Pharmacokinetics, safety, and efficacy of 20% subcutaneous immunoglobulin (Ig20Gly) administered weekly or every 2 weeks in Japanese patients with primary immunodeficiency diseases: a phase 3, open-label study.

This phase 3, open-label, multidose study (NCT04346108) evaluated the pharmacokinetics, safety, tolerability, and efficacy of immunoglobulin subcutaneous (human) 20% solution (Ig20Gly) administered weekly and every 2 weeks in Japanese patients with primary immunodeficiency diseases (PIDs). The study was conducted at eight study sites in Japan and enrolled patients aged ≥2 years with PIDs treated using a stable intravenous immunoglobulin dose for ≥3 months prior to the study. Patients received intravenous immunoglobulin every 3 or 4 weeks at pre-study dose (200-600 mg/kg) for 13 weeks (Epoch 1), subcutaneous Ig20Gly (50-200 mg/kg) once weekly for 24 weeks (Epoch 2), and Ig20Gly (100-400 mg/kg) every 2 weeks for 12 weeks (Epoch 3). The primary endpoint was serum total immunoglobulin G (IgG) trough levels during Epochs 2 and 3. Overall, 17 patients were enrolled (median [range] age: 24 [5-69] years; 59% male) and participated in Epochs 1 and 2; seven patients entered Epoch 3. Serum total IgG trough levels were maintained at >8 g/l: geometric means (95% confidence intervals) at the end of Epochs 2 and 3 were 8.56 (8.03-9.12) g/l and 8.39 (7.89-8.91) g/l, respectively. Related treatment-emergent adverse events were all mild in severity; the most common treatment-emergent adverse events (excluding infections) in Epochs 2 and 3 were injection site swelling (24%) and injection site erythema (18%). This is the first trial to demonstrate the efficacy and favourable safety profile of 20% subcutaneous immunoglobulin administered every 2 weeks in adult and paediatric Japanese patients with PIDs.

Evidence of off-label inhalation therapy on pediatric asthma practice in Japan.

BACKGROUND: In Japan, many asthma inhalers do not have formal approval for use in the pediatric population because of the lack of domestic data. In real-world settings, however, numerous off-label medications are prescribed. Currently, the nature of off-label prescriptions of asthma inhalers on pediatric patients in Japan remains unclear. METHODS: Using public open-source national medical claims data, we investigated the real-world descriptive epidemiology of off-label prescriptions for asthma inhalers for pediatric patients. We obtained the number of off-label prescriptions of formulations for patients aged 0-14 years from anonymously summarized prescription data for a 7-year period starting from April 2014. The actual prescription numbers and their chronology over time were then analyzed. RESULTS: In 2019, 143,439 asthma inhalers were used off label in children and adolescents. Overall, 96.1% were inhaled corticosteroids (ICSs) or long-acting beta stimulants (LABAs), and 3.9% were high-dose ICS. Of ICSs and LABAs, 18.8% were off-label prescriptions. The total number of off-label ICS/LABA prescriptions and their percentage relative to the overall formulations gradually decreased but a notable disparity was observed among inhaler types. CONCLUSIONS: There was a surprisingly large number of off-label prescriptions of asthma inhalers in the pediatric population in Japan. The proper use of ICSs/LABAs and expansion of insurance coverage should be advocated to reduce off-label use.

Clinical practice guideline for activated phosphatidyl inositol 3-kinase-delta syndrome in Japan.

Activated phosphatidyl inositol 3-kinase-delta syndrome (APDS) due to gain-of-function variant in the class IA PI3K catalytic subunit p110δ (responsible gene: PIK3CD) was described in 2013. The disease is characterized by recurrent airway infections and bronchiectasis. It is associated with hyper-IgM syndrome due to the defect of immunoglobulin class switch recombination and decreased CD27-positive memory B cells. Patients also suffered from immune dysregulations, such as lymphadenopathy, autoimmune cytopenia or enteropathy. T-cell dysfunction due to increased senescence is associated with a decrease in CD4-positive T lymphocytes and CD45RA-positive naive T lymphocytes, along with increased susceptibility to Epstein-Barr virus/cytomegalovirus infections. In 2014, loss-of-function (LOF) mutation of p85α (responsible gene: PIK3R1), a regulatory subunit of p110δ, was identified as a causative gene, followed in 2016 by the identification of the LOF mutation of PTEN, which dephosphorylates PIP3, leading to the differentiation of APDS1 (PIK3CD-GOF), APDS2 (PIK3R1-LOF) and APDS-L (PTEN-LOF). Since the pathophysiology of patients with APDS varies with a wide range of severity, it is crucial that patients receive appropriate treatment and management. Our research group created a disease outline and a diagnostic flow chart and summarized clinical information such as the severity classification of APDS and treatment options.

