Mesenchymal Stem Cell Therapy Overcomes Steroid Resistance in Severe Gastrointestinal Acute Graft-Versus-Host Disease.

The authors describe the high effectiveness of human mesenchymal stem cell (hMSC) therapy to treat steroid-refractory gastrointestinal acute graft-versus-host Disease (aGVHD) in a 15-year-old boy with acute lymphoblastic leukemia (ALL). He received allogeneic hematopoietic stem cell transplantation due to high-risk hypodiploid ALL. Around the time of engraftment, he developed severe diarrhea following high-grade fever and erythema. Although methylprednisolone pulse therapy was added to tacrolimus and mycophenolate mofetil, diarrhea progressed up to 5000~6000 ml/day and brought about hypocalcemia, hypoalbuminemia, and edema. Daily fresh frozen plasma (FFP), albumin, and calcium replacements were required to maintain blood circulation. After aGVHD was confirmed by colonoscopic biopsy, MSC therapy was administered. The patient received 8 biweekly intravenous infusions of 2×106 hMSCs/kg for 4 weeks, after which additional 4 weekly infusions were performed. A few weeks after initiation, diarrhea gradually resolved, and at the eighth dose of hMSC, lab data improved without replacements. MSC therapy successfully treated steroid-refractory gastrointestinal GVHD without complications. Despite life-threatening diarrhea, the regeneration potential of children and adolescents undergoing SMC therapy successfully supports restoration of gastrointestinal damage. Even with its high treatment costs, SMC therapy should be proactively considered in cases where young patients suffer from severe gastrointestinal GVHD.

Identification of autoantibodies using human proteome microarrays in patients with IPEX syndrome.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is one of the inborn errors of immunity, characterized by impaired function of the regulatory T cells. Clinical manifestations of IPEX syndrome are characterized by various autoimmune diseases with autoantibodies. The comprehensive analysis for autoantibodies using human proteome microarrays in the four patients with IPEX syndrome was performed. The numbers of the highly expressed autoantibody showing relative log2 ratios greater than 1 were 1876, 513, 234 and 831 (mean: 864), respectively. Some novel autoantibodies which could explain the phenotypes of patients, adrenal dysfunction, muscular hypotonia, afibrinogenemia, enteropathy and pancytopenia were identified. Various kinds of autoantibodies targeting testis-specific antigens were also identified. Human proteome microarray is a powerful tool to understand the pathophysiology of IPEX syndrome. The larger cohort analysis using this method will provide further understanding of the impaired immune tolerance in humans.

Early detection of the PAX3-FOXO1 fusion gene in circulating tumor-derived DNA in a case of alveolar rhabdomyosarcoma.

Cell-free DNA (cfDNA), which are small DNA fragments in blood derived from dead cells including tumor cells, could serve as useful biomarkers and provide valuable genetic information about the tumors. cfDNA is now used for the genetic analysis of several types of cancers, as a surrogate for tumor biopsy, designated as "liquid biopsy." Rhabdomyosarcoma (RMS), the most frequent soft tissue tumor in childhood, can arise in any part of the body, and radiological imaging is the only available method for estimating the tumor burden, because no useful specific biological markers are present in the blood. Because tumor volume is one of the determinants of treatment response and outcome, early detection at diagnosis as well as relapse is essential for improving the treatment outcome. A 15-year-old male patient was diagnosed with alveolar RMS of prostate origin with bone marrow invasion. The PAX3-FOXO1 fusion was identified in the tumor cells in the bone marrow. After the diagnosis, cfDNA was serially collected to detect the PAX3-FOXO1 fusion sequence as a tumor marker. cfDNA could be an appropriate source for detecting the fusion gene; assays using cfDNA have proved to be useful for the early detection of tumor progression/recurrence. Additionally, the fusion gene dosage estimated by quantitative polymerase chain reaction reflected the tumor volume during the course of the treatment. We suggest that for fusion gene-positive RMSs, and other soft tissue tumors, the fusion sequence should be used for monitoring the tumor burden in the body to determine the diagnosis and treatment options for the patients.

Lineage-dependent skewing of loss of heterozygosity (LOH) of KRAS gene in a case of juvenile myelomonocytic leukemia.

Juvenile myelomonocytic leukemia (JMML) is a clonal disease arising from abnormal hematopoietic stem cells, although the involvement of lymphoid lineage differs among reported cases. Here, we present a case of JMML with a KRAS G13D mutation. The mutation was detected in various hematopoietic lineages, including T and B lymphocytes and also in lineage(-) CD34(+) CD38(-) hematopoietic stem cells, showing a different percentage of affected cells in each lineage. Single cell-based analysis of hematopoietic cells revealed the loss of wild-type KRAS in a significant proportion of G13D-harboring cells. The percentage of loss of heterozygosity (LOH)/non-LOH cells showed lineage-dependent skewing in hematopoietic cells. The loss of the wild-type KRAS allele may be a common secondary genetic change in KRAS-related JMML and may affect the differentiation behavior of early JMML progenitors.

