Exclusive Characteristics of the p.E555K Dominant-Negative Variant in Autosomal Dominant E47 Deficiency.

PURPOSE: Transcription factor 3 (TCF3) encodes 2 transcription factors generated by alternative splicing, E12 and E47, which contribute to early lymphocyte differentiation. In humans, autosomal dominant (AD) E47 transcription factor deficiency is an inborn error of immunity characterized by B-cell deficiency and agammaglobulinemia. Only the recurrent de novo p.E555K pathogenic variant has been associated with this disease and acts via a dominant-negative (DN) mechanism. In this study, we describe the first Asian patient with agammaglobulinemia caused by the TCF3 p.E555K variant and provide insights into the structure and function of this variant. METHODS: TCF3 variant was identified by inborn errors of immunity-related gene panel sequencing. The variant E555K was characterized by alanine scanning of the E47 basic region and comprehensive mutational analysis focused on position 555. RESULTS: The patient was a 25-year-old male with B-cell deficiency, agammaglobulinemia, and mild facial dysmorphic features. We confirmed the diagnosis of AD E47 transcription factor deficiency by identifying a heterozygous missense variant, c.1663 G>A; p.E555K, in TCF3. Alanine scanning of the E47 basic region revealed the structural importance of position 555. Comprehensive mutational analysis focused on position 555 showed that only the glutamate-to-lysine substitution had a strong DN effect. 3D modeling demonstrated that this variant not only abolished hydrogen bonds involved in protein‒DNA interactions, but also inverted the charge on the surface of the E47 protein. CONCLUSIONS: Our study reveals the causative mutation hotspot in the TCF3 DN variant and highlights the weak negative selection associated with the TCF3 gene.

Efficacy and safety of abatacept for systemic juvenile idiopathic arthritis: a systematic review.

OBJECTIVES: This systematic review assessed the efficacy and safety of abatacept in patients with systemic juvenile idiopathic arthritis (JIA). METHODS: Studies published between 2000 and 2021 were searched using PubMed, Embase, Cochrane, Ichushi-Web and clinical trial registries. The risk of bias was assessed according to the manual for development clinical practice guidelines by Minds, a project to promote evidence-based medicine in Japan. RESULTS: Seven observational studies were included. American College of Rheumatology pediatric 30/50/70 responses at 3, 6 and 12 months were 64.8%/50.3%/27.9%, 85.7%/71.4%/42.9% and 80.0%/50.0%/40.0%, respectively. Outcomes on systemic symptoms, joint symptoms and activities of daily living were not obtained. No macrophage activation syndrome or infusion reaction occurred. Serious infection occurred in 2.6% of cases. CONCLUSIONS: Abatacept improved the disease activity index. In addition, abatacept was as safe as interleukin-6 (IL -6) and IL-1 inhibitors. However, both the efficacy and safety data in this systematic review should be reviewed with caution because their quality of evidence is low or very low. Further studies are needed to confirm the efficacy and safety of abatacept for systemic JIA, especially its efficacy on joint symptoms.

Efficacy and safety of tumor necrosis factor inhibitors for systemic juvenile idiopathic arthritis: a systematic review.

OBJECTIVES: This systematic review assessed the efficacy and safety of tumor necrosis factor (TNF) inhibitors in patients with systemic juvenile idiopathic arthritis (JIA). METHODS: Studies were searched using PubMed, Embase, Cochrane, Ichushi-Web, and clinical trial registries (from 2000 to 2021). The risk of bias was assessed using the Cochrane Risk of Bias version 2 for randomized controlled trials (RCTs) and the manual for development clinical practice guidelines by Minds, a project promoting evidence-based medicine in Japan, for observational studies. RESULTS: One RCT and 22 observational studies were included. In the RCT on infliximab, the American College of Rheumatology pediatric (ACR Pedi) 30/50/70 responses at 14 weeks were 63.8%/50.0%/22.4%, with relative risks of 1.30 (95% confidence interval [CI]: 0.94-1.79)/1.48 (95% CI: 0.95-2.29)/1.89 (95% CI: 0.81-4.40), respectively. In the observational studies, ACR Pedi 30/50/70 responses for etanercept at 12 months were 76.7%/64.7%/46.4%, respectively. Infliximab treatment caused anaphylaxis in 17% and an infusion reaction in 23% of patients. The incidence of macrophage activation syndrome, serious infection and malignancy caused by TNF inhibitors was 0%-4%. CONCLUSIONS: Thus, although TNF inhibitors were relatively safe, they were unlikely to be preferentially administered in patients with systemic JIA because of their inadequate efficacy. Further studies, particularly well-designed RCTs, are necessary to confirm the efficacy and safety of TNF inhibitors for systemic JIA.

