Curriculum Vitaes
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Annals of hematology, 101(9) 1959-1969, Sep, 2022SARS-CoV-2 infection has been reported to be associated with a positive direct antiglobulin test (DAT). In this study, an analysis of 40 consecutive coronavirus disease 2019 (COVID-19) cases from December 2020 to September 2021 in Japan revealed that patients of 70 years and over were predisposed to a positive DAT. DAT positivity was related to a decrease in the hemoglobin level. Anemia in DAT-positive COVID-19 patients was attributed to hemolysis, which was corroborated by high reticulocyte counts and an increase in the red blood cell distribution width. Human leukocyte antigen (HLA)-DRB1*12:01 and DRB1*12:02 were exclusively found in DAT-positive COVID-19 patients. In silico assays for the Spike protein of SARS-CoV-2 predicted several common core peptides that met the criteria for a B cell epitope and strong binding to both HLA-DRB1*12:01 and DRB1*12:02. Among these peptides, the amino acids sequence TSNFR, which is found within the S1 subunit of SARS-CoV-2 Spike protein, is shared by human blood group antigen Rhesus (Rh) CE polypeptides. In vitro analysis showed that the expression of HLA-DR in CD4+ T cells and CD8+ T cells from a DAT-positive patient was increased after pulsation with TSNFR-sequence-containing peptides. In summary, positive DAT is related to enhanced anemia and to HLA-DR12 in the Japanese population. A peptide sequence within SARS-CoV-2 Spike protein may act as an epitope for IgG binding to RBCs in DAT-positive COVID-19 patients.
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Therapeutic apheresis and dialysis : official peer-reviewed journal of the International Society for Apheresis, the Japanese Society for Apheresis, the Japanese Society for Dialysis Therapy, 26(4) 827-835, Aug, 2022INTRODUCTION: Quantitative measurement of anti-A/-B antibody titers is important during ABO-incompatible living kidney transplantation (ABOi-LKT). METHODS: We conducted a multi-institutional study to measure the antibody titers using the automated column agglutination technique (auto-CAT) and tube test (TT) method in ABOi-LKT recipients. Statistical analysis was performed to evaluate the two methods. RESULTS: We examined 111 samples from 35 ABOi-LKT recipients at four institutions. The correlation coefficient of the two methods was >0.9; the concordance rate and clinically acceptable concordance rate for the IgG titers were 60.4% and 88.3%, respectively. Perioperative status did not influence the statistical significance. Parallel changes were observed in the IgG antibody titers measured using the auto-CAT or TT technique by desensitizing therapy in time-course monitoring. CONCLUSION: Auto-CAT is comparable with the TT technique and is feasible for IgG anti-A/B antibody titration in ABOi-LKT recipients.
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International journal of hematology, 115(3) 440-445, Mar, 2022A 43-year-old Japanese male, who had undergone open liver surgery for tumor resection, presented with decreased hemoglobin levels on Day 13 post-emergency-release transfusion of 16 units of Fy(a +) red blood cells. As the anemia was accompanied by increased lactate dehydrogenase, indirect bilirubin, and reticulocytes, as well as decreased haptoglobin, it was attributed to hemolysis. In the diagnostic workup for hemolytic reaction, the direct antiglobulin test result for IgG was positive and the antibody dissociated from the patient's peripheral red blood cells was identified as anti-Fya (titer, 4). The hemolytic reaction was transient (approximately 10 days), of moderate severity, and did not result in any obvious organ damage. However, a single compatible red blood cell transfusion of 2 units was required on Day 17 after the causative transfusion. Notably, HLA typing revealed that the patient carried the HLA-DRB1*04:03 allele, which has been implicated in immunogenicity and induction of anti-Fya response in Caucasian populations. In summary, this is the first documented case of definitive anti-Fya-mediated delayed hemolytic transfusion reaction associated with HLA-DRB1*04:03 in the Japanese population.
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Transfusion, 61(9) 2782-2787, Sep, 2021BACKGROUND: The occurrence of transfusion-transmitted hepatitis B virus (HBV) infection has fallen dramatically due to continuous improvements in pre-transfusion laboratory testing. However, the characteristics of transfusion-transmitted HBV infection caused by individual donor nucleic acid amplification test (ID-NAT)-negative blood products are unclear. CASE PRESENTATION: A 76-year-old woman with acute myeloid leukemia was diagnosed with transfusion-transmitted HBV infection after receiving apheresis platelets derived from an ID-NAT-negative blood donation. This case was diagnosed definitively as transfusion-mediated because complete nucleotide homology of a 1556 bp region of the HBV Pol/preS1-preS2-S genes and a 23 bp region of the HBV core promoter/precore between the donor and recipient strains was confirmed by PCR-directed sequencing. The case is uncommon with respect to the unexpectedly prolonged HBV-DNA incubation period of nearly 5 months after transfusion (previously, the longest period observed since the recent implementation of ID-NAT pre-transfusion laboratory testing in Japan was 84 days). Slow-replicating HBV genotype A2 may contribute to the prolonged incubation period; also, the quantity of apheresis platelets delivered in a large volume of plasma, and/or the immune response of the recipient suffering from a hematological neoplasm, may have contributed to establishment of HBV infection in the recipient. This was supported by analysis of three previously documented cases of transfusion-transmitted HBV infection by blood products derived from ID-NAT-negative donations in Japan. CONCLUSION: Continuous monitoring of HBV infection for longer periods (>3 months) may be required after transfusion of blood components from an ID-NAT-negative HBV window donation.
