Temporal maturation of neutralizing antibodies in COVID-19 convalescent individuals improves potency and breadth to circulating SARS-CoV-2 variants.

Antibody titers against SARS-CoV-2 slowly wane over time. Here, we examined how time affects antibody potency. To assess the impact of antibody maturation on durable neutralizing activity against original SARS-CoV-2 and emerging variants of concern (VOCs), we analyzed receptor binding domain (RBD)-specific IgG antibodies in convalescent plasma taken 1-10 months after SARS-CoV-2 infection. Longitudinal evaluation of total RBD IgG and neutralizing antibody revealed declining total antibody titers but improved neutralization potency per antibody to original SARS-CoV-2, indicative of antibody response maturation. Neutralization assays with authentic viruses revealed that early antibodies capable of neutralizing original SARS-CoV-2 had limited reactivity toward B.1.351 (501Y.V2) and P.1 (501Y.V3) variants. Antibodies from late convalescents exhibited increased neutralization potency to VOCs, suggesting persistence of cross-neutralizing antibodies in plasma. Thus, maturation of the antibody response to SARS-CoV-2 potentiates cross-neutralizing ability to circulating variants, suggesting that declining antibody titers may not be indicative of declining protection.

Characterization of human tibrovirus envelope glycoproteins.

Tibroviruses are novel rhabdoviruses detected in humans, cattle, and arthropods. Four tibroviruses are known to infect humans: Bas-Congo virus (BASV), Ekpoma virus 1 (EKV-1), Ekpoma virus 2, and Mundri virus. However, since none of them has been isolated, their biological properties are largely unknown. We aimed to characterize the human tibrovirus glycoprotein (G), which likely plays a pivotal role in viral tropism and pathogenicity. Human tibrovirus Gs were found to share some primary structures and display 14 conserved cysteine residues, although their overall amino acid homology was low (29%-48%). Multiple potential glycosylation sites were found on the G molecules, and endoglycosidase H- and peptide-N-glycosidase F-sensitive glycosylation was confirmed. AlphaFold-predicted three-dimensional (3D) structures of human tibrovirus Gs were overall similar. Membrane fusion mediated by these tibrovirus Gs was induced by acidic pH. The low pH-induced conformational change that triggers fusion was reversible. Virus-like particles (VLPs) were produced by transient expression of Gs in cultured cells and used to produce mouse antisera. Using vesicular stomatitis Indiana virus pseudotyped with Gs, we found that the antisera to the respective tibrovirus VLPs showed limited cross-neutralizing activity. It was also found that human C-type lectins and T-cell immunoglobulin mucin 1 acted as attachment factors for G-mediated entry into cells. Interestingly, BASV-G showed the highest ability to utilize these molecules. The viruses infected a wide range of cell lines with preferential tropism for human-derived cells whereas the preference of EKV-1 was unique compared with the other human tibroviruses. These findings provide fundamental information to understand the biological properties of the human tibroviruses. IMPORTANCE: Human tibroviruses are poorly characterized emerging rhabdoviruses associated with either asymptomatic infection or severe disease with a case fatality rate as high as 60% in humans. However, the extent and burden of human infection as well as factors behind differences in infection outcomes are largely unknown. In this study, we characterized human tibrovirus glycoproteins, which play a key role in virus-host interactions, mainly focusing on their structural and antigenic differences and cellular tropism. Our results provide critical information for understanding the biological properties of these novel viruses and for developing appropriate preparedness interventions such as diagnostic tools, vaccines, and effective therapies.

Potential Anti-Mpox Virus Activity of Atovaquone, Mefloquine, and Molnupiravir, and Their Potential Use as Treatments.