Survey of diversity awareness and environment among members of the Pediatric Rheumatology Association of Japan.

BACKGROUND: Diversity management has gained traction in Japan. The Pediatric Rheumatology Association of Japan (PRAJ) has an Advisory Committee for Diversity Promotion with a broader focus on promoting diversity. The objectives of this study were to better understand the problems faced by PRAJ members regarding the work environment, childcare and nursing care, and work-life balance. METHODS: A web-based questionnaire was administered to members of the PRAJ and 79 responses were evaluated. RESULTS: Of the respondents, 73% were male and 27% were female. A total of 14% worked for more than 12 h on weekdays, and 22% worked for more than 60 h per week and 38% had fewer than 4 days off per month. Regarding childcare, 54% of the respondents were raising preschool children and 83% had taken parental leave for less than 1 year. A total of 17% of participants had family members in need of care. For both childcare and caregiving, the burden was greater for women. Only 18% of the respondents reported a well-balanced work-life balance, and the most common reasons for a lack of balance were not having enough time, heavy workload, and heavy housework load. CONCLUSIONS: The working hours of the respondents were long, and female members had a greater burden of childcare and caregiving, which was considered a barrier to the career development of women. In the future, there will be a need to promote a sense of equality in diverse human resources, develop support for family life, and shorten working hours.

Decreased levels of histidine-rich glycoprotein and increased levels of high-mobility group box 1 are risk factors for refractory Kawasaki disease.

OBJECTIVES: Histidine-rich glycoprotein (HRG) and high-mobility group box 1 (HMGB1) regulate the activation of neutrophils and vascular endothelium. The aim of this study was to quantify HRG and HMGB1 levels in patients with Kawasaki disease (KD) and evaluate their use in the clinical management of KD. METHODS: This study was prospectively performed. Patients were divided into two groups and analysed depending on whether KD symptoms improved by Day 10 of illness. HRG, HMGB1, and other laboratory variables were measured before the first treatment in all cases and, in most cases, afterwards for assessing trends. RESULTS: In this prospective study, we enrolled 60 patients with KD and 48 healthy controls. The HRG level in the KD group was significantly lower than that in the healthy control group; HMGB1 levels showed no obvious differences. In the KD group, HRG levels were negatively correlated with white blood cell and neutrophil counts. In the poor responders and responders groups, a tendency for a decrease in HRG and HMGB1 levels, respectively, was observed from pretreatment to post-treatment. CONCLUSIONS: HRG and HMGB1 are related to the pathogenesis of KD; low HRG and high HMGB1 levels cause resistance against KD treatment.

Correlation between national surveillance and search engine query data on respiratory syncytial virus infections in Japan.

BACKGROUND: The respiratory syncytial virus (RSV) disease burden is significant, especially in infants and children with an underlying disease. Prophylaxis with palivizumab is recommended for these high-risk groups. Early recognition of a RSV epidemic is important for timely administration of palivizumab. We herein aimed to assess the correlation between national surveillance and Google Trends data pertaining to RSV infections in Japan. METHODS: The present, retrospective survey was performed between January 1, 2018 and November 14, 2021 and evaluated the correlation between national surveillance data and Google Trends data. Joinpoint regression was used to identify the points at which changes in trends occurred. RESULTS: A strong correlation was observed every study year (2018 [r = 0.87, p < 0.01], 2019 [r = 0.83, p < 0.01], 2020 [r = 0.83, p < 0.01], and 2021 [r = 0.96, p < 0.01]). The change-points in the Google Trends data indicating the start of the RSV epidemic were observed earlier than by sentinel surveillance in 2018 and 2021 and simultaneously with sentinel surveillance in 2019. No epidemic surge was observed in either the Google Trends or the surveillance data from 2020. CONCLUSIONS: Our data suggested that Google Trends has the potential to enable the early identification of RSV epidemics. In countries without a national surveillance system, Google Trends may serve as an alternative early warning system.