CLTC-ALK fusion as a primary event in congenital blastic plasmacytoid dendritic cell neoplasm.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a subtype of acute myeloid leukemia, affecting mainly the elderly. It is thought to be derived from plasmacytoid dendritic cell precursors, which frequently present as cutaneous lesions. We have made a detailed analysis of an infant with BPDCN, who manifested with hemophagocytic lymphohistiocytosis. The peripheral blood leukocytes revealed the t(2;17;8)(p23;q23;p23) translocation and a CLTC-ALK fusion gene, which have never been reported in BPDCN or in any myeloid malignancies thus far. Neonatal blood spots on the patient's Guthrie card were analyzed for the presence of the CLTC-ALK fusion gene, identifying the in utero origin of the leukemic cell. Although the leukemic cells were positive for CD4, CD56, CD123, and CD303, indicating a plasmacytoid dendritic cell phenotype, detailed analysis of the lineage distribution of CLTC-ALK revealed that part of monocytes, neutrophils, and T cells possessed the fusion gene and were involved in the leukemic clone. These results indicated that leukemic cells with CLTC-ALK originated in a multipotent hematopoietic progenitor in utero. This is the first report of the CLTC-ALK fusion gene being associated with a myeloid malignancy, which may give us an important clue to the origin of this rare neoplasm.

High aromatase activity and overexpression of epidermal growth factor receptor in fibrolamellar hepatocellular carcinoma in a child.

An 11-year-old boy was admitted with a liver tumor and underwent right trisegmentectomy for a diagnosis of fibrolamellar hepatocellular carcinoma. He had suffered from bilateral gynecomastia for a year, which improved after complete resection of the tumor. The tumor cells had significant aromatase activity (8.03 pmol/g/h) and contained high levels of estradiol (82.1 pg/mL), which contributed to gynecomastia. Furthermore, overexpression of epidermal growth factor receptor was determined in the tumor cells, which suggests that antitumor strategies using epidermal growth factor receptor antagonists may be effective.

Reversible coma associated with prolonged high-dose phenobarbital therapy in bilateral Sturge-Weber syndrome.

High-dose phenobarbital therapy is an effective treatment for refractory status epilepticus in children. The advantages of this therapy include milder adverse effects without limits for maximal phenobarbital levels or doses during the initial phase of treatment. However, little is known about the safety of continuing the treatment. We describe an infant with intractable epilepsy associated with bilateral Sturge-Weber syndrome who became comatose after 1(2/3) months of high-dose phenobarbital treatment. The patient regained consciousness as serum phenobarbital concentration decreased to below 40 microg/mL. The progression and recovery were also documented by electroencephalogram and brainstem auditory evoked potentials. The present case suggests that prolonged high-dose phenobarbital therapy may cause cerebral and brainstem dysfunction in patients with severe cerebrovascular diseases. The underlying baseline metabolic and perfusion deficit related to the disease can precipitate the neurological complication during long-term high-dose phenobarbital therapy.

A complete remission of sclerosing rhabdomyosarcoma with multiple lung and bone metastases treated with multi-agent chemotherapy and peripheral blood stem cell transplantation (PBSCT): a case report.

A case of sclerosing rhabdomyosarcoma (RMS) in a young adult with multiple lung and skip bone metastases is reported. Complete remission was achieved with this patient by treatment with multi-agent chemotherapy and peripheral blood stem cell transplantation (PBSCT) based on the pathological diagnosis of RMS using a specimen obtained during an open biopsy at the first consultation. He is still alive and has been continuously disease free for 12 years after surgery. This is a very rare case with successful treatment using PBSCT for a sclerosing RMS that presented with multiple distant metastases at the first consultation.

Outcome of non-T-cell-depleted HLA-haploidentical hematopoietic stem cell transplantation from family donors in children and adolescents.

Non-T-cell-depleted HLA-haploidentical hematopoietic stem cell transplantation (SCT) from family members has been reported, but its effectiveness and safety are not fully known. In this study, we examined the outcomes of 83 children and adolescents with nonmalignant (n = 11) or malignant (n = 72) disorders who underwent SCT mismatched at 2 or 3 HLA loci, either from the mother (n = 56), a noninherited maternal antigen (NIMA)-mismatched sibling (n = 14), or the father/a noninherited paternal antigen (NIPA)-mismatched sibling (n = 13). Engraftment was satisfactory. Severe (grade III-IV) acute graft-versushost disease (GVHD) was noted only in malignant disease, with an incidence of 21 of 64 evaluable patients. GVHD prophylaxis with a combination of tacrolimus and methotrexate was significantly associated with a lower risk of severe acute GVHD, compared with other types of prophylaxis (P = .04). Nine of 11 patients with nonmalignant disease and 29 of 72 patients with malignant disease were alive at a median follow-up of 26 months (range, 4-57 months). Outcomes were not significantly different among the 3 donor groups (mother versus NIMA-mismatched sibling versus father/NIPA-mismatched sibling) for the malignancy disorders. Our results indicate that non-T-cell-depleted HLA-haploidentical SCT may be feasible, with appropriate GVHD prophylaxis, for young recipients who lack immediate access to a conventional stem cell source.