BACKGROUND: Mpox virus (MPXV) is a zoonotic orthopoxvirus and caused an outbreak in 2022. Although tecovirimat and brincidofovir are approved as anti-smallpox drugs, their effects in mpox patients have not been well documented. In this study, by a drug repurposing approach, we identified potential drug candidates for treating mpox and predicted their clinical impacts by mathematical modeling. METHODS: We screened 132 approved drugs using an MPXV infection cell system. We quantified antiviral activities of potential drug candidates by measuring intracellular viral DNA and analyzed the modes of action by time-of-addition assay and electron microscopic analysis. We further predicted the efficacy of drugs under clinical concentrations by mathematical simulation and examined combination treatment. RESULTS: Atovaquone, mefloquine, and molnupiravir exhibited anti-MPXV activity, with 50% inhibitory concentrations of 0.51-5.2 µM, which was more potent than cidofovir. Whereas mefloquine was suggested to inhibit viral entry, atovaquone and molnupiravir targeted postentry processes. Atovaquone was suggested to exert its activity through inhibiting dihydroorotate dehydrogenase. Combining atovaquone with tecovirimat enhanced the anti-MPXV effect of tecovirimat. Quantitative mathematical simulations predicted that atovaquone can promote viral clearance in patients by 7 days at clinically relevant drug concentrations. CONCLUSIONS: These data suggest that atovaquone would be a potential candidate for treating mpox.

Reverse Genetics System for Heartland Bandavirus: NSs Protein Contributes to Heartland Bandavirus Virulence.

Heartland bandavirus (HRTV), which is an emerging tick-borne virus first identified in Missouri in 2009, causes fever, fatigue, decreased appetite, headache, nausea, diarrhea, and muscle or joint pain in humans. HRTV is genetically close to Dabie bandavirus, which is the causative agent of severe fever with thrombocytopenia syndrome (SFTS) in humans and is known as SFTS virus (SFTSV). The generation of infectious HRTV entirely from cloned cDNAs has not yet been reported. The absence of a reverse genetics system for HRTV has delayed efforts to understand its pathogenesis and to generate vaccines and antiviral drugs. Here, we developed a reverse genetics system for HRTV, which employs an RNA polymerase I-mediated expression system. A recombinant nonstructural protein (NSs)-knockout HRTV (rHRTV-NSsKO) was generated. We found that NSs interrupted signaling associated with innate immunity in HRTV-infected cells. The rHRTV-NSsKO was highly attenuated, indicated by the apparent absence of symptoms in a mouse model of HRTV infection. Moreover, mice immunized with rHRTV-NSsKO survived a lethal dose of HRTV. These findings suggest that NSs is a virulence factor of HRTV and that rHRTV-NSsKO could be a vaccine candidate for HRTV. IMPORTANCE Heartland bandavirus (HRTV) is a tick-borne virus identified in the United States in 2009. HRTV causes fever, fatigue, decreased appetite, headache, nausea, diarrhea, and muscle or joint pain in humans. FDA-approved vaccines and antiviral drugs are unavailable. The lack of a reverse genetics system hampers efforts to develop such antiviral therapeutics. Here, we developed a reverse genetics system for HRTV that led to the generation of a recombinant nonstructural protein (NSs)-knockout HRTV (rHRTV-NSsKO). We found that NSs interrupted signaling associated with innate immunity in HRTV-infected cells. Furthermore, rHRTV-NSsKO was highly attenuated and immunogenic in a mouse model. These findings suggest that NSs is a virulence factor of HRTV and that rHRTV-NSsKO could be a vaccine candidate for HRTV.

Subacute SARS-CoV-2 replication can be controlled in the absence of CD8+ T cells in cynomolgus macaques.

