Predictive potential of various plasma inflammation-, angiogenesis-, and extracellular matrix remodeling-associated mediators for intra-amniotic inflammation and/or microbial invasion of the amniotic cavity in preterm labor.

PURPOSE: To determine whether various inflammatory-, angiogenic/anti-angiogenic-, and extracellular matrix remodeling-associated proteins in plasma, alone or in combination with conventional blood-based markers, can predict intra-amniotic inflammation and/or microbial invasion of the amniotic cavity (IAI/MIAC) in women with spontaneous preterm labor (PTL). METHODS: A total of 193 singleton pregnant women with PTL (23-33 weeks) were included in this retrospective cohort study. Plasma samples were obtained at the time of amniocentesis. Amniotic fluid (AF) was cultured for microorganism detection and consequent MIAC diagnosis. IL-6 levels were determined in AF and used to identify IAI (AF IL-6 ≥ 2.6 ng/mL). Endostatin, haptoglobin, IGFBP-2/3, LBP, M-CSF, MMP-2/8, pentraxin 3, PlGF, S100A8/A9, and VEGFR-1 levels were assayed in plasma samples by ELISA. CRP levels and neutrophil-to-lymphocyte ratio (NLR) were measured. RESULTS: Plasma LBP, MMP-8, and S100A8/A9 levels, CRP levels, and NLR were significantly higher, and plasma IGFBP-2 and MMP-2 levels were significantly lower in women with IAI/MIAC than in those without this condition, whereas no baseline variables differed significantly between the two groups. Using a stepwise regression analysis, a noninvasive prediction model for IAI/MIAC was developed, which included plasma LBP, MMP-2, and MMP-8 levels (area under the curve [AUC], 0.785). The AUC for this prediction model was significantly or borderline greater than that of any single factor included in the model. CONCLUSIONS: IGFBP-2, LBP, MMP-2, MMP-8, and S100A8/A9 may represent valuable plasma biomarkers for predicting IAI/MIAC in women with PTL. Combination of LBP, MMP-2, and MMP-8 expression data can significantly improve the predictive potential for IAI/MIAC.

Changing Epidemiology of Pathogenic Bacteria Over the Past 20 Years in Korea.

BACKGROUND: The epidemiology of pathogenic bacteria varies according to the socioeconomic status and antimicrobial resistance status. However, longitudinal epidemiological studies to evaluate the changes in species distribution and antimicrobial susceptibility of pathogenic bacteria nationwide are lacking. We retrospectively investigated the nationwide trends in species distribution and antimicrobial susceptibility of pathogenic bacteria over the last 20 years in Korea. METHODS: From 1997 to 2016, annual cumulative antimicrobial susceptibility and species distribution data were collected from 12 university hospitals in five provinces and four metropolitan cities in South Korea. RESULTS: The prevalence of Staphylococcus aureus was the highest (13.1%) until 2012 but decreased to 10.3% in 2016, consistent with the decrease in oxacillin resistance from 76.1% in 2008 to 62.5% in 2016. While the cefotaxime resistance of Escherichia coli increased from 9.0% in 1997 to 34.2% in 2016, E. coli became the most common species since 2013, accounting for 14.5% of all isolates in 2016. Pseudomonas aeruginosa and Acinetobacter baumannii rose to third and fifth places in 2008 and 2010, respectively, while imipenem resistance increased from 13.9% to 30.8% and 0.7% to 73.5% during the study period, respectively. Streptococcus agalactiae became the most common pathogenic streptococcal species in 2016, as the prevalence of Streptococcus pneumoniae decreased since 2010. During the same period, pneumococcal penicillin susceptibility decreased to 79.0%, and levofloxacin susceptibility of S. agalactiae decreased to 77.1% in 2016. CONCLUSION: The epidemiology of pathogenic bacteria has changed significantly over the past 20 years according to trends in antimicrobial resistance in Korea. Efforts to confine antimicrobial resistance would change the epidemiology of pathogenic bacteria and, consequently, the diagnosis and treatment of infectious diseases.

