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.

Recombinant human thrombomodulin for pneumonia-induced severe ARDS complicated by DIC in children: a preliminary study.

PURPOSE: Recombinant human soluble thrombomodulin (rTM) has been used to treat disseminated intravascular coagulation (DIC). Recent studies have shown the efficacy of rTM through its anti-inflammatory effects for treatment of adults with acute respiratory distress syndrome (ARDS). However, the safety and efficacy of rTM in children with severe ARDS complicated by DIC have not been reported. In this preliminary study, we reported the feasibility of using rTM for the treatment of pneumonia-induced severe ARDS complicated by DIC in children. METHODS: Six children (age: median 10 months old) with pneumonia-induced severe ARDS complicated by DIC were enrolled in this preliminary study. rTM (380 U/kg) was administered for a maximum of 6 days, in addition to conventional therapies after diagnosis of severe ARDS complicated by DIC. After administration of rTM, we measured changes in the plasma TM concentration and evaluated the clinical course, status of DIC and ARDS, and other laboratory findings, including levels of cytokines, chemokines, and biomarkers. RESULTS: In all six children, the plasma concentration of TM increased and DIC scores decreased after administration of rTM. Four of the six children recovered from the severe ARDS complicated by DIC after treatment, and were discharged from the hospital with no complications. In survived children, levels of soluble receptors for advanced glycation end products, interleukin-6, interleukin-8 and monocyte chemotactic protein-1 decreased after administration of rTM compared to those before rTM. CONCLUSIONS: The rTM administration is feasible as an adjunctive therapeutic strategy for children over 2 months with pneumonia-induced severe ARDS complicated by DIC.

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.

Influence of food texture on energy metabolism and adiposity in male rats.

NEW FINDINGS: What is the central question of this manuscript? What is the effect of food texture on fat accumulation, lipogenesis and proinflammatory factors in the adipose tissue and on energy balance in male rats? What is the main finding and its importance? Calorie intake and fat accumulation in rats fed soft pellets ad libitum increased, but their body weight did not. The data suggest that, even when BMI is normal, frequent consumption of soft food may contribute to the development of lifestyle-related diseases. ABSTRACT: Dietary factors such as food texture are known to affect feeding behaviour and energy metabolism. We recently found that rats fed soft pellets (SPs) on a 3 h restricted feeding schedule showed glucose intolerance, insulin resistance with disruption of insulin signalling, and hyperplasia of pancreatic ß-cells, even though there were no differences in energy intake and body weight between rats fed control pellets (CPs) and rats fed SPs. We investigated the effect of food texture on fat accumulation, lipogenesis and proinflammatory factors in the mesenteric fat, as well as on energy balance in male rats fed CPs or SPs. We used 7-week-old Wistar rats that were randomly divided into two groups, ad libitum fed either CPs or SPs for 27 weeks. Body weight and calorie intake were monitored once a week throughout the experiment. The calorie intake, lipogenesis and fat accumulation of the rats fed SPs increased, whereas their body weight did not. Additionally, SP rats used their fat mainly as a source of energy and increased their energy expenditure. Our data suggest that the habit of frequently eating soft food causes visceral fat accumulation without an increase in body weight. Further investigations using soft-textured foods could lead to the development of appropriate interventions for non-overweight patients with lifestyle-related diseases.

Necrotizing Ulcer After BCG Vaccination in a Girl With Leukocyte-adhesion Deficiency Type 1.

Leukocyte-adhesion deficiency-1 is a recessively inherited disorder associated with recurrent bacterial infections, severe periodontitis, peripheral leukocytosis, and impaired wound healing. We diagnosed moderate-type leukocyte-adhesion deficiency-1 in a 7-year-old girl who developed a necrotizing ulcer after Bacillus Calmette-Guerin vaccination. The patient showed moderate expression of CD18 in neutrophils with a homozygous splice mutation with c.41_c.58+2dup20 of ITGB2 and experienced recurrent severe infections complicated with systemic lupus erythematosus. She received hematopoietic stem cell transplantation from a matched elder brother with heterozygous mutation of ITGB2, and has since remained free of infection and systemic lupus erythematosus symptoms without immunosuppression therapy.

TBCD may be a causal gene in progressive neurodegenerative encephalopathy with atypical infantile spinal muscular atrophy.