SARS-CoV-2 infection presents clinical manifestations ranging from asymptomatic to fatal respiratory failure. Despite the induction of functional SARS-CoV-2-specific CD8+ T-cell responses in convalescent individuals, the role of virus-specific CD8+ T-cell responses in the control of SARS-CoV-2 replication remains unknown. In the present study, we show that subacute SARS-CoV-2 replication can be controlled in the absence of CD8+ T cells in cynomolgus macaques. Eight macaques were intranasally inoculated with 105 or 106 TCID50 of SARS-CoV-2, and three of the eight macaques were treated with a monoclonal anti-CD8 antibody on days 5 and 7 post-infection. In these three macaques, CD8+ T cells were undetectable on day 7 and thereafter, while virus-specific CD8+ T-cell responses were induced in the remaining five untreated animals. Viral RNA was detected in nasopharyngeal swabs for 10-17 days post-infection in all macaques, and the kinetics of viral RNA levels in pharyngeal swabs and plasma neutralizing antibody titers were comparable between the anti-CD8 antibody treated and untreated animals. SARS-CoV-2 RNA was detected in the pharyngeal mucosa and/or retropharyngeal lymph node obtained at necropsy on day 21 in two of the untreated group but undetectable in all macaques treated with anti-CD8 antibody. CD8+ T-cell responses may contribute to viral control in SARS-CoV-2 infection, but our results indicate possible containment of subacute viral replication in the absence of CD8+ T cells, implying that CD8+ T-cell dysfunction may not solely lead to viral control failure.

Neurodevelopmental Outcomes of Neonatal Rotavirus-Associated Leukoencephalopathy.

Rotavirus infection has been reported to be associated with neonatal seizures with a diffuse and symmetrical diffusion restriction of periventricular white matter, namely, neonatal rotavirus-associated leukoencephalopathy. The extensive white matter injury seen in this cohort raises concerns about the long-term neurodevelopmental outcomes. In the present study, we prospectively assessed the neurodevelopmental outcomes of 13 patients with neonatal rotavirus-associated leukoencephalopathy at a median age of 26 months (range, 23-68 months). Neurodevelopmental outcomes were evaluated using a neurological examination, developmental evaluations, and magnetic resonance imaging (MRI) of the brain. Overall, 6 of the 13 patients (46%) had abnormal neurodevelopmental outcomes: 1 patient had mental retardation, visual-motor integration (VMI) dysfunction, cerebral palsy, and epilepsy; 1 patient had cerebral palsy and VMI dysfunction; remaining 4 patients had VMI dysfunction. Follow-up MRI in 12 of 13 patients showed an increased signal intensity on periventricular white matter in all patients. These findings suggested that neonatal rotavirus-associated leukoencephalopathy could not be assumed to be benign in long-term neurodevelopment, particularly in VMI function. Early intervention and long-term follow-up are necessary for these patients. Our findings raise caution for rotavirus infection in this vulnerable population for infants.

Erratum: Correction of Affiliations in the Article "Clinical Characteristics and Treatment Outcomes in Children, Adolescents, and Young-adults with Hodgkin's Lymphoma: a KPHOG Lymphoma Working-party, Multicenter, Retrospective Study".

This corrects the article on p. e393 in vol. 35, PMID: 33258329.

Serum cytokine profiles in infants with infantile hemangiomas on oral propranolol treatment: VEGF and bFGF, potential biomarkers predicting clinical outcomes.

