressure Liquid/methods , Dietary Supplements , Female , Humans , Male , Middle Aged , Plasma/chemistry , Reference Values , SARS-CoV-2/pathogenicity , Tandem Mass Spectrometry/methods , Young Adult
18.
Chin Med J (Engl) ; 133(16): 1900-1907, 2020 Aug 20.
Article in English | MEDLINE | ID: covidwho-1050187

ABSTRACT

BACKGROUND: Total and differential white blood cell counts are important for the diagnostic evaluation of suspected diseases. To facilitate the interpretation of total and differential white blood cell counts in pediatric patients, the present study investigated age-dependent changes in total and differential white blood cell counts in healthy reference children. METHODS: Data were obtained from the Pediatric Reference Intervals in China study (PRINCE), which aims to establish and verify pediatric reference intervals for Chinese children based on a nationwide multicenter cross-sectional study from January 2017 to December 2018. Quantile curves were calculated using the generalized additive models for location, shape, and scale method. The 2.5th, 50th, and 97.5th quantile curves were calculated for both total and differential white blood counts. Percents of stacked area charts were used to demonstrate the proportions of differential white blood cells. All statistical analyses were performed using R software. RESULTS: Both 50th and 97.5th quantiles of total white blood cell count and monocyte count were highest at birth, then rapidly decreased in the first 6 months of life; relatively slow reduction continued until 2 years of age. The lymphocyte count was low during infancy and increased to its highest level at 6 months of age; it then exhibited moderate and continuous reduction until approximately 9 years of age. The pattern of neutrophil count changed with age in a manner opposite to that of lymphocyte count. Besides, there were two inter-sections of lymphocyte count and neutrophil count during infancy and at approximately 5 years of age, based on locally weighted regression (LOESS) analysis. There were no apparent age-related changes in eosinophil or basophil counts. CONCLUSION: These data regarding age-related changes in total and differential white blood cell counts can be used to assess the health of pediatric patients and guide clinical decisions.


Subject(s)
Neutrophils , Child , China , Cross-Sectional Studies , Humans , Infant, Newborn , Leukocyte Count , Lymphocyte Count , Reference Values
19.
Cochrane Database Syst Rev ; 11: CD013787, 2020 11 19.
Article in English | MEDLINE | ID: covidwho-1047119

ABSTRACT

BACKGROUND: Specific diagnostic tests to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and resulting COVID-19 disease are not always available and take time to obtain results. Routine laboratory markers such as white blood cell count, measures of anticoagulation, C-reactive protein (CRP) and procalcitonin, are used to assess the clinical status of a patient. These laboratory tests may be useful for the triage of people with potential COVID-19 to prioritize them for different levels of treatment, especially in situations where time and resources are limited. OBJECTIVES: To assess the diagnostic accuracy of routine laboratory testing as a triage test to determine if a person has COVID-19. SEARCH METHODS: On 4 May 2020 we undertook electronic searches in the Cochrane COVID-19 Study Register and the COVID-19 Living Evidence Database from the University of Bern, which is updated daily with published articles from PubMed and Embase and with preprints from medRxiv and bioRxiv. In addition, we checked repositories of COVID-19 publications. We did not apply any language restrictions. SELECTION CRITERIA: We included both case-control designs and consecutive series of patients that assessed the diagnostic accuracy of routine laboratory testing as a triage test to determine if a person has COVID-19. The reference standard could be reverse transcriptase polymerase chain reaction (RT-PCR) alone; RT-PCR plus clinical expertise or and imaging; repeated RT-PCR several days apart or from different samples; WHO and other case definitions; and any other reference standard used by the study authors. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data from each included study. They also assessed the methodological quality of the studies, using QUADAS-2. We used the 'NLMIXED' procedure in SAS 9.4 for the hierarchical summary receiver operating characteristic (HSROC) meta-analyses of tests for which we included four or more studies. To facilitate interpretation of results, for each meta-analysis we estimated summary sensitivity at the points on the SROC curve that corresponded to the median and interquartile range boundaries of specificities in the included studies. MAIN RESULTS: We included 21 studies in this review, including 14,126 COVID-19 patients and 56,585 non-COVID-19 patients in total. Studies evaluated a total of 67 different laboratory tests. Although we were interested in the diagnotic accuracy of routine tests for COVID-19, the included studies used detection of SARS-CoV-2 infection through RT-PCR as reference standard. There was considerable heterogeneity between tests, threshold values and the settings in which they were applied. For some tests a positive result was defined as a decrease compared to normal vaues, for other tests a positive result was defined as an increase, and for some tests both increase and decrease may have indicated test positivity. None of the studies had either low risk of bias on all domains or low concerns for applicability for all domains. Only three of the tests evaluated had a summary sensitivity and specificity over 50%. These were: increase in interleukin-6, increase in C-reactive protein and lymphocyte count decrease. Blood count Eleven studies evaluated a decrease in white blood cell count, with a median specificity of 93% and a summary sensitivity of 25% (95% CI 8.0% to 27%; very low-certainty evidence). The 15 studies that evaluated an increase in white blood cell count had a lower median specificity and a lower corresponding sensitivity. Four studies evaluated a decrease in neutrophil count. Their median specificity was 93%, corresponding to a summary sensitivity of 10% (95% CI 1.0% to 56%; low-certainty evidence). The 11 studies that evaluated an increase in neutrophil count had a lower median specificity and a lower corresponding sensitivity. The summary sensitivity of an increase in neutrophil percentage (4 studies) was 59% (95% CI 1.0% to 100%) at median specificity (38%; very low-certainty evidence). The summary sensitivity of an increase in monocyte count (4 studies) was 13% (95% CI 6.0% to 26%) at median specificity (73%; very low-certainty evidence). The summary sensitivity of a decrease in lymphocyte count (13 studies) was 64% (95% CI 28% to 89%) at median specificity (53%; low-certainty evidence). Four studies that evaluated a decrease in lymphocyte percentage showed a lower median specificity and lower corresponding sensitivity. The summary sensitivity of a decrease in platelets (4 studies) was 19% (95% CI 10% to 32%) at median specificity (88%; low-certainty evidence). Liver function tests The summary sensitivity of an increase in alanine aminotransferase (9 studies) was 12% (95% CI 3% to 34%) at median specificity (92%; low-certainty evidence). The summary sensitivity of an increase in aspartate aminotransferase (7 studies) was 29% (95% CI 17% to 45%) at median specificity (81%) (low-certainty evidence). The summary sensitivity of a decrease in albumin (4 studies) was 21% (95% CI 3% to 67%) at median specificity (66%; low-certainty evidence). The summary sensitivity of an increase in total bilirubin (4 studies) was 12% (95% CI 3.0% to 34%) at median specificity (92%; very low-certainty evidence). Markers of inflammation The summary sensitivity of an increase in CRP (14 studies) was 66% (95% CI 55% to 75%) at median specificity (44%; very low-certainty evidence). The summary sensitivity of an increase in procalcitonin (6 studies) was 3% (95% CI 1% to 19%) at median specificity (86%; very low-certainty evidence). The summary sensitivity of an increase in IL-6 (four studies) was 73% (95% CI 36% to 93%) at median specificity (58%) (very low-certainty evidence). Other biomarkers The summary sensitivity of an increase in creatine kinase (5 studies) was 11% (95% CI 6% to 19%) at median specificity (94%) (low-certainty evidence). The summary sensitivity of an increase in serum creatinine (four studies) was 7% (95% CI 1% to 37%) at median specificity (91%; low-certainty evidence). The summary sensitivity of an increase in lactate dehydrogenase (4 studies) was 25% (95% CI 15% to 38%) at median specificity (72%; very low-certainty evidence). AUTHORS' CONCLUSIONS: Although these tests give an indication about the general health status of patients and some tests may be specific indicators for inflammatory processes, none of the tests we investigated are useful for accurately ruling in or ruling out COVID-19 on their own. Studies were done in specific hospitalized populations, and future studies should consider non-hospital settings to evaluate how these tests would perform in people with milder symptoms.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , Diagnostic Tests, Routine/methods , SARS-CoV-2/isolation & purification , Bias , Biomarkers/blood , C-Reactive Protein/analysis , COVID-19/blood , COVID-19/epidemiology , COVID-19 Testing/standards , Creatine Kinase/blood , Creatinine/blood , Diagnostic Tests, Routine/standards , Humans , Interleukin-6/blood , L-Lactate Dehydrogenase/blood , Leukocyte Count , Liver Function Tests , Lymphocyte Count , Pandemics , Platelet Count , ROC Curve , Reference Values , Reverse Transcriptase Polymerase Chain Reaction/standards , Sensitivity and Specificity , Triage
20.
J Am Coll Nutr ; 40(2): 104-110, 2021 02.
Article in English | MEDLINE | ID: covidwho-1024026

