Long-term survival of transfused patients was studied at a single institution. This study, to our knowledge the first such report in Japan, compared long-term survival before (Group 1: 1986-1987, 1, 781 patients) and after implementation (Group 2:1992-1993 1, 326 patients) of HCV antibody screening. Unexpectedly, post-transfusion survival rate by Kaplan-Meier analysis showed no significant difference between the two groups. Female-s had a greater survival rate than male-s in both group 1 (1-year survival; male 74.1%, female 79.9%; p<0.05) and group 2 (1 year survival; male 73.7%, female 82.9%; p<0.01). There was no difference in survival between those aged 65 or more and under 65. Internal medicine patient-s had markedly lower survival than surgical patient-s (Group 2, 1-year survival; internal medicine group 58.2%, surgical patient group 84.3%; p<0.001). Transfused patients had a very high risk of death, with almost 1/4 of all patients dying within 1 year after the first transfusion.

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The First WHO International Standard for HCV RNA for Nucleic Acid Amplification Technology (NAT) Assay (96/790) was established in 1997. The aim of our collaborative study was the establishment of the Japanese National Standard for HCV RNA calibrated against the WHO International Standard. The candidate materials were evaluated in the following two steps. First, titers of two HCV positive plasma (119 and 122) diluted in cryosupernatant were evaluated, and plasma 122 was chosen as the source plasma for the candidate for the national standard. Then, candidate 122 was prepared by diluting the source plasma to approximately 10⁵ international units (IU)/ml in cryosupernatant. The relative potency of the candidate was measured against the International Standard by the end-point method. Seven laboratories from three countries participated in the collaborative study. Four laboratories used the Roche Amplicor assay (Version 1) and 3 laboratories used in-house PCR methods. There was reasonable agreement among the mean estimates from the laboratories. The overall mean potency of the candidate relative to the International Standard was 10^5.00 (10^4.80-10^5.20) IU/ml. The sample was accepted as the first Japanese national standard and assigned a titer of 100, 000IU/ml. Each vial of the National Standard contains 0.5ml of HCV plasma (genotype 1b) diluted in cryosupernatant and should be stored at-80°C.

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Refractoriness to platelet transfusions is considered one of the major obstacles in treating patients with hematological disorders. Although various transfusion procedures have been tried to prevent HLA alloimmunization, some patients still develop HLA and/or HPA antibodies and become refractory to platelet transfusions. We investigated the AHG-LCT, MPHA, LIFT and FlowPRA methods for detecting HLA antibodies and MPHA using chloroquine-treated platelets for HPA antibodies to analyze immunological factors in platelet transfusion-refractory (PTR) patients. Results showed that HLA antibodies were detected in 55 patients, HPA antibodies in 2 and both HLA and HPA antibodies in 2 patients. HLA-A and -B-compatible platelet transfusions were successful in boosting platelet levels in 27 of the patients. Nine patients developed not only HLA-A and/or -B antibodies but also HLA-C antibodies and became refractory to HLA-A and -B-compatible platelet transfusions. Matching of the HLA-C antigens was required in these patients to ensure the effectiveness of platelet transfusions. In some patients, ABH incompatibility reduced the effectiveness of transfusions. In these patients, platelet crossmatching was useful for predicting platelet survival. Of the 68 ABH-incompatible transfusions evaluated at 24 hours post-transfusion, 20 with positive crossmatches had corrected platelet count increments of 3.1±4.1 (×10⁹)/L. In contrast, 48 transfusions with negative crossmatches had corrected platelet count increments of 18.1±7.6 (×10⁹)/L. Other weak HLA antibodies in ten patients were not detected by the conventional methods but were detected by the FlowPRA method. Owing to screening and crossmatch tests, platelet transfusion efficacy was improved in 59 immunological PTR patients.

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We encountered an apheresis donor with a suspected case of mosaicism. The donor, K. A., was a 46-year-old Japanese female registered as an HLA-compatible platelet concentrate (HLA-PCs) donor. In her HLA serological typing for HLA-PCs donor registration, three antigens, HLA-B55, -B61 and -B62, were assigned in the HLA-B locus. She was not a twin and had never undergone transfusion or transplantation. Flow cytometric analysis using platelets and lymphocytes indicated that HLA-B55, -B61 and -B62 antigens were simultaneously expressed on the surface of platelets and lymphocytes. HLA-B allele typing with the polymerase chain reaction restriction fragment length polymorphism technique using genomic DNA from peripheral blood and nails as a somatic sample was carried out to establish HLA-B mosaicism. Three alleles, HLA-B*5502, -B*4002 and B*1501, were assigned in both exon 2 and exon 3. HLA-B mosaicism was observed in both her peripheral blood and nails. The HLA-B*4002 and -B*1501 alleles were inherited by her son, who carried three HLA-B alleles, HLA-B*4002, -B*1501 and -B*4001. No other sign of chimerism or mosaicism was observed in other HLA loci antigens or red cell antigens. These results suggest that this donor has a chimeric allele consisting of a mixture of the nucleotide sequences of HLA-B*4002 and -B*1501 alleles.

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We performed therapeutic angiogenesis by cell transplantation (TACT) for patients with peripheral obstructive arterial disease using autologous bone marrow mononuclear cells. The patients' symptom has begun to improve within several days after therapy, as did laboratory data (i. e., anklebrachial blood pressure index, thermography, percutaneous measurement of oxygen pressure). We quantified the mRNA expression of endothelial progenitor cell (EPC) -specific molecules (e. g., Flk-1, CD133, VE-cadherin, etc.) in bone marrow- or peripheral blood-derived mononuclear cells obtained from patients with ischemic limbs, using real time reverse transcription-PCR. The mRNA expression level of EPC markers was significantly lower in the patients than in healthy controls. We furthermore revealed the different expression pattern of EPC markers in several sources, including bone marrow and peripheral blood obtained from healthy volunteers or recombinant G-CSF-treated donors. The finding that the expression of EPC-specific molecules was decreased in the patients' marrow and blood suggests that patients with peripheral obstructive arterial diseases may have lower angiogenic potential. However, TACT with autologous marrow mononuclear cells was effective and increased the number of circulating EPCs in the patients' blood.

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The measurement of anti-blood group A/B (anti-A/B) IgG antibody levels is important for ABO unmatched-organ recipients because the effective removal of the antibodies improves their prognosis. However, currently existing methods to detect anti-A/B IgG antibodies suffer limitations due to high costs, low throughput, and poor adaptability to automation. We have developed a rapid means to quantitate anti-A/B IgG antibodies by surface plasmon resonance (SPR). The change in titers when the same plasma was diluted was precisely reflected by the SPR method. The coefficients of correlation between SPR and test tube (TT) methods for anti-A and -B IgG antibodies were 0.85 and 0.56, respectively. The SPR values also paralleled the TT values that showed a decline in titers after the removal of antibodies by double filtration plasma apheresis or plasma exchange.
**This article is partly based on a study first reported in the Transfusion (Kimura, S., Yurugi, K., Yuasa, T., Tsuji, H., Segawa, H., Kuroda, J., Sato, K., Nogawa, M., Egawa, H., Tanaka, K., Maekawa, T.: Rapid quantitation of IgG antibodies specific for blood group antigens A and B by surface plasmon resonance. Transfusion, 45 (1): 56-62, 2005.)

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