Long-term lymphocyte subset number reconstitution is unique but comparable between umbilical cord blood and unrelated bone marrow transplantation.

The number of umbilical cord blood transplantation (U-CBT) procedures has been growing annually, but little research has been done on long-term immune recovery after U-CBT. Infection risk is high in U-CBT recipients, and this can be partially attributed to immature immunocompetent cells in umbilical cord blood. In this study, we analyzed lymphocyte subset (LST) number to determine the long-term recovery timeline.

A case report of a truncated ABL1 mutation in 2 cases with Philadelphia chromosome-positive B cell precursor acute lymphoblastic leukemia.

Acquired point mutations in the ABL1 gene are widely recognized as a cause of Philadelphia chromosome-positive B cell precursor acute lymphoblastic leukemia (Ph B-ALL) that is resistant to tyrosine kinase inhibitors, whereas there are few reports about other types of the ABL1 mutation. Here, we report 2 cases of Ph B-ALL gaining a partial deletion type mutation of the ABL1 gene (Δ184-274 mutation), which resulted in truncation of the ABL1 molecule and loss of kinase activity. In both cases, the disease was refractory to multiple agents in the recurrent phase after allogeneic hematopoietic cell transplantation.

Development and validation of a scoring system to predict vasovagal reaction upon whole-blood donation.

Background And Objectives: Risk factors for vasovagal reaction (VVR) have been extensively studied. With knowledge of the relative importance of these risk factors for VVR, collection staff could take care of blood donors from the same standpoint, leading to improved donor safety. We therefore developed a scoring system to predict VVR, which incorporates registration information.

Cord blood index predicts engraftment and early non-relapse mortality in adult patients with single-unit cord blood transplantation.

How to select optimal cord blood (CB) remains an important clinical question. We developed and validated an index of CB engraftment, the cord blood index (CBI), which uses three weighted variables representing cell doses and HLA mismatches. We modeled the neutrophil engraftment time with competing events by random survival forests for competing risks as a function of the predictors: total nucleated cells, CD34, colony-forming units for granulocytes/macrophages, and the number of HLA mismatches at the antigen and allele levels.

Syncopal-type reactions tend to be delayed and result in falls among elderly blood donors.

Background: Delayed syncopal-type complications are infrequent among blood donors, but sometimes have critical consequences, such as severe injury. We retrospectively investigated the characteristics of donors with delayed syncopal-type complications or falls.

Study Design And Methods: We defined a delayed reaction (DR) as syncopal-type complications occurring >20 min after needle removal.

Patient rescue and blood utilization in the Ogasawara blood rotation system.

Background: In the past, blood products were not transported to the Ogasawara Islands because of the distance; the islands are approximately 1000 km from the mainland and lack an airport. The Ogasawara Blood Rotation system involves the routine, long-distance transportation of Type O, RhD-positive, irradiated red blood cells to rescue patients with acute hemorrhage and severe anemia and to reduce wastage from the expiration of red blood cell solution.

Study Design And Methods: Blood transfusion and utilization in the Ogasawara blood rotation (BR) system were examined from December 2014 to March 2017.

Homozygous HLA-C1 is Associated with Reduced Risk of Relapse after HLA-Matched Transplantation in Patients with Myeloid Leukemia.

Natural killer (NK) cells assume graft-versus-leukemia alloreactivity after hematopoietic stem cell transplantation (HSCT) through their inhibitory killer cell immunoglobulin-like receptors (KIRs). KIR2D family members recognize HLA-C alleles with Asn80 (HLA-C1) or Lys80 (HLA-C2). The predominance of HLA-C1 over HLA-C2 and the frequent presence of KIR2DL1 are characteristic of Japanese people.

Upper-extremity Deep Vein Thrombosis Complicating Apheresis in a Healthy Donor.

Venous thrombus was recognized in the upper extremity of a 53-year-old man after blood donation. The patient presented with a 15-day history of swelling in the left upper-extremity that started 6 hours after apheresis. Contrast-enhanced computed tomography revealed clots in the deep veins of the left arm and the peripheral pulmonary artery.

Influence of Differently Licensed KIR2DL1-Positive Natural Killer Cells in Transplant Recipients with Acute Leukemia: A Japanese National Registry Study.

