Epstein-Barr virus DNA load in peripheral blood mononuclear cells and whole blood from pediatric transplant...

Monitoring of circulating Epstein-Barr virus (EBV) DNA in pediatric transplant patients has been shown to be useful in post-transplant patient management. It still remains unclear which blood sample type is more suitable, and how EBV DNA levels in whole blood (WB) correlate with those in peripheral blood mononuclear cells (PBMCs). The aim of this study was to compare EBV DNA load in WB and PBMCs of pediatric transplant recipients. After liver, kidney, or combined liver-kidney transplantation, 172 matched WB and PBMCs samples were collected from 84 children (130 samples from 42 patients consisted of multiple collections). The EBV DNA level in PBMCs was determined by home-made real-time polymerase chain reaction using TaqMan chemistry. In parallel, the viral load (VL) in WB was measured by a commercial LightCycler EBV Quant Kit. The EBV DNA levels and dynamics of VL changes were assessed and compared between WB and PBMCs. The overall correlation between EBV DNA level in PBMCs and WB was statistically significant and high, r(2) =0.87 (P<0.001). However, the sensitivity of EBV detection was lower in WB (93.9%). Longitudinal analysis of EBV DNA load dynamics in PBMCs and WB indicated that EBV DNA load fluctuations were larger in WB, but the trend of decreases and increases, with minor exceptions, was similar in both sample types. The high correlation of EBV DNA levels, as well as the similar dynamics of EBV DNA changes in both sample types, make WB a good alternative to EBV DNA monitoring in PBMCs of pediatric transplant recipients. However, the subtle increase of the VL may be detected earlier in PBMCs.