There are more opportunities to perform human leukocyte antigen (HLA) -haploidentical stem cell transplantation and cord blood transplantation, and such procedures have become quicker. Since the management of infection and graft-versus-host disease (GVHD) has recently improved, the number of HLA-mismatched transplantations has increased. The HLA-Flow method detects mismatched HLA antigens between donor and recipient using specific anti-HLA antibodies, and analyzes mixed chimerism by flow cytometry. When recipient-derived cells are detected, their cell surface markers can be analyzed. Therefore, the HLA-Flow method is very valuable in early diagnosis of engraftment failure and relapse of leukemia, and in monitoring the number of tumor cells in a rapid and convenient manner. Loss of mismatched HLA in leukemia cells can be estimated using the combination of donor-specific HLA markers and leukemia markers. Since the HLA-Flow method provides a way of detecting chimerism at a high accuracy and high sensitivity, detection of microchimerism in peripheral blood after organ transplantation has become possible. If anti-HLA IgG-isotype antibodies with high affinity can be produced instead of commercially available IgM antibodies with low affinity, the HLA-Flow method is expected to become more prevalent.
Adult T-cell leukemia-lymphoma (ATL) is a mature T-cell neoplasm caused by human T-cell leukemia virus type-Ⅰ (HTLV-1) that has a poor prognosis. Median overall survival (OS) of patients with aggressive ATL treated by chemotherapy alone is about 1 year. Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) has helped achieve OS improvement in aggressive ATL, transplant-related mortality (TRM) is high. To reduce TRM in allo-HSCT, prospective studies of reduced-intensity stem cell transplantation (RIST) using hematopoietic stem cells from peripheral blood, bone marrow, and umbilical cord blood have been conducted. The results suggest that RIST is feasible for elderly patients with ATL, and the existence of mild graft-versus-host disease contributes to better survival outcomes. It has been also demonstrated that Tax-specific T-cell responses might be associated with the graft-versus-ATL effect in patients with relapsed ATL who received RIST. Lack of immunity to viruses, such as cytomegalovirus, in patients who received allo-HSCT is a critical matter. Donor selection in allo-HSCT for ATL is also important, especially with respect to HTLV-1 carrier donor cell-derived ATL. An appropriate combination of allo-HSCT and molecularly targeted therapy is needed to improve OS in patients with ATL.
This retrospective study evaluated the clinical significance of post-allogeneic hematopoietic cell transplantation serum ferritin (SF) levels and liver iron content (LIC), measured using liver magnetic resonance imaging (MRI). Twenty-three transplant recipients with hematologic diseases were included. The median duration from transplant to LIC measurement was 13.4 months (range: 2.2-84.6 months). The median SF and LIC values were 947ng/mL (range: 191-8,082ng/mL) and 250µmol/gdw (range: 60-360µmol/gdw), respectively. LIC was moderately correlated to SF (r=0.53) and the units of transfused red blood cells (r=0.50). SF was moderately correlated to the units of RBCs (r=0.45), transferrin (r=-0.43), unsaturated iron binding capacity (r=-0.50), and C-reactive protein (r=0.40). In conclusion, in post-transplant recipients, it is suggested that SF reflects a combination of factors including iron overload and inflammation or hepatitis, while LIC seems to be a good non-invasive technique to quantify total body iron stores.
Adult T cell leukemia/lymphoma (ATLL) is an aggressive peripheral T-cell neoplasm. Humanized anti-CC chemokine receptor 4 monoclonal antibody (mogamulizumab) has been shown to be effective for relapsed/refractory ATLL. However, the effects of mogamulizumab application before allogeneic stem cell transplantation are uncertain. Here, we present an ATLL patient who was administered mogamulizumab and suffered from refractory acute graft-versus-host disease (GVHD) following umbilical cord blood transplantation (UCBT). This was accompanied by delayed reconstitution and a long-lasting reduction of regulatory T cells (Tregs). We suggest that this attenuation of Tregs influenced the clinical course of the severe/refractory GVHD following UCBT in a patient pretreated with mogamulizumab therapy.