Two Years of Experience and Methodology of Korean COVID-19 Living Clinical Practice Guideline Development.

BACKGROUND: In Korea, during the early phase of the coronavirus disease 2019 (COVID-19) pandemic, we responded to the uncertainty of treatments under various conditions, consistently playing catch up with the speed of evidence updates. Therefore, there was high demand for national-level evidence-based clinical practice guidelines for clinicians in a timely manner. We developed evidence-based and updated living recommendations for clinicians through a transparent development process and multidisciplinary expert collaboration. METHODS: The National Evidence-based Healthcare Collaborating Agency (NECA) and the Korean Academy of Medical Sciences (KAMS) collaborated to develop trustworthy Korean living guidelines. The NECA-supported methodological sections and 8 professional medical societies of the KAMS worked with clinical experts, and 31 clinicians were involved annually. We developed a total of 35 clinical questions, including medications, respiratory/critical care, pediatric care, emergency care, diagnostic tests, and radiological examinations. RESULTS: An evidence-based search for treatments began in March 2021 and monthly updates were performed. It was expanded to other areas, and the search interval was organized by a steering committee owing to priority changes. Evidence synthesis and recommendation review was performed by researchers, and living recommendations were updated within 3-4 months. CONCLUSION: We provided timely recommendations on living schemes and disseminated them to the public, policymakers and various stakeholders using webpages and social media. Although the output was successful, there were some limitations. The rigor of development issues, urgent timelines for public dissemination, education for new developers, and spread of several new COVID-19 variants have worked as barriers. Therefore, we must prepare systematic processes and funding for future pandemics.

SARS-CoV-2 Infectivity and Antibody Titer Reduction for 6 Months After Second Dose of BNT162b2 mRNA Vaccine in Health Care Workers: A Prospective Cohort Study.

Several studies reported that severe acute respiratory syndrome coronavirus-2 antibody levels change over 6 months in participants receiving the vaccination. From the enrolled 272 health care workers (HCWs), blood samples were obtained at 2, 16, and 24 weeks after the second vaccination dose. In the 267 noninfected HCWs, the neutralizing antibodies decreased by 23.9%, and the anti-spike/receptor binding domain antibody decreased by 53.8% at 24 weeks. We observed no significant difference in antibody reduction between the sexes; however, in younger individuals, there was higher antibody formation and lower reduction rates of the neutralizing antibody. In 3 HCWs with breakthrough infections, the antibody levels were relatively low just before the coronavirus disease 2019 infection. In conclusion, as antibody titers decrease over time after the second vaccination dose and HCWs with low antibody titers tend to have a high probability of breakthrough infection, an additional dose should be considered after several months. Blood samples were obtained from health care workers at 2, 16, and 24 weeks after a second vaccination dose. Antibody titers decreased over time and the participants with low antibody titers tended to have a high probability of breakthrough infection.

Metabolic Dysfunction-Associated Fatty Liver Disease and Subsequent Development of Adverse Pregnancy Outcomes.

