EPSTEIN BARR VIRUS INFECTION IN NEWLY DIAGNOSED CD38-POSITIVE AND CD38-NEGATIVE PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA

BACKGROUND AND AIM:Infections and immune deregulation frequently complicate chronic lymphocytic leukemia (CLL) disease. In immunocopromised individuals, EBV can either become reactivated or establish latency programs II and III. The aim of this study was to analyze the types of EBV infection in newly-diagnosed CLL patients with the CD38-negative (CD38<6%), CD38-moderate (CD38>6%<30%), and CD38-positive (CD38>30%) leukemic cells in peripheral blood (PB).
METHODS:PB cells of 53 newly diagnosed CLL patients were examined for the EBV copy number and mRNA expression of the EBV-encoded genes, BZLF, LMP1, EBNA2, and LMP2A, and the CLL negative prognostic ZAP70. RESULTS:There were not significant differences in the ZAP70 mRNA levels between the CLL patient groups. In the CD38-negative patients (n=21), the EBV copy number was low (< 29 copies per 105 cells) or undetectable. In two patients of the CD38-moderate group (n=20), the EBV copy number was 264 and 522. In the CD38-positive group (n=12), in one patient, 250 EBV copies were detected. BZLF mRNA was found in one patient of the CD38-positive group, indicating early stage of lytic EBV infection. LMP1 mRNA was detected in two patients in the CD38-positive group: one patient had EBNA2 mRNA, another one was EBNA2-negative but LMP2A-positive what suggest the latency type II and III, respectively.
CONCLUSIONS:Possible EBV involvement was revealed in 5 out of 53 patients with newly diagnosed CLL. To assess the putative role of EBV in CLL progression, following up of these patients is being conducted. The studies were funded by the Latvian Council of Science projects No.651/2014 and No.lzp-2018/1-0156.