Hideo Harigae

Clinical utility of next-generation sequencing for inherited bone marrow failure syndromes

Purpose:Precise genetic diagnosis of inherited bone marrow failure syndromes (IBMFS), a heterogeneous group of genetic disorders, is challenging but essential for precise clinical decision making.Methods:We analyzed 121 IBMFS patients using a targeted sequencing covering 184 associated genes and 250 IBMFS patients using whole-exome sequencing (WES).Results:We achieved successful genetic diagnoses for 53 of 121 patients (44%) using targeted sequencing and for 68 of 250 patients (27%) using WES. In the majority of cases (targeted sequencing: 45/53, 85%; WES: 63/68, 93%), the detected variants were concordant with, and therefore supported, the clinical diagnoses. However, in the remaining 13 cases (8 patients by target sequencing and 5 patients by WES), the clinical diagnoses were incompatible with the detected variants.Conclusion:Our approach utilizing targeted sequencing and WES achieved satisfactory diagnostic rates and supported the efficacy of massive parallel sequencing as a diagnostic tool for IBMFS.Genet Med advance online publication 19 January 2017

GATA2 regulates dendritic cell differentiation

Dendritic cells (DCs) are critical immune response regulators; however, the mechanism of DC differentiation is not fully understood. Heterozygous germ line GATA2 mutations induce GATA2-deficiency syndrome, characterized by monocytopenia, a predisposition to myelodysplasia/acute myeloid leukemia, and a profoundly reduced DC population, which is associated with increased susceptibility to viral infections, impaired phagocytosis, and decreased cytokine production. To define the role of GATA2 in DC differentiation and function, we studied Gata2 conditional knockout and haploinsufficient mice. Gata2 conditional deficiency significantly reduced the DC count, whereas Gata2 haploinsufficiency did not affect this population. GATA2 was required for the in vitro generation of DCs from Lin(-)Sca-1(+)Kit(+) cells, common myeloid-restricted progenitors, and common dendritic cell precursors, but not common lymphoid-restricted progenitors or granulocyte-macrophage progenitors, suggesting that GATA2 functions in the myeloid pathway of DC differentiation. Moreover, expression profiling demonstrated reduced expression of myeloid-related genes, including mafb, and increased expression of T-lymphocyte-related genes, including Gata3 and Tcf7, in Gata2-deficient DC progenitors. In addition, GATA2 was found to bind an enhancer element 190-kb downstream region of Gata3, and a reporter assay exhibited significantly reduced luciferase activity after adding this enhancer region to the Gata3 promoter, which was recovered by GATA sequence deletion within Gata3 +190. These results suggest that GATA2 plays an important role in cell-fate specification toward the myeloid vs T-lymphocyte lineage by regulating lineage-specific transcription factors in DC progenitors, thereby contributing to DC differentiation.

Retrospective analysis of 95 patients with large vessel vasculitis: a single center experience

Although Takayasu arteritis (TAK) and giant cell arteritis (GCA) have been considered as distinct disease entities, similarities of these diseases have been recently reported. However, little data is available regarding this issue in Japanese patients with TAK and GCA. In addition, the classification criteria for TAK established in 1990 by the American College of Rheumatology (ACR) have been criticized due to the age restriction for disease onset (≤ 40 years). Thus, we aimed to compare the clinical characteristics of Japanese patients with TAK and those with GCA and to clarify whether clinical differences existed between patients with early‐onset (≤ 40 years) and late‐onset (> 40 years) TAK.

Extracorporeal Shock Wave Therapy for Digital Ulcers of Systemic Sclerosis: A Phase 2 Pilot Study

Patients with systemic sclerosis (SSc) often display Raynauds phenomenon and digital skin ulcers. As these ulcers are not associated with autoimmune factors or abnormal coagulation, conventional immunosuppressive therapies, vasodilators, and anticoagulants are often ineffective. Here, we used extracorporeal shock wave therapy (ESWT) to treat these ulcers. Nine SSc patients with new digital ulcers, previously treated with at least one currently available vasodilator or anticoagulant were enrolled. One ESWT session consisted of 100 pulses at 0.08-0.25 mJ/mm(2) in 20 areas on both hands and 15 areas on both feet, totaling 7,000 pulses. Treatment was performed once per week for 9 weeks with observations over 20 weeks. Outcomes were evaluated according to the number and diameter of ulcers, Rodnan skin score, Health Assessment Questionnaire (HAQ), EuroQol 5 dimensions (EQ-5D), visual analog scale for pain, and the PainVision system. The surface skin temperature of all the fingers was measured using thermography. Ulcers showed signs of healing after one session, and their mean number decreased from 5.4 to 1.1 at 9 weeks. In particular, of the 18 large ulcers (> 5 mm) observed in 7 patients before the treatment, 10 disappeared and the rest became smaller; namely, the mean size decreased from 10.9 mm to 2.5 mm at 20 weeks. The average scores on the HAQ, EQ-5D, and PainVision system also improved. Treatment was minimally invasive and could be repeated without any adverse effects. ESWT may be added to standard treatments for indolent digital ulcers of SSc, as an effective and safe method.