BACKGROUND: Oral propranolol has become first-line treatment for infantile hemangiomas (IHs). This study focused on identifying cytokines related to the biology of IH and early regression indicators of IH after propranolol treatment. METHODS: For inclusion, the patients had to be aged less than 1 year and have an IH with a largest diameter ≥2 cm. Patients were scheduled to receive 1 year of propranolol treatment. Serum cytokines involved in angiogenesis, vasculogenesis, and/or chronic inflammation were analyzed at 0, 1, and/or 12 months after treatment using Multiplex Luminex assays. RESULTS: Among the 49 evaluable patients, 33 completed the 1-year treatment: 16 showed excellent response and 12 had good response to propranolol. Significant decreases in serum MMP-2, bFGF, VEGF-α, and MCP-1 levels were observed after 1 year of treatment compared to pretreatment values. The maximal diameters of the lesions significantly correlated with pretreatment serum VEGF-α, bFGF, and MMP-9. Patients with higher bFGF and VEGF levels showed better response to propranolol at 1 year. CONCLUSION: MMP-2, VEGF-α, bFGF, and MCP-1 may involve in the biology of IH and their downregulation may be associated with involution processes of IH. Pretreatment bFGF and VEGF could be novel biomarkers for predicting response to propranolol. IMPACT: We found that decreases in the concentrations of MMP-2, bFGF, VEGF, and MCP-1 were associated with regression of the hemangioma, which indicates that one of the mechanisms of propranolol in the treatment of proliferative hemangiomas may involve downregulation of those cytokines. Patients with higher bFGF and VEGF levels showed better response to propranolol at 1 year. Importantly, serum bFGF higher than 37.07 pg/mL may predict an excellent response to propranolol. Therefore, along with the patient's age and the size and visual characteristics of the lesion, bFGF levels could help determine the viability of propranolol use in the treatment of IHs. Our study represented extensive serum profiling in IH, reporting the indicators and molecules clearly related to IH regression with propranolol treatment. The authors believe that monitoring serum cytokines, including MMP-2, bFGF, VEGF, and MCP-1, in IH patients could be important, in addition to clinical follow-up, for determining when to start and end propranolol treatment.

Increased proportion of apoptotic cells in cat kidney tissues infected with feline morbillivirus.

In order to study potential pathogenic mechanisms of feline morbillivirus (FeMV) in infected kidney cells, we performed a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and an immunofluorescence assay (IFA) with an anti-FeMV P protein antibody on a total of 38 cat kidney tissues, 12 of which were positive for FeMV. Among these samples, we detected significantly larger numbers of apoptotic cells in FeMV-positive tissues than in FeMV-negative tissues, and in these tissues, a substantial percentage of TUNEL-positive (TUNEL+) cells contained the FeMV P protein (mean, 37.4; range, 17.4-82.9), suggesting that induction of apoptosis may be an important mechanism for pathological changes associated with FeMV infection in cat kidney tissues.

Report: central diabetes insipidus and schwannoma in a male with X-linked congenital adrenal hypoplasia.

BACKGROUND: DAX1 mutations are related to the X-linked form of adrenal hypoplasia congenita (AHC) in infancy and to hypogonadotropic hypogonadism (HH) in puberty. We report a male patient affected by X-linked AHC who presented with central diabetes insipidus and schwannoma in adulthood, which has not been described in association with AHC. CASE PRESENTATION: A 36-day-old male infant who presented with severe dehydration was admitted to the intensive care unit. His laboratory findings showed hyponatremia, hyperkalemia, hypoglycemia, and metabolic acidosis. After hormonal evaluation, he was diagnosed with adrenal insufficiency, and he recovered after treatment with hydrocortisone and a mineralocorticoid. He continued to take hydrocortisone and the mineralocorticoid after discharge. At the age of 17, he did not show any signs of puberty. On the basis of a GnRH test, a diagnosis of HH was made. At the age of 24, he was hospitalized with thirst, polydipsia and polyuria. He underwent a water deprivation test for polydipsia and was diagnosed with central diabetes insipidus. By quantitative polymerase chain reaction analysis, we identified a hemizygous frameshift mutation in DAX1 (c.543delA). CONCLUSIONS: We suggest that DAX1 mutations affect a wider variety of endocrine organs than previously known, including the posterior pituitary gland.

Treatment Outcome in Pediatric Acute Lymphoblastic Leukemia With Hyperleukocytosis in the Yeungnam Region of Korea: A Multicenter Retrospective Study.

