[Infection status and clinical significance of Epstein-Barr virus in pediatric leukemia---a report of 35 cases].

Background & Objective: Epstein-Barr virus (EBV) is associated with genesis of many human tumors. This study was to detect EBV infection in pediatric leukemia, and to explore its clinical significance.

Methods: EBV DNA in peripheral blood mononuclear cells in 35 pediatric leukemia patients, including 26 cases of acute lymphoblastic leukemia (ALL) (24 received initial treatment and 2 received retreatment), 8 cases of acute non-lymphocytic leukemia (ANLL) and 1 case of chronic lymphocytic leukemia (CLL), and in 14 healthy children was detected by fluorescent quantitative polymerase chain reaction (FQ-PCR). Its clinical significance was analyzed according to the clinical manifestations, prednisone sensitivity test, and complete remission (CR) rate after induction chemotherapy.

Results: EBV DNA was detected in 8 (22.86%) of the 35 pediatric leukemia patients. The positive rate of EBV DNA was 26.92% (7/26) in ALL with quantity of (5.144+/-6.91)x10(5) copies/ml, and 12.5% (1/8) in ANLL patients with quantity of 4.031x10(3) copies/ml. No EBV DNA was detected in CLL patients and healthy controls. The occurrence rates of peripheral leukocytosis and hepatosplenomegaly were significantly higher in the patients with EBV infection than in the patients without EBV infection (P <0.001). In ALL, the rate of no response to prednisone was significantly higher in the patients with EBV infection than in the patients without EBV infection (100% vs. 26.32%, P =0.001); CR rate after induction chemotherapy was significantly lower in the patients with EBV infection than in the patients without EBV infection (28.57% vs. 84.21%, P=0.003). In ANLL, the differences of CR rate and relapse rate were not significant between the patients with and without EBV infection (P=0.5).

Conclusions: Pediatric leukemia patients with EBV infection have higher incidence of peripheral leukocytosis and hepatosplenomegaly. ALL patients with EBV infection have poor prednisone response and low CR rate.