Hisami Ikeda

Transfusion-transmitted hepatitis E caused by apparently indigenous hepatitis E virus strain in Hokkaido, Japan

BACKGROUND:  In industrialized countries, sporadic cases of hepatitis E have been reported in individuals who have never been in an endemic area. Hepatitis E virus (HEV) infection commonly occurs via the fecal‐oral route but a potential risk of transfusion transmission route has been suggested.

A case of transfusion‐transmitted hepatitis E caused by blood from a donor infected with hepatitis E virus via zoonotic food‐borne route

BACKGROUND: Five cases of transfusion transmission of hepatitis E virus (HEV) have been reported so far. The infection routes of the causative donors remain unclear, however. Also, the progress of virus markers in the entire course of HEV infection has not been well documented.

Infectivity of blood components with low hepatitis B virus DNA levels identified in a lookback program

BACKGROUND: Japanese Red Cross (JRC) blood centers implemented anti‐hepatitis B core antigen (HBc) screening in 1989 and 50‐minipool (MP)‐nucleic acid testing (NAT) in 2000. A systematic lookback study has been conducted to determine the hepatitis B virus (HBV) transmission risk of donations drawn in the pre‐hepatitis B surface antigen (HBsAg) and/or MP‐NAT window phase and by donors with occult HBV infection.

A New Platelet-Specific Antigen, Naka, Involved in the Refractoriness of HLA-Matched Platelet Transfusion

Abstract. Serum from a thrombocytopenic patient who was refractory to the transfusions of HLA‐matched platelets contained a platelet‐specific alloantibody, anti‐Naka. Immunofluorescence analyses revealed that the Naka antigen defined by the serum was expressed exclusively on platelets and its distribution was different from PlA1, Baka, Yuka or Yukb. Analysis by Dr. von dem Bornes group revealed the Naka was also different from Koa, Kob or Zwb. Family studies showed that the Naka antigen was inherited as an autosomal codominant trait. Its antigen frequency in the Japanese population was over 97%. The results of the enzyme immunoassay using monoclonal antibodies for antigen immobilization showed that the Naka epitope did not appear to reside on GPIIb/IIIa or Ib. The transfusions of Naka‐compatible platelets improved the patients thrombocytopenia.

Spontaneous In Vivo Reversion of an Inherited Mutation in the Wiskott-Aldrich Syndrome

The Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency disease, arising from mutations of the WAS-protein (WASP) gene. Previously, we have reported that mononuclear cells from WAS patients showed lack/reduced of the intracellular WASP (WASPdim) by flow cytometric analysis, and analysis of WASP by flow cytometry (FCM-WASP) was useful for WAS diagnosis. In this study, we report a WAS patient who showed the unique pattern of FCM-WASP. The patient had the small population of normal expression of WASP (WASPbright) mononuclear cells together with the major WASPdim population. The WASPbright cells were detected in T cells, not in B cells or in monocytes. Surprisingly, the molecular studies of the WASPbright cells revealed that the inherited mutation of WASP gene was reversed to normal. His mother was proved as a WAS carrier, and HLA studies and microsatellite polymorphic studies proved that the WASPbright cells were derived from the patient himself. Therefore, we concluded that the WASPbright cells were resulted from spontaneous in vivo reversion of the inherited mutation. Furthermore, the scanning electron microscopic studies indicated that WASP-positive cells from the patient restored the dense microvillus surface projections that were hardly observed in the WASPdim cells. This case might have significant implications regarding the prospects of the future gene therapy for WAS patients.

Reduction in adverse reactions to platelets by the removal of plasma supernatant and resuspension in a new additive solution (M-sol).

BACKGROUND: Leukodepletion reduces but does not eliminate adverse reactions to platelet concentrate (PC). As an alternative strategy, plasma reduction or washing of platelets should be considered. However, the efficacy of this strategy is still unclear.

