摘要:

Abstract.The successful cloning of a non‐structural antigen from the genome of what is now designated as the ‘hepatitis C virus’ (HCV) has transformed an erstwhile diagnosis of exclusion for non‐A, non‐B hepatitis (NANBH). The assay has been validated against panels of known infectivity for NANBH and sera from haemophiliac patients treated either with virally inactivated or uninactivated factor VIII. The predictive value of the assay is being assessed clinically in prospective studies of post‐transfusion hepatitis and by using laboratory techniques such as polymerase chain reaction. While the assay shows good predictability in high‐risk subjects, an appreciable number of false‐positive results are likely in blood donor populations. Furthermore, the extent of infectivity of seropositive blood donors is still the subject of active research. The prevalence of anti‐HCV in blood donors varies from approximately 0.2 to 1.5% around the world, based on repeat reactivity in the Ortho antiglobulin ELISA assay. These rates may be appreciably reduced following supplementary testing with recombinant immunoblot assay (RIBA). Prevalence data in African sera are as yet unreliable, pending assessment by RIBA, presumably because of high levels of IgG interfering with the assay. Presence of anti‐HBc or elevated alanine aminotransferase associates to a greater or lesser extent with seropositivity, especially when both surrogate markers are present, but conversely many (unconfirmed) seropositive subjects lack these surrogate markers. An understanding of the modes of transmission of HVC is of obvious importance to transfusion practice. Intravenous drug use is a striking risk factor, but the contribution made by sexual transmission is not so clear. Results with the highly innovative anti‐HCV assay represent the first dramatic ‘ranging shots’ to hit the target of NANBH, albeit at the periphery. Some of the various limitations of this expensive assay and associated supplementary tests are likely to be resolved by the advent of improved tests based on other HCV antigens, including structural ones. Hopefully, they will produce results closer to

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00863.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.A new ion‐exchange chromatographic procedure has been developed to produce a highly purified factor VIII (FVIII) concentrate from plasma cryoprecipitate. Solubilized cryoprecipitate, after adsorption on aluminium hydroxide and cold precipitation, was treated with 0.3% tri(n‐butyl)phosphate and 1% Tween 80 at 25°c for at least 8 h to inactivate lipid‐enveloped viruses. The fraction was then loaded onto a column packed with DEAE‐Fractogel TSK 650 M and chromatographed. Most proteins and TnBP‐Tween 80 flowed through the gel unretarded. FVIII:c, which bound to the gel, was eluted by increasing the ionic strength, then was directly filter‐sterilized without ultrafiltration or addition of a protein stabilizer. Chromatographic recovery of FVIII:c was 80–90%. After freeze‐drying, FVIII:c was at a concentration of 42.5 ± 9.5 IU/ml and had a specific activity of 175.4 ± 37.8 IU/mg (n = 40), corresponding to a purification factor of over 12,000 from plasma. The typical yield of the freeze‐dried FVIII:c from cryoprecipitate was 55–65%. FVIII:c was stable for over 24 h at room temperature in the liquid state. The mean content of fibrinogen and immunoglobulin G was only 65 and 100mg/l, respectively, corresponding to 1.4 and 2.3 mg/1,000 IU FVIII:c. This concentrate, which is much purer than traditional FVIII concentrates, has been found to be well tolerated and effective in clinical treatment of

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00864.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Human blood platelets, prepared by the buffy‐coat method, were prepared and stored in different synthetic media. In a synthetic medium based on gluconate, acetate and citrate (GAC), the pH was 6.8 on day 6. This medium was chosen for further evaluation. The total platelet count and the leukocyte contamination were significantly lower in the platelet concentrates (PCs) prepared in GAC compared to PCs prepared in plasma. Platelets stored in plasma or in GAC were equally functional when tested for aggregation and adenosine triphosphate (ATP) secretion. Only stimuli that act through the arachidonic‐acid pathway induced a lower platelet response in GAC. Platelet morphology was quantified by measuring the difference in light transmission during stirring at different rates in an aggregometer; no significant differences for platelets stored in GAC as compared to plasma were observed. Activation of platelets was measured by binding of monoclonal antibodies (McAb) against the Gp IIb/IIIa complex and against activation‐dependent antigens (GMP 140 from the α‐granules and a 53‐kD glycoprotein from the lysosomal granules). There was no difference in binding of these McAb between platelets prepared and stored in plasma or GAC. We conclude that platelets prepared by the buffy‐coat method and stored in GAC have the same in vitro qualitities as platelets stored in plasma, except for the lower aggregation response by the archidonic‐acid pathway. This is probably due to an acetate‐induced decrease in

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00865.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Bone marrow transplant recipients at Huddinge Hospital have routinely received single‐donor platelet concentrates (PC) from blood group 0 donors. These PC contain approximately 350 ml plasma, which is incompatible with patients of group A, B and AB. In 27 patients transplanted with an ABO‐identical bone marrow, serological investigations have been performed every week after transplantation (median 6 weeks, range 3–14). Nine of 11 recipients with blood group A developed a positive direct antiglobulin test (DAT) after PC transfusions, while none of 15 patients of blood group 0 developed a positive DAT. Anti‐A could be eluted in DAT‐positive cases. In no case was there any clinical sign of hemolysis. Nor did recipients of groups A, B or AB (n = 34) require more red blood cells or PC transfusions compared to recipients of group 0

