Myelodysplasia after clonal hematopoiesis with APOBEC3-mediated CYBB inactivation in retroviral gene therapy for X-CGD.

Stem cell gene therapy using the MFGS-gp91phox retroviral vector was performed on a 27-year-old patient with X-linked chronic granulomatous disease (X-CGD) in 2014. The patient's refractory infections were resolved, whereas the oxidase-positive neutrophils disappeared within 6 months. Thirty-two months after gene therapy, the patient developed myelodysplastic syndrome (MDS), and vector integration into the MECOM locus was identified in blast cells. The vector integration into MECOM was detectable in most myeloid cells at 12 months after gene therapy. However, the patient exhibited normal hematopoiesis until the onset of MDS, suggesting that MECOM transactivation contributed to clonal hematopoiesis, and the blast transformation likely arose after the acquisition of additional genetic lesions. In whole-genome sequencing, the biallelic loss of the WT1 tumor suppressor gene, which occurred immediately before tumorigenesis, was identified as a potential candidate genetic alteration. The provirus CYBB cDNA in the blasts contained 108 G-to-A mutations exclusively in the coding strand, suggesting the occurrence of APOBEC3-mediated hypermutations during the transduction of CD34-positive cells. A hypermutation-mediated loss of oxidase activity may have facilitated the survival and proliferation of the clone with MECOM transactivation. Our data provide valuable insights into the complex mechanisms underlying the development of leukemia in X-CGD gene therapy.

Epidemiology conduction of paediatric rheumatic diseases based on the registry database of the Pediatric Rheumatology Association of Japan.

OBJECTIVES: Although epidemiological surveys of paediatric rheumatic diseases in Japan have been conducted, they were single surveys with no continuity. This is the first report of the Pediatric Rheumatology Association of Japan registry database, which was established to continuously collect data for paediatric rheumatic diseases. METHODS: Pediatric Rheumatology International Collaborate Unit Registry version 2 (PRICUREv2) is a registry database established by the Pediatric Rheumatology Association of Japan. The registry data were analysed for the age of onset, time to diagnosis, sex differences, seasonality, and other factors. RESULTS: Our data showed the same trend regarding rates of paediatric rheumatic diseases reported in Japan and other countries. The age of onset was lower in juvenile idiopathic arthritis (JIA) and juvenile dermatomyositis and higher in systemic lupus erythematosus and Sjögren's syndrome. The time to diagnosis was relatively short in JIA and systemic lupus erythematosus but longer in juvenile dermatomyositis and Sjögren's syndrome. Rheumatoid factor-positive polyarticular JIA showed a seasonality cluster with regard to onset. CONCLUSION: PRICUREv2 aided the retrieval and evaluation of current epidemiological information on patients with paediatric rheumatic diseases. It is expected that the data collection will be continued and will be useful for expanding research in Japan.

Recent topics and advanced therapies in chronic granulomatous disease.

Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by the inability of phagocytes to produce reactive oxygen species (ROS) owing to a defect in any of the five components (CYBB/gp91phox, CYBA/p22phox, NCF1/p47phox, NCF2/p67phox, and NCF4/p40phox) and a concomitant regulatory component of Rac1/2 and CYBC1/Eros of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. Patients with CGD are at an increased risk of life-threatening infections caused by catalase-positive bacteria and fungi and of inflammatory complications such as CGD colitis. Antimicrobial and azole antifungal prophylaxes have considerably reduced the incidence and severity of bacterial and improved fungal infections and overall survival. CGD studies have revealed the precise epidemiology and role of NADPH oxidase in innate immunity which has led to a new understanding of the importance of phagocyte oxygen metabolism in various host-defense systems and the fields leading to cell death processes. Moreover, ROS plays central roles in the determination of cell fate as secondary messengers and by modifying of various signaling molecules. According to this increasing knowledge about the effects of ROS on the inflammasomal system, immunomodulatory treatments, such as IFN-γ and anti-IL-1 antibodies, have been established. This review covers the current topics in CGD and the relationship between ROS and ROS-mediated pathophysiological phenomena. In addition to the shirt summary of hematopoietic stem cell transplantation and gene therapy, we introduce a novel ROS-producing enzyme replacement therapy using PEG-fDAO to compensate for NADPH oxidase deficiency.

