Koichi Oshima

High Incidence of NLRP3 Somatic Mosaicism in Patients With Chronic Infantile Neurologic, Cutaneous, Articular Syndrome: Results of an International Multicenter Collaborative Study

OBJECTIVEnChronic infantile neurologic, cutaneous, articular (CINCA) syndrome, also known as neonatal-onset multisystem inflammatory disease (NOMID), is a dominantly inherited systemic autoinflammatory disease. Although heterozygous germline gain-of-function NLRP3 mutations are a known cause of this disease, conventional genetic analyses fail to detect disease-causing mutations in ∼40% of patients. Since somatic NLRP3 mosaicism has been detected in several mutation-negative NOMID/CINCA syndrome patients, we undertook this study to determine the precise contribution of somatic NLRP3 mosaicism to the etiology of NOMID/CINCA syndrome.nnnMETHODSnAn international case-control study was performed to detect somatic NLRP3 mosaicism in NOMID/CINCA syndrome patients who had shown no mutation during conventional sequencing. Subcloning and sequencing of NLRP3 was performed in these mutation-negative NOMID/CINCA syndrome patients and their healthy relatives. Clinical features were analyzed to identify potential genotype-phenotype associations.nnnRESULTSnSomatic NLRP3 mosaicism was identified in 18 of the 26 patients (69.2%). Estimates of the level of mosaicism ranged from 4.2% to 35.8% (mean ± SD 12.1 ± 7.9%). Mosaicism was not detected in any of the 19 healthy relatives (18 of 26 patients versus 0 of 19 relatives; P < 0.0001). In vitro functional assays indicated that the detected somatic NLRP3 mutations had disease-causing functional effects. No differences in NLRP3 mosaicism were detected between different cell lineages. Among nondescript clinical features, a lower incidence of mental retardation was noted in patients with somatic mosaicism. Genotype-matched comparison confirmed that patients with somatic NLRP3 mosaicism presented with milder neurologic symptoms.nnnCONCLUSIONnSomatic NLRP3 mutations were identified in 69.2% of patients with mutation-negative NOMID/CINCA syndrome. This indicates that somatic NLRP3 mosaicism is a major cause of NOMID/CINCA syndrome.

A novel serum-free monolayer culture for orderly hematopoietic differentiation of human pluripotent cells via mesodermal progenitors.

Elucidating the in vitro differentiation of human embryonic stem (ES) and induced pluripotent stem (iPS) cells is important for understanding both normal and pathological hematopoietic development in vivo. For this purpose, a robust and simple hematopoietic differentiation system that can faithfully trace in vivo hematopoiesis is necessary. In this study, we established a novel serum-free monolayer culture that can trace the in vivo hematopoietic pathway from ES/iPS cells to functional definitive blood cells via mesodermal progenitors. Stepwise tuning of exogenous cytokine cocktails induced the hematopoietic mesodermal progenitors via primitive streak cells. These progenitors were then differentiated into various cell lineages depending on the hematopoietic cytokines present. Moreover, single cell deposition assay revealed that common bipotential hemoangiogenic progenitors were induced in our culture. Our system provides a new, robust, and simple method for investigating the mechanisms of mesodermal and hematopoietic differentiation.

Induced pluripotent stem cells from CINCA syndrome patients as a model for dissecting somatic mosaicism and drug discovery

Chronic infantile neurologic cutaneous and articular (CINCA) syndrome is an IL-1-driven autoinflammatory disorder caused mainly by NLRP3 mutations. The pathogenesis of CINCA syndrome patients who carry NLRP3 mutations as somatic mosaicism has not been precisely described because of the difficulty in separating individual cells based on the presence or absence of the mutation. Here we report the generation of NLRP3-mutant and nonmutant-induced pluripotent stem cell (iPSC) lines from 2 CINCA syndrome patients with somatic mosaicism, and describe their differentiation into macrophages (iPS-MPs). We found that mutant cells are predominantly responsible for the pathogenesis in these mosaic patients because only mutant iPS-MPs showed the disease relevant phenotype of abnormal IL-1β secretion. We also confirmed that the existing anti-inflammatory compounds inhibited the abnormal IL-1β secretion, indicating that mutant iPS-MPs are applicable for drug screening for CINCA syndrome and other NLRP3-related inflammatory conditions. Our results illustrate that patient-derived iPSCs are useful for dissecting somatic mosaicism and that NLRP3-mutant iPSCs can provide a valuable platform for drug discovery for multiple NLRP3-related disorders.

