The Risk of Polyomavirus-Associated Graft Nephropathy Is Increased by a Combined Suppression of CD8 and CD4 Cell-Dependent Immune Effects

• Published in: Transplantation proceedings Vol. 45; no. 4; pp. 1608 - 1610
• Main Authors: Renner, F.C, Dietrich, H, Bulut, N, Celik, D, Freitag, E, Gaertner, N, Karoui, S, Mark, J, Raatz, C, Weimer, R, Feustel, A
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2013
• Subjects: BK Virus - isolation & purification; CD4-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - immunology; Cyclosporine - administration & dosage; Everolimus; Flow Cytometry; Graft Rejection - etiology; Humans; Immunosuppressive Agents - administration & dosage; Kidney Transplantation; Mycophenolic Acid - administration & dosage; Mycophenolic Acid - analogs & derivatives; Polyomavirus Infections - complications; Polyomavirus Infections - immunology; Polyomavirus Infections - virology; Prospective Studies; Reverse Transcriptase Polymerase Chain Reaction; Risk Factors; Sirolimus - administration & dosage; Sirolimus - analogs & derivatives; Surgery; Tacrolimus - administration & dosage; Viremia - complications; Viremia - immunology; Viremia - virology
• ISSN: 0041-1345; 1873-2623
• DOI: 10.1016/j.transproceed.2013.01.026

Abstract Polyomavirus-associated graft nephropathy (PAN) has emerged as a significant risk factor for kidney graft loss. We analyzed intracellular cytokine responses for possible protective versus permissive immunologic effects on BK-virus replication. One hundred five renal transplant patients included in a prospective single-center study were randomized to receive cyclosporine mycophenolate mofetil (MMF) (CM: n = 31), tacrolimus (Tac)/MMF (TM: n = 32) or Tac/MMF with conversion to everolimus (TErl; n = 32). Ten patients were not randomized (NR) due to contraindications to MMF. The immunosuppressive therapy was monitored pre- and posttransplantation at 4, 12, and 24 months using triple fluorescence flow cytometry for intracellular interleukin (Il)-2 Il-4 and interferon (IFN)-γ production in phorbol myristate acetate- and lipopolysaccharide- stimulated lymphocyte cultures. BK viremia screening was performed by reverse-transcriptase polymerase chain reaction testing on days 0, 14, 30, 60, 90, 120, 180, 270, 360, and 720. Seven of 105 (6.7%) patients developed biopsy-proven PAN (CM: n = 1, TM: n = 3, TErl: n = 2, NR: n = 1), among whom 4 lost their grafts (TM: n = 1, TErl: n = 2, NR: n = 1). Twenty-one of 105 (20.0%) patients had documented BK viremia. BK viremia which preceded PAN in all cases, was significantly associated with TM immunosuppression: 4/31 (12.9%) CM: 11/32 (34.4%) TM; 5/32 (15.6%) TErl, and 1/10 (10.0%) NR patients ( P = .034). BK-viremic patients showed significantly diminished CD8+ T-cell Il-2 production at 120 days ( P = .011) and 1 year posttransplantation ( P = .014) compared with non-BK-viremic patients. Patients with PAN displayed significantly lower CD4+ T-cell Il-4 responses at 1 and 2 years after transplantation (1 year: P = .007; 2 years: P = .001) with diminished IFN-γ responses at 1 year after transplantation ( P = .011). Our analysis showed the incidence of BK viremia to be increased among patients with defective cytotoxic CD8+ T-cell -dependent immune reactivity. Recipients who progressed from BK viremia to overt PAN showed an additional immunologic defect in CD4+ T-cell function. Patients on a Tac- plus MMF-based immunosuppression were at higher risk to develop BK viremia.