tailieunhanh - Mollison’s Blood Transfusion in Clinical Medicine - part 4

Các tác giả này vẽ ra một tương tự giữa các ràng buộc của cấu trúc carbohydrate Ii để các bản vá kỵ nước Kau và cách thức trong đó chuỗi oligosaccharide của các phân tử kháng thể liên kết với một bản vá kỵ nước trên Cγ2 lĩnh vực của IgGFc. Vùng kháng nguyên mang tính ràng buộc carbohydrate thay thế này cũng cung cấp một lời giải thích | CHAPTER 7 antigens bind to additional as yet unidentified antigens. These authors draw an analogy between the binding of li carbohydrate structures to the hydrophobic patch on KAU and the way in which oligosaccharide chains of antibody molecules bind to a hydrophobic patch on the Cy2 domains of IgGFc. This alternative carbohydrate antigen-binding region also provides a possible explanation for the cold agglutinin activity of other V4-34 encoded antibodies including monoclonal anti-Ds Thorpe et al. 1998 . Of the relatively few examples of anti-Pr six were IgAK and five of these had Pri and one Pra specificity Angevine et al. 1966 Garratty et al. 1973 Roelcke 1973 Tonthat et al. 1976 Roelcke et al. 1993 one that was IgMK was anti-Pr2 and another IgMX anti-Pr3 Roelcke etal. 1974 1976 . An IgAK cold agglutinin had anti-Sa specificity Roelcke et al. 1993 . IgM cold agglutinins with X light chains are rarely directed against the I antigen. They are frequently cryoprecipitable and are often found in malignant conditions. Such agglutinins thus differ markedly from cold agglutinins with K light chains. Patients with chronic CHAD synthesize IgM at approximately 10 times the normal rate treatment with alkylating agents results in a diminished rate of synthesis Brown and Cooper 1970 . Occasionally cold IgM anti-I is accompanied by a warm IgG autoantibody of the same or another specificity see below . Examples of anti-I cold agglutinins that appeared to be solely IgG were described by Ambrus and Bajtai 1969 and Mygind and Ahrons 1973 and two cases in which the anti-Pr was IgG1K have been described Dellagi et al. 1981 Curtis et al. 1990 . The latter case was unusual because the cold agglutinins failed to activate complement. The possibility that IgM anti-I is always accompanied by at least traces of IgG and IgA autoantibodies is raised by the finding of Hsu and co-workers 1974 . Using a PVP-augmented antiglobulin test in the autoanalyzer they found that in patients with typical