Quantification of κ-deleting recombination excision circles in Guthrie cards for the identification of early B-cell maturation defects

In conclusion, the associations among asthma, biofilmforming bacteria, and revision ESS are strong and robust after adjusting for other factors in patients with CRS from a tertiary medical center. Despite its limitations, this study may improve our understanding of refractory CRS pathogenesis, possibly leading to more effective treatment strategies, such as incorporating the treatments of asthma and biofilm infection into conventional CRS therapies. Prospective cohort studies in diverse populations are needed to assess the causality of these associations.

Robust and Highly-Efficient Differentiation of Functional Monocytic Cells from Human Pluripotent Stem Cells under Serum- and Feeder Cell-Free Conditions.

Monocytic lineage cells (monocytes, macrophages and dendritic cells) play important roles in immune responses and are involved in various pathological conditions. The development of monocytic cells from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) is of particular interest because it provides an unlimited cell source for clinical application and basic research on disease pathology. Although the methods for monocytic cell differentiation from ESCs/iPSCs using embryonic body or feeder co-culture systems have already been established, these methods depend on the use of xenogeneic materials and, therefore, have a relatively poor-reproducibility. Here, we established a robust and highly-efficient method to differentiate functional monocytic cells from ESCs/iPSCs under serum- and feeder cell-free conditions. This method produced 1.3×106±0.3×106 floating monocytes from approximately 30 clusters of ESCs/iPSCs 5–6 times per course of differentiation. Such monocytes could be differentiated into functional macrophages and dendritic cells. This method should be useful for regenerative medicine, disease-specific iPSC studies and drug discovery.

Rapid diagnosis of FHL3 by flow cytometric detection of intraplatelet Munc13-4 protein.

Familial hemophagocytic lymphohistiocytosis (FHL) is a potentially lethal genetic disorder of immune dysregulation that requires prompt and accurate diagnosis to initiate life-saving immunosuppressive therapy and to prepare for hematopoietic stem cell transplantation. In the present study, 85 patients with hemophagocytic lymphohistiocytosis were screened for FHL3 by Western blotting using platelets and by natural killer cell lysosomal exocytosis assay. Six of these patients were diagnosed with FHL3. In the acute disease phase requiring platelet transfusion, it was difficult to diagnose FHL3 by Western blot analysis or by lysosomal exocytosis assay. In contrast, the newly established flow cytometric analysis of intraplatelet Munc13-4 protein expression revealed bimodal populations of normal and Munc13-4-deficient platelets. These findings indicate that flow cytometric detection of intraplatelet Munc13-4 protein is a sensitive and reliable method to rapidly screen for FHL3 with a very small amount of whole blood, even in the acute phase of the disease.

Chronic Granulomatous Disease: Two Decades of Experience From a Tertiary Care Centre in North West India