BACKGROUND & AIMS: Recently, metabolic dysfunction-associated fatty liver disease (MAFLD), rather than nonalcoholic fatty liver disease (NAFLD), was proposed to better describe liver disease associated with metabolic dysfunction (MD). In this study, we attempted to investigate the impact of MAFLD on pregnancy complications. METHODS: The current study is a secondary analysis of a multicenter prospective cohort designed to examine the risk of NAFLD during pregnancy. In the first trimester, enrolled pregnant women were evaluated for hepatic steatosis by liver ultrasonography, and blood samples were collected for biochemical measurements. The study population was divided into 3 groups: no NAFLD, hepatic steatosis but without metabolic dysfunction (non-MD NAFLD), and MAFLD. The primary outcome was the subsequent development of adverse pregnancy outcomes, including gestational diabetes mellitus, pregnancy-associated hypertension, preterm birth, and fetal growth abnormalities. RESULTS: The study population consisted of 1744 pregnant women, including 1523 with no NAFLD, 43 with non-MD NAFLD, and 178 with MAFLD. The risk of subsequent development of adverse pregnancy outcomes was higher in MAFLD than in non-MD NAFLD (adjusted odds ratio, 4.03; 95% CI, 1.68-9.67), whereas the risk was not significantly different between no NAFLD and non-MD NAFLD. Among women with no NAFLD, the presence of MD increased the risk of adverse pregnancy outcomes. However, women with MAFLD were at higher risk for adverse pregnancy outcomes than women with no NAFLD without MD or those with no NAFLD with MD. CONCLUSIONS: In pregnant women, MAFLD may be associated with an increased risk of subsequent adverse pregnancy outcomes.

Characteristics of Korean BCR-ABL1-Negative Myeloproliferative Neoplasms Related to the 2016 WHO Criteria Revision.

BACKGROUND: We aimed to identify changes in the diagnosis and subtype classification of Korean patients with BCR-ABL1-negative MPN related to the revision of the WHO classification in 2016. METHODS: We evaluated 76 Korean patients with BCR-ABL1-negative MPN who underwent diagnostic work-ups, including bone marrow (BM) examinations and JAK2 V617F mutation analysis, from January 2013 to June 2018. Additionally, we reclassified the subtype of 43 patients who were diagnosed based on the WHO 2008 classification. RESULTS: From January 2013 to April 2016, 43 patients were diagnosed with BCR-ABL1-negative MPN (12 PV, 17 ET, 14 PMF) according to the 2008 WHO classification, and from May 2016 to June 2018, 33 patients were diagnosed according to the 2016 classification (15 PV, 11 ET, 7 PMF). With the application of 2016 classification, 3 cases of ET were reclassified as pre-PMF, and the proportion of PV increased from 27.9% to 45.5%. There were significant differences in CBC between pre-PMF and overt PMF, between ET and overt-PMF, but no difference between ET and pre-PMF. CONCLUSIONS: The overall characteristics of BCR-ABL1-negative MPN patients were not significantly different from those of previous reports. 'Masked PV', which could not be diagnosed according to the WHO 2008 classification, may have been diagnosed as PV since 2016 due to the increase in the diagnostic value of the BM findings and the lowering of the hemoglobin (Hb) threshold.

Clinically refined epidemiology of nontuberculous mycobacterial pulmonary disease in South Korea: overestimation when relying only on diagnostic codes.

BACKGROUND: There have been reports of increases in the incidence and prevalence of nontuberculous mycobacterial pulmonary disease (NTM-PD) in several countries, but no studies have analyzed claims data using laboratory tests. This study aimed to estimate the nationwide epidemiology and medical treatments of NTM-PD according to laboratory tests run in Korea. METHODS: Using claims data from the Health Insurance Review and Assessment Service, we analyzed patients with nontuberculous mycobacterium (ICD-10: A31) who were diagnosed from Jan 2007 to Jun 2019. The incidence and prevalence of NTM-PD and whether related laboratory tests were performed were analyzed. Diagnostic code-based NTM-PD patients were defined as patients who had NTM as a diagnosis on at least 2 occasions within 180 days. Clinically refined NTM-PD patients were defined as those excluding hospital-diagnosed patients with acid-fast bacilli (AFB) culture rates less than 5%. Laboratory tests included AFB smears, AFB culture, NTM identification, and drug susceptibility tests (DSTs). RESULTS: A total of 60,071 diagnostic code-based NTM-PD patients were evaluated. Clinically refined NTM-PD included 45,321 patients, excluding 14,750 (24.6%) patients diagnosed in hospitals with low AFB culture rates. The annual incidence per 100,000 population increased from 2.9 cases in 2008 to 12.3 cases in 2018. The annual prevalence per 100,000 population increased from 5.3 cases in 2008 to 41.7 cases in 2018. After removing outliers according to the AFB culture rate, a significant decrease in incidence was observed in women younger than 50 years. Among patients with clinically refined NTM-PD, the test rates for AFB culture, NTM identification, and DST were 84.3%, 59.1%, and 40.4%, respectively. From the outpatient clinic, 17,977 (39.7%) patients were prescribed drugs related to NTM treatment, with a median number of prescriptions of 7 (interquartile range (IQR) 3-11) and a median duration from the diagnosis to end of treatment of 330 (IQR 118-578) days. CONCLUSIONS: Although the incidence and prevalence of NTM-PD are on the rise, the recent surge in women 50 years of age is overestimated in patients not adequately tested. In claim-based studies, there may be limitations in estimating the epidemiological data with only the diagnostic codes.

