Sonoko Kamoshita

Dexamethasone palmitate successfully attenuates hemophagocytic syndrome after allogeneic stem cell transplantation: macrophage-targeted steroid therapy

Hemophagocytic syndrome (HPS) induced by uncontrolled macrophage activation and subsequent graft failure is a frequent and prominent complication after allogeneic stem cell transplantation (allo-SCT), a cause of severe morbidity and death, and a therapeutic challenge. Liposome-incorporated dexamethasone, dexamethasone palmitate (DP), shows greater efficacy against macrophages as compared to dexamethasone sodium phosphate (DSP). Based on our findings that DP achieves significantly larger decrease than DSP on the viability of primary human macrophages compared in vitro, we tested the effects of DP in patients with HPS. A decrease in number of macrophages in the bone marrow and prevention of engraftment failure were observed in all patients without any severe complications. In conclusion, these data provide a rationale for testing DP as a first-line treatment for patients with HPS after allo-SCT.

High incidence of extensive chronic graft-versus-host disease in patients with the REG3A rs7588571 non-GG genotype

Regenerating islet-derived protein 3 alpha (REG3A) is a biomarker of lower gastrointestinal graft-versus-host disease (GVHD); however, the biological role of REG3A in the pathophysiology of GVHD is not understood. Here, we examined the association between a single nucleotide polymorphism in the REG3A gene, rs7588571, which is located upstream and within 2 kb of the REG3A gene, and transplant outcomes including the incidence of GVHD. The study population consisted of 126 adult Japanese patients who had undergone bone marrow transplantation from a HLA-matched sibling. There was no association between rs7588571 polymorphism and the incidence of acute GVHD. However, a significantly higher incidence of extensive chronic GVHD was observed in patients with the rs7588571 non-GG genotype than in those with the GG genotype (Odds ratio 2.6; 95% confidence interval, 1.1–6.0; P = 0.029). Semi-quantitative reverse transcription PCR demonstrated that the rs7588571 non-GG genotype exhibited a significantly lower REG3A mRNA expression level than the GG genotype (P = 0.032), and Western blot analysis demonstrated that the rs7588571 non-GG genotype exhibited a trend toward lower REG3A protein expression level than the GG genotype (P = 0.053). Since REG proteins have several activities that function to control intestinal microbiota, and since intestinal dysbiosis is in part responsible for the development of GVHD, our findings lead to the novel concept that REG3A could have some protective effect in the pathogenesis of GVHD through the regulation of gut microbiota.

Quantitative assessment of T cell clonotypes in human acute graft-versus-host disease tissues

Owing to the difficulty in isolating T cells from human biopsy samples, the characteristics of T cells that are infiltratinghuman acute graft-versus-host disease (GVHD) tissues remain largely uninvestigated. In the present study, TCR-β deep sequencing of various GVHD tissue samples and concurrent peripheral blood obtained from transplant recipients was performed in combination with functional assays of tissue-infiltrating T cell clones. The T cell repertoire was more skewed in GVHD tissues than in the peripheral blood. The frequent clonotypes differed from tissue to tissue in the same patient, and the frequent clonotypes in the same tissue differed from patient to patient. Two T cell clones were successfully isolated from GVHD skin of a patient. In a cytotoxicity assay, both Tcell clones lysed patient peripheral blood mononuclear cells, but not donor-derived Epstein-Barr virus-transformed lymphoblastoid cells. Their clonotypes were identical to the most and second most frequent T cell clonotypes in the original GVHD skin and accounted for almost all of the skin-infiltrating T cells. These results suggest that human acute GVHD may result from only a few different alloreactive cytotoxic T cell clones, which differ from tissue to tissue and from patient to patient. The characterization of T cells infiltrating human GVHD tissues should be further investigated.

Successful treatment with allogeneic stem cell transplantation followed by DLI and TKIs for e6a2 BCR-ABL-positive acute myeloid leukaemia: A case report and literature review

Rationale: Patients with the e6a2 BCR-ABL transcript, 1 of the atypical transcripts, have been reported to have a poor prognosis, and allogeneic stem cell transplantation (ASCT) can be considered as additional therapy. However, long-term survival after ASCT for this disease is rare. Patient concerns: This report concerns a 55-year-old female patient with e6a2 BCR-ABL-positive acute myeloid leukemia including the outcome of ASCT followed by donor lymphocyte infusion (DLI). Diagnoses: The breakpoint was confirmed by direct sequencing. Her minimal residual disease could be detected by nested reverse-transcription polymerase chain reaction using primers for the minor BCR-ABL (e1a2) transcript. Interventions: Treatment with tyrosine kinase inhibitors (TKIs) and ASCT followed by DLI. Outcomes: Despite multiple cytogenetic and molecular relapses after ASCT, she remains in molecular remission at 46 months after ASCT. Lessons: This case indicates the efficacy of the combination of the graft-versus-leukemia effect and TKIs for e6a2 BCR-ABL-positive acute leukemia. When the Philadelphia chromosome with an unusual chromosomal breakpoint is suggested, we should clarify the breakpoint because that information can aid molecular assessments and decisions to provide an additional or alternative therapy.