Treatment with Polyethylene Glycol-Conjugated Fungal D-Amino Acid Oxidase Reduces Lung Inflammation in a Mouse Model of Chronic Granulomatous Disease.

Chronic granulomatous disease (CGD) is a primary immunodeficiency wherein phagocytes are unable to produce reactive oxygen species (ROS) owing to a defect in the nicotinamide adenine dinucleotide phosphate oxidase (NADPH) complex. Patients with CGD experience bacterial and fungal infections and excessive inflammatory disorders. Bone marrow transplantation and gene therapy are theoretically curative; however, residual pathogenic components cause inflammation and/or organic damage in patients. Moreover, antibiotic treatments may not help in preventing excessive inflammation due to the residual presence of fungal cell wall ß-glucan. Thus, better treatment strategies against CGD are urgently required. Polyethylene glycol-conjugated recombinant porcine D-amino acid oxidase (PEG-pDAO) supplies ROS to defective NADPH oxidase in neutrophils of patients with CGD, following which the neutrophils regain bactericidal activity in vitro. In this study, we employed an in vivo nonviable Candida albicans (nCA)-induced lung inflammation model of gp91-phox knockout CGD mice and supplied novel PEG conjugates of Fusarium spp. D-amino acid oxidase (PEG-fDAO), as it exhibits higher enzyme activity than PEG-pDAO. The body weight, lung weight, and lung pathology were evaluated using three experimental strategies with the in vivo lung inflammation model to test the efficacy of the ROS-generating enzyme replacement therapy with PEG-fDAO. The lung weight and pathological findings suggest the condition was ameliorated by administration PEG-fDAO, followed by intraperitoneal injection of D-phenylalanine or D-proline. Although a more precise protocol is essential, these data reveal the targeted delivery of PEG-fDAO to the nCA-induced inflammation site and show that PEG-fDAO can be used to treat inflammation in CGD in vivo.

Functional analysis of novel A20 variants in patients with atypical inflammatory diseases.

BACKGROUND: A20 haploinsufficiency (HA20) is an early-onset autoinflammatory disease caused by mutations in the TNFAIP3 gene, which encodes the protein A20. Numerous truncating mutations in the TNFAIP3 gene have been reported in HA20 patients, whereas fewer missense variants have had their pathogenicity confirmed. Here, we evaluated the pathogenic significance of three previously unreported missense variants of the TNFAIP3 gene in suspected cases of HA20. METHODS: We obtained the clinical features and immunological data of three patients with missense variants (Glu192Lys, Ile310Thr, and Gln709Arg) of unknown significance of TNFAIP3. We then performed in vitro functional assays including analysis of nuclear factor (NF)-κB reporter gene activity, detection of A20 expression and phosphorylation of A20 by IκB kinase ß (IKKß), and K63-deubiquitination assay using TNFAIP3-deficient HEK293 cells. Three known pathogenic missense mutations reported previously were also investigated. RESULTS: The inhibitory effect on NF-κB reporter gene activity was significantly disrupted by A20 Glu192Lys and the three known mutations. The variants Ile310Thr and Gln709Arg did not show a difference from the wild type in any of the assays performed in this study. CONCLUSIONS: Among the three variants in the TNFAIP3 gene, Glu192Lys was interpreted as being likely pathogenic, but Ile310Thr and Gln709Arg as being not pathogenic (uncertain significance and likely benign, respectively), based on the American College of Medical Genetics and Genomics standards and guidelines. Our study highlights the necessity of performing in vitro functional assays, notably, NF-κB reporter gene assay, to evaluate the pathogenicity of TNFAIP3 missense variants for the accurate diagnosis of HA20.

Bordetella pertussis is a common pathogen in infants hospitalized for acute lower respiratory tract infection during the winter season.

