1792. Viral DNA Loads in Various Blood Components of Patients with EBV-Positive T/NK Cell Lymphoproliferative Diseases

Abstract

Abstract Background Epstein–Barr virus (EBV) is associated with T- and NK-cell lymphoproliferative disorders (EBV T/NK-LPD). For diagnosis of EBV T/NK-LPD, quantification of EBV DNA loads in peripheral blood by real-time PCR has been widely used. However, optimal blood components and cut-off values for diagnosis were not fully evaluated. Methods Fifty-nine patients with EBV T/NK-LPD including chronic active EBV infection (CAEBV), severe mosquito bite allergy, hydroa vacciniforme-like lymphoproliferative disorder (HV), and EBV- hemophagocytic lymphohistiocytosis (EBV-HLH) were enrolled. EBV DNA loads were compared among disease categories in each blood component from the same whole blood sample. The association between EBV DNA loads and disease activity were evaluated in CAEBV patients. Furthermore, the diagnostic cut-off value for EBV DNA loads in whole blood from CAEBV patients as compared with infectious mononucleosis patients was determined. Results EBV DNA loads in whole blood and peripheral blood mononuclear cells (PBMCs) were not significantly different among disease categories, whereas EBV DNA loads in plasma were significantly higher in EBV- HLH patients than in HV patients. EBV DNA loads in whole blood and PBMCs showed strong correlation (Figure 1). EBV DNA loads in plasma were significantly higher in CAEBV patients with active disease than in those with inactive disease (median: 104.5 IU/mL vs. 100.8 IU/mL, P < 0.001) (Figure 2). Diagnostic cut-off values for whole blood EBV DNA loads of CAEBV patients as compared with those of infectious mononucleosis was 104.2 ( = 15,800) IU/mL (Figure 3). Conclusion Measuring EBV DNA loads in whole blood can be considered as initial evaluation for diagnosis of EBV T/NK-LPD. EBV DNA loads in plasma are more closely related to disease activity of CAEBV than EBV DNA loads in whole blood and PBMCs. Disclosures All authors: No reported disclosures.