Aldehyde Dehydrogenase Activity as a Marker of Quality in Cryopreserved Cord Blood

We investigated the effects of cryopreservation on CD34+ cells and aldehyde dehydrogenase (ALDH) -positive cells (ALDH (+) cells) in the umbilical cord blood (UCB) of unrelated donors. Ten units of UCB were collected at the Kanagawa Cord Blood Bank from September 2009 to November 2010. These UCB units were frozen for 2 weeks or 1 year, and then assayed for quality by flow cytometry analysis and colony-forming assay. We found that both ALDH (+) cells and the numbers of total colony-forming units and colony-forming units of granulocyte/macrophage from the isolated CD34+ cells were significantly decreased after all cryopreservation. The numbers of ALDH (+) /CD34+ cells, ALDH (+) /CD34+CD38- cells, and total colony-forming units from the cryopreserved UCB units continued to decrease over time with cryopreservation. In contrast, levels of traditional primitive surface markers were not significantly decreased in CD34+ cells and CD34+CD38- cells after cryopreservation, although this result depended on the duration of cryopreservation. These findings suggested that ALDH (+) cells could be a new marker for assessing cryopreserved UCB quality prior to hematopoietic cell transplantation

Cord Blood Transplantation from Unrelated Donors for Children with Acute Lymphoblastic Leukemia in Japan: The Impact of Methotrexate on Clinical Outcomes

Cord blood transplantation (CBT) from an unrelated donor is recognized as one of the major treatment modalities in allogeneic stem cell transplantation (SCT) for children with hematologic malignancies. We analyzed the clinical outcomes of CBT for children with acute lymphoblastic leukemia (ALL) in Japan and identified the risk factors for the transplant outcomes. From 1997 to 2006, 332 children with ALL underwent CBT from unrelated donors, 270 of which had no prior transplant. Their disease statuses at transplant were first complete remission (CR) (n = 120), second CR (n = 71), and more advanced stages (n = 75). As preconditioning for SCT, total body irradiation (TBI) was given to 194 patients and, for the prophylaxis of graft-versus-host disease (GVHD), methotrexate (MTX) was given to 159 patients. The cumulative incidents of neutrophil and platelet recovery (>20 K) were 88.5% and 78.4%, respectively. The incidents of grade II-IV, III-IV acute GVHD (aGVHD), and chronic GVHD (cGVHD) were 45.6%, 20.4%, and 19.2%, respectively, and treatment-related mortality was 22.6%. The 5-year event-free survival (EFS) and overall survival (OS) at CR1, CR2, and advanced status were 47.4%, 45.5%, 15.0%, and 63.7%, 59.7%, and 20.7%, respectively. Multivariate analysis revealed that MTX with calcineurin inhibitor (CNI) was associated with decreased incidence of grade II-IV GVHD (CNI alone: hazard ratio [HR] = 1.74, 95% confidence interval [CI] = 1.06-2.83, P = .027; CNI + prednisolone (PSL), HR = 1.61, 95% CI = 1.03-2.50, P = .036), III-IV aGVHD (CNI alone: HR = 3.02, 95% CI = 1.55-5.91, P = 0.001; CNI + PSL, HR = 1.89, 95% CI = 0.93-3.83, P = .078), or cGVHD (CNI alone: HR = 1.78, 95% CI = 0.83-3.82, P = .143; CNI + PSL, HR = 2.44, 95% CI = 1.24-4.82, P = .01), compared with CNI alone or CNI + PSL. At an advanced stage of disease, GVHD prophylaxis with MTX + CNI is associated with improved OS compared with CNI alone (CNI alone: HR = 3.20, 95% CI = 1.43-7.15, P = .005; CNI + PSL, HR = 1.47, CI = 0.67-3.20, P = .332). Our retrospective study showed that CBT for children with ALL is feasible and GVHD prophylaxis with MTX + CNI is associated with significant favorable outcomes in prevention of aGVHD and cGVHD as well as survival advantage in advanced cases

Wiskott–Aldrich syndrome that was initially diagnosed as immune thrombocytopenic purpura secondary to a cytomegalovirus infection

Wiskott–Aldrich syndrome is a rare X-linked recessive disease resulting from variations in the WAS gene. Wiskott–Aldrich syndrome is sometimes difficult to differentiate from immune thrombocytopenic purpura. A 2-month-old boy was admitted to our hospital for purpura and thrombocytopenia. His mean platelet volume was reported to be normal. Treatment with intravenous immunoglobulins failed to improve the patient’s platelet count. Subsequently, an acute cytomegalovirus infection was confirmed by serological testing and antigenemia. The patient was diagnosed with immune thrombocytopenic purpura secondary to a cytomegalovirus infection. However, based on the patient’s clinical course and the refractoriness of his condition, Wiskott–Aldrich syndrome was strongly suspected. Through direct sequencing of the genomic DNA of the Wiskott–Aldrich syndrome protein (WASP) gene, we identified a novel missense mutation in exon 3 of the patient’s WASP gene (c. 343 C>T, p. H115T), and the patient was diagnosed with Wiskott–Aldrich syndrome at 3 months after onset. Children with Wiskott–Aldrich syndrome are often initially diagnosed with immune thrombocytopenic purpura, which can lead to inappropriate treatment and delays to life-saving definitive therapy. Our findings imply that Wiskott–Aldrich syndrome should be considered as a differential diagnosis in cases of refractory immune thrombocytopenic purpura combined with a cytomegalovirus infection