Acute lymphoblastic leukemia (ALL) with hyperleukocytosis at diagnosis is associated with early morbidity and mortality due to complications of leukostasis. Of 535 pediatric ALL patients (January 2004 to December 2016 from the Yeungnam region of Korea), 72 (13.5%) patients with an initial white blood cell (WBC) count of ≥100×10/L were included in this study, of whom 38 patients had extreme hyperleukocytosis (WBC>200×10/L) at diagnosis. Fourteen patients (19.4%) had ≥1 early respiratory and neurologic complications during induction therapy. Relapse occurred in 8 patients (24.2%) with extreme hyperleukocytosis and in 1 patient (3.0%) with an initial WBC count of 100 to 200×10/L (P=0.012). Estimated 10-year event-free survival rate (EFS) and overall survival rate were 78.3%±8.4% and 82.6%±7.7%, respectively. The 10-year EFS was significantly lower in patients with an initial WBC count of >200×10/L than in those with an initial WBC count of 100 to 200×10/L (65.7%±13.4% vs. 91.2%±7.9%; P=0.011). The 10-year EFS and overall survival rate did not differ significantly between patients with extreme hyperleukocytosis who received hematopoietic stem cell transplantation and those who received chemotherapy. In conclusion, pediatric ALL with hyperleukocytosis can lead to early complications and mortality. Patients with initial extreme hyperleukocytosis showed significantly poorer prognosis than those with WBC counts of 100 to 200×10/L.

Changes in Seroprevalence of Helicobacter pylori Infection over 20 Years in Jinju, Korea, from Newborns to the Elderly.

BACKGROUND: The objective of this study was to examine changes in the prevalence of cytotoxic-associated gene A (CagA) positive Helicobacter pylori infection in Jinju, Korea, over the last 20 years. METHODS: Three cross-sectional analyses were conducted concurrently. A total of 1,305 serum samples were collected from 1994-1995, 2004-2005, and 2014-2015, respectively. The presence of immunoglobulin (Ig) G, IgA, and IgM antibodies against H. pylori CagA protein was examined by western blotting. RESULTS: Overall, seropositivity for anti-CagA IgG antibody was significantly decreased from 63.2% to 42.5% over the last 20 years (P < 0.001). Anti-CagA IgG seropositivities in children and young adults aged 10-29 years decreased from 1994 (60.0%-85.0%) to 2015 (12.5%-28.9%). The age when plateau of increasing IgG seropositivity was reached in each study period shifted from the 15-19 year-old group in 1994-1995 (85.0%) to the 40-49 year-old group in 2014-2015 (82.5%). Overall seropositive rates of anti-CagA IgA and IgM antibodies did not change significantly either over the last 20 years. CONCLUSION: H. pylori infection rate in children and young adults declined over 20 years in Jinju, probably due to improved sanitation, housing, or economy.

Epidemiological Study of Hereditary Hemolytic Anemia in the Korean Pediatric Population during 1997-2016: a Nationwide Retrospective Cohort Study.

BACKGROUND: Hereditary hemolytic anemia (HHA) is a rare disease characterized by premature red blood cell (RBC) destruction due to intrinsic RBC defects. The RBC Disorder Working Party of the Korean Society of Hematology established and updated the standard operating procedure for making an accurate diagnosis of HHA since 2007. The aim of this study was to investigate a nationwide epidemiology of Korean HHA. METHODS: We collected the data of a newly diagnosed pediatric HHA cohort (2007-2016) and compared this cohort's characteristics with those of a previously surveyed pediatric HHA cohort (1997-2006) in Korea. Each participant's information was retrospectively collected by a questionnaire survey. RESULTS: A total of 369 children with HHA from 38 hospitals distributed in 16 of 17 districts of Korea were investigated. RBC membranopathies, hemoglobinopathies, RBC enzymopathies, and unknown etiologies accounted for 263 (71.3%), 59 (16.0%), 23 (6.2%), and 24 (6.5%) of the cases, respectively. Compared to the cohort from the previous decade, the proportions of hemoglobinopathies and RBC enzymopathies significantly increased (P < 0.001 and P = 0.008, respectively). Twenty-three of the 59 hemoglobinopathy patients had immigrant mothers, mostly from South-East Asia. CONCLUSION: In Korea, thalassemia traits have increased over the past 10 years, reflecting both increased awareness of this disease and increased international marriages. The enhanced recognition of RBC enzymopathies is due to advances in diagnostic technique; however, 6.5% of HHA patients still do not have a clear diagnosis. It is necessary to improve accessibility of diagnosing HHA.