ABSTRACT

BACKGROUND: The severity of Coronavirus Disease 2019 (COVID-19) is a multifactorial condition. An increasing body of evidence argues for a direct implication of vitamin D deficiency, low serum calcium on poor outcomes in COVID-19 patients. This study was designed to investigate the relationship between these two factors and COVID-19 in-hospital mortality. MATERIALS: This is a prospective study, including 120 severe cases of COVID-19, admitted at the department of Reanimation-Anesthesia. Vitamin D was assessed by an immuno-fluoroassay method. Total serum calcium by a colorimetric method, then, corrected for serum albumin levels. The association with in-hospital mortality was assessed using the Kaplan-Meier survival curve, proportional Cox regression analyses and the receiver operating characteristic curve. RESULTS: Hypovitaminosis D and hypocalcemia were very common, occurring in 75% and 35.8% of patients. When analyzing survival, both were significantly associated with in-hospital mortality in a dose-effect manner (pLog-Rank = 0.009 and 0.001 respectively). A cutoff value of 39 nmol/l for vitamin D and 2.05 mmol/l for corrected calcemia could predict poor prognosis with a sensitivity of 76% and 84%, and a specificity of 69% and 60% respectively. Hazard ratios were (HR = 6.9, 95% CI [2.0-24.1], p = 0.002 and HR = 6.2, 95% CI [2.1-18.3], p = 0.001) respectively. CONCLUSION: This study demonstrates the high frequency of hypocalcemia and hypovitaminosis D in severe COVID-19 patients and provides further evidence of their potential link to poor short-term prognosis. It is, therefore, possible that the correction of hypocalcemia, as well as supplementation with vitamin D, may improve the vital prognosis.


Subject(s)
COVID-19/mortality , Calcium/blood , Hypocalcemia/mortality , Vitamin D Deficiency/mortality , Vitamin D/analogs & derivatives , Aged , Algeria/epidemiology , COVID-19/blood , COVID-19/complications , Female , Hospital Mortality , Hospitalization , Humans , Hypocalcemia/blood , Hypocalcemia/virology , Kaplan-Meier Estimate , Male , Middle Aged , Prognosis , Proportional Hazards Models , Prospective Studies , Reference Values , Risk Factors , SARS-CoV-2 , Severity of Illness Index , Vitamin D/blood , Vitamin D Deficiency/blood , Vitamin D Deficiency/virology
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