Neonatal hemochromatosis with εγδß-thalassemia: a case report and analysis of serum iron regulators.

BACKGROUND: Neonatal hemochromatosis causes acute liver failure during the neonatal period, mostly due to gestational alloimmune liver disease (GALD). Thalassemia causes hemolytic anemia and ineffective erythropoiesis due to mutations in the globin gene. Although neonatal hemochromatosis and thalassemia have completely different causes, the coexistence of these diseases can synergistically exacerbate iron overload. We report that a newborn with εγδß-thalassemia developed neonatal hemochromatosis, which did not respond to iron chelators and rapidly worsened, requiring living-donor liver transplantation. CASE PRESENTATION: A 1-day-old Japanese boy with hemolytic anemia and targeted red blood cells was diagnosed with εγδß-thalassemia by genetic testing, and required frequent red blood cell transfusions. At 2 months after birth, exacerbation of jaundice, grayish-white stool, and high serum ferritin levels were observed, and liver biopsy showed iron deposition in hepatocytes and Kupffer cells. Magnetic resonance imaging scans showed findings suggestive of iron deposits in the liver, spleen, pancreas, and bone marrow. The total amount of red blood cell transfusions administered did not meet the criteria for post-transfusion iron overload. Administration of an iron-chelating agent was initiated, but iron overload rapidly progressed to liver failure without improvement in jaundice and liver damage. He underwent living-donor liver transplantation from his mother, after which iron overload disappeared, and no recurrence of iron overload was observed. Immunohistochemical staining for C5b-9 in the liver was positive. Serum hepcidin levels were low and serum growth differentiation factor-15 levels were high prior to living-donor liver transplantation. CONCLUSIONS: We reported that an infant with εγδß-thalassemia developed NH due to GALD, and that coexistence of ineffective erythropoiesis in addition to erythrocyte transfusions may have exacerbated iron overload. Low serum hepcidin levels, in this case, might have been caused by decreased hepcidin production arising from fetal liver damage due to neonatal hemochromatosis and increased hepcidin-inhibiting hematopoietic mediators due to the ineffective hematopoiesis observed in thalassemia.

Anti-high mobility group box 1 monoclonal antibody suppressed hyper-permeability and cytokine production in human pulmonary endothelial cells infected with influenza A virus.

OBJECTIVE: High mobility group box-1 (HMGB1) has been reported to be involved in influenza A virus-induced acute respiratory distress syndrome (ARDS). We studied the efficacy of an anti-HMGB1 mAb using an in vitro model of TNF-α stimulation or influenza A virus infection in human pulmonary microvascular endothelial cells (HMVECs). METHODS: Vascular permeability of HMVECs was quantified using the Boyden chamber assay under tumor necrosis factor-α (TNF-α) stimulation or influenza A virus infection in the presence of anti-HMGB1 mAb or control mAb. The intracellular localization of HMGB1 was assessed by immunostaining. Extracellular cytokine concentrations and intracellular viral mRNA expression were quantified by the enzyme-linked immunosorbent assay and quantitative reverse transcription PCR, respectively. RESULTS: Vascular permeability was increased by TNF-α stimulation or influenza A infection; HMVECs became elongated and the intercellular gaps were extended. Anti-HMGB1 mAb suppressed both the increase in permeability and the cell morphology changes. Translocation of HMGB1 to the cytoplasm was observed in the non-infected cells. Although anti-HMGB1 mAb did not suppress viral replication, it did suppress cytokine production in HMVECs. CONCLUSION: Anti-HMGB1 mAb might be an effective therapy for severe influenza ARDS.

