title: Quantitative analysis of EBV-specific CD4/CD8 T cell numbers, absolute CD4/CD8 T cell numbers and EBV load in solid organ transplant recipients with PLTD.
abstract: Post transplant lymphoproliferative disease (PTLD) in solid organ transplant (SOT) recipients is assumed to be the result of impaired Epstein-Barr Virus (EBV)-specific cellular immunity. We analyzed the absolute CD4 and CD8 T cell counts as well as the EBV-specific CD4 and CD8 T cell responses in relation to EBV load in SOT recipients with PTLD. A prospective, single center study was initiated and 10 immunosuppressed patients with diagnosis of PTLD were analyzed and compared to 3 patients without PTLD (2 SOT recipients with EBV-reactivation, 1 patient with Infectious Mononucleosis) and 6 healthy EBV positive controls. EBV-specific CD8 T cells were enumerated using HLA class I tetramers and the IFN-gamma cytokine secretion assay. EBNA1-specific CD4 T cells were analyzed after protein stimulation and EBV load was quantified by real-time PCR. Absolute CD8 T cell counts were highly variable in all 19 cases analyzed. In contrast, the absolute EBV-specific CD8 T cell count was found to be low in 7/9 patients with PTLD (<5/microl whole blood). These frequencies were similar to absolute EBV-specific CD8 T cell numbers observed in healthy EBV positive donors, but much lower compared to patients with EBV reactivation but no PTLD. Absolute CD4 T cell counts were significantly lower in PTLD patients (mean: 336/microl+/-161 vs. controls 1008/microl+/-424, p=0.0001), with EBNA1-specific CD4 T cell responses being also low, but highly variable. Moreover, low absolute CD4 T cell counts (<230/microl) were associated with an elevated EBV load (>1000 copies/microg DNA). We conclude that SOT recipients with PTLD have an inadequate functional EBV-specific T cell response. Our data suggest that the frequency and function of circulating EBV-specific CD8 T cells are dependent on absolute CD4 T cell counts. Further studies are needed to verify if a low absolute CD4 T cell count presents a risk factor for the development of PTLD in SOT recipients.
authors.affiliation: Charité-Universitaetsmedizin Berlin, Campus Virchow Klinikum, Med. Klinik m. S. Haematologie/Onkologie, D-13353 Berlin, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Sebelin-Wulf
authors.forename: Tuan D
authors.initials: TD
authors.lastname: Nguyen
authors.forename: Stephan
authors.initials: S
authors.lastname: Oertel
authors.forename: Matthias
authors.initials: M
authors.lastname: Papp-Vary
authors.forename: Ralf Ulrich
authors.initials: RU
authors.lastname: Trappe
authors.forename: Antje
authors.initials: A
authors.lastname: Schulzki
authors.forename: Antonio
authors.initials: A
authors.lastname: Pezzutto
authors.forename: Hanno
authors.initials: H
authors.lastname: Riess
authors.forename: Marion
authors.initials: M
authors.lastname: Subklewe
mesh_terms: D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002452:Cell Count; D002648:Child; D020031:Epstein-Barr Virus Infections / Q000276:immunology*; D019309:Epstein-Barr Virus Nuclear Antigens / Q000276:immunology; D005260:Female; D004854:Herpesvirus 4, Human; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000821:virology*; D008297:Male; D008875:Middle Aged; D016377:Organ Transplantation / Q000009:adverse effects*; D011183:Postoperative Complications / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019562:Viral Load
chemical_list: D019309:Epstein-Barr Virus Nuclear Antigens; C417029:EBV-encoded nuclear antigen 1