Impact of respiratory bacterial infections on mortality in Japanese patients with COVID-19: a retrospective cohort study.

BACKGROUND: Although cases of respiratory bacterial infections associated with coronavirus disease 2019 (COVID-19) have often been reported, their impact on the clinical course remains unclear. Herein, we evaluated and analyzed the complication rates of bacterial infections, causative organisms, patient backgrounds, and clinical outcome in Japanese patients with COVID-19. METHODS: We performed a retrospective cohort study that included inpatients with COVID-19 from multiple centers participating in the Japan COVID-19 Taskforce (April 2020 to May 2021) and obtained demographic, epidemiological, and microbiological results and the clinical course and analyzed the cases of COVID-19 complicated by respiratory bacterial infections. RESULTS: Of the 1,863 patients with COVID-19 included in the analysis, 140 (7.5%) had respiratory bacterial infections. Community-acquired co-infection at COVID-19 diagnosis was uncommon (55/1,863, 3.0%) and was mainly caused by Staphylococcus aureus, Klebsiella pneumoniae and Streptococcus pneumoniae. Hospital-acquired bacterial secondary infections, mostly caused by Staphylococcus aureus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia, were diagnosed in 86 patients (4.6%). Severity-associated comorbidities were frequently observed in hospital-acquired secondary infection cases, including hypertension, diabetes, and chronic kidney disease. The study results suggest that the neutrophil-lymphocyte ratio (> 5.28) may be useful in diagnosing complications of respiratory bacterial infections. COVID-19 patients with community-acquired or hospital-acquired secondary infections had significantly increased mortality. CONCLUSIONS: Respiratory bacterial co-infections and secondary infections are uncommon in patients with COVID-19 but may worsen outcomes. Assessment of bacterial complications is important in hospitalized patients with COVID-19, and the study findings are meaningful for the appropriate use of antimicrobial agents and management strategies.

Low billing rates for pediatric sedation fee on magnetic resonance imaging.

BACKGROUND: The 2018 revision of social insurance in Japan allows additional fees to be calculated for pediatric magnetic resonance imaging (MRI) that must be performed under sedation. The number and trend of actual claims since this revision was established is unknown. The aim of this study to investigate the use of the additional fees and any regional differences in the use. METHODS: To analyze the claims of additional fees for pediatric sedated MRI after the fiscal year (FY) 2018, the actual claims in inpatient and outpatient practice was analyzed using publicly-available data from the Ministry of Health, Labour and Welfare (MHLW). We analyzed the calculation rate for all MRI scans. Annual changes in the actual number and calculation rate were analyzed. The ratio of the number of additional fees to the overall number of pediatric radiological procedures was used to examine the geographic disparity. RESULTS: The number of calculations from FY 2018 to FY 2020 was available. In FY 2020, only 1347 additional fees were calculated, corresponding to 0.35% of the total number of MRI scans. The number of fees showed a decreasing trend. Most cases were in the 0-4 year age group; however, there were a few cases in the 10-14 year age group without such a decrease. The relative number of calculations by prefecture showed an up to 14-fold disparity. CONCLUSIONS: The requirements for sedation for pediatric MRI are strict, but they are not fully utilized. Measures such as relaxing the requirements for the fee are needed to make MRI-related sedation safer.

Successful TCRαß/CD19-Depleted Hematopoietic Cell Transplantation for a Patient With Artemis Deficiency.

