Kazuhiro Kogawa

Identification of Severe Combined Immunodeficiency by T-Cell Receptor Excision Circles Quantification Using Neonatal Guthrie Cards

OBJECTIVE To assess the feasibility of T-cell receptor excision circles (TRECs) quantification for neonatal mass screening of severe combined immunodeficiency (SCID). STUDY DESIGN Real-time PCR based quantification of TRECs for 471 healthy control patients and 18 patients with SCID with various genetic abnormalities (IL2RG, JAK3, ADA, LIG4, RAG1) were performed, including patients with maternal T-cell engraftment (n = 4) and leaky T cells (n = 3). RESULTS TRECs were detectable in all normal neonatal Guthrie cards (n = 326) at the levels of 10(4) to 10(5) copies/microg DNA. In contrast, TRECs were extremely low in all neonatal Guthrie cards (n = 15) and peripheral blood (n = 14) from patients with SCID, including those with maternal T-cell engraftment or leaky T cells with hypomorphic RAG1 mutations or LIG4 deficiency. There were no false-positive or negative results in this study. CONCLUSION TRECs quantification can be used as a neonatal mass screening for patients with SCID.

Hematopoietic stem cell transplantation for 30 patients with primary immunodeficiency diseases: 20 years experience of a single team.

We retrospectively analyzed our results of 30 patients with three distinctive primary immunodeficiency diseases (PIDs) – severe combined immunodeficiency (SCID, n=11), Wiskott–Aldrich syndrome (WAS, n=11) and X-linked hyper-immunoglobulin M (IgM) syndrome (XHIM, n=8) – who underwent hematopoietic SCT (HSCT) during the past 20 years. Until 1995, all donors were HLA-haploidentical relatives with T-cell depletion (TCD) (n=8). Since 1996, the donors have been HLA-matched related donors (MRD) (n=8), unrelated BM (UR-BM) (n=7) and unrelated cord blood (UR-CB) (n=7). Twenty-seven of 30 patients had various pre-existing infections with or without organ damages before HSCT. Conditioning regimen and GVHD prophylaxis were determined according to disease, donor and pretransplant status. Although one of eight patients transplanted with TCD is alive with full engraftment, the other seven died. On the other hand, 18 of 22 patients transplanted without TCD are alive and well, including six of eight transplanted from MRD, seven of seven from UR-BM and five of seven from UR-CB. All 19 survivors did not require Ig supplementation after HSCT. These results indicate that UR-CBT as well as UR-BMT provides good results for PID comparable to MRD-SCT, and that early diagnosis, HSCT at early stage, careful supportive therapy and monitoring for various pathogens are important for the successful HSCT.

Down syndrome and GATA1 mutations in transient abnormal myeloproliferative disorder: mutation classes correlate with progression to myeloid leukemia

Twenty percent to 30% of transient abnormal myelopoiesis (TAM) observed in newborns with Down syndrome (DS) develop myeloid leukemia of DS (ML-DS). Most cases of TAM carry somatic GATA1 mutations resulting in the exclusive expression of a truncated protein (GATA1s). However, there are no reports on the expression levels of GATA1s in TAM blasts, and the risk factors for the progression to ML-DS are unidentified. To test whether the spectrum of transcripts derived from the mutant GATA1 genes affects the expression levels, we classified the mutations according to the types of transcripts, and investigated the modalities of expression by in vitro transfection experiments using GATA1 expression constructs harboring mutations. We show here that the mutations affected the amount of mutant protein. Based on our estimates of GATA1s protein expression, the mutations were classified into GATA1s high and low groups. Phenotypic analyses of 66 TAM patients with GATA1 mutations revealed that GATA1s low mutations were significantly associated with a risk of progression to ML-DS (P < .001) and lower white blood cell counts (P = .004). Our study indicates that quantitative differences in mutant protein levels have significant effects on the phenotype of TAM and warrants further investigation in a prospective study.