Misc.
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Japanese Journal of Medical Technology, 71(4) 698-703, Oct 25, 2022Cryoprecipitates contain high concentrations of coagulation factors such as fibrinogen. Hence, a cryoprecipitate infusion for massive bleeding may reduce blood loss and blood transfusion requirement. We introduced processes for the supply of in-hospital-prepared cryoprecipitates and found changes in transfusion-related clinical parameters in our hospital. In this study, we compared the use and non-use of cryoprecipitates in major and nonmajor cardiovascular surgeries. The parameters compared were the amounts of blood loss, red blood cells (RBC), fresh frozen plasma (FFP), and platelet concentrate administered, the ratio of RBC to FFP (R/F ratio), and the duration of intensive care unit admission. The levels of serum fibrinogen increased after cryoprecipitate infusion. However, the amount of blood loss was greater in use than non-use of cryoprecipitates for both major and nonmajor cardiovascular surgeries. There was no significant differences in RBC and FFP administered for patients use and non-use cryoprecipitates for major cardiovascular surgery. Reducing the requirement of blood products in cardiovascular surgeries requires not only the use of cryoprecipitates but also identifying the cases for which cryoprecipitate infusion is effective as well as changing the minds of the medical staff involved in transfusion therapy.
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Japanese Journal of Transfusion and Cell Therapy, 68(3) 449-456, Jun 24, 2022
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Japanese Journal of Transfusion and Cell Therapy, 67(5) 531-537, Sep 25, 2021
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Japanese Journal of Medical Technology, 70(2) 312-317, Apr 25, 2021Amid the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (COVID-19) pandemic, control and preventive measures against SARS-CoV-2 infection are required to be implemented in medical institutes. In our hospital, a screening approach to detect COVID-19 patients using rapid immunochromatographic tests has been implemented to reduce the risk of infection among the hospital staff and prevent nosocomial infections. Here, we report the outcomes of the screening tests and significance of engaging professional medical technologists licensed by the Japanese government in the triage of patients with scheduled surgery by performing finger-prick blood sampling and evaluating the test results. A total of 325 patients were admitted to the hospital to undergo scheduled surgery under general anesthesia between May 11 and June 17, 2020. Antibodies against SARS-CoV-2 were detected in 16 patients (4.9%) using the immunochromatographic tests. The antibodies identified were IgM and IgG in 14 and 2 patients, respectively. All patients identified to be positive using antibody tests were then subjected to the nasopharyngeal swab examination; however, none of the patients were identified to be positive for SARS-CoV-2 RNA using polymerase chain reaction (PCR) or loop-mediated isothermal amplification (LAMP) assays. Consequently, all surgeries were performed as scheduled, except for five that were postponed for other reasons, and the occurrence of COVID-19 was not reported among patients admitted to our hospital. Our data suggest that antibody testing using rapid immunochromatography could be considered an alternative to the cost- and time-consuming PCR or LAMP assays for screening COVID-19 patients. Furthermore, medical technologists may provide crucial professional clinical laboratory skills as members of the COVID-19 task force.
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医学と薬学, 78(4) 419-427, Mar, 2021VITROS-5600 II装置を用いたSARS-CoV-2 Total抗体の試薬特性とその臨床的有用性について基礎的検討を行った。RT-PCR法で陰性患者3例、陽性患者3例の2種類のプール血清を作成し日内変動について確認した。その結果、検体1は陰性血清でその測定値は0.034±0.0057、変動係数(CV)16.62%、検体2は陽性血清で166.20±4.067、CV 2.45%であった。共存物質の影響について、ビリルビンF、ビリルビンC、ヘモグロビン、乳ビの影響は認められず、10倍希釈血清のCOI値はTotal抗体57.4、IgG抗体2.47で陽性と判定された。また、PCR陽性患者5例のプール血清を作成し原血清からカットオフ値(COI)付近まで希釈系列を作成しTotal抗体とIgG抗体を同時に測定した。その結果、IgG抗体がCOI(1.0)以下を示した時点でのTotal抗体値はCOI値を上回る反応を示していた。COVID-19戦略の一案として、PCR法とともに抗体測定方法の選択が重要であると考えられた。