Evidence for two B-cell alloantigen loci in theHLA-D Region

Antigenic determinants recognizable by human antisera (Hon 7 and 2075abs sera) were found in a partially purified antigen preparation obtained from an HLA-D and -DR homozygous cell line (EBV-Wa). Sequential coprecipition tests showed that two determinants detectable with Hon 7 and 2075abs sera (Hon 7 and 2075abs determinants) were present on different molecules. These two antigenic determinants were shown to be allotypic and were expressed predominantly in the B-cell-rich fraction. Family studies showed that both antigenic determinants segregated concordantly with respectiveHLA haplotypes. In the population study, the 2075abs and Hon 7 determinants were shown to be in strong linkage disequilibrium and the 2075abs determinant perfectly correlated with the HLA-DRw4 specificity. The results indicate that the Hon 7 determinant is coded for by a gene distinct from alleles at theHLA-DR locus. Furthermore, the locus (Hon 7) coding for the Hon 7 determinant is suggested to be very closely linked with theHLA-DR locus.

Comparison of the sensitivity of NAT using pooled donor samples for HBV and that of a serologic HBsAg assay

BACKGROUND : Studies were conducted using samples from early and late‐stage HBV‐infected persons to determine the pool size at which PCR had better sensitivity than a sensitive HBsAg chemoluminescence immunoassay (CLIA‐HBsAg).

Serum-free coculture system for ex vivo expansion of human cord blood primitive progenitors and SCID mouse-reconstituting cells using human bone marrow primary stromal cells

OBJECTIVE In an attempt to maintain and expand human stem cells, many investigators have used xenogeneic, especially murine, stromal cells and fetal calf serum. Because of the possible transmission of infectious diseases, however, the safety of the delivery of grafts expanded in culture using xenogeneic cells and serum has been debated. Using primary human marrow stromal cells, we established a novel serum-free culture system to expand human primitive progenitors and transplantable stem cells. MATERIALS AND METHODS Cord blood CD34(+) cells were cultured on a monolayer of human primary marrow stromal cells in the presence of thrombopoietin (TPO), flt3/flk2 ligand (FL), and/or stem cell factor (SCF) under serum-free conditions. After 2 or 4 weeks of culture, cells were examined for clonogenic progenitors and severe combined immunodeficient disorder (SCID) mouse-reconstituting cells (SRC). RESULTS In the presence of TPO, FL, and SCF, marrow stromal cells supported more than a 100- and 1,000-fold expansion of CD34(+) cells and colony-forming units in culture after 2 and 4 weeks of incubation, respectively. In addition, cobblestone area-forming cells were expanded more than 18- and 60-fold after 2 and 4 weeks of culture, respectively. Furthermore, SRC assay demonstrated augmented engraftment by cultured cells. CONCLUSION This ex vivo expansion system should prove valuable in clinical settings in which stromal cells are available from recipients or stem cell donors.

Predictive value of screening tests for persistent hepatitis C virus infection evidenced by viraemia : Japanese experience

In November 1989, Japanese Red Cross Blood Centres started screening for heaptitis C virus (HCV) with enzyme‐linked immunosorbent assay (Elisa) for the C100‐3 viral peptide as the first such nationwide programme in the world. Thereafter post‐transfusion non‐A non‐B hepatitis (PTNANBH) was reduced by 61–80%, but this was not as complete a success as our programme to prevent post‐transfusion hepatitis B by screening for high titer hepatitis B core antibody, which we began in the same period. In order to acquire more effective control of PTNANBH, the HCV core‐related antigen (GOR, N14) and second‐generation Elisa (Ortho2, Abbott2)and second‐generation antigen agglutination (PA, PHA) tests have been employed. Among 16,500 donors in 11 blood centers, 365 were serologically positive by at least one of these tests. Among these, HCV RNA was detected in 138 units and the remaining 227 were HCV RNA negatives. The effectiveness of these serological tests to detect HCV RNA‐positive status were analyzed. Passive haemagglutination and particle agglutination (PHA and PA) tests were highly effective to predict HCV viraemia among blood donors. Also, these tests can easily determine antibody titre. By either PHA or PA, all units with ≧212 agglutination titre (120 and 122 units) were HCV RNA positive and all agglutination‐positive units with serum alanine aminotransferase level higher than 35 Karmen units were HCV RNA positive. These results have formed the basis for implementing a more effective screening for HCV viraemia in blood donors, where effectiveness is defined as enhancing the protection of patients from post‐transfusion hepatitis C and providing higher quality information to achieve more effective donor counselling.