INTRODUCTION: There is some evidence that Bordetella pertussis (B. pertussis) can co-infect with viral respiratory infections in young infants. METHODS: B. pertussis infection was studied by culture, polymerase chain reaction (PCR), and loop-mediated isothermal amplification (LAMP) from nasopharyngeal swabs (NPSs) in 49 infants < 12 months of age, who were admitted for lower respiratory tract infections during the winter season. Seven other possible viral pathogens were documented by antigen detection or PCR in NPSs. The clinical feature of infants with mixed infection of B. pertussis and respiratory viruses were examined. RESULTS: Overall, B. pertussis infection was found in 10 (20.4%) cases, nine were less than 6 months of age and seven were unvaccinated. Viral etiology was found in 41 (84%) cases and pertussis-viral co-infection was present in eight patients, five of whom had mixed infection with respiratory syncytial virus. Only the presence of staccato coughing, cyanosis, and lymphocytosis were significantly different in B. pertussis-positive cases compared with B. pertussis-negative cases. Of the 10 pertussis cases, only the culture-positive cases showed the typical symptoms and laboratory findings of pertussis in addition to virus-associated respiratory symptoms with severe hospital course, whereas cases identified as DNA-positive lacked the characteristics of pertussis and their clinical severities were the same as B. pertussis-negative cases. CONCLUSION: In the absence of typical paroxysmal cough and lymphocytosis, we should carefully consider diagnosis of pertussis in young children hospitalized for presumed viral respiratory illness according to local epidemiological surveillance.

Hematopoietic Cell Transplantation for Chronic Granulomatous Disease in Japan.

Hematopoietic cell transplantation (HCT) is established as a curative treatment for severe chronic granulomatous disease (CGD). However, outcomes of HCT for CGD in Japan had not been precisely reported. We evaluated the outcome of HCT for CGD in Japan by means of a nationwide survey. A total of 91 patients (86 males and 5 females) with CGD who received HCT between 1992 and 2013 was investigated. Their median age at HCT was 11 years (0-39). Sixty-four patients had X-linked CGD caused by CYBB gene mutations, 13 had autosomal recessive CGD (7 CYBA and 6 NCF2), and 14 were genetically undetermined. Seventy patients are still alive at a median follow-up of 38.9 (3.7-230) months. Three-year OS and EFS was 73.7 and 67.6%, respectively. Twenty-one patients died mainly from transplant-related mortality. The cumulative incidence of grade II to IV acute GVHD and extensive chronic GVHD was 27.2 and 17.9%, respectively. Risk factors for EFS after HCT for CGD were age >30 years (P < 0.01), non-CYBB gene mutations (P < 0.01) and CBT (P < 0.01). Regarding the reduced intensity conditioning (RIC) regimen, risk factors for EFS included anti-thymocyte globulin (P = 0.048) and not using low-dose irradiation therapy (P < 0.01), in addition to the preceding risk factors. We report outcomes of HCT for CGD in Japan. Future studies are needed to improve such outcomes, especially for patients harboring non-CYBB gene mutations and suffering from adult CGD. A RIC regimen including low-dose irradiation may be a good option to explore further.

A hot-spot mutation in CDC42 (p.Tyr64Cys) and novel phenotypes in the third patient with Takenouchi-Kosaki syndrome.

Takenouchi-Kosaki syndrome (TKS) is a congenital malformation syndrome characterized by severe developmental delay, macrothrombocytopenia, camptodactyly, sensorineural hearing loss, and dysmorphic facial features. Recently, a heterozygous de novo mutation (p.Tyr64Cys) in the CDC42 gene, which encodes a key small GTP-binding protein of the Rho-subfamily, was identified in two unrelated patients with TKS. We herein report a third patient with TKS who had the same heterozygous CDC42 mutation. The phenotype of the patient was very similar to those of the two previously reported patients with TKS; however, she also demonstrated novel clinical manifestations, such as congenital hypothyroidism and immunological disturbance. Thus, despite the heterozygous mutation of CDC42 (p.Tyr64Cys) likely being a hot-spot mutation for TKS, its phenotype may be variable. Further studies and the accumulation of patients with CDC42 mutations are needed to clarify the phenotype in patients with TKS and the pathophysiological roles of the CDC42 mutation.