Causes of macrocytic anemia among 628 patients: mean corpuscular volumes of 114 and 130 fL as critical markers for categorization

There have been no studies on the distribution of causes of macrocytic anemia with respect to mean corpuscular volume (MCV) cutoff values. We retrospectively investigated the causes of macrocytic anemia (MCV ≥100xa0fL) among 628 patients who visited the outpatient hematology clinic in Tohoku University Hospital. To ensure data validity, we also analyzed data from 307 patients in eight other hospitals in the Tohoku district. The leading causes of macrocytic anemia (number of patients, %) were myelodysplastic syndromes (121, 19.3xa0%), suspected bone marrow failure syndromes (BMF; 74, 11.8xa0%), aplastic anemia (51, 8.1xa0%), plasma cell dyscrasia (45, 7.2xa0%), and vitamin B12 deficiency (40, 6.4xa0%) in Tohoku University Hospital. We made three primary findings as follows. First, the most common cause of macrocytic anemia is BMF. Second, lymphoid and solid malignancies are also common causes of macrocytosis. Third, macrocytic anemia may be classified into three groups: Group 1 (megaloblastic anemia and medications), which can exceed MCV 130xa0fL; Group 2 (alcoholism/liver disease, BMF, myeloid malignancy, and hemolytic anemia), which can exceed MCV 114xa0fL; and Group 3 (lymphoid malignancy, chronic renal failure, hypothyroidism, and solid tumors), which does not exceed MCV 114xa0fL. These conclusions were supported by the results from eight other hospitals.

Systemic Activation of NRF2 Alleviates Lethal Autoimmune Inflammation in Scurfy Mice

ABSTRACT The transcription factor NRF2 (nuclear factor [erythroid-derived 2]-like 2) plays crucial roles in the defense mechanisms against oxidative stress and mediates anti-inflammatory actions under various pathological conditions. Recent studies showed that the dysfunction of regulatory T cells (Tregs) is directly linked to the initiation and progression of various autoimmune diseases. To determine the Treg-independent impact of NRF2 activation on autoimmune inflammation, we examined scurfy (Sf) mice, which are deficient in Tregs and succumb to severe multiorgan inflammation by 4 weeks of age. We found that systemic activation of NRF2 by Keap1 (Kelch-like ECH-associated protein 1) knockdown ameliorated tissue inflammation and lethality in Sf mice. Activated T cells and their cytokine production were accordingly decreased by Keap1 knockdown. In contrast, NRF2 activation through cell lineage-specific Keap1 disruption (i.e., in T cells, myeloid cells, and dendritic cells) achieved only partial or no improvement in the inflammatory status of Sf mice. Our results indicate that systemic activation of NRF2 suppresses effector T cell activities independently of Tregs and that NRF2 activation in multiple cell lineages appears to be required for sufficient anti-inflammatory effects. This study emphasizes the possible therapeutic application of NRF2 inducers in autoimmune diseases that are accompanied by Treg dysfunction.

An LPA1/3 Axis Governs Cellular Senescence of Mesenchymal Stromal Cells (MSCs) and Promotes Growth and Vascularization of Multiple Myeloma

Mesenchymal stromal cells (MSCs) are multipotent progenitor cells and there is much interest in how MSCs contribute to the regulation of the tumor microenvironment. Whether MSCs exert a supportive or suppressive effect on tumor progression is still controversial, but is likely dependent on a variety of factors that are tumor‐type dependent. Multiple myeloma (MM) is characterized by growth of malignant plasma cells in the bone marrow. It has been shown that the progression of MM is governed by MSCs, which act as a stroma of the myeloma cells. Although stroma is created via mutual communication between myeloma cells and MSCs, the mechanism is poorly understood. Here we explored the role of lysophosphatidic acid (LPA) signaling in cellular events where MSCs were converted into either MM‐supportive or MM‐suppressive stroma. We found that myeloma cells stimulate MSCs to produce autotaxin, an indispensable enzyme for the biosynthesis of LPA, and LPA receptor 1 (LPA1) and 3 (LPA3) transduce opposite signals to MSCs to determine the fate of MSCs. LPA3‐silenced MSCs (siLPA3‐MSCs) exhibited cellular senescence‐related phenotypes in vitro, and significantly promoted progression of MM and tumor‐related angiogenesis in vivo. In contrast, siLPA1‐MSCs showed resistance to cellular senescence in vitro, and efficiently delayed progression of MM and tumor‐related angiogenesis in vivo. Consistently, anti‐MM effects obtained by LPA1‐silencing in MSCs were completely reproduced by systemic administration of Ki6425, an LPA1 antagonist. Collectively, our results indicate that LPA signaling determines the fate of MSCs and has potential as a therapeutic target in MM. Stem Cells 2017;35:739–753

