神田 善伸

The optimal bridge strategy at the decision for allogeneic hematopoietic stem cell transplantation (HSCT) in patients with myelodysplastic syndrome (MDS) is unclear. We performed a prospective observational study in which 110 patients with MDS who were decided to undergo HSCT were enrolled. Among these 110 patients, 77 patients were enrolled in this study within 1 month from the decision for HSCT. Among these 77 patients, 13 patients had a human leukocyte antigen (HLA)-matched sibling, 54 patients started an unrelated donor search, and the other 10 patients directly selected cord blood (CB) at the decision for HSCT, and 13 (100%), 38 (70.4%), and 9 (90%) patients actually underwent HSCT within 1 year, respectively. The overall survival (OS) at 1 year from their enrollment was 70.9%, and the selection of azacitidine use at the decision for HSCT was not associated with OS. Among 60 of the 77 patients who actually underwent HSCT within a year from their enrollment, a lower relapse rate after HSCT was observed in those who selected CB at the decision to undergo HSCT. However, this preferable effect of CB selection disappeared when patients who were enrolled in this study in > 1 month from the decision for HSCT were additionally included in the analyses. In conclusion, the selection of bridge strategy at the decision for HSCT did not affect outcomes in patients with MDS. The immediate performance of HSCT may be associated with better outcomes.

Combination of calcineurin inhibitors (CIs) with short-term methotrexate is a standard prophylactic regimen for graft-versus-host disease (GVHD). However, it is sometimes difficult to continue CIs due to adverse effects, such as renal impairment and fluid overload. In such cases, we replace CIs with corticosteroids, considering that full dose of CIs is equivalent to prednisolone (PSL) at 1 mg/kg. We retrospectively evaluated the clinical significance of replacement of CIs with corticosteroids after allogeneic hematopoietic cell transplantation (HCT). We evaluated 42 patients switched from CIs to corticosteroids within 90 days among the 479 patients who underwent allogeneic HCT at our center between 2007 and 2019. Renal impairment (n = 33), fluid overload (n = 13), and thrombotic microangiopathy (n = 3) were the main reasons for switching. Although creatinine and body weight returned to baseline at 4 weeks after switching, 100-day non-relapse mortality was high (57.1%). Grade II-IV acute GVHD was seen in 10 (24.4%) patients who did not have it before switching treatment (n = 41). In conclusion, CIs were switched to corticosteroids in patients with severe clinical conditions. The incidence of acute GVHD was acceptable. Although the short-term mortality rate was high, improvement of renal function or fluid overload was observed in a certain proportion of the patients.

Chronic graft-versus-host disease (cGVHD) is a multiorgan syndrome with clinical features resembling those of autoimmune diseases. Thus, understanding commonalities in the pathophysiology of cGVHD and autoimmune diseases, such as the presence of disease-risk HLA alleles, is imperative for developing novel therapies against cGVHD. Alloantibodies against H-Y antigens encoded on the Y-chromosome are well-described risk factors for cGVHD in female-to-male transplantation. However, since H-Y antigens generally localize intracellularly in the male reproductive organs, how they emerge at affected organ levels remains elusive. Here, by analyzing nationwide registry data stratified according to donor-recipient sex, we identified specific HLA class II alleles that contributed to susceptibility to male cGVHD following transplantation from HLA-identical female siblings [HLA-DRB1*15:02: hazard ratio, 1.28; 95% confidence interval, 1.03-1.58; P = 0.025]. Co-expression of HLA-DRB1*15:02 efficiently transported full-length H-Y antigens, especially DBY, to the surface. The presence of alloantibodies against DBY/HLA class II complexes significantly predicted the occurrence of cGVHD [68.8% vs. 31.7% at 1 year, P = 0.002]. Notably, the ability of HLA class II molecules to transport and present DBY to alloantibodies was closely associated with the susceptibility of HLA class II alleles to cGVHD. DBY specifically colocalized with HLA class II molecules on the dermal vascular endothelium in cGVHD and provoked complement-dependent cytotoxicity. Moreover, these complexes were observed in some male leukemic cells. Altogether, these findings suggest that vascular endothelial cells facilitate alloantibody-mediated cGVHD, and highlight that alloantibodies against DBY/HLA class II complexes could be common targets for cGVHD and a graft-versus-leukemia effect.

Abstract Allogeneic hematopoietic cell transplantation between female donors and male recipients (female-to-male allo-HCT) is a well-established risk factor for inferior survival outcomes due to a higher incidence of graft-versus-host disease (GVHD). However, a clinical significance of anti-thymocyte globulin (ATG) in the female-to-male allo-HCT has not been elucidated. In this study, we retrospectively evaluated male patients who underwent allo-HCT between 2012 and 2019 in Japan. In the female-to-male allo-HCT cohort (n = 828), the use of ATG was not associated with a decreased risk of GVHD (HR of acute GVHD 0.691 [95% CI: 0.461–1.04], P = 0.074; HR of chronic GVHD 1.06 [95% CI: 0.738–1.52], P = 0.76), but was associated with favorable overall survival (OS) and a decreased risk of non-relapse mortality (NRM) (HR of OS 0.603 [95% CI: 0.400–0.909], P = 0.016; HR of NRM 0.506 [95% CI: 0.300–0.856], P = 0.011). The use of ATG in female-to-male allo-HCT resulted in survival outcomes that were almost equivalent to those in the male-to-male allo-HCT group. Therefore, GVHD prophylaxis with ATG might overcome the inferiority of survival outcomes in female-to-male allo-HCT.

34歳男性。KMT2A-MLLT1陽性急性骨髄性白血病の第1寛解期で,busulfan/高用量cyclophosphamideを前処置としてHLA適合の妹より同種末梢血幹細胞移植を施行した。Day14に生着し以降は寛解を維持した。重篤な移植片対宿主病も認めなかったが,経口cyclosporin(CsA)10mg/dayまで減量した移植後6ヶ月の時点で間質性肺炎を発症した。間質性肺炎に対して投与したprednisolone(PSL)の効果は一時的で,間質性肺炎は急速に増悪した。追加精査にて抗MDA5抗体陽性が判明したためcyclophosphamide+PSL+CsAによる3剤併用療法を開始して奏効が得られた。しかし,後遺症の呼吸不全で人工呼吸器管理を要したため,弟と妹より生体肺移植を施行した。3剤併用療法と生体肺移植により呼吸状態の改善を得た抗MDA5抗体陽性急速進行性間質性肺疾患の症例を経験したため,ここに報告する。(著者抄録)