ABSTRACT
Methods are described for preparing large amounts of horse anti-human thymocyte globulin (ATG, ATGAM; The Upjohn Company) for clinical use. These methods have been used since 1968 to provide material for clinical trials. Characteristics of 40 lots of ATG are summarized.
Subject(s)
Antilymphocyte Serum , T-Lymphocytes/immunology , Animals , Antilymphocyte Serum/analysis , Antilymphocyte Serum/standards , Antilymphocyte Serum/toxicity , Drug Compounding , Female , Haplorhini , Horses/immunology , Humans , MaleSubject(s)
Antibodies/isolation & purification , Antilymphocyte Serum/isolation & purification , Chromatography/methods , Erythrocytes/immunology , T-Lymphocytes , gamma-Globulins/isolation & purification , Animals , Carboxymethylcellulose Sodium , Hemagglutination Tests , Horses , Humans , Hydroxyapatites , Rosette FormationABSTRACT
Results obtained using a modified rosette inhibition assay with human and monkey lymphocytes were compared. The monkey lymphocytes tended to yield lower titers against a series of antithymocyte globulin preparations. Titers or relative rosette inhibition activities obtained with monkey lymphocytes correlated more poorly with skin graft prolongation in monkeys than assays using human lymphocytes in previous studies.
Subject(s)
Lymphocytes/immunology , Animals , Antilymphocyte Serum/pharmacology , Haplorhini , Humans , Immunologic Techniques , Macaca mulatta , Skin Transplantation , T-Lymphocytes/immunology , Transplantation, HomologousABSTRACT
Two equine antithymocyte globulin preparations were studied with respect to their relative rosette inhibition activity after storage at 4 and 25 C. After storage at 4 C for 48 months no activity loss was observed; 25 C storage resulted in fragmentation and eventual loss of relative rosette inhibition activity. A third preparation was studied by monkey skin graft prolongation. During a 1-year period, there was no loss of immunosuppressive activity as measured by this method and the rosette inhibition assay.
Subject(s)
Antilymphocyte Serum/analysis , T-Lymphocytes/immunology , Animals , Centrifugation, Density Gradient , Drug Stability , Graft Survival , Haplorhini , Horses , Immunologic Techniques , Immunosuppressive Agents/analysis , Macaca mulatta , Skin Transplantation , Transplantation, Autologous , Transplantation, HomologousABSTRACT
The rosette inhibition assay for immunosuppressive activity of antilymphocyte globulin or plasma has been studied in an effort to improve its reliability. Important changes include the elimination of calcium and magnesium ions from salt solutions used in the assay, the use of deoxyribonuclease to prevent lymphocyte clumping, and pretreatment of plasma samples (heating at 63 C for 10 min followed by acrinol precipitation) to prevent nonspecific inhibition of rosette formation. The use of a graded dose response potency assay against a house standard is discussed. A significant correlation was established between the in vitro activity of several series of antilymphocyte globulin or antithymocyte globulin preparations and their ability to prolong skin graft survival in primates. The best correlation was achieved using a potency estimate relative to a house standard, rather than the conventional titer estimate.