Chronic granulomatous disease (CGD) results from an inherited defect in the phagocytic cells of the immune system. It is a genetically heterogenous disease caused by defects in one of the five major subunits of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. There is a paucity of data from India on CGD. We herein describe the clinical features in 17 children with CGD from a single tertiary referral center in India. A detailed analysis of the clinical features, laboratory investigations and outcome of 17 children 7 with X-linked (XL) and 10 with autosomal recessive (AR) form was performed. Diagnosis of CGD was based on an abnormal granulocyte oxidative burst evaluated by either Nitroblue Tetrazolium (NBT) test or flow cytometry based Dihyrorhodamine 123 assay or both. The molecular diagnosis was confirmed by genetic mutation analysis in 13 cases. The mean age at diagnosis and the age at onset of symptoms was significantly lower in children diagnosed with XL- CGD compared those with AR disease. Mutations were detected in CYBB gene in 6 patients with XL-CGD and NCF-1 gene mutations were observed in 7 cases of AR- CGD. The course and outcome of the disease was much worse in children diagnosed with X-linked form of disease compared to AR forms of the disease; 4/7 (57xa0%) children with X-CGD were dead at the time of data analysis. This is one of the largest series on chronic granulomatous disease from any developing country.

Hematopoietic Stem Cell Transplantation for X-Linked Thrombocytopenia With Mutations in the WAS gene

X-linked thrombocytopenia (XLT) is a mild form of the Wiskott-Aldrich syndrome (WAS) caused by mutations in the WAS gene. A recent retrospective study of the clinical outcome and molecular basis of a large cohort of XLT patients demonstrated that although overall survival is excellent, event free survival is severely affected with conservative treatment. To answer the question whether hematopoietic stem cell transplantation (HSCT) offers a viable alternative therapeutic option in XLT, we retrospectively investigated the outcome of HSCT in a cohort of 24 XLT patients who received HSCT between 1990 and 2011 at 14 transplant centers in the United States, Italy, Germany, Canada, and Japan. The engraftment rate was 100xa0% and the overall survival rate was 83.3xa0%. Of the four non-survivors, 2 underwent splenectomy prior to HSCT and died of sepsis, and two of aspergillus infections associated with severe GVHD. In all but one patient, pretransplant complications were resolved by HSCT. Our data indicate that HSCT following myeloablative conditioning is curative and associated with acceptable risks as a treatment option for XLT.

Reticular dysgenesis: international survey on clinical presentation, transplantation and outcome

Reticular dysgenesis (RD) is a rare congenital disorder defined clinically by the combination of severe combined immunodeficiency (SCID), agranulocytosis, and sensorineural deafness. Mutations in the gene encoding adenylate kinase 2 were identified to cause the disorder. Hematopoietic stem cell transplantation (HSCT) is the only option to cure this otherwise fatal disease. Retrospective data on clinical presentation, genetics, and outcome of HSCT were collected from centers in Europe, Asia, and North America for a total of 32 patients born between 1982 and 2011. Age at presentation was <4 weeks in 30 of 32 patients (94%). Grafts originated from mismatched family donors in 17 patients (55%), from matched family donors in 6 patients (19%), and from unrelated marrow or umbilical cord blood donors in 8 patients (26%). Thirteen patients received secondary or tertiary transplants. After transplantation, 21 of 31 patients were reported alive at a mean follow-up of 7.9 years (range: 0.6-23.6 years). All patients who died beyond 6 months after HSCT had persistent or recurrent agranulocytosis due to failure of donor myeloid engraftment. In the absence of conditioning, HSCT was ineffective to overcome agranulocytosis, and inclusion of myeloablative components in the conditioning regimens was required to achieve stable lymphomyeloid engraftment. In comparison with other SCID entities, considerable differences were noted regarding age at presentation, onset, and type of infectious complications, as well as the requirement of conditioning prior to HSCT. Although long-term survival is possible in the presence of mixed chimerism, high-level donor myeloid engraftment should be targeted to avoid posttransplant neutropenia.

Hemophagocytosis after bone marrow transplantation for JAK3-deficient severe combined immunodeficiency

Hashii Y, Yoshida H, Kuroda S, Kusuki S, Sato E, Tokimasa S, Ohta H, Matsubara Y, Kinoshita S, Nakagawa N, Imai K, Nonoyama S, Oshima K, Ohara O, Ozono K. Hemophagocytosis after bone marrow transplantation for JAK3‐deficient severe combined immunodeficiency.u2028Pediatr Transplantation 2010: 14:E105–E109.