Strong SARS-CoV-2 Antibody Response After Booster Dose of BNT162b2 mRNA Vaccines in Uninfected Healthcare Workers.

Despite strict guidelines for coronavirus disease 2019 (COVID-19), South Korea is facing its fourth pandemic wave. In this study, by using an automated electrochemiluminescence immunoassay assay, we tracked anti-spike protein receptor-binding domain (anti-S-RBD) antibody titer from the second dose to 2 weeks after the booster dose vaccination. After the second dose, 234 participants had their anti-S-RBD antibody titers decrease over time. We also showed the booster dose (the third dose) increased antibody titer by average 14 (min-max, 2-255)-fold higher compared to the second dose among the 211-booster group participants, therefore, the booster dose could be recommended for low responders to the second dose. Our findings showed a distinct humoral response after booster doses of BNT162b2 mRNA vaccines and may provide further evidence of booster vaccination efficacy. These data will also be helpful in vaccination policy decisions that determine the need for the booster dose.

Evaluation of Five User-Friendly Whole Genome Sequencing Software for Mycobacterium tuberculosis in Clinical Application.

BACKGROUND: Whole genome sequencing (WGS) is an increasingly useful tool for tuberculosis (TB) diagnosis and disease management. In this study, we evaluated the utility of user-friendly WGS tools in reporting resistance profiles and identifying lineages of clinical TB isolates from South Korea. METHODS: Forty clinical samples from TB patients showing discrepancies between their rapid molecular and conventional drug susceptibility tests were used in this study. Among these clinical isolates, 37 strains were successfully evaluated via WGS software, using the GenTB, TB Profiler, PhyResSE, CASTB, and Mykrobe. RESULTS: More accurate and faster susceptibility results could be obtained with isoniazid than with rifampin. Using the phenotypic test as the gold standard, the isoniazid concordance rate between phenotypic drug susceptibility test (DST) and WGS (GenTB: 45.9%, TB profiler: 40.5%, PhyResSE: 40.5%, CASTB: 48.6%, and Mykrobe: 43.2%) was much higher than between phenotypic DST and rapid molecular genotypic DST (18.9%) among the 37 strains. In contrast, the rifampin concordance rate between phenotypic DST and WGS and that between phenotypic DST and rapid molecular genotypic DST was similar (81.1-89.2%). We also found novel mutations associated with INH in katG and ahpC gene region, not covered by the line probe assay. In addition, lineage analysis identified 81.1% of these samples as L2 East Asian lineage strains, and 18.9% as L4 Euro-American lineage strains. CONCLUSION: WGS may play a pivotal role in TB diagnosis and the detection of drug resistance, genetic diversity, and transmission dynamics in the near future because of its accuracy, speed, and extensibility.

Prevalence of granular corneal dystrophy type 2-related TGFBI p.R124H variant in a South Korean population.

