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.

Background: We analyzed cell-free serum Epstein‒Barr virus (EBV) DNA to identify its prognostic role in patients with newly diagnosed lymphoma. Methods: We retrospectively reviewed patients diagnosed with lymphoma between January 2014 and July 2020. Patients were enrolled according to the following criteria: i) pathologically confirmed lymphomas according to the World Health Organization criteria, ii) age over 18 years, iii) serum EBV DNA measurement using polymerase chain reaction prior to first-line therapy, and iv) receipt of curative standard chemotherapy. In total, 263 patients met these criteria and were included in this study. Results: Serum EBV DNA was detected in 79 patients (30.0%). Patients with positive serum EBV tended to be older (P =0.090), and the proportion of T-cell lineage lymphomas was higher than that of B-cell lymphomas (P =0.003). EBV positivity was significantly associated with more advanced disease based on the Ann Arbor staging system (P =0.008) and the International Prognostic Index (P =0.009). EBV positivity was also associated with higher disease relapse (P =0.038) and death rates (P =0.005). EBV-positive lymphomas further showed inferior long-term survival outcomes in terms of progression-free survival (PFS) (P =0.053) and overall survival (OS) (P =0.014). In the subgroup analyses, serum EBV positivity was a significant prognostic factor for patients with B-cell lineage lymphomas in terms of PFS (P =0.003) and OS (P =0.033). Conclusion We demonstrated that cell-free serum EBV DNA status at the time of diagnosis has potential as a prognostic biomarker for patients with newly diagnosed malignant lymphomas.

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.

Background: We analyzed cell-free serum Epstein‒Barr virus (EBV) DNA to identify its prognostic role in patients with newly diagnosed lymphoma. Methods: We retrospectively reviewed patients diagnosed with lymphoma between January 2014 and July 2020. Patients were enrolled according to the following criteria: i) pathologically confirmed lymphomas according to the World Health Organization criteria, ii) age over 18 years, iii) serum EBV DNA measurement using polymerase chain reaction prior to first-line therapy, and iv) receipt of curative standard chemotherapy. In total, 263 patients met these criteria and were included in this study. Results: Serum EBV DNA was detected in 79 patients (30.0%). Patients with positive serum EBV tended to be older (P =0.090), and the proportion of T-cell lineage lymphomas was higher than that of B-cell lymphomas (P =0.003). EBV positivity was significantly associated with more advanced disease based on the Ann Arbor staging system (P =0.008) and the International Prognostic Index (P =0.009). EBV positivity was also associated with higher disease relapse (P =0.038) and death rates (P =0.005). EBV-positive lymphomas further showed inferior long-term survival outcomes in terms of progression-free survival (PFS) (P =0.053) and overall survival (OS) (P =0.014). In the subgroup analyses, serum EBV positivity was a significant prognostic factor for patients with B-cell lineage lymphomas in terms of PFS (P =0.003) and OS (P =0.033). Conclusion We demonstrated that cell-free serum EBV DNA status at the time of diagnosis has potential as a prognostic biomarker for patients with newly diagnosed malignant lymphomas.

The explosive growth of next-generation sequencing data has resulted in ultra-large-scale datasets and ensuing computational problems. In Korea, the amount of genomic data has been increasing rapidly in the recent years. Leveraging these big data requires researchers to use large-scale computational resources and analysis pipelines. A promising solution for addressing this computational challenge is cloud computing, where CPUs, memory, storage, and programs are accessible in the form of virtual machines. Here, we present a cloud computing-based system, Bio-Express, that provides user-friendly, cost-effective analysis of massive genomic datasets. Bio-Express is loaded with predefined multi-omics data analysis pipelines, which are divided into genome, transcriptome, epigenome, and metagenome pipelines. Users can employ predefined pipelines or create a new pipeline for analyzing their own omics data. We also developed several web-based services for facilitating downstream analysis of genome data. Bio-Express web service is freely available at https://www.bioexpress.re.kr/.

Background: There is currently a lack of evidence-based postresuscitation or postmortem guidelines for patients with out-of-hospital cardiac arrest (OHCA) in the setting of an emerging infectious disease. This study aimed to develop and validate a multimodal screening tool that aids in predicting the disease confirmation in emergency situations and patients with OHCA during a coronavirus disease 2019 (COVID-19) outbreak. Materials and Methods: We conducted a retrospective, multicenter observational study of adult patients with OHCA in Daegu, Korea. To identify the potential predictors that could be used in screening tools in the emergency department, we applied logistic regression to data collected from March 1 to March 14. The prediction performance of the screening variables was then assessed and validated on the data of patients with OHCA who were treated between February 19 and March 31, 2020. General patient characteristics and hematological findings of the COVID-19-negative and COVID-19-positive groups were compared. We also evaluated confirmation test criteria as predictors for COVID-19 positivity in patients with OHCA. Results: Advanced age, body temperature, and abnormal chest X-ray (CXR) revealed significant predictive ability in the derivation cohort. Of the 184 adult patients with OHCA identified in the validation cohort, 80 patients were included in the analysis. Notably, 9 patients were positive and 71 were negative on the COVID-19 reverse transcription polymerase chain reaction test. Five patients (55.6%) in the COVID-19-positive group had a fever before OHCA, and 12 (16.9%) of the COVID-19-negative group had a fever before OHCA (P = 0.018).Eight patients (88.9%) in the COVID-19-positive group had a CXR indicating pneumonic infiltration. Of the criteria for predicting COVID-19, fever or an abnormal CXR had a sensitivity of 100% (95% confidence interval [CI]: 65.4 – 100) and a specificity of 22.5% (95% CI: 13.5 – 34.0). Conclusion The screening tools that combined fever or abnormal CXR had a good discriminatory ability for COVID-19 infection in adult patients with OHCA. Therefore, during the COVID-19 outbreak period, it is recommended to suspect COVID-19 infection and perform COVID-19 test if patients present with a history of fever or show abnormal findings in postmortem CXR

