The First Case of a Korean Patient with a Mutation-Confirmed Tumor Necrosis Factor Receptor-Associated Periodic Syndrome.

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS, OMIM: #142680) is a rare autoinflammatory disease (AID) with recurrent febrile episodes. To our knowledge, we report herein the first case of a patient with TRAPS in South Korea whose symptoms included fever, arthralgia, abdominal pain, rash, myalgia, cough, and lymphadenopathy. A pathogenic de novo mutation, c.175T>C (p.Cys59Arg), in the tumor necrosis factor receptor superfamily member 1A (TNFRSF1A) gene, was confirmed by gene sequencing. The patient has been with tocilizumab (an interleukin-6 inhibitor); tocilizumab administration every other week has completely alleviated the patient's symptoms. Our report further expands the clinical spectrum of patients with TRAPS and reaffirms the use of tocilizumab as a viable alternative treatment option for those patients who are unsatisfactorily responsive to other commonly used biologics, such as canakinumab, anakinra, infliximab, and etanercept. Furthermore, our report may aid in increasing awareness about the existence of mutation-confirmed TRAPS in South Korea in addition to emphasizing the importance of actively pursuing genetic testing to correctly diagnose rare AID.

Changes in tuberculosis risk after transplantation in the setting of decreased community tuberculosis incidence: a national population-based study, 2008-2020.

BACKGROUND: Transplant recipients are immunocompromised and vulnerable to developing tuberculosis. However, active tuberculosis incidence is rapidly declining in South Korea, but the trend of tuberculosis infection among transplant recipients has not been elucidated. This study aimed to evaluate the risk of active tuberculosis after transplantation, including risk factors for tuberculosis and standardized incidence ratios, compared with that in the general population. METHODS: This retrospective study was conducted based on the South Korean health insurance review and assessment database among those who underwent transplantation (62,484 recipients) between 2008 and 2020. Tuberculosis incidence was compared in recipients treated during higher- (2010-2012) and lower-disease burden (2016-2018) periods. Standardized incidence ratios were analyzed using the Korean Tuberculosis Surveillance System. The primary outcome was the number of new tuberculosis cases after transplantation. RESULTS: Of 57,103 recipients analyzed, the overall cumulative incidence rate 1 year after transplantation was 0.8% (95% confidence interval [CI]: 0.7-0.8), significantly higher in the higher-burden period than in the lower-burden period (1.7% vs. 1.0% 3 years after transplantation, P < 0.001). Individuals who underwent allogeneic hematopoietic stem cell transplantation had the highest tuberculosis incidence, followed by those who underwent solid organ transplantation and autologous hematopoietic stem cell transplantation (P < 0.001). The overall standardized incidence ratio was 3.9 (95% CI 3.7-4.2) and was the highest in children aged 0-19 years, at 9.0 (95% CI 5.7-13.5). Male sex, older age, tuberculosis history, liver transplantation, and allogeneic hematopoietic stem cell transplantation were risk factors for tuberculosis. CONCLUSIONS: Transplant recipients are vulnerable to developing tuberculosis, possibly influenced by their immunocompromised status, solid organ transplant type, age, and community prevalence of tuberculosis. Tuberculosis prevalence by country, transplant type, and age should be considered to establish an appropriate tuberculosis prevention strategy for high-risk groups.

Incidence and Features of Lymphoid Proliferation and Lymphomas after Solid Organ or Hematopoietic Stem Cell Transplantation in a National Database Cohort.

PURPOSE: Post-transplantation lymphoproliferative disorders (PTLDs) after hematopoietic stem transplantation (HCT) or solid organ transplantation (SOT) result in poorer outcomes, including death. There are limited large cohort data on the incidence and natural course of PTLD in Asians. MATERIALS AND METHODS: We investigated PTLD using Korean national health insurance claims data of 47,518 patients who underwent HCT or SOT in 2008-2020. Patient demographics, time and type of PTLD diagnosis, type of PTLD treatment, and death data were collected. We used Fine and Gray subdistribution hazard models to calculate the cumulative incidence and risk factors for PTLD. RESULTS: During median follow-up of 5.32 years, PTLD occurred in 294 of 36,945 SOT patients (0.79%) and 235 of 10,573 HCT patients (2.22%). Cumulative incidence of PTLD were 0.49% at 1 year, 1.02% at 5 years, and 1.50% at 10 years post-transplantation. Age < 20 years (subdistribution hazard ratio [SHR] of 1.67 in age 10-19, SHR 1.51 in age 0-9), HCT (SHR 3.02), heart transplantation (SHR 2.27), and liver transplantation (SHR 1.47) were significant risk factors for PTLD. The presence of PTLD was associated with an increased risk of death (hazard ratio of 2.84). Overall, 5-year survival of PTLD patients was 68.9% (95% confidence interval, 64.9 to 73.2). CONCLUSION: We observed a steady increase in PTLD over 10 years after HCT or SOT in this large cohort study. Pediatric age group, HCT, liver transplantation, and heart transplantation were suggested to be risk factors for PTLD, and PTLD was associated with a higher risk of death.

