title: Predicting graft-versus-host disease in HLA-identical bone marrow transplant: a comparison of T-cell frequency analysis and a human skin explant model.
abstract: BACKGROUND
  Graft-versus-host disease (GVHD) occurring after HLA-identical sibling bone marrow transplantation (BMT) is considered to be mainly caused by minor histocompatibility antigen (mHag) disparities between the recipient and donor. In our laboratory, a human skin explant model has been successfully used to predict acute GVHD in HLA-identical sibling BMT. More recently, the frequency analysis of host-reactive helper and cytotoxic T lymphocyte precursors (HTLp and CTLp, respectively) has been shown to have potential application for predicting GVHD. In the present study, HTLp and CTLp frequency analysis and the skin explant model were directly compared for their ability to predict acute GVHD in HLA-identical sibling BMT.
  
  
  METHODS
  Host-reactive HTLp and CTLp frequencies were determined using a combined limiting dilution assay. A human skin explant model was used to detect graft-versus-host reactions in vitro. The results from the skin explant model (graft-versus-host reaction grades I-IV) and T cell frequency analysis (>/< 1:100,000) were correlated with posttransplant GVHD outcome, respectively.
  
  
  RESULTS
  The skin explant model correctly predicted GVHD outcome in 77% of cases (P=0.03). HTLp frequencies were very low in all patient/donor pairs tested. None of them exceeded 1:100,000, although 9/18 recipients developed GVHD (> or =clinical grade II) after transplant. In all patients tested, the relationship between either high (>1:100,000) or low (<1:100,000) CTLp frequency and occurrence of GVHD appeared to be random (P=1.0).
  
  
  CONCLUSIONS
  HTLp and CTLp frequency analysis did not predict the occurrence of acute GVHD after HLA-identical sibling BMT. The human skin explant model, however, remained an accurate indicator of acute GVHD and probably detects mHag disparities.
authors.affiliation: Department of Haematology, School of Clinical and Laboratory Sciences, University of Newcastle, Newcastle-upon-Tyne, United Kingdom.
authors.forename: A M
authors.initials: AM
authors.lastname: Dickinson
authors.forename: L
authors.initials: L
authors.lastname: Sviland
authors.forename: X N
authors.initials: XN
authors.lastname: Wang
authors.forename: G
authors.initials: G
authors.lastname: Jackson
authors.forename: P R
authors.initials: PR
authors.lastname: Taylor
authors.forename: A
authors.initials: A
authors.lastname: Dunn
authors.forename: S J
authors.initials: SJ
authors.lastname: Proctor
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D016026:Bone Marrow Transplantation; D005260:Female; D005544:Forecasting; D006086:Graft vs Host Disease / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D006680:HLA Antigens / Q000145:classification*; D006648:Histocompatibility / Q000276:immunology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015778:Minor Histocompatibility Antigens / Q000032:analysis; D012867:Skin / Q000473:pathology; D013234:Stem Cells / Q000473:pathology; D013602:T-Lymphocytes, Cytotoxic / Q000473:pathology; D006377:T-Lymphocytes, Helper-Inducer / Q000473:pathology
chemical_list: D006680:HLA Antigens; D015778:Minor Histocompatibility Antigens