The explosive growth of next-generation sequencing data has resulted in ultra-large-scale datasets and ensuing computational problems. In Korea, the amount of genomic data has been increasing rapidly in the recent years. Leveraging these big data requires researchers to use large-scale computational resources and analysis pipelines. A promising solution for addressing this computational challenge is cloud computing, where CPUs, memory, storage, and programs are accessible in the form of virtual machines. Here, we present a cloud computing-based system, Bio-Express, that provides user-friendly, cost-effective analysis of massive genomic datasets. Bio-Express is loaded with predefined multi-omics data analysis pipelines, which are divided into genome, transcriptome, epigenome, and metagenome pipelines. Users can employ predefined pipelines or create a new pipeline for analyzing their own omics data. We also developed several web-based services for facilitating downstream analysis of genome data. Bio-Express web service is freely available at https://www.bioexpress.re.kr/.

Background: There is currently a lack of evidence-based postresuscitation or postmortem guidelines for patients with out-of-hospital cardiac arrest (OHCA) in the setting of an emerging infectious disease. This study aimed to develop and validate a multimodal screening tool that aids in predicting the disease confirmation in emergency situations and patients with OHCA during a coronavirus disease 2019 (COVID-19) outbreak. Materials and Methods: We conducted a retrospective, multicenter observational study of adult patients with OHCA in Daegu, Korea. To identify the potential predictors that could be used in screening tools in the emergency department, we applied logistic regression to data collected from March 1 to March 14. The prediction performance of the screening variables was then assessed and validated on the data of patients with OHCA who were treated between February 19 and March 31, 2020. General patient characteristics and hematological findings of the COVID-19-negative and COVID-19-positive groups were compared. We also evaluated confirmation test criteria as predictors for COVID-19 positivity in patients with OHCA. Results: Advanced age, body temperature, and abnormal chest X-ray (CXR) revealed significant predictive ability in the derivation cohort. Of the 184 adult patients with OHCA identified in the validation cohort, 80 patients were included in the analysis. Notably, 9 patients were positive and 71 were negative on the COVID-19 reverse transcription polymerase chain reaction test. Five patients (55.6%) in the COVID-19-positive group had a fever before OHCA, and 12 (16.9%) of the COVID-19-negative group had a fever before OHCA (P = 0.018).Eight patients (88.9%) in the COVID-19-positive group had a CXR indicating pneumonic infiltration. Of the criteria for predicting COVID-19, fever or an abnormal CXR had a sensitivity of 100% (95% confidence interval [CI]: 65.4 – 100) and a specificity of 22.5% (95% CI: 13.5 – 34.0). Conclusion The screening tools that combined fever or abnormal CXR had a good discriminatory ability for COVID-19 infection in adult patients with OHCA. Therefore, during the COVID-19 outbreak period, it is recommended to suspect COVID-19 infection and perform COVID-19 test if patients present with a history of fever or show abnormal findings in postmortem CXR

Background: The Korean Society of Thoracic Radiology (KSTR) recently constructed a nation-wide coronavirus disease 2019 (COVID-19) database and imaging repository, referred to the Korean imaging cohort of COVID-19 (KICC-19) based on the collaborative efforts of its members. The purpose of this study was to provide a summary of the clinico-epidemiological data and imaging data of the KICC-19. Methods: The KSTR members at 17 COVID-19 referral centers retrospectively collected imaging data and clinical information of consecutive patients with reverse transcription polymerase chain reaction-proven COVID-19 in respiratory specimens from February 2020 through May 2020 who underwent diagnostic chest computed tomography (CT) or radiograph in each participating hospital. Results: The cohort consisted of 239 men and 283 women (mean age, 52.3 years; age range, 11–97 years). Of the 522 subjects, 201 (38.5%) had an underlying disease. The most common symptoms were fever (n = 292) and cough (n = 245). The 151 patients (28.9%) had lymphocytopenia, 86 had (16.5%) thrombocytopenia, and 227 patients (43.5%) had an elevated CRP at admission. The 121 (23.4%) needed nasal oxygen therapy or mechanical ventilation (n = 38; 7.3%), and 49 patients (9.4%) were admitted to an intensive care unit.Although most patients had cured, 21 patients (4.0%) died. The 465 (89.1%) subjects underwent a low to standard-dose chest CT scan at least once during hospitalization, resulting in a total of 658 CT scans. The 497 subjects (95.2%) underwent chest radiography at least once during hospitalization, which resulted in a total of 1,475 chest radiographs. Conclusion The KICC-19 was successfully established and comprised of 658 CT scans and 1,475 chest radiographs of 522 hospitalized Korean COVID-19 patients. The KICC-19 will provide a more comprehensive understanding of the clinical, epidemiological, and radiologic characteristics of patients with COVID-19.