Clinical characteristics and treatment of 50 cases of Blau syndrome in Japan confirmed by genetic analysis of the NOD2 mutation.

OBJECTIVES: To collect clinical information and NOD2 mutation data on patients with Blau syndrome and to evaluate their prognosis. METHODS: Fifty patients with NOD2 mutations were analysed. The activity of each NOD2 mutant was evaluated in HEK293 cells by reporter assay. Clinical information was collected from medical records through the attending physicians. RESULTS: The study population comprised 26 males and 24 females aged 0-61 years. Thirty-two cases were sporadic, and 18 were familial from 9 unrelated families. Fifteen different mutations in NOD2 were identified, including 2 novel mutations (p.W490S and D512V); all showed spontaneous nuclear factor kappa B activation, and the most common mutation was p.R334W. Twenty-six patients had fever at relatively early timepoints in the disease course. Forty-three of 47 patients had a skin rash. The onset of disease in 9 patients was recognised after BCG vaccination. Forty-five of 49 patients had joint lesions. Thirty-eight of 50 patients had ocular symptoms, 7 of which resulted in blindness. After the diagnosis of Blau syndrome, 26 patients were treated with biologics; all were antitumour necrosis factor agents. Only 3 patients were treated with biologics alone; the others received a biologic in combination with methotrexate and/or prednisolone. None of the patients who became blind received biologic treatment. CONCLUSIONS: In patients with Blau syndrome, severe joint contractures and blindness may occur if diagnosis and appropriate treatment are delayed. Early treatment with a biologic agent may improve the prognosis.

Idiopathic Chondrolysis of the Hip Treated by Immunosuppressive Therapy and Arthroscopic Intervention.

Idiopathic chondrolysis of the hip (ICH), a very rare disorder of unknown etiology, occurs mainly in female adolescents. Characterized by pain, limp, stiffness and radiological narrowing joint space from the rapid destruction of the articular cartilage, ICH sometimes results in ankyloses. We present the case of a 10-year-old girl diagnosed with ICH based on arthroscopic inspection and synovium biopsy. The femoral deformity appeared gradually, like a cam-type femoroacetabular impingement. She was treated with intensive rehabilitation and immunosuppressive drug. We later performed an arthroscopic bumpectomy for residual symptoms. She achieved a favorable outcome as a 15-year-old at the latest follow-up.

Combined effect of anti-high-mobility group box-1 monoclonal antibody and peramivir against influenza A virus-induced pneumonia in mice.

Human pandemic H1N1 2009 influenza virus causes significant morbidity and mortality with severe acute lung injury due to the excessive inflammatory reaction, even with neuraminidase inhibitor use. The anti-inflammatory effect of anti-high-mobility group box-1 (HMGB1) monoclonal antibody (mAb) against influenza pneumonia has been reported. In this study, we evaluated the combined effect of anti-HMGB1 mAb and peramivir against pneumonia induced by influenza A (H1N1) virus in mice. Nine-week-old male C57BL/6 mice were inoculated with H1N1 and treated with intramuscularly administered peramivir at 2 and 3 days post-infection (dpi). The anti-HMGB1 mAb or a control mAb was administered at 2, 3, and 4 dpi. Survival rates were assessed, and lung lavage and pathological analyses were conducted at 5 and 7 dpi. The combination of peramivir with the anti-HMGB1 mAb significantly improved survival rate whereas the anti-HMGB1 mAb alone did not affect virus proliferation in the lungs. This combination therapy also significantly ameliorated histopathological changes, neutrophil infiltration, and macrophage aggregation by inhibiting HMGB1, inflammatory cytokines, and oxidative stress. Fluorescence immunostaining showed that the anti-HMGB1 mAb inhibited HMGB1 translocation from type I alveolar epithelial cells. In summary, combining anti-HMGB1 with conventional anti-influenza therapy might be useful against severe influenza virus infection.