High Prevalence of Acute Exacerbation of Interstitial Lung Disease in Japanese Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a systemic autoimmune disease characterized by extensive fibrosis and autoantibodies. Its clinical manifestations are diverse and include Raynauds phenomenon, gastrointestinal dysmotility, interstitial lung disease (ILD), pulmonary hypertension, and renal crisis. Among these, ILD is the primary cause of SSc-related death. It has been considered that acute exacerbation of ILD (AE-ILD) is not common in patients with SSc; however, little is known about the prevalence of AE-ILD in Japanese patients with SSc. In this study, we aimed to clarify the prevalence, clinical characteristics, and prognosis of patients with SSc who developed AE-ILD and to identify predictive factors for AE-ILD in our Japanese cohorts. Clinical data of patients who visited our department from 1990 to 2014 and fulfilled the 2013 classification criteria for SSc were retrospectively reviewed. A total of 139 patients were enrolled. The mean age of onset was 49.1 years, and 113 (81.3%) patients were female; 116 (83.5%) had limited cutaneous involvement, and the overall 10-year survival rate was 92.0%. Among 66 (47.5%) patients with ILD, 13 (9.4%) developed AE-ILD. Patients with AE-ILD had a significantly higher incidence of overlap with polymyositis (PM) or dermatomyositis (DM) and lower prevalence of anticentromere antibodies with higher mortality rate compared with those without AE-ILD. Multivariate Cox regression analysis identified that an overlap with PM or DM was the most significant predictive factor for AE-ILD. Our study results suggest that Japanese patients with SSc, particularly patients overlapped with PM or DM, have a high risk of AE-ILD.

Evaluation of the safety and efficacy of recombinant soluble thrombomodulin for patients with disseminated intravascular coagulation associated with acute leukemia: multicenter prospective study by the Tohoku Hematology Forum

It has been suggested that use of recombinant soluble thrombomodulin (rTM) is superior to conventional drugs in treatment of disseminated intravascular coagulation (DIC) complicating acute leukemia. However, its safety and efficacy have not been fully examined in prospective studies. Here, we performed a multicenter prospective study to examine outcomes of rTM treatment for DIC in patients with acute leukemia. Of 33 patients registered in this study, 13 had acute myeloid leukemia (AML), three had acute lymphoblastic leukemia (ALL), and 17 had acute promyelocytic leukemia (APL). The cumulative rates of DIC resolution at day 7 and day 35 were 56 and 81% in AML/ALL and 53 and 77% in APL, respectively. The median time from the initiation of rTM to DIC resolution was 4xa0days in AML/ALL and 6xa0days in APL patients. Adverse events related to hemorrhage occurred in two AML/ALL patients (13%) and three APL patients (18%). Of these, one AML/ALL patient died with intracranial hemorrhage, and two APL patients died with intracranial hemorrhage and pulmonary hemorrhage. These results suggest that rTM may improve the survival of acute leukemia patients with DIC by inhibiting early death related to hemorrhagic events, as reported previously.

Impact of TET2 deficiency on iron metabolism in erythroblasts

Sideroblastic anemia is characterized by the presence of ring sideroblasts (RSs), which are caused by iron accumulation in the mitochondria of erythroblasts and are present in both the acquired and congenital forms of the disease. However, the mechanism leading to RS formationxa0remains elusive. Acquired sideroblastic anemia is usually observed in myelodysplastic syndrome (MDS). Because a subset of MDS harbors a somatic mutation of TET2, it may be involved in iron metabolism and/or heme biosynthesis in erythroblasts. Tet2 knockdown (Tet2trap) induced exhibited mild normocytic anemia and elevated serum ferritin levels in 4-month-old mice. Although typical RSs were not observed, increased mitochondrial ferritin (FTMT) amounts were observed in the erythroblasts of Tet2-knockdown mice. Quantitative real-time polymerase chain reaction demonstrated significant dysregulation of genes involved in iron and heme metabolism, including Hmox1, Fech, Abcb7, and Sf3b1 downregulation. After the identification of a cytosine-guanine island in the promoters of Fech, Abcb7, and Sf3b1, we evaluated DNA methylation status and found significantly higher methylation levels at the CpG sites in the erythroblasts of Tet2-knockdown mice. Furthermore, Tet2 knockdown in erythroblasts resulted in decreased heme concentration and accumulation of FTMT. Therefore, TET2 plays a role in the iron and heme metabolism in erythroblasts.