Dose titration during anti-thymocyte globulin therapy: monitoring by CD3 count or total lymphocyte count?
Anti-thymocyte globulin (ATG) is extensively used for both prophylaxis and treatment of rejection episodes in renal transplantation, but it is expensive and potentially hazardous. We report the utility of therapeutic monitoring by the readily available total lymphocyte count, compared with the more complex and expensive assay of CD3 counts by flow cytometry in eight renal transplant patients receiving ATG. Aiming for an absolute CD3 count of 0.2-0.5 x 10(9)/l, it was possible to reduce the mean daily dose of ATG from the recommended 2.5 mg/kg/d to a mean of 1.6 mg/kg/d. Analysis of simultaneously taken total lymphocyte counts showed that the same dose reductions could have been made if the target for therapeutic effect had been a total lymphocyte count of < 0.3 x 10(9)/l. Anti-rejection therapy was successful in all cases, with satisfactory graft function at 6-9 months post-therapy. Lower than recommended doses of ATG proved effective prophylaxis and treatment of renal allograft rejection, with considerable cost savings. A simple protocol may be followed titrating dose against total lymphocyte count, provided it remains below 0.3 x 10(9)/l. CD3 estimation can be reserved for those times when the total lymphocyte count rises to 0.3 x 10(9)/l or above.
Gorrie
M
M
Department of Haematology, Royal Devon & Exeter Hospital, UK.
Thomson
G
G
Lewis
D M
DM
Boyce
M
M
Riad
H N
HN
Beaman
M
M
Nicholls
A J
AJ
D018941:Antigens, CD19 / Q000097:blood; D000961:Antilymphocyte Serum / Q000008:administration & dosage* / Q000627:therapeutic use*; D017252:CD3 Complex / Q000097:blood* / Q000187:drug effects; D004306:Dose-Response Relationship, Immunologic; D005434:Flow Cytometry; D006801:Humans; D016030:Kidney Transplantation / Q000276:immunology; D018655:Lymphocyte Count / Q000187:drug effects; D015166:Monitoring, Immunologic; D013601:T-Lymphocytes / Q000166:cytology* / Q000187:drug effects
D018941:Antigens, CD19; D000961:Antilymphocyte Serum; D017252:CD3 Complex