Performance of STANDARD™ M10 SARS-CoV-2 Assay for the Diagnosis of COVID-19 from a Nasopharyngeal Swab

The STANDARD™ M10 severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) assay (M10 assay) (SD Biosensor Inc., Suwon, Korea) is a rapid, fully-automated, cartridgetype molecular diagnostic assay that detects SARS-CoV-2 RNA using primers and probes for each target gene (ORF1ab gene, E gene). This study evaluated its performance by assessing its concordance with the approved SARS-CoV-2 real-time PCR assay. Tests were performed on 80 nasopharyngeal samples. The sensitivity and specificity of the M10 assay were 100%.The M10 assay effectively diagnosed SARS-CoV-2 infection, and it was comparable to the approved SARS-CoV-2 real-time PCR assay. It is a viable point-of-care test due to its short turnaround time.

Clinical and Laboratory Factors Associated with Symptom Development in Asymptomatic COVID-19 Patients at the Time of Diagnosis

In preparation for the surge of coronavirus disease 2019 (COVID-19), it is crucial to allocate medical resources efficiently for distinguishing people who remain asymptomatic until the end of the disease. Between January 27, 2020, and April 21, 2020, 517 COVID-19 cases from 13 healthcare facilities in Gyeonggi province, Korea, were identified out of which the epidemiologic and clinical information of 66 asymptomatic patients at the time of diagnosis were analyzed retrospectively. An exposure-diagnosis interval within 7 days and abnormal aspartate aminotransferase levels were identified as characteristic symptom development in asymptomatic COVID-19 patients. If asymptomatic patients without these characteristics at the time of diagnosis could be differentiated early, more medical resources could be secured for mild or moderate cases in this COVID-19 surge.

Clinical Application of the Standard Q COVID-19 Ag Test for the Detection of SARS-CoV-2 Infection

We evaluated the Standard Q COVID-19 Ag test for the diagnosis of coronavirus disease 2019 (COVID-19) compared to the reverse transcription-polymerase chain reaction (RT-PCR) test.We applied both tests to patients who were about to be hospitalized, had visited an emergency room, or had been admitted due to COVID-19 confirmed by RT-PCR. Two nasopharyngeal swabs were obtained; one was tested by RT-PCR and the other by the Standard Q COVID-19 Ag test. A total of 118 pairs of tests from 98 patients were performed between January 5 and 11, 2021. The overall sensitivity and specificity for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for the Standard Q COVID-19 Ag test compared to RT-PCR were 17.5% (95% confidence interval [CI], 8.8–32.0%) and 100% (95% CI, 95.3–100.0%). Analysis of the results using RT-PCR cycle thresholds of ≤ 30 or ≤ 25 increased the sensitivity to 26.9% (95% CI, 13.7–46.1%), and 41.1% (95% CI, 21.6–64.0%), respectively.

Clinical Application of the Standard Q COVID-19 Ag Test for the Detection of SARS-CoV-2 Infection

We evaluated the Standard Q COVID-19 Ag test for the diagnosis of coronavirus disease 2019 (COVID-19) compared to the reverse transcription-polymerase chain reaction (RT-PCR) test.We applied both tests to patients who were about to be hospitalized, had visited an emergency room, or had been admitted due to COVID-19 confirmed by RT-PCR. Two nasopharyngeal swabs were obtained; one was tested by RT-PCR and the other by the Standard Q COVID-19 Ag test. A total of 118 pairs of tests from 98 patients were performed between January 5 and 11, 2021. The overall sensitivity and specificity for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for the Standard Q COVID-19 Ag test compared to RT-PCR were 17.5% (95% confidence interval [CI], 8.8–32.0%) and 100% (95% CI, 95.3–100.0%). Analysis of the results using RT-PCR cycle thresholds of ≤ 30 or ≤ 25 increased the sensitivity to 26.9% (95% CI, 13.7–46.1%), and 41.1% (95% CI, 21.6–64.0%), respectively.

Dynamics of viral load and anti-SARS-CoV-2 antibodies in patients with positive RT-PCR results after recovery from COVID-19

Recently, the number of patients with coronavirus disease 2019 (COVID-19) who have tested positive for severe acute respiratory syndrome coronavirus 2 (SARSCoV-2), via the reverse transcription polymerase chain reaction (RT-PCR) test, after recovery has increased; this has caused a dilemma regarding the medical measures and policies. We evaluated the dynamics of viral load and anti-SARSCoV-2 antibodies in four patients with positive RT-PCR results after recovery. In all patients, the highest levels of immunoglobulin G (IgG) and IgM antibodies were reached after about a month of the onset of the initial symptoms. Then, the IgG titers plateaued, and the IgM titers decreased, regardless of RT-PCR results.The IgG and IgM levels did not increase after the post-negative positive RT-PCR results in any of the patients. Our results reinforced that the post-negative positive RT-PCR results may be due to the detection of RNA particles rather than reinfection in individuals who have recovered from COVID-19.