Risk of Dental Discoloration and Enamel Dysplasia in Children Exposed to Tetracycline and Its Derivatives.

PURPOSE: To examine the risk of dental abnormalities after exposure to tetracycline and its derivatives (TCs) in Korean children. MATERIALS AND METHODS: Children aged 0-17 years with a claim for prescriptions of TCs between 2002 and 2015 were identified from the Sample Research Database 2.0 of the National Health Insurance Service. Children not exposed to TCs were selected as the control group by matching sex and age (1:4). Cumulative incidence rate and relative risk of dental abnormalities after TCs exposure were investigated. RESULTS: The 10-year cumulative incidence rate in the 0-12 years group was 3.1% [95% confidence interval (CI), 2.3-3.9]. The 10-year cumulative incidence rates were 7.0%, 1.9%, and 1.6% in the 0-7, 8-12, and 13-17 years age groups (95% CI: 4.7-9.3, 1.2-2.6, and 1.3-1.9, respectively). There was no significant difference in the risk of dental abnormalities according to TC exposure among the age groups of 0-7 years [adjusted hazard ratio (aHR)=1.0], 8-12 years (aHR=1.1), and 13-17 years (aHR=1.2). CONCLUSION: Short-term exposure to TCs does not appear to increase the risk of dental abnormalities in children aged 0-7 and 0-12 years. Restrictions on the use of TCs in children aged 8-12 years, in some countries, may warrant consideration.

Pediatric Sarcoidosis Misdiagnosed as Hepatosplenic Abscesses: A Case Report and Review.

Sarcoidosis is a systemic granulomatous disorder of unknown etiology characterized by granuloma formation. Due to the limited incidence of sarcoidosis in pediatric patients, little is known about the clinical course of this disease. A combination of clinical, radiologic, and pathologic examination is necessary to exclude other differential diagnoses (i.e., infection and granulomatous inflammatory disorder) and establish a diagnosis of sarcoidosis. Here, we report a case of histologically confirmed sarcoidosis initially misdiagnosed as hepatosplenic abscesses in an 11-year-old male. Treatment with corticosteroids improved his symptoms and resolved his skin and hepatosplenic lesions. A three-year follow-up was uneventful. This study emphasizes the importance of considering sarcoidosis in children presenting with findings of multi-organ involvement in the presence of histologic evidence of granuloma.

Impact of maternal engrafted cytomegalovirus-specific CD8+ T cells in a patient with severe combined immunodeficiency.

OBJECTIVES: In patients with severe combined immunodeficiency (SCID), the immune system often fails to eradicate maternal cells that enter the foetus via the placenta, resulting in transplacental maternal engraftment (TME) syndrome. However, the clinical significance of TME has not been comprehensively elucidated. METHODS: Here, we describe a patient with SCID with a novel frameshift IL2RG mutation associated with maternal engrafted CD8+ T cells that had been expanded by viral infection. To evaluate the origin of the expanded T cells, we HLA-typed the myeloid and T cells of the patient and analysed the immunological characteristics of the expanded CD8+ T cells using T-cell receptor (TCR) repertoire and flow cytometry analysis. RESULTS: In our patient, the maternal engrafted CD8+ T cells expanded and exerted in vitro antiviral function against human cytomegalovirus (CMV) infection before and after haematopoietic cell transplantation (HCT). After haploidentical HCT from the maternal donor, maternal engrafted CMV-specific CD8+ T cells were maintained, successfully proliferated and activated against CMV. We found no evidence of acute graft-versus-host disease or infectious complications other than recurrent episodes of CMV viraemia, which were well controlled by ganciclovir and, possibly by, the maternal engrafted CMV-specific CD8+ T cells. CONCLUSION: Our findings elucidate a possible functional role of TME in controlling CMV infection in patient with SCID and suggest an optimal strategy for donor selection in patients with SCID with TME.