Clinical Characteristics and Treatment Outcomes in Children, Adolescents, and Young-adults with Hodgkin's Lymphoma: a KPHOG Lymphoma Working-party, Multicenter, Retrospective Study.

BACKGROUND: Hodgkin's lymphoma (HL) constitutes 10%-20% of all malignant lymphomas and has a high cure rate (5-year survival, around 90%). Recently, interest has increased concerning preventing secondary complications (secondary cancer, endocrine disorders) in long-term survivors. We aimed to study the epidemiologic features and therapeutic outcomes of HL in children, adolescents, and young adults in Korea. METHODS: We performed a multicenter, retrospective study of 224 patients aged < 25 years diagnosed with HL at 22 participating institutes in Korea from January 2007 to August 2016. RESULTS: A higher percentage of males was diagnosed at a younger age. Nodular sclerosis histopathological HL subtype was most common, followed by mixed cellularity subtype. Eighty-one (36.2%), 101 (45.1%), and 42 (18.8%) patients were classified into low, intermediate, and high-risk groups, respectively. Doxorubicin, bleomycin, vinblastine, dacarbazine was the most common protocol (n = 102, 45.5%). Event-free survival rate was 86.0% ± 2.4%, while five-year overall survival (OS) rate was 96.1% ± 1.4%: 98.7% ± 1.3%, 97.7% ± 1.6%, and 86.5% ± 5.6% in the low, intermediate, and high-risk groups, respectively (P = 0.021). Five-year OS was worse in patients with B-symptoms, stage IV disease, high-risk, splenic involvement, extra-nodal lymphoma, and elevated lactate dehydrogenase level. In multivariate analysis, B-symptoms and extra-nodal involvement were prognostic factors for poor OS. Late complications of endocrine disorders and secondary malignancy were observed in 17 and 6 patients, respectively. CONCLUSION: This is the first study on the epidemiology and treatment outcomes of HL in children, adolescents, and young adults in Korea. Future prospective studies are indicated to develop therapies that minimize treatment toxicity while maximizing cure rates in children, adolescents, and young adults with HL.

NFAT1 Regulates Systemic Autoimmunity through the Modulation of a Dendritic Cell Property.

The transcription factor NFAT1 plays a pivotal role in the homeostasis of T lymphocytes. However, its functional importance in non-CD4+ T cells, especially in systemic immune disorders, is largely unknown. In this study, we report that NFAT1 regulates dendritic cell (DC) tolerance and suppresses systemic autoimmunity using the experimental autoimmune myasthenia gravis (EAMG) as a model. Myasthenia gravis and EAMG are T cell-dependent, Ab-mediated autoimmune disorders in which the acetylcholine receptor is the major autoantigen. NFAT1-knockout mice showed higher susceptibility to EAMG development with enhanced Th1/Th17 cell responses. NFAT1 deficiency led to a phenotypic alteration of DCs that show hyperactivation of NF-κB-mediated signaling pathways and enhanced binding of NF-κB (p50) to the promoters of IL-6 and IL-12. As a result, NFAT1-knockout DCs produced much higher levels of proinflammatory cytokines such as IL-1ß, IL-6, IL-12, and TNF-α, which preferentially induce Th1/Th17 cell differentiation. Our data suggest that NFAT1 may limit the hyperactivation of the NF-κB-mediated proinflammatory response in DCs and suppress autoimmunity by serving as a key regulator of DC tolerance.