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder caused by survival motor neuron gene mutations. Variant forms of SMA accompanied by additional clinical presentations have been classified as atypical SMA and are thought to be caused by variants in as yet unidentified causative genes. Here, we presented the clinical findings of two siblings with an SMA variant followed by progressive cerebral atrophy, and the results of whole-exome sequencing analyses of the family quartet that was performed to identify potential causative variants. We identified two candidate homozygous missense variants, R942Q in the tubulin-folding cofactor D (TBCD) gene and H250Q in the bromo-adjacent homology domain and coiled-coil containing 1 (BAHCC1) gene, located on chromosome 17q25.3 with an interval of 1.4 Mbp. The in silico analysis of both variants suggested that TBCD rather than BAHCC1 was likely the pathogenic gene (TBCD sensitivity, 0.68; specificity, 0.97; BAHCC1 sensitivity, 1.00; specificity, 0.00). Thus, our results show that TBCD is a likely novel candidate gene for atypical SMA with progressive cerebral atrophy. TBCD is predicted to have important functions on tubulin integrity in motor neurons as well as in the central nervous system.

Leopard Skin-Like Colonic Mucosa: A Novel Endoscopic Finding of Chronic Granulomatous Disease-Associated Colitis.

BACKGROUND: Chronic granulomatous disease (CGD) is a rare inherited disorder in which phagocytes are unable to eradicate pathogens because of a deficit of nicotinamide adenine dinucleotide phosphate oxidase. Among CGD patients, ∼ 30% to 50% develop severe gastrointestinal tract symptoms. Although characteristic histologic findings of CGD-associated colitis have been reported, information on endoscopic features remained vague. METHODS: A total of 8 male patients with CGD (ages 2-23 years) from 2 Japanese institutions underwent colonoscopy for the evaluation of their fever, diarrhea, bloody stool, and abdominal pain. The endoscopic and histologic findings were retrospectively reviewed. RESULTS: The endoscopic findings of CGD-associated colitis appeared varied. Notably, brownish dots over a yellowish edematous mucosa were observed in 3 of the 8 patients. Prominent pigment-laden macrophages were noted histologically on the mucosa. CONCLUSIONS: Although nonspecific endoscopic findings of CGD-associated colitis have been reported before, our observation of brownish dots spread across a yellowish edematous mucosa, termed "leopard sign," could be a unique feature of this condition.

Sporadic paraganglioma caused by de novo SDHB mutations in a 6-year-old girl.

Germline mutations in the succinate dehydrogenase complex subunit B (SDHB) gene (SDHB) cause susceptibility to paragangliomas and pheochromocytomas; however, it is exceedingly rare in childhood and especially in sporadic cases. We report the first Japanese pediatric case of paraganglioma with a de novo mutation in the SDHB gene. A 6-year-old girl with convulsions and hypertension was found to have a paravertebral abdominal tumor. Urinary and blood examinations revealed markedly elevated levels of norepinephrine. Following treatment for hypertension, the tumor was removed completely and histological findings were consistent with paraganglioma. Immunohistochemistry studies demonstrated the absence of SDHB protein expression, indicating an underlying SDH mutation with high probability. Germline mutation analysis of the SDHB gene revealed a heterozygous splice site mutation in intron 4 (C.423 + 1G > A). Subsequently, a second somatic genetic change was confirmed by multiplex ligation-dependent probe amplification (MLPA) analysis, showing that deletion of the wild-type allele resulted in loss of function of SDHB. No germline mutations in SDHB were detected in her parents. CONCLUSION: Genetic testing should be considered for pediatric patients with paragangliomas, even in the absence of familial history, as closer lifelong screening to detect the development of malignancy will be required for patients with SDHB mutations. WHAT IS KNOWN: Most sporadic cases of paraganglioma with SDHB mutations occur between adolescence and adulthood. Screening methods for carriers of SDHB mutations assessing recurrence and detecting developing metastases are yet to be standardized. WHAT IS NEW: The current case of an extra-adrenal paraganglioma with a de novo SDHB mutation had an onset at 6 years. We suggest much closer periodical observation for these high-risk children.

Clinical and histological findings of autosomal dominant renal-limited disease with LMX1B mutation.

AIM: Mutations of LMX1B cause nail-patella syndrome, a rare autosomal dominant disorder. Recently, LMX1B R246Q heterozygous mutations were recognised in nephropathy without extrarenal manifestation. The aim of this study was to clarify characteristics of nephropathy caused by R246Q mutation. METHODS: Whole exome sequencing was performed on a large family with nonsyndromic autosomal dominant nephropathy without extrarenal manifestation. Clinical and histological findings of patients with LMX1B mutation were investigated. RESULTS: LMX1B R246Q heterozygous mutation was identified in five patients over three generations. Proteinuria or haematoproteinuria was recognized by urinary screening from all patients in childhood. Proteinuria gradually increased to nephrotic levels and renal function decreased in adolescence. Two patients progressed to end-stage renal disease in adulthood. Renal histology demonstrated minimal change in childhood and focal segmental glomerulosclerosis in adulthood. Using electron microscopy, focal collagen deposition could be detected in glomeruli even when a "moth-eaten appearance" was not apparent in the glomerular basement membrane. In addition, podocin expression in glomerular podocytes was significantly decreased, even in the early stages of disease progression. CONCLUSION: Comprehensive genetic analyses and collagen or tannic acid staining may be useful for diagnosis of LMX1B-associated nephropathy. While renal prognosis of R246Q may be worse than that of typical NPS nephropathy, signs of podocytopathy can be detected during the infantile period; thus, childhood urinary screening may facilitate early detection.