Presepsin as a diagnostic marker of sepsis in children and adolescents: a systemic review and meta-analysis.

BACKGROUND: Early diagnosis of sepsis in pediatric patients is vital but remains a major challenge. Previous studies showed that presepsin is potentially a reliable diagnostic biomarker for sepsis in adult and neonates. However, there is no pooled analysis of its efficacy as a diagnostic biomarker for sepsis in children. The aims of the present meta-analysis were to assess the overall diagnostic accuracy of presepsin in pediatric sepsis and compare it to those for C-reactive protein (CRP) and procalcitonin (PCT). METHODS: A systematic literature search was performed in Medline/Pubmed, Embase, the Cochrane Library, and ISI Web of Science to identify relevant studies reporting the diagnostic accuracy of presepsin in patients with pediatric sepsis. Sensitivities and specificities were pooled by bivariate meta-analysis. Heterogeneity was evaluated by χ2 test. RESULTS: We identified 129 studies in total. Most were disqualified on the basis of their titles/abstracts and duplication. Four studies were included in the final analysis. They comprised 308 patients aged between 1 mo and 18 y. The pooled diagnostic sensitivity and specificity of presepsin were 0.94 (95% confidence interval [CI]: 0.74-0.99) and 0.71 (95% CI: 0.35-0.92), respectively. The pooled diagnostic odds ratio, positive likelihood ratio (LR), and negative LR of presepsin were 32.87 (95% CI: 2.12-510.09), 3.24 (95% CI, 1.14-12.38), and 0.08 (95% CI, 0.01-0.74), respectively. Heterogeneity was found in both sensitivity (χ2 = 11.17; P = 0.011) and specificity (χ2 = 65.78; P < 0.001). No threshold effect was identified among the studies (r = - 0.938). The pooled sensitivity of presepsin (0.94) was higher than that of CRP (0.51) and PCT (0.76), whereas the overall specificity of presepsin (0.71) was lower than that of CRP (0.81) and PCT (0.76). The AUC of presepsin (0.925) was higher than that of CRP (0.715) and PCT (0.820). CONCLUSION: Currently available evidence indicates that presepsin has higher sensitivity and diagnostic accuracy, but lower specificity, than PCT or CRP in detecting sepsis in children. However, these results must be carefully interpreted as the number of studies included was small and the studies were statistically heterogeneous.

Clinical characteristics and cytokine profiles of children with acute lower respiratory tract infections caused by human rhinovirus.

The clinical profile of human rhinovirus (HRV) with regard to lower respiratory infections remains unclear. We analyzed the clinical features and cytokine responses of HRV isolates in children with respiratory infections. Quantitative analysis and genotyping of the HRV-positive samples from 601 nasopharyngeal aspirates (NPAs) were performed using VP4/VP2 sequencing. To compare T-helper1 (Th1) type (IFN-γ, TNF-α) and Th2 type (IL-4, IL-10) cytokine responses between HRV-A, B and C, the levels of the four cytokines were measured. The HRV-positive children had shorter fever duration (P = 0.018), and higher frequencies of chest retraction (P = 0.002) and wheezing (P = 0.022) than did the HRV-negative group. HRV-A was identified in 55 cases (58.5%), HRV-B in 8 (8.5%), and HRV-C in 31 (33.0%). There were no significant differences in the clinical data or NPA cytokines levels between patients with HRV-A and HRV-C infections. HRV is an important pathogen of the lower respiratory tract in young children. HRV-A and HRV-C are the dominant species that cause respiratory difficulty in young children.

Characterization of Oropharyngeal Carriage Isolates of Neisseria meningitidis in Healthy Korean Adolescents in 2015.

