EBV Conference 2008 Guangzhou - Baylor College of Medicine

200 (RegID: 1832)
Upton Allen
Institution: Hospital for Sick Children, University of Toronto
e-mail: upton.allen@sickkids.ca
DIFFERENTIALLY EXPRESSED HOST GENES IN RELATION TO VIRAL LOADS IN
EPSTEIN-BARR (EBV) VIRUS INFECTION AFTER PEDIATRIC ORGAN
TRANSPLANTATION
Upton Allen, Michelle Barton, Joseph Beyene, Pingzhao Hu, Nasser Khodai-Booran, Diane Hébert, Anne
Dipchand, Vicky Ng, Melinda Solomon, David Grant, Bo Ngan, Maria Zielenska, and Sheila Weitzman.
Hospital for Sick Children, Toronto, Canada.
Posterabstract:
INTRODUCTION: There is an inconsistent relationship between elevated EBV loads and the risk of
progression to post-transplant lymphoproliferative disorder (PTLD). We hypothesized that aspects of the
virus-host interaction could be measured to help predict progression to PTLD.
OBJECTIVE: To examine differentially expressed host genes and their interaction patterns in different
EBV viral load settings after transplantation compared with healthy controls.
METHODS: Gene expression was measured by microarray analysis of RNA from CD19+ B lymphocytes
using the Human Genome U133 plus 2.0 GeneChip. Moderated t-statistics were computed for each gene
using a local pooled error (LPE) test. The false discovery rates (FDR) of the differentially expressed genes
were evaluated and validated using RT-PCR. Using average-linkage hierarchical clustering analysis, a set
of genes with the largest variation, as measured by coefficient of variation, was used to explore the
patterns of viral loads (VL). Gene network analysis was also performed.
RESULTS: Among 27 samples from 26 transplant recipients, there were 4 episodes of PTLD. The VL
categories were: low or undetectable loads (LU), N = 14; high or intermediate loads (HI), N = 13. There
were 7 healthy EBV-seropositive (P) and -seronegative controls (N). Median age of transplant patients =
12.1 yrs (range 1-16.9); Median time post-transplant 0.5 yr (range 0.1-3.8). Using the LPE test, we
identified 24-54 differentially expressed genes with FDR