Relapsed childhood acute myeloid leukemia patient with inversion of chromosome 16 harboring a low FLT3 internal tandem duplication allelic burden and KIT mutations.

Inversion of chromosome 16 [inv(16)] has a good prognosis in acute myeloid leukemia (AML), but additional genetic aberrations influence the outcome. We herein describe the case of a 15-year-old Japanese boy with inv(16) harboring a low-allelic burden internal tandem duplication of FLT3 (FLT3-ITD) and KIT mutations. Conventional chemotherapy eradicated a clone with a low-allelic burden FLT3-ITD mutation, although another clone with a KIT mutation occurred 17 months later. Further investigation is necessary to identify AML with inv(16) conferring poor prognosis, to facilitate appropriate treatment with additional drugs, such as dasatinib or gemtuzumab ozogamicin.

Familial C3 glomerulonephritis associated with mutations in the gene for complement factor B.

We report the first case of familial C3 glomerulonephritis (C3GN) associated with mutations in the gene for complement factor B (CFB). A 12-year-old girl was diagnosed with biopsy-proven C3GN. Her mother had a history of treatment for membranoproliferative glomerulonephritis, and her brother had hypocomplementemia without urinary abnormalities. DNA analysis revealed heterozygosity for CFB p.S367R in the patient, mother and brother. Evaluation of the structure-function relationship supports that this mutation has gain-of-function effects in CFB. The present case suggests that CFB has an important role in the etiology of C3GN and provides a new insight into anticomplement therapy approaches.

Frequent somatic mosaicism of NEMO in T cells of patients with X-linked anhidrotic ectodermal dysplasia with immunodeficiency.

Somatic mosaicism has been described in several primary immunodeficiency diseases and causes modified phenotypes in affected patients. X-linked anhidrotic ectodermal dysplasia with immunodeficiency (XL-EDA-ID) is caused by hypomorphic mutations in the NF-κB essential modulator (NEMO) gene and manifests clinically in various ways. We have previously reported a case of XL-EDA-ID with somatic mosaicism caused by a duplication mutation of the NEMO gene, but the frequency of somatic mosaicism of NEMO and its clinical impact on XL-EDA-ID is not fully understood. In this study, somatic mosaicism of NEMO was evaluated in XL-EDA-ID patients in Japan. Cells expressing wild-type NEMO, most of which were derived from the T-cell lineage, were detected in 9 of 10 XL-EDA-ID patients. These data indicate that the frequency of somatic mosaicism of NEMO is high in XL-ED-ID patients and that the presence of somatic mosaicism of NEMO could have an impact on the diagnosis and treatment of XL-ED-ID patients.

Proposed strategy for the use of high-dose chemotherapy with stem cell rescue and intrathecal topotecan without whole-brain irradiation for infantile classic medulloblastoma.

We describe a 6-month-old infant with classic medulloblastoma. Gross total resection of the left cerebellar tumor was performed; however, relapse occurred during the administration of intrathecal and intravenous methotrexate-based chemotherapy. After undergoing resection, high-dose chemotherapy was administered consisting of topotecan, melphalan, and cyclophosphamide with autologous peripheral stem cell rescue followed by local irradiation and intrathecal topotecan, which resulted in a complete response for more than two years. The administration of high-dose chemotherapy followed by intrathecal topotecan as maintenance therapy is an effective strategy, without losses in the cognitive function, for avoiding the use of whole-brain irradiation for infantile classic medulloblastoma.

Nephrotic syndrome complicated by idiopathic central diabetes insipidus.