Artemis deficiency is characterized by DNA double-strand breaks repairing dysfunction and increased sensitivity to ionizing radiation and alkylating reagents. We describe the first successful case of T-cell receptor [TCR]αß/CD19-depleted hematopoietic cell transplantation [HCT] for Artemis deficiency in Japan. A 6-month-old Korean boy was diagnosed with Artemis-deficient severe combined immunodeficiency. He had no human leukocyte antigen (HLA)-matched sibling or unrelated donor. Therefore, TCRαß/CD19-depleted HCT from his haploidentical mother was performed. Despite mixed chimerism in whole blood, T cells achieved complete donor chimerism 6 months after HCT. TCRαß/CD19-depleted HCT could be an effective treatment for patients with radiation-sensitive severe combined immunodeficiency.

Diagnostic significance of secondary bacteremia in patients with COVID-19.

OBJECTIVES: We investigated the occurrence of non-respiratory bacterial and fungal secondary infections, causative organisms, impact on clinical outcomes, and association between the secondary pathogens and mortality in hospitalized patients with coronavirus disease 2019 (COVID-19). METHODS: This was a retrospective cohort study that included data from inpatients with COVID-19 from multiple centers participating in the Japan COVID-19 Taskforce (April 2020 to May 2021). We obtained demographic, epidemiological, and microbiological data throughout the course of hospitalization and analyzed the cases of COVID-19 complicated by non-respiratory bacterial infections. RESULTS: Of the 1914 patients included, non-respiratory bacterial infections with COVID-19 were diagnosed in 81 patients (4.2%). Of these, 59 (3.1%) were secondary infections. Bacteremia was the most frequent bacterial infection, occurring in 33 cases (55.9%), followed by urinary tract infections in 16 cases (27.1%). Staphylococcus epidermidis was the most common causative organism of bacteremia. Patients with COVID-19 with non-respiratory secondary bacterial infections had significantly higher mortality, and a multivariate logistic regression analysis demonstrated that those with bacteremia (aOdds Ratio = 15.3 [5.97-39.1]) were at higher risk of death. Multivariate logistic regression analysis showed that age, male sex, use of steroids to treat COVID-19, and intensive care unit admission increased the risk for nosocomial bacteremia. CONCLUSIONS: Secondary bacteremia is an important complication that may lead to poor prognosis in cases with COVID-19. An appropriate medical management strategy must be established, especially for patients with concomitant predisposing factors.

Neutralizing Type I Interferon Autoantibodies in Japanese Patients with Severe COVID-19.

PURPOSE: Autoantibodies (aAbs) to type I interferons (IFNs) have been found in less than 1% of individuals under the age of 60 in the general population, with the prevalence increasing among those over 65. Neutralizing autoantibodies (naAbs) to type I IFNs have been found in at least 15% of patients with life-threatening COVID-19 pneumonia in several cohorts of primarily European descent. We aimed to evaluate the prevalence of aAbs and naAbs to IFN-α2 or IFN-ω in Japanese patients who suffered from COVID-19 as well as in the general population. METHODS: Patients who suffered from COVID-19 (n = 622, aged 0-104) and an uninfected healthy control population (n = 3,456, aged 20-91) were enrolled in this study. The severities of the COVID-19 patients were as follows: critical (n = 170), severe (n = 235), moderate (n = 112), and mild (n = 105). ELISA and ISRE reporter assays were used to detect aAbs and naAbs to IFN-α2 and IFN-ω using E. coli-produced IFNs. RESULTS: In an uninfected general Japanese population aged 20-91, aAbs to IFNs were detected in 0.087% of individuals. By contrast, naAbs to type I IFNs (IFN-α2 and/or IFN-ω, 100 pg/mL) were detected in 10.6% of patients with critical infections, 2.6% of patients with severe infections, and 1% of patients with mild infections. The presence of naAbs to IFNs was significantly associated with critical disease (P = 0.0012), age over 50 (P = 0.0002), and male sex (P = 0.137). A significant but not strong correlation between aAbs and naAbs to IFN-α2 existed (r = - 0.307, p value < 0.0001) reinforced the importance of measuring naAbs in COVID-19 patients, including those of Japanese ancestry. CONCLUSION: In this study, we revealed that patients with pre-existing naAbs have a much higher risk of life-threatening COVID-19 pneumonia in Japanese population.

Neutralizing Type I Interferon Autoantibodies in Japanese Patients With Severe COVID-19.