Licensing by self MHC class I ligands is required for proper natural killer (NK) cell response. NK cells with inhibitory killer cell immunoglobulin-like receptors for nonself MHC exhibit transient alloreactivity after hematopoietic stem cell transplantation (HSCT). We analyzed 3866 recipients in the Japan national registry who underwent their first allogeneic HSCT for acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) from HLA-A, -B, and -DRB1 allele-genomatched unrelated donors.

Donor killer immunoglobulin-like receptor (KIR) genotype-patient cognate KIR ligand combination and antithymocyte globulin preadministration are critical factors in outcome of HLA-C-KIR ligand-mismatched T cell-replete unrelated bone marrow transplantation.

We previously reported the potent adverse effects of killer immunoglobulin-like receptor (KIR) ligand mismatch (KIR-L-MM) on the outcome of T cell-replete unrelated hematopoietic stem cell transplantation (UR-HSCT) through the Japan Marrow Donor Program. Other UR-HSCT studies have yielded inconsistent results. To address this discrepancy, we evaluated candidate factors contributing to the effects of KIR-L-MM on transplantation outcomes in retrospectively selected hematologic malignancy cases with uniform graft-versus-host disease (GVHD) prophylaxis (n = 1489).

The CD1d natural killer T-cell antigen presentation pathway is highly conserved between humans and rhesus macaques.

Natural killer T (NKT) cells play an important role in controlling cancers, infectious diseases and autoimmune diseases. Although the rhesus macaque is a useful primate model for many human diseases such as infectious and autoimmune diseases, little is known about their NKT cells. We analyzed V alpha 24TCR+ T cells from rhesus macaque peripheral blood mononuclear cells stimulated with alpha-galactosylceramide (alpha-GalCer) and interleukin-2.

Analysis of HLA genes and haplotypes in Ainu (from Hokkaido, northern Japan) supports the premise that they descent from Upper Paleolithic populations of East Asia.

The Ainu people are assumed to be the descendants of pre-agricultural native populations of northern Japan, while the majority of population of present-day Japan (Hondo-Japanese) is considered to have descended mainly from post-neolithic migrants. Sequence-level polymorphisms of the HLA-class I (HLA-A and HLA-B) genes were investigated in DNA samples of 50 Ainu living in Hidaka district, Hokkaido. HLA-A*2402, A*0201, A*0206, A*2601, A*3101, B*1501, B*5101, B*3901, and B*3501 were observed at frequencies of more than 10% and most of these have previously been found in populations of not only Asians but also North and South American Indians.

Different alleles cause an imbalance in A2 and A2B phenotypes of the ABO blood group.

Background And Objectives: In several populations, including the Japanese, the frequency of the A2B phenotype is significantly higher than expected based on the A2 phenotype frequency. To understand the genetic basis of this 'excess' of A2B, we examined ABO alleles in individuals with A2-related phenotypes.

Materials And Methods: ABO alleles were identified by means of polymerase chain reaction single-strand conformation polymorphism (SSCP) and nucleotide sequence analyses.

Five HLA-B22 group alleles in Japanese.

HLA-B22-group alleles in Japanese were identified using PCR-single-strand conformation polymorphism (SSCP) and sequence analyses. We analyzed genomic DNAs obtained from Japanese individuals positive for HLA-B22 group antigens (HLA-B54, B55, B56) including two locally proposed splits (B55.2, and B22N).

Molecular genetic analysis of variant phenotypes of the ABO blood group system.

ABO is clinically the most important blood group system in transfusion medicine and includes many variant phenotypes. To understand the molecular genetic basis of this polymorphic system, we have analyzed genomic DNAs obtained from Japanese individuals possessing variant ABO phenotypes including A2, Ax, Ael, cis-AB, Bx, and Bel. By polymerase chain reaction-single-strand conformation polymorphism (SSCP) and nucleotide sequence analyses, we identified 11 different alleles.

HLA class II alleles in Ainu living in Hidaka District, Hokkaido, northern Japan.