The meningococcus carriage rate is age-dependent, with a high prevalence in adolescents and young adults. This cross-sectional study aimed to estimate the oropharyngeal carriage rate of meningococcus among healthy Korean adolescents and its relationship with several population characteristics. The survey was conducted from April to May 2015 among 1,460 first-year high-school students in 9 high schools located in Gyeonggi province, Korea. Each student answered a short questionnaire assessing risk factors for carriage, and posterior pharyngeal wall swab samples were obtained. These samples were cultured on meningococcus-selective media, with colonies resembling meningococci identified using the Vitek® MS system (bioMérieux, Marcy l'Etoile, France). All isolates were characterized by molecular serogrouping and multilocus sequence typing (MLST). Meningococci were identified from 3.4% (49/1,460) swabs. Current smokers had significantly higher carriage rates than non-smokers (8.2% vs. 2.9%, P = 0.002), and boys had significantly higher carriage rates than girls (4.4% vs. 1.6%, P = 0.004). Serogroup B was the most common serogroup, followed by serogroup C, then 29E and Y. Twenty-seven different sequence types (STs) were identified; the most common were ST-3091, ST-11278, and ST-44. These belonged to clonal complexes (CCs) 269, 32, and 41/44, respectively, known as the hypervirulent clones. Evaluating meningococcal carriage is important to understand the epidemiology of meningococcal disease; however, little data exist in Korea. Similar to western countries, meningococcal serogroup B has emerged in Korea, and hypervirulent clones were identified. It is necessary to monitor the genetic and serologic characteristics of circulating meningococci and to assess the potential strain coverage of meningococcal vaccines.

Nosocomial exposure to active pulmonary tuberculosis in a neonatal intensive care unit.

BACKGROUND: Nosocomial transmission of tuberculosis (TB) in a neonatal intensive care unit (NICU) is a recognized risk. We investigated TB transmission to neonates and health care workers (HCWs) exposed to a nurse with active TB in a NICU. METHODS: A NICU nurse in a tertiary referral hospital in Seoul, Korea, developed pulmonary TB. The investigation included 108 infants and 75 HCWs. Tuberculin skin test (TST) and chest radiograph were performed at baseline. Isoniazid prophylaxis was started in neonates. After 3 months of prophylaxis, infants underwent repeat TST and chest radiograph. HCWs underwent a second TST after 3 months. RESULTS: Baseline chest radiographs were negative in infants and HCWs. Four (3.7%) of 108 infants screened had a positive TST, including 2 conversions, and received isoniazid for 6-9 months. Among the 59 HCWs screened, 27 (45.8%) had an initial positive TST result, and 6 (10.2%) had a positive TST result at 3 months. Four of the 6 HCWs with TST conversions received isoniazid treatment for 9 months. In the 2-year period after exposure, none of the exposed infants or HCWs developed active TB. CONCLUSION: In this investigation, 4 (3.7%) of 108 infants exposed to a nurse with active TB developed latent TB infection. They were given isoniazid therapy without any adverse events and did not progress to TB disease in the 2 years after exposure.

Human bocavirus isolated from children with acute respiratory tract infections in Korea, 2010-2011.

Human bocavirus (HBoV) was first recognized in respiratory samples in 2005. The clinical importance of HBoV infection remains unclear. This report describes the clinical features and molecular phylogeny of HBoV isolates in children with acute respiratory infections. Nasopharyngeal aspirates were obtained from 1,528 children with acute respiratory infections between 2010 and 2011. Respiratory samples were screened for HBoV by multiplex PCR. A phylogenetic analysis of the HBoV VP1/VP2 gene was also undertaken. HBoV was detected in 187 (12.2%) of the 1,528 patients with a peak incidence of infection observed in patients aged 12-24 months. Coinfection with other respiratory viruses was observed in 107 (57.2%) of the HBoV-positive children. The peak of HBoV activity occurred during the month of June in both 2010 and 2011. A higher previous history of wheezing (P = 0.016), a higher frequency of chest retraction (P < 0.001) and wheezing (P = 0.022), a higher respiratory symptom score (P = 0.002), and a longer duration of hospital stay (P = 0.021) were observed in HBoV-positive children compared with the HBoV-negative group. Phylogenetic analysis showed all 187 HBoV-positive isolates were identified as HBoV 1, indicating minimal sequence variations among the isolates. A single lineage of HBoV 1 was found to have circulated in children with acute respiratory infections between 2010 and 2011 and was associated with several clinical characteristics including age, seasonality, and clinical severity with retraction, wheezing, and longer hospitalization. The clinical relevance of the minimal sequence variations of HBoV remains to be determined.