血型单克隆抗体试剂稳定剂的研究

为了进一步提高抗A、抗B血型单克隆抗体试剂的稳定性,实验中分别以不同配比的甘油、蔗糖、明胶和EDTA为稳定剂主要成分加入血型单抗试剂,放置在不同条件下观察试剂的稳定性。结果表明,所筛选出的一种稳定剂对血型单抗试剂具有良好的保护作用,试剂在2~8℃条件下放置12个月,凝集效价保持不变,并且该稳定剂对血型单抗的特异性、亲和力、凝集效价和凝集强度均无影响。     

Immunoadsorption for removal of anti-A and anti-B blood group antibodies in ABO-incompatible bone marrow transplantation

About 10-15 percent of all patients undergoing allogeneic bone marrow transplantation have a major ABO-incompatibility with their donors. The risk of acute hemolytic reactions due to the infusion of an incompatible donor marrow into the recipient can basically be prevented by recipient antibody depletion or by donor marrow red cell depletion. Nine patients were treated by immunoadsorption using a cartridge with chemically synthesized human blood group A and B antigen as immunoadsorbent for antibody depletion. Within a four-hour-procedure about 2-4 times the patient plasma volume could be processed, thus lowering the anti-A and -B hemagglutinins by 2 to 3 tubes. There was a tendency of better IgG removal when titers initially were high, showing a high antibody clearing capacity. There was no significant correlation between starting titer or amount of plasma volume processed and titer reduction. No decrease in titers were observed in one case. We propose repeated immunoadsorption procedures over 2-3 consecutive days before BMT. The procedure is largely safe and without serious side effects. A major advantage is the avoidance of nonautologous human blood products compared to the conventional plasma exchange. All 8 patients surviving long enough had prompt and stable engraftment of all three cell lines post BMT. No late serological complications occurred when patients were regularly monitored and in vivo adsorption was used when titers increased.     

Immunochemical studies on blood groups. The combining site specificities of mouse monoclonal hybridoma anti-A and anti-B

Mouse monoclonal hybridomas, five anti-blood group A, three anti-B, and one anti-AB, produced by various methods of immunization, have been characterized by quantitative precipitin tests and the fine structures of their combining sites have been mapped by oligosaccharide inhibition assays. The combining sites of antibodies of each specificity differed among themselves. Three of the five monoclonals were specific for difucosyl and two for monofucosyl A determinants. All but the anti-AB were strictly specific for blood group A or blood group B erythrocytes; all of the anti-A monoclonals gave essentially equivalent titers in hemagglutination tests with A1 and A2 erythrocytes except for a monoclonal anti-A prepared by immunization with a human gastric cancer cell line. The data provide additional evidence for the heterogeneity of the antibody response to the different antigenic determinants present on blood A and B substances and emphasize the importance of difucosyl determinants which comprise most of the determinants on the water-soluble blood group substances.     

Differing reactions of monoclonal anti-A antibodies with oligosaccharides related to blood group A

Inhibition radioimmunoassays with blood group A-related oligosaccharides have been used to investigate the specificities of six monoclonal anti-A antibodies, three of which had been intentionally generated by immunization of mice with blood group A erythrocytes and A-active blood group substance, and three were incidentally produced following immunization of mice with human tonsil cell membranes or a human colon cancer cell line. By hemagglutination, these antibodies are highly specific for human blood group A erythrocytes. However, they differ from one another in their reaction patterns with mono- and difucosyl A antigen structures and the corresponding afucosyl sequences on Type 1 and Type 2 backbone structures. The six antibodies, together with four previously characterized anti-A monoclonal antibodies (originally raised against the receptor for epidermal growth factor) have been classified into five groups. The first two groups consist of antibodies with broad specificities for A-related structures. There are five antibodies in the first group (TL5, 29.1, A17/3D1, MH2/6D4, and MH1/5D1) reacting to varying degrees with the mono- and difucosyl A antigen structures on either type of backbone sequence. In the second group are two antibodies (A15/3D4 and A15/3D3) which are difficult to inhibit with the oligosaccharides tested, but they reacted best with monofucosyl A structure on either type of backbone. Each of the remaining three antibodies had a distinct and more restricted reaction pattern, with a specificity for the difucosyl A antigen on both types of backbone (antibody EGR/G49) or the Type 1-based mono- and difucosyl A antigen structures (antibody MAS 016c) or the Type 2-based monofucosyl A antigen structure (antibody 455). The reactions of four of the antibodies with N-acetylgalactosamine or with oligosaccharides containing the afucosyl sequence GalNAc alpha 1-3Gal suggest that they may react with certain glycoconjugates with alpha-N-acetylgalactosaminyl termini ("A-like" structures) that are unrelated to the products of the blood group A gene-specified alpha-N-acetylgalactosaminyl-transferase. Knowledge of the differing reactions of these monoclonal antibodies is important for interpreting their reactions with glycoproteins and glycolipids of diverse origins.     

Epitope specificity of hemagglutinating monoclonal anti-B antibodies]

Fine epitope specificity of ten monoclonal antibodies (MA) agglutinating red blood cells B was studied. Three methods were used: 1) inhibition of MA binding to natural antigen by synthetic oligosaccharides (OS) and their polyacrylamide conjugates, 2) direct MA binding to a series of synthetic OS-polyacrylamide conjugates differing in carbohydrate epitope density, 3) direct MA binding to the affinity sorbents. It is shown that all antibodies studied prefer trisaccharide B determinant Gal alpha 1-3(Fuc alpha 1-2) Gal independently of their ability to discriminate serological subgroups of B erythrocytes (B, Bweak, B3). The correlation of the MAs epitope specificity with their ability to agglutinate red blood cells B subgroups is discussed. Of an interest is that MAs which are able to agglutinate any B subgroups also bing the synthetic tetrasaccharide Gal alpha 1-3(Fuc alpha 1-2)Gal beta 1-3GalNAc, a B type 3 determinant.     

Plasma exchange for removal of anti-A and anti-B group antibodies in AB0 major-incompatible bone marrow transplantation

Between 1980-1986 seven patients underwent AB0-major incompatible bone marrow transplantation. Incompatible anti-A and anti-B antibodies could be decreased by the plasma exchange from titers 8-256 down to 0-8. Our practice combined with additional depletion of erythrocytes from marrow allowed to transplant all patients successfully, however, one patient demonstrated an acute haemolytic reaction during infusion of marrow. Plasma exchange was fairly well tolerated, however, 4 patients developed slight urticarial reactions. Both thrombocytopenic patients overcompensated the platelet loss caused by the exchange.     

单克隆抗体血型定型试剂转瓶培养生产工艺

研制成功单克隆抗体ABO血型定型试剂转瓶培养生产工艺,生产周期从静置培养生产的5～6天缩短到2～3天。产品所有质量指标均达到或超过国家标准,特别是抗体效价明显提高。实验及生产结果显示,该法简单易行,经济快速．投入低,产出高,生产时间短,产品质量高。