Purpose: Granular corneal dystrophy type 2 (GCD2) is an autosomal dominant disorder and is associated with the arginine to histidine substitution at codon 124 (p.R124H) of the TGFBI gene. Although TGFBI p.R124H is known to be the most common corneal dystrophy-related pathogenic variant, there are few data on the frequency of this variant in the South Korean population. Methods: In total, 2,060 anonymous DNA samples from a public umbilical cord blood bank were tested for the TFGBI p.R124H variant using real-time PCR. Results: Six of the 2,060 samples [0.29%; 95% confidence interval (CI), 0.12-0.67%] were heterozygous for the TGFBI p.R124H variant. The prevalence of the GCD2-related TGFBI p.R124H variant in this population was estimated to be 291.3 per 100,000 [95% confidence interval (CI), 118.5-667.0]. Conclusions: To our knowledge, this is the largest study that has estimated the prevalence of the GCD2-related TGFBI p.R124H variant in South Korea.

Effects of corticosteroids and platelet-rich plasma on synoviocytes in IL-1ß-induced inflammatory condition.

AIMS: Corticosteroid injections are used to treat shoulder pain. Platelet-rich plasma (PRP) is known to have anti-inflammatory and anabolic effects, as well as cytoprotective effects against corticosteroids. Thus, this study was to investigate the effects of co-treatment of corticosteroid and PRP on anti-inflammatory and matrix homeostasis of synoviocytes in IL-1ß-induced inflammatory conditions. MATERIALS AND METHODS: Synoviocytes were cultured with 1 ng/mL IL-1ß, 1 µM dexamethasone, and 10% (vol/vol) Platelet-poor plasma (PPP), PRP200, PRP1000, and PRP4000 X 103/µL. Gene expressions of pro-inflammatory and anti-inflammatory cytokines, degradative enzymes, and their inhibitors were evaluated and protein synthesis of degradative enzymes and their inhibitors were also examined. RESULTS: Corticosteroid modulated anti-inflammatory and pro-inflammatory cytokines, and subsequent PRP treatment did not interfere with the effect of a corticosteroid and modulated the gene expressions of cytokines such as TNF-α and IL-4, which were not regulated by the corticosteroid alone. Gene expressions and protein expressions of degradative enzymes and their inhibitors were suppressed by corticosteroid. Additional PRPs did not alter the gene expression and protein regulated by the corticosteroid and inhibited the gene expression of ADAMTS-5 and protein synthesis of MMP-9 and ADAMTS-5, which were not modulated by the corticosteroid alone. CONCLUSION: Corticosteroid regulated the inflammation and synovial homeostasis. When PRP and the corticosteroid were used together, it exhibited synergistic effects on synoviocytes by regulating the parts that were not controlled by corticosteroid alone while not interfering with the effects of the corticosteroid in an inflammatory condition.

Evaluation of LabType-SSO HLA Typing for HLA-A, -B, -C, -DRB1, and -DQB1 loci.

BACKGROUND: For HLA genotyping, PCR sequence-specific oligonucleotide (SSO) methods using the Luminex platform are widely used. We evaluated the performance of LabType-SSO (One Lambda, USA) in Koreans. METHODS: LabType-SSO were performed on 50 residual DNA samples analyzed by sequence-based typing (SBT) for all HLA-A, -B, -C, -DRB1, and -DQB1 alleles with gene frequency > 0.1% in Koreans. RESULTS: The LabType-SSO results were in complete agreement with SBT at the 2-digit level. For 4-digit level, 9 HLA-A alleles, 1 HLA-B allele, 3 HLA-C alleles, neither HLA-DRB1 nor -DQB1 allele showed ambiguous results for assignment of most probable types considering HLA gene frequency in Koreans. In addition, two cases of DQB1*04:01 allele were incorrectly assigned to DQB1*04:02. CONCLUSIONS: LabType-SSO tests showed accurate assignment of 2-digit level and LabType-SSO HLA-DRB1 test showed correct 4-digit most probable HLA type. The tests can be useful as intermediate resolution typing for solid organ transplantation.

Performance evaluation of immunoassay for infectious diseases on the Alinity i system.

BACKGROUND: Although a diagnosis of infectious diseases is essential for timely treatment, the performance of diagnostic tests has been hardly evaluated due to variable results that are influenced by multiple factors in different conditions. In the present study, the performance of the Alinity i system, which is a newly developed immunoassay to diagnose infectious diseases, was evaluated. METHODS: We evaluated the precision, linearity, correlation, and carryover of 16 analytes (HAV Ab IgG, HBsAg, HBeAg, anti-HBc, anti-HBe, anti-HBs, anti-HCV, HIV Ag/Ab, EBV VCA IgM, EBV VCA IgG, EBV EBNA IgG, CMV IgM, CMV IgG, Toxoplasma IgG, Rubella IgG, and Syphilis TP) of Alinity i by comparison with ARCHITECT i2000SR system following the rationale of the Clinical and Laboratory Standards Institute (CLSI). RESULTS: For quantitative tests, the coefficients of variation (CV) % of repeatability and intermediate precision were between 0% and 4.18%. The coefficients of the linearity (r2 ) over a widely tested analytical range were ≥ 0.990 and the correlation between Alinity i and the ARCHITECT i2000SR system was strong (r ≥ 0.994). For qualitative tests, the agreement between Alinity i and the ARCHITECT i2000SR system was excellent (kappa coefficient 1) with 100% sensitivity and specificity. Carryover rates for all analytes were less than 1.0% (-0.11% ~ 0.21%). CONCLUSION: The Alinity i system showed good analytical performance and favorable comparability with the ARCHITECT i2000SR. It could be suitable as a routine immunoassay analyzer for screening and diagnosis of infectious disease.

Performance evaluation of three automated quantitative immunoassays and their correlation with a surrogate virus neutralization test in coronavirus disease 19 patients and pre-pandemic controls.

BACKGROUND: SARS-CoV-2 pandemic is currently ongoing, meanwhile vaccinations are rapidly underway in some countries. The quantitative immunoassays detecting antibodies against spike antigen of SARS-CoV-2 have been developed based on the findings that they have a better correlation with the neutralizing antibody. METHODS: The performances of the Abbott Architect SARS-CoV-2 IgG II Quant, DiaSorin LIAISON SARS-CoV-2 TrimericS IgG, and Roche Elecsys anti-SARS-CoV-2 S were evaluated on 173 sera from 126 SARS-CoV-2 patients and 151 pre-pandemic sera. Their correlations with GenScript cPass SARS-CoV-2 Neutralization Antibody Detection Kit were also analyzed on 173 sera from 126 SARS-CoV-2 patients. RESULTS: Architect SARS-CoV-2 IgG II Quant and Elecsys anti-SARS-CoV-2 S showed the highest overall sensitivity (96.0%), followed by LIAISON SARS-CoV-2 TrimericS IgG (93.6%). The specificities of Elecsys anti-SARS-CoV-2 S and LIAISON SARS-CoV-2 TrimericS IgG were 100.0%, followed by Architect SARS-CoV-2 IgG II Quant (99.3%). Regarding the correlation with cPass neutralization antibody assay, LIAISON SARS-CoV-2 TrimericS IgG showed the best correlation (Spearman rho = 0.88), followed by Architect SARS-CoV-2 IgG II Quant and Elecsys anti-SARS-CoV-2 S (all rho = 0.87). CONCLUSIONS: The three automated quantitative immunoassays showed good diagnostic performance and strong correlations with neutralization antibodies. These assays will be useful in diagnostic assistance, evaluating the response to vaccination, and the assessment of herd immunity in the future.

Positivity of SARS-CoV-2 Antibodies among Korean Healthy Healthcare Workers 1 and 2 Weeks after Second Dose of Pfizer-BioNTech Vaccination.