Usefulness of procalcitonin serum level for the discrimination of severe sepsis from sepsis: a multicenter prospective study

Procalcitonin serum level has been recommended as a new marker of bacterial infectious diseases. The aim of this prospective, multicenter study was to determine the clinical usefulness of procalcitonin in differentiating patients with sepsis from those with severe sepsis. Eighty-two patients were enrolled: 20 without systemic inflammatory response syndrome (SIRS), 9 with SIRS, 34 with sepsis, and 19 with severe sepsis. The patients with severe sepsis had significantly higher procalcitonin levels (median, 36.1 ng/ml) than those with sepsis (median, 0.6 ng/ml). With a procalcitonin cutoff value of 2.0 ng/ml, sensitivity for the detection of severe sepsis and specificity for the detection of sepsis were 94.7% and 78.1%, respectively. A good correlation was found between the serum procalcitonin level and the Sepsis-Related Organ Failure Assessment (SOFA) score (r = 0.680), although no correlation was found between the C-reactive protein (CRP) level and the SOFA score. In conclusion, the procalcitonin serum level may be useful not only for aiding the diagnosis of sepsis but also for discriminating between sepsis and severe sepsis.

Minimal residual disease-based augmented therapy in childhood acute lymphoblastic leukemia: A report from the Japanese Childhood Cancer and Leukemia Study Group†

The majority of minimal residual disease (MRD)‐positive patients with acute lymphoblastic leukemia (ALL) have poor outcomes. The ALL2000 study was performed to evaluate the efficacy of augmented chemotherapy based on MRD‐restratification in childhood ALL.

Prognostic factors of Epstein–Barr virus-associated hemophagocytic lymphohistiocytosis in children: Report of the Japan Histiocytosis Study Group

Despite several advances in the treatment of Epstein–Barr virus (EBV) in recent years, patients with Epstein–Barr virus‐associated hemophagocytic lymphohistiocytosis (EBV‐HLH) do not always show satisfactory outcomes. We here conducted a nationwide survey in Japan to identify prognostic factors of EBV‐HLH in children with this disease in an effort to improve the management and the outcomes of these patients.

Clinical characteristics and outcomes of chédiak–Higashi syndrome: A nationwide survey of Japan

Chédiak–Higashi syndrome (CHS) is a rare autosomal recessive disorder characterized by immunodeficiency, neurological dysfunction, and oculocutaneous albinism. Recently, several clinical CHS phenotypes have been reported. Here, we report results of a nationwide survey performed to clarify clinical characteristics and outcomes of CHS patients in Japan.

Neonatal Herpes Encephalitis Caused by a Virologically Confirmed Acyclovir-Resistant Herpes Simplex Virus 1 Strain

ABSTRACT A neonate with herpes simplex virus 1 encephalitis was treated with intravenous acyclovir. During the course of therapy, the infection became intractable to the treatment and a mutation in the viral thymidine kinase gene (nucleotide G375T, amino acid Q125H) developed. This mutation was demonstrated in vitro to confer acyclovir resistance.

Continuous and high-dose cytarabine combined chemotherapy in children with down syndrome and acute myeloid leukemia: Report from the Japanese children's cancer and leukemia study group (JCCLSG) AML 9805 down study.

The aim of the JCCLSG AML 9805 Down study was to evaluate the effect of continuous and high‐dose cytarabine combined chemotherapy on the survival outcome of acute myeloid leukemia (AML) with Down syndrome (DS).

Thrombocytopenia with Absent Radii Syndrome: Studies on Serum Thrombopoietin Levels and Megakaryopoiesis In Vitro

PURPOSE The pathogenesis of thrombocytopenia in patients with thrombocytopenia with absent radii (TAR) syndrome has not been clarified yet. PATIENTS AND METHODS This is the first report of a Japanese patient with TAR syndrome. We studied his megakaryopoiesis in vitro and serum levels of thrombopoietin (TPO). RESULTS Serum levels of TPO in the patient with TAR syndrome were comparable with those of an age-matched control. The bone marrow cells from the patient with TAR syndrome actually generated megakaryocyte colonies in the presence of TPO and the numbers were significantly greater than those from the age-matched control marrow. However, megakaryocyte colonies from the marrow cells with TAR syndrome contained a much lower number of cells per colony and the size of the individual megakaryocytes appeared to be smaller. CONCLUSION These data suggest that megakaryocyte progenitors from patients with TAR syndrome may have decreased proliferative and differentiative capacity to respond to TPO, leading to thrombocytopenia.