Purpose Autoantibodies (aAbs) to type I interferons (IFNs) have been found in <1% of individuals under the age of 60 in the general population, with the prevalence increasing among those over 65. Neutralizing autoantibodies (naAbs) to type I IFNs have been found in at least 15% of patients with life-threatening COVID-19 pneumonia in several cohorts of primarily European descent. We aimed to define the prevalence of aAbs to IFN-α2 in 3,456 Japanese controls aged 20-91 and of aAbs and naAbs to IFN-α2 and IFN-ω in 627 Japanese COVID-19 patients aged 0-104, among whom were 170 critical, 235 severe, 112 moderate, 105 mild, and 5 asymptomatic infections. Methods ELISA and ISRE reporter assays were used to detect aAbs and naAbs using E. coli-produced IFNs. Results In an uninfected general Japanese population aged 20-91, we found aAbs in 0.087% of individuals. naAbs to type I IFNs (IFN-α2 and/or IFN-ω, 100 pg/mL) were detected in 10.6% of patients with critical infections, 2.6% of patients with severe infections, and ≤1% of patients with asymptomatic to mild infections. They were higher in COVID-19 patients over 50 (5.8%) than in younger patients (0%) and higher in men (5.5%) than in women (1.1%). A significant but not strong correlation between aAbs and naAbs to IFN-α2 existed (r=-0.307, p-value<0.0001), stressing the importance of measuring naAbs. Conclusion In the largest study focusing on a single ethnic and geographic group, we show that Japanese individuals with pre-existing naAbs have a much higher risk of life-threatening COVID-19 pneumonia.

Vedolizumab therapy for pediatric steroid-refractory gastrointestinal acute graft-versus-host disease.

Vedolizumab, an immunosuppressive drug that acts locally on the gastrointestinal tract, is mainly used for the treatment of inflammatory bowel disease, and has been reported to be effective against gastrointestinal acute graft-versus-host disease (GI-aGVHD) in adults. However, there is insufficient evidence for pediatric GI-aGVHD. We used vedolizumab to treat three cases of GI-aGVHD in patients aged 1.5-4.4 years. It was significantly effective in two patients and did not cause serious side effects in any patient. Vedolizumab might be effective and safe for pediatric GI-aGVHD refractory to other treatments, but this must be confirmed in future studies.

Hematopoietic Cell Transplantation with Reduced Intensity Conditioning Using Fludarabine/Busulfan or Fludarabine/Melphalan for Primary Immunodeficiency Diseases.

PURPOSE: The purpose of our study was to compare the safety and efficacy of hematopoietic cell transplantation (HCT) using fludarabine (Flu)-based reduced intensity conditioning (RIC) with busulfan (BU) or melphalan (Mel) for primary immunodeficiency diseases (PID). METHODS: We retrospectively analyzed transplant outcome, including engraftment, chimerism, immune reconstitution, and complications in 15 patients with severe combined immunodeficiency (SCID) and 27 patients with non-SCID PID. The patients underwent Flu-based RIC-HCT with BU (FluBU: 7 SCID, 16 non-SCID) or Mel (FluMel: 8 SCID, 11 non-SCID). The targeted low-dose BU with therapeutic drug monitoring was set to 30 mg hour/L for SCID. RESULTS: The 2-year overall survival of all patients was 79.6% and that of patients with SCID in the FluBU and FluMel groups was 100% and 62.5%, respectively. In the FluBU group, all seven patients achieved engraftment, good immune reconstitution, and long-term survival. All five patients receiving umbilical cord blood transplantation achieved complete or high-level mixed chimerism and sufficient specific IgG production. In the FluMel group, six of eight patients achieved complete or high-level mixed chimerism. Viral reactivation or new viral infection occurred in one FluBU group patient and four FluMel group patients. In the non-SCID group, 10 of 11 patients (91%) who received FluMel achieved complete or high-level mixed chimerism but had variable outcomes. Patients with WAS (2/2 patients), NEMO deficiency (2/2 patients), and X-linked hyper IgM syndrome (2/3 patients) who received FluBU achieved complete or high-level mixed chimerism and long-term survival. CONCLUSIONS: RIC-HCT with FluBU is a safe and effective strategy for obtaining high-level donor chimerism, immune reconstitution including B cell function, and long-term survival in patients with SCID. In patients with non-SCID PID, the results varied according to the subtype of the disease. Further prospective studies are required to optimize the conditioning regimen for non-SCID PID.