The antibody titer of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was observed in 289 healthy healthcare workers who had completed the second dose of the Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine. Antibody tests were performed using both the automated electrochemiluminescence immunoassay (ECLIA) and the chromatographic lateral flow immunoassay (LFIA). All subjects had antibodies against the receptor binding domain of the spike protein of SARS-CoV-2 only one week after completing the vaccination, and the antibody titer became significantly higher after another week (P < 0.001). Since there was a large amount of antibody formation within two weeks after completion of vaccination, the less sensitive method, LFIA, also showed high sensitivity. There was no significant difference between whole blood and serum in detecting SARS-CoV-2 antibodies after vaccination. This is an early study of vaccinations among Koreans and is expected to contribute to the establishment of national guidelines on COVID-19 vaccination.

Evaluation of Three Multiplex Real-time Reverse Transcription PCR Assays for Simultaneous Detection of SARS-CoV-2, Influenza A/B, and Respiratory Syncytial Virus in Nasopharyngeal Swabs.

BACKGROUND: In the coronavirus disease 2019 (COVID-19) pandemic era, the simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus (Flu), and respiratory syncytial virus (RSV) is important in the rapid differential diagnosis in patients with respiratory symptoms. Three multiplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assays have been recently developed commercially in Korea: PowerChek™ SARS-CoV-2, Influenza A&B Multiplex Real-time PCR Kit (PowerChek; KogeneBiotech); STANDARD™ M Flu/SARS-CoV-2 Real-time Detection Kit (STANDARD M; SD BioSensor); and Allplex™ SARS-CoV-2/FluA/FluB/RSV Assay (Allplex; Seegene). We evaluated the analytical and clinical performances of these kits. METHODS: A limit of detection tests were performed and cross-reactivity analysis was executed using clinical respiratory samples. Ninety-seven SARS-CoV-2-positive, 201 SARS-CoV-2-negative, 71 influenza A-positive, 50 influenza B-positive, 78 RSV-positive, and 207 other respiratory virus-positive nasopharyngeal swabs were tested using the three assays. The AdvanSure™ respiratory viruses rRT-PCR assay (AdvanSure; LG Life Sciences) was used as a comparator assay for RSV. RESULTS: Except in influenza B, in SARS-CoV-2 and influenza A, there were no significant differences in detecting specific genes of the viruses among the three assays. All three kits did not cross-react with common respiratory viruses. All three kits had greater than 92% positive percent agreement and negative percent agreement and ≥ 0.95 kappa value in the detection of SARS-CoV-2 and flu A/B. Allplex detected RSV more sensitively than AdvanSure. CONCLUSION: The overall performance of three multiplex rRT-PCR assays for the concurrent detection of SARS-CoV-2, influenza A/B, and RSV was comparable. These kits will promote prompt differential diagnosis of COVID-19, influenza, and RSV infection in the COVID-19 pandemic era.

Sequential Analysis of Viral Load in a Neonate and Her Mother Infected With Severe Acute Respiratory Syndrome Coronavirus 2.

We report changes in viral load over time in a 27-day-old neonate with coronavirus disease 2019 who presented with fever, cough, and vomiting. Severe acute respiratory syndrome coronavirus 2 RNA was detected in the nasopharynx, oropharynx, stool, saliva, plasma, and urine. The highest viral RNA copies in nasopharynx decreased over time while viral load in stool remained high.

Viral RNA Load in Mildly Symptomatic and Asymptomatic Children with COVID-19, Seoul, South Korea.

Along with positive SARS-CoV-2 RNA in nasopharyngeal swabs, viral RNA was detectable at high concentration for >3 weeks in fecal samples from 12 mildly symptomatic and asymptomatic children with COVID-19 in Seoul, South Korea. Saliva also tested positive during the early phase of infection. If proven infectious, feces and saliva could serve as transmission sources.

Usefulness of the Hematopoietic Stem Cell Donor Pool as a Source of HLA-Homozygous Induced Pluripotent Stem Cells for Haplobanking: Combined Analysis of the Cord Blood Inventory and Bone Marrow Donor Registry.

Induced pluripotent stem cells (iPSCs) have opened up unprecedented opportunities for novel therapeutic options for precision medicine. Hematopoietic stem cell (HSC) donor pools with previously determined HLA types may be ideal sources for iPSC production. Based on the HLA distribution of cryopreserved cord blood units (CBUs) and registered bone marrow (BM) donors, we estimated how much of the Korean population could be covered by HLA-homozygous iPSCs. We analyzed a total of 143,866 Korean HSC donors (27,904 CBUs and 115,962 BM donors). Each donor sample was typed for the HLA-A, -B, and -DRB1 alleles at low to intermediate resolution by DNA-based molecular techniques: PCR sequence-specific oligonucleotide (PCR-SSOP), PCR with sequence-specific primers (PCR-SSP) and PCR with sequence-based typing (PCR-SBT). We also identified individuals possessing homozygous HLA haplotypes by direct counting. The matching probabilities for zero-mismatch transplantation were calculated for 143,866 Koreans and 50 million potential Korean patients. Among the HSC donor pool, 17 HLA-A alleles, 41 HLA-B alleles, and 13 HLA-DRB1 alleles, as well as 128 homozygous HLA-A-B-DRB1 haplotypes, were identified at serologic equivalents, and those haplotypes cumulatively matched 93.20% of the 143,866 Korean donors as zero HLA-mismatch iPSC sources. Among the combinations of 2,056 haplotypes with frequencies ≥ 0.001% in a population of 50 million, those 128 homozygous haplotypes can provide 93.65% coverage for potential Korean recipients. Haplobanking of a reasonable number of HLA-A, -B, and -DRB1 homozygous iPSC lines derived from CBUs and cells of registered BM donors may be an efficient option for allogenic iPSC therapy.

Fifteen new nucleotide substitutions in variants of human papillomavirus 18 in Korea : Korean HPV18 variants and clinical manifestation.

High-risk human papillomavirus (HPV) infection is an essential factor for the development of cervical cancer. HPV18 is the second most common carcinogenic HPV type following HPV16, but the lineages of HPV18 have been less well studied than those of HPV 16. The purpose of this study was to analyze the nucleotide variants in the E6, E7, and L1 genes of HPV18, to assess the prevalence of HPV18 variants in Korea and to explore the relationship between HPV18 genetic variants and the risk for cervical cancer.A total of 170 DNA samples from HPV18-positive cervical specimens were collected from women admitted to a secondary referral hospital located in Seoul. Among them, the lineages of the 97 samples could be successfully determined by historical nomenclature.All the studied HPV 18 variants were lineage A. Sublineages A1 and A4 comprised 91.7% (89/97) and 1.0% (1/97), respectively. Sublineages other than A1 or A4 comprised 7.2% (7/97). We identified 15 new nucleotide substitutions among 44 nucleotide substitutions: C158T, T317G, T443G, A560G, A5467G, A5560C, A5678C, A6155G, G6462A, T6650G, G6701A, T6809C, A6823G, T6941C and T6953C. Among them, 6 substitutions at positions 317, 443, 5467, 5560, 6462, and 6823 resulted in amino acid changes (E6: F71L and N113K; L1: H13R, H44P, A345T, and N465S, respectively). The pathologic results were classified as normal in 25.8% (25/97) of the women, atypical squamous cells of undermined significance (ASCUS) in 7.2% (7/97), cervical intraepithelial neoplasia (CIN) 1 in 36.1% (35/97), CIN2/3 in 19.6% (18/97), and carcinoma in 12.4% (12/97). There was no significant association between the HPV18 sublineages and the severity of pathologic lesion or the disease progression.This study is the first to analyze the distribution of HPV18 variants in Korean and to associate the results with pathologic findings. Although the HPV18 variants had no significant effect on the degree and progression of the disease, the newly discovered nonsynonymous mutation in L1 might serve as a database to determine vaccine efficacy in Korean women.