BACKGROUND: There is ongoing discussion regarding the mechanisms underlying edema formation in nephrotic syndrome (NS). Many studies published in the last decade reported that primary renal sodium retention was a major factor in edema formation. However, many of the factors influencing edema formation in NS remain unclear, including the role of arginine vasopressin (AVP). CASE-DIAGNOSIS/TREATMENT: We report a 12-year-old boy with steroid-dependent NS complicated by idiopathic central diabetes insipidus (CDI). He did not develop edema during his first relapse of NS after developing CDI, despite having hypoalbuminemia. He had polydipsia, polyuria, low urine osmolality, and a low serum arginine AVP level. His fractional excretion of sodium was only slightly low. Endocrinological testing and magnetic resonance imaging revealed idiopathic CDI. After starting desmopressin therapy, he developed edema when his NS relapsed. CONCLUSIONS: This is the first known reported case of NS in a patient with CDI. The findings suggest that appropriate AVP secretion in response to an increase in serum osmolality caused by renal sodium retention is necessary for excess extracellular fluid accumulation in NS. Further investigation is needed to more fully understand the role of AVP in edema formation in NS.

Cytomegalovirus retinitis as an adverse immunological effect of pulses of vincristine and dexamethasone in maintenance therapy for childhood acute lymphoblastic leukemia.

We describe a 5-year-old female with acute lymphoblastic leukemia (ALL) who suffered from cytomegalovirus (CMV) retinitis during maintenance therapy consisting of 6-mercaptopurine (6-MP) and methotrexate (MTX) with pulses of vincristine (VCR) and dexamethasone (DEX). Administration of anticytomegaloviral drugs led to a complete regression of active retinitis. Her low CD4 positive T cells and serum immunoglobulin G (IgG) recovered when maintenance therapy was resumed without VCR and DEX. The patient has been in complete remission (CR) for more than 5 months after completion of maintenance therapy without recurrence of CMV retinitis.

Efficacy of temozolomide in a central nervous system relapse of neuroblastoma with O 6 -methylguanine methyltransferase (MGMT) promoter methylation.

We describe a case of a 5-year-old girl with central nervous system relapse of neuroblastoma after high-dose chemotherapy and autologous stem cell transplantation. Although the brain metastasis was surgically removed, she had a second relapse in the same region with leptomeningeal dissemination despite receiving irinotecan. Administration of temozolomide in addition to irinotecan led to her third complete response and the patient has been in complete response for >24 months. The tumor had no expression of the O -methylguanine methyltransferase (MGMT) gene due to promoter methylation. Temozolomide is an attractive candidate treatment in neuroblastoma with methylated MGMT, especially in central nervous system relapsed cases.

[Refractory acute myeloid leukemia developed malignancy-associated hemophagocytic lymphohistiocytosis during treatment of invasive fungal infection].

We here report a 2-year-old female with relapsed acute myeloid leukemia (AML) with MLL gene rearrangement in the bone marrow and central nervous system. The 3'-RACE (Rapid Amplification of cDNA Ends) method identified the MLLT10 gene as a fusion partner of the MLL gene. The patient was complicated with hemophagocytic lymphohistiocytosis (HLH) and invasive aspergillosis (IPA) after re-induction treatment with FLAG-IDA following etoposide, cytarabine, and mitoxantrone. Although treatment with systemic anti-fungal drugs was effective for IPA, HLH did not improve. We considered tumor-associated HLH to be initiated from leukemic stem cells (LSCs) in the bone marrow niche because reverse transcription-polymerase chain reaction (RT-PCR) analysis of a bone marrow biopsy sample was positive for MLL-MLLT10. Gemtuzumab ozogamicin and sorafenib had no major effect on acquiring complete remission, and the patient died of progressive AML with an exacerbation of HLH and aspergillosis. LSCs are known to be resistant to conventional chemotherapy due to their quiescence in the cell cycle. Novel therapeutic concepts are important to eradicate LSCs in order to cure AML patients.

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.

Successful treatment with infliximab for inflammatory colitis in a patient with X-linked anhidrotic ectodermal dysplasia with immunodeficiency.

X-linked anhidrotic ectodermal dysplasia with immunodeficiency (X-EDA-ID) is caused by hypomorphic mutations in the gene encoding nuclear factor-κB essential modulator protein (NEMO). Patients are susceptibile to diverse pathogens due to insufficient cytokine and frequently show severe chronic colitis. An 11-year-old boy with X-EDA-ID was hospitalized with autoimmune symptoms and severe chronic colitis which had been refractory to immunosuppressive drugs. Since tumor necrosis factor (TNF) α is responsible for the pathogenesis of NEMO colitis according to intestinal NEMO and additional TNFR1 knockout mice studies, and high levels of TNFα-producing mononuclear cells were detected in the patient due to the unexpected gene reversion mosaicism of NEMO, an anti-TNFα monoclonal antibody was administered to ameliorate his abdominal symptoms. Repeated administrations improved his colonoscopic findings as well as his dry skin along with a reduction of TNFα-expressing T cells. These findings suggest TNF blockade therapy is of value for refractory NEMO colitis with gene reversion.