Monocyte Chemoattractant Protein (MCP)-1 in Rotavirus-Associated White Matter Injury in Newborns.

Recent reports have suggested an association between rotavirus infection and a distinctive pattern of white matter injury (WMI) in neonates with seizures; however, the connection between the two is not fully understood. To evaluate the underlying mechanism, we profiled and compared eight cytokines (IL [interleukin]-1ß, IL-6, IL-8, IL-10, IFN-γ [interferon-γ ], MCP-1 [monocyte chemoattractant protein-1], MIP-1ß [macrophage inflammatory protein-1ß], and TNF-α [tumor necrosis factor-α]) in the cerebrospinal fluid (CSF) of 33 neonates with seizures who had no other well-known causes of seizures and 13 control patients (rotavirus-induced gastroenteritis but without seizures). Among the 33 neonates with seizures, 9 showed WMI and all were infected with rotavirus (R + W + ). Among the 24 patients without WMI, 11 were infected with rotavirus (R + W - ) and 13 were not (R - W - ).Only MCP-1 and MIP-1ß were different between the groups. MCP-1 was increased in R+ W+ compared with R + W- (p < 0.01), R - W- (p < 0.01), and control (p = 0.03) patients. MIP-1ß was decreased in R + W+ compared with R - W- (p < 0.01) and control (p < 0.01), but not R + W- (p = 0.23) patients. MCP-1 and MIP-1ß are C-C chemokines that recruit immune cells to the site of inflammation. Our pilot study suggests MCP-1-mediated monocyte recruitment may be linked with this complication caused by rotavirus.

Factors associated with permanent hypothyroidism in infants with congenital hypothyroidism.

BACKGROUND: Congenital hypothyroidism (CH) is one of the most common endocrine diseases in childhood. A significant proportion of CH cases are transient, but the risk factors for permanent CH (PCH) are not yet well established. The current guidelines suggest using levothyroxine until the age of 3 years, but some studies suggest the possibility of earlier discontinuation. However, few, if any, studies have followed up on the results of early discontinuation. This study aimed to identify predictive factors of transient CH among infants with CH. We also investigated the results in patients who underwent a trial of early discontinuation. METHODS: We gathered data regarding infants diagnosed with CH between July 2005 and July 2015 by retrospective chart review. Those with aplastic, hypoplastic or ectopic glands on thyroid ultrasonography or scan were excluded. Among them, early discontinuation subgroup was defined as those who discontinued levothyroxine before 30 months of age. RESULTS: From the 80 infants (40 males, 40 females) enrolled in this study, 51 were preterm. Nine (11.3%) were diagnosed with PCH. Compared with transient cases, those with PCH were on higher levothyroxine dose at discontinuation (4.3 vs 2.9 µg/kg, P < 0.001). There was no difference in the proportion of permanent cases between preterm and full-term groups. In preterm group,infants with PCH required higher levothyroxine dose at discontinuation than those with transient CH (3.8 vs 2.5 µg/kg, P = 0.018). Levothyroxine discontinuation at a dose of 2.86 µg/kg could suggest PCH (sensitivity, 88.9%; specificity, 71.0%). Among the 9 patients who underwent a trial of early discontinuation, 8 successfully discontinued levothyroxine. CONCLUSION: The majority of CH patients discontinued levothyroxine successfully, including those who underwent a trial of early discontinuation. Higher levothyroxine dose at the time of discontinuation was found to be a predictive factor for PCH.

Venous Thromboembolism in Children and Young Adults in Korea: Analysis of the Korean Health Insurance Review and Assessment Service Database.