The Ainu people are considered to be the descendants of preagricultural native populations of northern Japan, while the majority of the population of contemporary Japan (Wajin) is descended mainly from postneolithic migrants. Polymorphisms of the HLA-DRB1, DRB3, and DQB1 alleles were investigated in DNA samples of 50 Ainu living in Hidaka district, Hokkaido. Unique features of the Ainu in this study were high incidences of DRB1*1401, DRB1*1406, and a newly described allele, DRB1*1106 (20%, 17%, and 5%, respectively).

Extensive polymorphism of ABO blood group gene: three major lineages of the alleles for the common ABO phenotypes.

Polymorphism of the ABO blood group gene was investigated in 262 healthy Japanese donors by a polymerase chain reactions-single-strand conformation polymorphism (PCR-SSCP) method, and 13 different alleles were identified. The number of alleles identified in each group was 4 for A1 (provisionally called ABO*A101, *A102, *A103 and *A104 according to the guidelines for human gene nomenclature), 3 for B (ABO*B101, *B102 and *B103), and 6 for O (ABO*O101, *O102, *O103, *O201, *O202 and *O203). Nucleotide sequences of the amplified fragments with different SSCP patterns were determined by direct sequencing.

HLA-B40, B18, B27, and B37 allele discrimination using group-specific amplification and SSCP method.

We developed a system for discriminating HLA-B40, B18, B27, and B37 alleles using a two-step PCR method followed by SSCP analysis. Fragments (0.8 kb) including exon 2, intron 2, and exon 3 were amplified in the first PCR.

Discrimination of human HLA-DRB1 alleles by PCR-SSCP (single-strand conformation polymorphism) method.

A single-strand conformation polymorphism (PCR-SSCP) method has been adopted for discrimination of human HLA-DRB1 alleles. This method enabled the detection of DNA polymorphisms including point mutations at a variety of positions in the DNA fragments of the HLA-DRB1 gene. A total of 27 HLA-DRB1 alleles from 172 healthy donors were analysed using a combination of PCR-SSCP with group-specific amplifications.

Study on the expression of ABH antigens on platelets.

We recently examined a case of refractoriness to HLA-matched, ABO-incompatible platelet transfusions. The transfused platelets that were rapidly cleared from the circulation of the recipient expressed an amount of B antigen more than 20 times that expressed by the blood group B platelets that were successfully transfused to the recipient. These observations led us to conduct enzyme-linked immunosorbent assay (ELISA) and immunoblotting studies of the amount of blood A and B antigens expressed on the surface of platelets from randomly selected donors.

Follow-up study of anti-hepatitis C virus antibodies in blood donors implicated in post-transfusion non-A, non-B hepatitis.

We retrospectively examined the antibodies to p22, a hepatitis C virus (HCV) nucleocapsid protein, and to c100-3, a HCV nonstructural protein, in donors whose blood was transfused to patients who later developed post-transfusion non-A, non-B hepatitis. Of 13 such blood donors, three seroconverted and three seroreverted with the anti-c100-3 test. In contrast, 12 of the 13 blood donors showed the same results at transfusion and follow-up, and one donor showed seroconversion with the anti-p22 assay.

The effect of prior transfusion history on blood donor anti-hepatitis C virus antibody.

In Japan, the major transfusion-associated disease is non-A, non-B hepatitis. We studied the relationship between transfusion history and blood donor antibodies to hepatitis C virus (HCV). The positive rate of antibodies to the HCV nonstructural protein (c100-3) depended on age and the time elapsed since transfusion.

Effectiveness of the Imugard E leukocyte removal filter for preparation of leukocyte-poor concentrated red cells.

Concentrated red cells (CRC) were filtered through a new leukocyte removal filter, the Imugard E, which consists of a polyvinyl alcohol porous sheet. CRC were filtered through the Imugard E with neither priming before filtration nor rinsing after filtration. Leukocyte removal was 99.

Family study and frequency of blood group with strong B transferase accompanied by decreased A and H antigens.

Subgroups of type A blood, named A1, A2, and A1-A2 intermediate (Aint), are specifically characterized by their peculiar A alleles and have their own A1-, A2- or Aint-forms of alpha-N-acetyl-D-galactosaminyltransferase (A-transferase). It is known, however, that certain type A2B persons exhibit A1-transferase. The reason may be an unusual alpha-galactosyltransferase (B-transferase).