Anti-high mobility group box-1 monoclonal antibody treatment of brain edema induced by influenza infection and lipopolysaccharide.

Encephalopathy is a major cause of influenza-associated child death and severe neurological sequelae in Japan, highlighting the urgent need for new therapeutic strategies. In this study, we evaluated the effects of anti-high mobility group box-1 monoclonal antibody (α-HMGB1) treatment on brain edema induced by influenza A virus (IAV) and lipopolysaccharide in 4-week-old BALB/c female mice. The results showed that administration of 7.5 mg/kg α-HMGB1 1 h after IAV (A/Puerto Rico/8/34) inoculation significantly alleviated brain edema at 48 h after IAV inoculation, as confirmed by the suppression of Evans Blue dye leakage and matrix metallopeptidase-9 mRNA expression in the brain. Moreover, we also observed suppression of oxidative stress and different cytokines in IAV-inoculated mice. The expression of plasminogen activator inhibitor-1 was also attenuated following treatment with α-HMGB1. Notably, α-HMGB1 treatment had no effect on virus propagation in the lung. In summary, anti-HMGB1 treatment may improve the prognosis in cases with influenza-associated encephalopathy by attenuating brain edema and reducing the inflammatory responses induced by HMGB1.

Epidemiology of Pediatric Acute Encephalitis/Encephalopathy in Japan.

We studied the etiology of pediatric acute encephalitis/encephalopathy (pAEE) using epidemiological data obtained from a nationwide survey in Japan. Two-step questionnaires were sent to the pediatric departments of hospitals throughout the country in 2007, querying the number of the cases during 2005-2006 as the first step, and asking for the details of clinical information as the second step. In all, 636 children with pAEE (age ≤ 15 years) were enrolled. For the known etiology of pAEE (63.5% of the total cases), 26 microbes and 2 clinical entities were listed, but the etiology of 36.5% remained unknown. Influenza virus (26.7%), exanthem subitum (12.3%), and rotavirus (4.1%) were the most common, and the incidence of pAEE peaked at the age of 1 year. This trend was common among all etiologies. Among the neurological symptoms observed at the onset of pAEE, seizures were observed more often in patients aged ≤ 3 years, although abnormal speech and behavior were also common in older children. Undesirable outcomes (death and neurological sequelae) occurred at high rates in patients with any known etiology other than mycoplasma. In conclusion, these findings provide comprehensive insight into pAEE in Japan.

Early prediction for over two years efficacy of the first biologic agent for polyarticular juvenile idiopathic arthritis: A multi-institutional study in Japan.

OBJECTIVE: To estimate target of treatment for long-term efficacy of the first biologic agent used to treat polyarticular juvenile idiopathic arthritis (pJIA). METHODS: A retrospective cohort of patients with pJIA treated at six medical institutions in Japan between 1 March 2005 and 31 October 2014 was identified. The patients were divided by 2-year treatment periods with the first biologic agent into continuous treatment group and switching group. Three markers were examined: matrix metalloproteinase-3 (MMP-3), erythrocyte sedimentation rate (ESR), and disease activity score (DAS) 28-ESR. RESULTS: Thirty-two pJIA patients (8 boys, 24 girls) from 43 recruited patients were included in this study. The treatment periods with the first biologic agent in continuous treatment group (24 patients, 75%) was 40 months (median, range 24-119) and switching group (8 patients; 25%) was 9.5 months (median, 6-18). Markers [odds ratio (95% confidence interval)] at 3 months were MMP-3 [1.02 (0.99-1.05), p = .219], ESR [1.00 (0.78-1.30), p = .998], and DAS28-ESR [13.9 (2.08-409.82), p = .035]. The cut-off point for DAS28-ESR at 3 months to distinguish the two groups was 2.49 (sensitivity, 87.5%; specificity, 87.5%). CONCLUSION: DAS28-ESR of 2.49 at 3 months after initiating the first biologic agent can be a target of sustained treatment in pJIA patients.