The Primary Immunodeficiency Database in Japan.

The Primary Immunodeficiency Database in Japan (PIDJ) is a registry of primary immunodeficiency diseases (PIDs) that was established in 2007. The database is a joint research project with research groups associated with the Ministry of Health, Labor and Welfare; the RIKEN Research Center for Allergy and Immunology (RCAI); and the Kazusa DNA Research Institute (KDRI). The PIDJ contains patient details, including the age, sex, clinical and laboratory findings, types of infections, genetic analysis results, and treatments administered. In addition, web-based case consultation is also provided. The PIDJ serves as a database for patients with PIDs and as a patient consultation service connecting general physicians with PID specialists and specialized hospitals. Thus, the database contributes to investigations related to disease pathogenesis and the early diagnosis and treatment of patients with PIDs. In the 9 years since the launch of PIDJ, 4,481 patients have been enrolled, of whom 64% have been subjected to genetic analysis. In 2017, the Japanese Society for Immunodeficiency and Autoinflammatory Diseases (JSIAD) was established to advance the diagnosis, treatment, and research in the field of PIDs and autoinflammatory diseases (AIDs). JSIAD promotes the analysis of the pathogenesis of PIDs and AIDs, enabling improved patient care and networking via the expansion of the database and construction of a biobank obtained from the PIDJ. The PIDJ was upgraded to "PIDJ ver.2" in 2019 by JSIAD. Currently, PIDJ ver.2 is used as a platform for epidemiological studies, genetic analysis, and pathogenesis evaluation for PIDs and AIDs.

Successful ruxolitinib administration for a patient with steroid-refractory idiopathic pneumonia syndrome following hematopoietic stem cell transplantation: A case report and literature review.

Idiopathic pneumonia syndrome (IPS) is an acute lung complication observed after the early posthematopoietic stem cell transplantation (HSCT) period. Ruxolitinib was effective for a patient with myelodysplastic syndrome who developed severe IPS after second HSCT. No severe adverse effects were observed. Ruxolitinib may be an alternative choice for HSCT-related IPS.

Association between Immunoglobulin M and Steroid Resistance in Children with Nephrotic Syndrome: A Retrospective Multicenter Study in Japan.

Background: The prognosis of steroid-resistant nephrotic syndrome (SRNS) in children is poorer than steroid-sensitive cases. Diagnosis of SRNS is made after observing the response to the initial 4-week corticosteroid therapy, which might be accompanied by side effects. However, predictive indicators at initial diagnosis remain unknown. We aimed to investigate whether selectivity index (SI) and other indicators at initial diagnosis-for example, serum IgM and total serum protein-albumin ratio (TA ratio, total serum protein level over albumin level)-can predict SRNS. Methods: A total of 80 children were enrolled from seven hospitals in Japan between January 2008 and December 2019 (mean age, 4.7 years; 65% male). Of the children enrolled, 13 (16%, M/F=5:8) had been diagnosed as steroid resistant after initial treatment with steroids. The association between serum IgM (tertile categories: low, 24-133; middle, 134-169; and high, 169.1-510 mg/dl), SI (<0.2 or ≥0.2), and TA ratio (tertile categories: low, 1.8-2.6; middle, 2.62-3.75; and high, 3.8-15.3) at initial diagnosis and steroid resistance was evaluated with logistic regression, adjusting for age and sex. Results: Low levels of serum IgM were significantly associated with steroid resistance (adjusted odds ratio, 6.94; 95% CI, 1.12 to 43.11). TA ratio and SI were not significantly associated with steroid resistance. Conclusions: Low levels of serum IgM at initial diagnosis might predict steroid resistance among Japanese children with idiopathic nephrotic syndrome.

Acute lymphoblastic leukemia in patients with Down syndrome with a previous history of acute myeloid leukemia.

Patients with Down syndrome (DS) are predisposed to acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) in early and later childhood, respectively, but rarely experience both. We herein discuss four patients with DS with ALL and a history of AML who were treated with various chemotherapies, one of whom later received a bone marrow transplantation. Three patients survived and remain in remission. One patient died of fulminant hepatitis during therapy. No common cytogenetic abnormalities in AML and ALL besides constitutional +21 were identified, indicating that the two leukemia types were independent events. However, the underlying pathomechanism of these conditions awaits clarification.

