title: Jurkat cell-reactive anti-thymocyte globulin assessed ex vivo by flow cytometry persists three weeks in circulation.
abstract: Rabbit anti-thymocyte globulin (ATG-Fresenius) is a polyclonal anti-serum raised against the lymphoblastic T cell line Jurkat. It is used for in vivo depletion of host and donor T cells for allogeneic stem cell transplantation. After administration of 90 mg/kg prior to transplant, rabbit immunoglobulin G (IgG) remains present for 4-5 weeks, but it is unknown how long T cell-reactive antibodies persist. Therefore, we measured anti-Jurkat antibodies by flow cytometry. The detection limit for Jurkat-reactive antibodies was 0.1 microg/ml rabbit IgG; half-maximal labeling of Jurkat cells required 183 microg/ml rabbit ATG. The mean half-life of Jurkat-reactive antibodies in 7 patients was 4 days. Detectable levels persisted up to 3 weeks with antibody levels equivalent to 0.2-4.1 microg/ml rabbit ATG. Jurkat-reactive antibodies were eliminated two-fold faster than rabbit IgG, as assessed by enzyme-linked immunosorbent assay (ELISA). The results suggest that in patients pretreated with ATG before transplantation, residual anti T-cell antibodies may effectively modulate recovery of T cells generated after transplantation, thereby lowering the incidence of severe GVHD.
authors.affiliation: Department of Transfusion Medicine and Bone Marrow Transplantation Center, University Hospital Eppendorf, Hamburg, Germany. eiermann@uke.uni-hamburg.de
authors.forename: T H
authors.initials: TH
authors.lastname: Eiermann
authors.forename: S
authors.initials: S
authors.lastname: Freitag
authors.forename: L
authors.initials: L
authors.lastname: Cortes-Dericks
authors.forename: H
authors.initials: H
authors.lastname: Sahm
authors.forename: A R
authors.initials: AR
authors.lastname: Zander
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D000961:Antilymphocyte Serum / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D016026:Bone Marrow Transplantation; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006207:Half-Life; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D007165:Immunosuppression Therapy; D019169:Jurkat Cells / Q000276:immunology*; D008212:Lymphocyte Depletion; D011817:Rabbits; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
chemical_list: D000961:Antilymphocyte Serum; D007074:Immunoglobulin G