• cytokine polymorphism;
  • Epstein–Barr virus;
  • post-transplant lymphoproliferative disorder

Abstract:  Objective:  Currently there are no tests to accurately identify paediatric liver transplant patients at risk for post-transplant lymphoproliferative disorder (PTLD). Herein we describe the use of cytokine polymorphisms and real-time quantitative polymerase chain reaction (qPCR) Epstein–Barr virus (EBV) viral load to identify patients at risk for PTLD development.

Methods:  Between 2001 and 2004, approximately 1047 patient samples were collected for qPCR for EBV in 59 patients. EBV viral load was reported in three groups: low EBV (<4 000 copies/μg DNA), high EBV/no PTLD (>4000 copies/μg DNA) and biopsy-proven PTLD. All 59 patients also had cytokine polymorphism genotyping performed for six cytokine polymorphisms (transforming growth factor (TGF)-β, tumor necrosis factor (TNF)-α, interleukins (IL)-6, IL-10, IL-2, and interferon (IFN)-γ) from DNA isolated from peripheral blood mononuclear cells. Positive predictive value (PPV) and negative predictive value (NPV) were calculated using qPCR and cytokine polymorphism results. Data are reported as a mean±standard error of the mean.

Results:  There were 35 males and 24 females with a mean follow-up of 34.9 months. EBV viral load had a PPV and NPV of 29 and 95%, respectively. The low IFN-γ (A/A) polymorphism was found to be present in 4/6 PTLD patients (67%) and only 17/53 (33%) non-PTLD patients. When the low A/A IFN-γ polymorphism was combined with EBV viral load for prediction of PTLD, PPV and NPV were 57 and 93%, respectively.

Discussion:  Use of cytokine genotyping in conjunction with qPCR for EBV viral load can significantly improve the predictive value of diagnostic tests for identification of patients at high risk for PTLD.