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00866.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.A prospective study of posttransfusion non‐A, non‐B hepatitis was conducted in Malmö, Sweden, in 1984–1985, in which donors were alanine aminotransferase (ALT) screened but not ALT selected. Among 741 patients studied at 0, 6, and 12 weeks after transfusion, 13 developed non‐A, non‐B hepatitis, and these were further followed up. Stored sera from the 13 hepatitis patients and their 123 donors were tested for anti‐hepatitis C virus (HCV) by ELISA and, if positive, analyzed by recombinant immunoblot assay (RIBA). All ALT‐elevated blood units (n = 301) and a similar number of ALT‐normal units were also tested. Only 4/13 patients with non‐A, non‐B hepatitis seroconverted to anti‐HCV, all with ALT peaks>10 times the upper normal. All seroconversions occurred within 5 months after transfusion and could be confirmed by RIBA. Hepatitis C in recipients occurred both after transfusion of blood that was strongly positive, weakly positive, and/or negative for anti‐HCV by ELISA. In donors grouped by ALT levels, the anti‐HCV prevalence varied between 0.4 (normal ALT) and 14% (ALT elevated ≥ 2 times). Of the total of 9 donor units positive by ELISA, only 5 were confirmed by RIBA. Of the 5 recipients of the RIBA‐positive blood units, 3 went into hepatitis, 1 remained normal at 10.5 weeks, and 1 showed a slight, transient ALT elevation at week 12. The recipients of ELISA‐positive but RIBA

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00867.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Fulminant hepatitis B developed in 8 recipients of blood units without detectable hepatitis B surface antigen on routine screening. All 124 hepatitis B virus (HBV) DNA clones propagated from their sera possessed defects in the precore region. A point mutation from guanine to adenine at nucleotide 83, converting codon 28 for tryptophan (TGG) to a stop codon (TAG), was the commonest, and it was found in all 113 clones from 7 cases. The remaining case displayed 1 clone with this point mutation and 10 clones with an insertion of 2 base pairs after nucleotide 26. Antibody to hepatitis B core antigen (anti‐HBc) was detected in a high titer in 1 of 10 pilot plasma samples of blood units transfused to this case. HBV DNA clones propagated from it exhibited the same precore‐region defects as those from the recipient. On the basis of these results HBV mutants, defective in the precore region, would appear to be responsible for posttransfusion fulminant hepatitis B, and the exclusion of blood units with high‐titered anti‐HBc would be efficacious in preven

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00868.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.In two patients suffering from post‐transfusion purpura, anti‐Zwawas demonstrated in ether eluates from autologous platelets harvested during the remission phase and after normalization of the platelet count. In both patients, platelet‐associated immunoglobulin (PAIg) was demonstrated during the acute phase. PAIg disappeared concomitantly with recovery and, thus, seems to be associated with the thrombocytopenia. These data support the assumption that immunocomplexes are adsorbed nonspecifically to the platelets and cause destruction of autologous platelets lacking the corresponding antigen. An association between the IgG3 subclass of anti‐Zwaantibodies and the destruction of autologous platelets was al

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00869.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Three of 46 patients with autoimmune hemolytic anemia (AIHA) satisfied the diagnostic criteria for mixed‐type AIHA in which both warm‐type and cold‐type autoantibodies against red blood cells (RBCs) are present. The specificities of these autoantibodies were analyzed. All of the warm‐type autoantibodies were IgG‐x, and the specificities were not serologically classified. The autoantibody of patient 1 reacted to the 41‐ and 80‐kD peptides on immunoblotting, and the epitope corresponding to it was papain sensitive. Two warm‐type autoantibodies from patients 2 and 3 resembled each other in serological analyses and reacted with a protease‐ and neuraminidase‐resistant antigen. However, the antigen corresponding to the autoantibody of patient 3 was located on the 37‐kD peptide by immunoprecipitation. All of the cold‐type autoantibodies were IgM‐xand showed high titer and high thermal amplitude. According to the reaction pattern with untreated and enzyme‐treated RBCs, the cold‐type autoantibodies of patients 2 and 3 were revealed to be anti‐Om and anti‐I, respectively. In patient 1, the cold‐type autoantibody was characterized as having high affinity for autologous RBCs, but its specificity was unclassified. The antigens corresponding to the cold‐type autoantibodies were not located by immunoblotting and immunoprecipitation. These serological and immunochemical approaches to autoantibodies in mixed‐type AIHA revealed that the warm and cold compo

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00870.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Immunoblotting under non‐reducing conditions with purified human anti‐Gyaand anti‐Hy locates both antigens to an erythrocyte membrane glycoprotein of apparent Mr46,750–57,500. The antigens are destroyed on intact red cells by the enzymes pronase, trypsin and chymotrypsin, and by treatment with reducing agents. Immunoblotting with anti‐Gyaand anti‐Hy to membranes prepared from red cells pre‐treated with an Endo F preparation caused a mean reduction in apparent Mrof the glycoprotein by 11kDa at the leading and trailing edges, when compared with control membranes. These results suggest that the glycoprotein has one or more complex N‐glycans that are not completely sensitive to Endo F digestion on intact cells. The majority of Gya/Hy‐active molecules are not tightly associated with the red cell membrane skeleton. A gross reduction in reactivity with anti‐Gyaand anti‐Hy by immunoblotting was observed in red cell membranes from patients with paroxysmal nocturnal haemoglobinuria, suggesting a possible membrane linkage via glycosylphosphatidylinositol for the glycoprotein that carries the Gyaand Hy antigens. Immunoprecipitation of the glycoprotein by anti‐Gyashowed that the protein migrates faster under reducing conditions (Mr45,000–54,000). A putative dimer was also evident in the precipitates. The glycoprotein was demonstrated to be distinct from lymphocytefunction‐associated antigen‐3 (CD58), the LWab‐active glycoprotein, the Fya‐active glycoprotein, the Oka‐active glycoprotein a

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00871.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0042-9007    

DOI:10.1111/j.1423-0410.1991.tb00872.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY