Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.

Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.

Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.

Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.

Background: AML is a heterogeneous disease, and despite intensive therapy, recurrence is still high in AML patients who achieve the criterion for cytomorphologic remission (residual tumor burden [measurable residual disease, MRD]<5%). This study aimed to develop a targeted next-generation sequencing (NGS) panel to detect MRD in AML patients and validate its performance. Methods: We designed an error-corrected, targeted MRD-NGS panel without using physical molecular barcodes, including 24 genes. Fifty-four bone marrow and peripheral blood samples from 23 AML patients were sequenced using the panel. The panel design was validated using reference material, and accuracy was assessed using droplet digital PCR. Results: Dilution tests showed excellent linearity and a strong correlation between expected and observed clonal frequencies (R>0.99). The test reproducibly detected MRD in three dilution series samples, with a sensitivity of 0.25% for single-nucleotide variants. More than half of samples from patients with morphologic remission after one month of chemotherapy had detectable mutations. NGS-MRD positivity for samples collected after one month of chemotherapy tended to be associated with poor overall survival and progression-free survival. Conclusions Our highly sensitive and accurate NGS-MRD panel can be readily used to monitor most AML patients in clinical practice, including patients without gene rearrangement. In addition, this NGS-MRD panel may allow the detection of newly emerging clones during clinical relapse, leading to more reliable prognoses of AML.

OBJECTIVES: We estimated the population prevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including unreported infections, through a Korea Seroprevalence Study of Monitoring of SARS-CoV-2 Antibody Retention and Transmission (K-SEROSMART) in 258 communities throughout Korea. METHODS: In August 2022, a survey was conducted among 10,000 household members aged 5 years and older, in households selected through two stage probability random sampling. During face-to-face household interviews, participants self-reported their health status, COVID-19 diagnosis and vaccination history, and general characteristics. Subsequently, participants visited a community health center or medical clinic for blood sampling. Blood samples were analyzed for the presence of antibodies to spike proteins (anti-S) and antibodies to nucleocapsid proteins (anti-N) SARS-CoV-2 proteins using an electrochemiluminescence immunoassay. To estimate the population prevalence, the PROC SURVEYMEANS statistical procedure was employed, with weighting to reflect demographic data from July 2022. RESULTS: In total, 9,945 individuals from 5,041 households were surveyed across 258 communities, representing all basic local governments in Korea. The overall population-adjusted prevalence rates of anti-S and anti-N were 97.6% and 57.1%, respectively. Since the Korea Disease Control and Prevention Agency has reported a cumulative incidence of confirmed cases of 37.8% through July 31, 2022, the proportion of unreported infections among all COVID-19 infection was suggested to be 33.9%. CONCLUSIONS The K-SEROSMART represents the first nationwide, community-based seroepidemiologic survey of COVID-19, confirming that most individuals possess antibodies to SARS-CoV-2 and that a significant number of unreported cases existed. Furthermore, this study lays the foundation for a surveillance system to continuously monitor transmission at the community level and the response to COVID-19.

Purpose: Li-Fraumeni syndrome (LFS) is a rare autosomal cancer syndrome caused by a germline mutation in the TP53 gene. Breast cancer in LFS patients is of various subtypes;however, limited data are available on the clinicopathological features of these subtypes and their appropriate treatments. This study aimed to review the clinical features and treatments for breast cancer in South Korean patients with germline TP53 mutations. Methods: Data on the clinicopathological features and treatment of all breast cancer patients with LFS were collected retrospectively from the available database of 4 tertiary hospitals in the Republic of Korea. Results: Twenty-one breast cancer cases in 12 unrelated women with confirmed germline TP53 mutations were included in the study. The median age at diagnosis was 33.5 years. The histopathological diagnosis included invasive ductal carcinoma (n = 16), ductal carcinoma in situ (n = 3), and malignant phyllodes tumor (n = 2). While 42% and 31% of the cases were positive for estrogen and progesterone receptors, respectively, 52.6% were human epidermal growth factor receptor 2 (HER2) positive, and 21% were triple-negative. The treatments included mastectomy (52%) and breast-conserving surgery (38%). Five patients underwent radiotherapy (RT). The median follow-up period was 87.5 (8–222) months. There were 3 ipsilateral and 4 contralateral breast recurrences during the follow-up, and 8 patients developed new primary cancers. In the post-RT subgroup, there were 2 ipsilateral and 2 contralateral breast recurrences in 1 patient, and 4 patients had a new primary cancer. Conclusion As reported in other countries, breast cancer in LFS patients in South Korea had an early onset and were predominantly but not exclusively positive for HER2.A multidisciplinary approach with adherence to the treatment guidelines, considering mastectomy, and avoiding RT is encouraged to prevent RT-associated sequelae in LFS patients.

Purpose: Li-Fraumeni syndrome (LFS) is a rare autosomal cancer syndrome caused by a germline mutation in the TP53 gene. Breast cancer in LFS patients is of various subtypes;however, limited data are available on the clinicopathological features of these subtypes and their appropriate treatments. This study aimed to review the clinical features and treatments for breast cancer in South Korean patients with germline TP53 mutations. Methods: Data on the clinicopathological features and treatment of all breast cancer patients with LFS were collected retrospectively from the available database of 4 tertiary hospitals in the Republic of Korea. Results: Twenty-one breast cancer cases in 12 unrelated women with confirmed germline TP53 mutations were included in the study. The median age at diagnosis was 33.5 years. The histopathological diagnosis included invasive ductal carcinoma (n = 16), ductal carcinoma in situ (n = 3), and malignant phyllodes tumor (n = 2). While 42% and 31% of the cases were positive for estrogen and progesterone receptors, respectively, 52.6% were human epidermal growth factor receptor 2 (HER2) positive, and 21% were triple-negative. The treatments included mastectomy (52%) and breast-conserving surgery (38%). Five patients underwent radiotherapy (RT). The median follow-up period was 87.5 (8–222) months. There were 3 ipsilateral and 4 contralateral breast recurrences during the follow-up, and 8 patients developed new primary cancers. In the post-RT subgroup, there were 2 ipsilateral and 2 contralateral breast recurrences in 1 patient, and 4 patients had a new primary cancer. Conclusion As reported in other countries, breast cancer in LFS patients in South Korea had an early onset and were predominantly but not exclusively positive for HER2.A multidisciplinary approach with adherence to the treatment guidelines, considering mastectomy, and avoiding RT is encouraged to prevent RT-associated sequelae in LFS patients.

Cohort Studies ; Coinfection ; Hepatitis B virus ; HIV Infections ; HIV ; Humans ; Immunization, Secondary ; Korea ; Parturition ; Prevalence ; Vaccination

From December 2006 to December 2016, 1093 human immunodeficiency virus (HIV) individuals < 70 years enrolled in Korea human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) cohort were analyzed to investigate the prevalence of HIV/HBV co-infection rate and hepatitis B virus surface antibody (HBsAb) positive rate based on birth year. The HBV co-infection prevalence rate was the highest (8.8%) in patients born between 1960 and 1964 and the lowest (0%) among those born between 1995 and 1999. A decreasing linear trend of HBV co-infection rate was observed according to the 5-year interval changes. HBsAb-positive rate was only 58.1% in our study. The national HBV vaccination programs have effectively lowered the HBV co-infection rate in HIV population. However, it is identified that the HIV population has low HBsAb positive rate. Further evidences supporting efficacy of booster immunization for HBsAb negative HIV patients are required and efforts should be made to increase HBsAb positive rates among HIV patients to prevent horizontal transmission.