Prevalence, Characteristics, and Clinical Significance of Concomitant Cardiomyopathies in Subjects with Bicuspid Aortic Valves

PURPOSE: The present study aimed to investigate the prevalence, characteristics, and clinical significance of concomitant specific cardiomyopathies in subjects with bicuspid aortic valves (BAVs). MATERIALS AND METHODS: A total of 1186 adults with BAV (850 males, mean age 56±14 years) at a single tertiary center were comprehensively reviewed. Left ventricular non-compaction, hypertrophic cardiomyopathy, and idiopathic dilated cardiomyopathy were confirmed when patients fulfilled current clinical and echocardiographic criteria. Clinical and echocardiographic characteristics, including comorbidities, heart failure presentation, BAV morphology, function, and aorta phenotypes, in BAV subjects with or without specific cardiomyopathies were compared. RESULTS: Overall, 67 subjects (5.6%) had concomitant cardiomyopathies: 40 (3.4%) patients with left ventricular non-compaction, 17 (1.4%) with hypertrophic cardiomyopathy, and 10 (0.8%) with dilated cardiomyopathy. BAV subjects with hypertrophic cardiomyopathy had higher prevalences of diabetes mellitus and heart failure with preserved ejection fraction, and tended to have type 0 phenotype, while BAV subjects with dilated cardiomyopathy showed higher prevalences of chronic kidney disease and heart failure with reduced ejection fraction. BAV subjects with left ventricular non-compaction were significantly younger and predominantly male, and had greater BAV dysfunction and a higher prevalence of normal aorta shape. In multiple regression analysis, cardiomyopathy was independently associated with heart failure (odds ratio 2.795, 95% confidential interval 1.603–4.873, p<0.001) after controlling for confounding factors. CONCLUSION: Concomitant cardiomyopathies were observed in 5.6% of subjects with BAV. A few different clinical and echocardiographic characteristics were found. The presence of cardiomyopathy was independently associated with heart failure.

Predictors of Severe or Moderate Coronary Artery Disease in Asymptomatic Individuals with Extremely Low Coronary Calcium Scores

PURPOSE: To evaluate predictors of severe or moderate coronary artery disease (CAD) in individuals with zero or very low (<10) coronary artery calcium (CAC) scores. MATERIALS AND METHODS: The 1175 asymptomatic persons with zero or very low (<10) CAC scores were analyzed for CAD stenosis using coronary computed tomography angiography. Moderate and severe CADs were defined as having more than 50% and more than 70% stenosis in any of the major coronary arteries, respectively. Age, gender, body mass index, hypertension, type II diabetes, dyslipidemia, lipid profile, creatinine, and smoking status were evaluated as predictors for moderate and severe CAD. RESULTS: In the study population, moderate and severe CADs were found in 7.5% and 3.3%, respectively. Among evaluated risk factors, age [odds ratio (OR) 1.04, 95% confidence interval (CI) 1.02−1.07, p<0.001], current smoking status (OR 3.12, 95% CI 1.82−5.34, p<0.001), and CAC 1−9 (OR 1.80, 95% CI 1.08−3.00, p=0.024) were significantly associated with moderate CAD. Meanwhile, age (OR 1.05, 95% CI 1.02−1.08, p=0.003), low high density lipoprotein (HDL) (OR 0.96, 95% CI 0.93−0.99, p=0.003), and current smoking status (OR 2.34, 95% CI 1.14−5.30, p=0.022) were found to be significantly associated with severe CAD. Improvement of discrimination power for predicting severe CAD was observed when smoking and HDL cholesterol were serially added into the age model. CONCLUSION: Smoking showed significant correlations with moderate or severe CAD, and low HDL cholesterol also proved to be a predictor of severe CAD in asymptomatic individuals with extremely low CAC scores.

Consumption of an Excessive Amount of Ionic Beverage Can Trigger Adrenal Adenoma - Induced Severe Hypokalemic Rhabdomyolysis / 대한내과학회지

Rhabdomyolysis results from acute damage to skeletal muscles caused by various conditions, of which hypokalemia is a recognized but rare example. Although primary aldosteronism may cause severe hypokalemia leading to rhabdomyolysis, the potassium level of such patients can be within the normal range. Hypokalemia is most frequently triggered when these patients are exposed to an additional insult, such as diuretic stress. Similarly, overzealous consumption of ionic beverages with osmotic diuretic effects can cause hypokalemia. Here, we describe a patient with an aldosterone-secreting adrenal adenoma, who presented with acute rhabdomyolysis secondary to severe hypokalemia triggered by consumption of a large volume of ionic beverage for 3 weeks.

A Case of Bilateral Renal Infarction of Unknown Cause in a Previously Healthy Young Male

We report a rare case of bilateral renal infarction resulting in acute renal failure in a previously healthy 26-year-old soldier. The patient presented with an abdominal pain and bilateral costovertebral angle tenderness. Laboratory studies showed elevated serum creatinine, mild leukocytosis, and increased lactate dehydrogenase. Contrast-enhanced computed tomography showed multiple perfusion defects in both kidneys with wedge-shaped infarction in right kidney. Kidney biopsy performed in the left kidney revealed microinfarction. Comprehensive work-up did not reveal any specific causes or risk factors except smoking, and the infarction was considered to be idiopathic. He emphasized that he received extremely strenuous military training several days before he came to the hospital. He was treated with low molecular weight heparin with significant improvement in renal function. Further studies are needed for the characterization of idiopathic renal infarction in previously healthy individuals and evaluating the mechanisms including strenuous physical activity on the renal blood flow.