BACKGROUND: Venous thromboembolism (VTE) is very rare in childhood. Nevertheless, its incidence has increased recently. This study aimed to identify risk factors for developing thrombosis in childhood cancers and other childhood diseases through the Korean Health Insurance Review and Assessment Service database. METHODS: Data were extracted from the Korean Health Insurance Review and Assessment Service database. Children and young adults from 1 month to 29 years of age were eligible, and 21,747 cases of VTE between January 2008 and December 2016 were identified. RESULTS: The VTE incidence was high in children younger than 1 year of age. After 1 year of age, its incidence decreased rapidly and gradually increased. The VTE incidence for children between 0 and 1 year of age was 10.23-fold higher than that for those between 1 and 5 years of age. Annual VTE incidence increased by year. The age-standardized annual incidence rates were 9.98 per 100,000 population in 2008 and 22.53 per 100,000 population in 2016. The age-standardized annual incidence rate increased 2.25-fold during the 8 years. The lower extremity was the most common site of venous thrombosis. CONCLUSION: The incidence of VTE in a population younger than 30 years was 13.11 per 100,000 persons in Korea. We found a bimodal age distribution of the VTE incidence with peaks at infancy and again after 16 years. The incidence of portal vein thrombosis was high in infants, and infection and malignancy were the most common comorbidities in patients with VTE.

Evaluation of Francisella tularensis ΔpdpC as a candidate live attenuated vaccine against respiratory challenge by a virulent SCHU P9 strain of Francisella tularensis in a C57BL/6J mouse model.

Francisella tularensis, which causes tularemia, is an intracellular gram-negative bacterium. F. tularensis has received significant attention in recent decades because of its history as a biological weapon. Thus, development of novel vaccines against tularemia has been an important goal. The attenuated F. tularensis strain ΔpdpC, in which the pathogenicity determinant protein C gene (pdpC) has been disrupted by TargeTron mutagenesis, was investigated as a potential vaccine candidate for tularemia in the present study. C57BL/6J mice immunized s.c. with 1 × 106 CFUs of ΔpdpC were challenged intranasally with 100× the median lethal dose (LD50 ) of a virulent SCHU P9 strain 21 days post immunization. Protection against this challenge was achieved in 38% of immunized C57BL/6J mice administered 100 LD50 of this strain. Conversely, all unimmunized mice succumbed to death 6 days post challenge. Survival rates were significantly higher in vaccinated than in unimmunized mice. In addition, ΔpdpC was passaged serially in mice to confirm its stable attenuation. Low bacterial loads persisted in mouse spleens during the first to tenth passages. No statistically significant changes in the number of CFUs were observed during in vivo passage of ΔpdpC. The inserted intron sequences for disrupting pdpC were completely maintained even after the tenth passage in mice. Considering the stable attenuation and intron sequences, it is suggested that ΔpdpC is a promising tularemia vaccine candidate.

A Pilot Study Evaluating Cerebral Vasculitis in Kawasaki's Disease.

Cerebral vasculitis is thought to be a possible underlying mechanism of severe neurological complications of Kawasaki's disease (KD), such as cerebral infarct or aneurysm rupture. To evaluate the intracranial inflammatory response in patients with acute-stage KD, we measured the levels of cytokines (interleukin [IL]-6 and tumor necrosis factor [TNF]-α) and pentraxin-3 (PTX3) in the cerebrospinal fluid of patients with KD (n = 7) and compared the levels to those of the age- and sex-matched febrile control patients (bacterial meningitis [n = 5], enteroviral meningitis [n = 10], nonspecific viral illness without central nervous system involvement [n = 10]). PTX3 and TNF-α were rarely detected and only in trace concentration in KD, and the levels of IL-6 were not different from those of nonspecific viral illnesses. These mediators are not established biomarkers for cerebral vasculitis but might reflect vascular inflammation in various diseases including KD. Therefore, intracranial inflammation including vasculitis seems to be insignificant in our patients with KD. However, our results might be attributed to the fact that these patients lacked any clinical signs of cerebral or coronary vessel involvement. None of them underwent brain imaging. To clarify this issue, further studies involving patients with neurologic symptoms and proven involvement of cerebral vessels are needed.