title: Enhancement of drug-specific lymphocyte proliferation using CD25(hi)-depleted CD3(+) effector cells.
abstract: BACKGROUND
  The lymphocyte transformation test (LTT) is used for in vitro diagnosis of drug hypersensitivity reactions. While its specificity is over 90%, sensitivity is limited and depends on the type of reaction, drug and possibly time interval between the event and analysis. Removal of regulatory T cells (Treg/CD25(hi)) from in vitro stimulated cell cultures was previously reported to be a promising method to increase the sensitivity of proliferation tests.
  
  
  OBJECTIVE
  The aim of this investigation is to evaluate the effect of removal of regulatory T cells on the sensitivity of the LTT.
  
  
  METHODS
  Patients with well-documented drug hypersensitivity were recruited. Peripheral blood mononuclear cells, isolated CD3(+) and CD3(+) T cells depleted of the CD25(hi) fraction were used as effector cells in the LTT. Irrelevant drugs were also included to determine specificity. (3)H-thymidine incorporation was utilized as the detection system and results were expressed as a stimulation index (SI).
  
  
  RESULTS
  SIs of 7/11 LTTs were reduced after a mean time interval of 10.5 months (LTT 1 vs. LTT 2). Removal of the CD25(hi) fraction, which was FOXP3(+) and had a suppressive effect on drug-induced proliferation, resulted in an increased response to the relevant drugs. Sensitivity was increased from 25 to 82.35% with dramatically enhanced SI (2.05 to 6.02). Specificity was not affected.
  
  
  CONCLUSIONS
  Removal of Treg/CD25(hi) cells can increase the frequency and strengths of drug-specific proliferation without affecting specificity. This approach might be useful in certain drug hypersensitivity reactions with borderline responses or long time interval since the hypersensitivity reaction.
authors: Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors: Yuttana
authors: Y
authors: Srinoulprasert
authors: Werner J
authors: WJ
authors: Pichler
mesh_terms: D000328:Adult; D000368:Aged; D017252:CD3 Complex / Q000302:isolation & purification*; D049109:Cell Proliferation; D004342:Drug Hypersensitivity / Q000175:diagnosis* / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007158:Immunologic Techniques / Q000379:methods*; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D055815:Young Adult
chemical_list: D017252:CD3 Complex; C508017:IL2RA protein, human; D053645:Interleukin-2 Receptor alpha Subunit