EWSR1/ELF5 induces acute myeloid leukemia by inhibiting p53/p21 pathway.

The Ewing sarcoma breakpoint region 1 (EWSR1) gene is known to fuse with various partner genes to promote the development of the Ewing sarcoma family of tumors and other sarcomas. In contrast, the association of EWSR1 chimeric fusion genes with leukemia has rarely been reported. We identified a novel EWSR1-associated chimeric fusion gene in a patient with acute myeloid leukemia harboring 46, XY, t (11; 22) (p13; q12) karyotype abnormality. The patient was refractory to intensified chemotherapy including hematopoietic stem cell transplantation. Total RNA paired-end sequencing identified a novel chimeric fusion gene as EWSR1/ELF5, a member of the E26 transformation-specific transcription factor family. Transduction of EWSR1/ELF5 to NIH3T3 cells induced transformation by attenuating with the p53/p21-dependent pathway. The injection of EWSR1/ELF5-transduced NIH3T3 cells into NSG-SCID mice systematically induced the development of tumors in vivo. These results revealed the oncogenic potency of EWSR1/ELF5.

Molecular and virological evidence of viral activation from chromosomally integrated human herpesvirus 6A in a patient with X-linked severe combined immunodeficiency.

It has been unclear whether chromosomally integrated human herpesvirus 6 (ciHHV-6) can be activated with pathogenic effects on the human body. We present molecular and virological evidence of ciHHV-6A activation in a patient with X-linked severe combined immunodeficiency. These findings have significant implications for the management of patients with ciHHV-6.

Graft versus host disease-dependent renal dysfunction after hematopoietic stem cell transplantation.

Nephropathy is an important complication in hematopoietic stem cell transplantation (HSCT) wherein multifactorial causes, i.e., radiation, drug toxicity, graft versus host disease (GVHD), are thought to contribute renal dysfunction. Here, we report a 10-year-old boy with high-risk acute myelocytic leukemia and severe but partially reversible renal dysfunction. The patient initially received umbilical cord blood transplantation (UCBT) with CY 120 mg/kg and kidney unshielded 12 Gy of total body irradiation. After the leukemic relapse, he received allogenic bone marrow transplantation (BMT) 270 days after the first transplantation. Two months later, his renal function started to deteriorate and urinary protein increased gradually to 1 g/day. Four months after BMT, by the symptoms of severe GVHD, the dose of tacrolimus, utilized to avoid GVHD, was increased although his serum Cre level elevated to 2.97 mg/dL. Serum Cre level improved to 2.0 mg/dL paralleled with GVHD improvement. Renal histological findings showed severe interstitial edema, features of thrombotic microangiopathy (TMA), and C4d deposition along the glomerular capillaries and peritubular capillaries. We suggested that control of GVHD had benefitted to ameliorate renal function of the patient. Treatment for GVHD improved renal dysfunction and TMA of our patients. Moreover, renal biopsy was powerful to elucidate the exact origin of renal dysfunction after HSCT.

Early coagulation disorder after allogeneic stem cell transplantation is a strong prognostic factor for transplantation-related mortality, and intervention with recombinant human thrombomodulin improves the outcome: a single-center experience.

We retrospectively analyzed 60 cases of pediatric patients who received allogeneic stem cell transplantation (SCT) between 2000 and 2008, using the tentative scoring system for evaluation of early (<30 days) coagulation disorders. In the 41 patients who survived, D-dimer levels showed a transient increase 2 weeks after SCT and normalized thereafter, but these levels were persistently elevated in the 19 patients who died. Of 19 patients with a positive score, 11 died of transplantation-related complications [transplantation-related mortality (TRM) = 0.579] within 1 year, while none of the 41 with a negative score died during the same period. Since 2009, 12 of 30 patients had positive scores within 30 days after SCT. Intervention with recombinant human thrombomodulin (rhTM) was introduced for patients with a positive score, and 10 of these patients survived (TRM = 0.167) along with a dramatic improvement of D-dimer level. Although the effects of this treatment were observed in a limited number of patients, our observations suggest that early coagulation disorder after allogeneic SCT is a strong prognostic factor for TRM, and that intervention with rhTM improves TRM.