Epstein-Barr virus (EBV), characterized as an omnipresent virus, has been found able to infect NK cells and leads to NK-cell type EBV-positive lymphoproliferative diseases (EBV-NK-LPDs). We retrospective analyzed 202 EBV-NK-LPDs (including 64 CAEBV-NK, 27
aggressive natural killer-cell leukemia (ANKL), and 111
extranodal NK/T-cell lymphoma (ENKTL)) patients' relationships between EBV
DNA copies laboratory test results and clinical features. In CAEBV-NK cohort, EBV
DNA loads in either plasma or PBMCs had significant differences between the active state and the inactive state. Receiver operating characteristic curves were used to measure the diagnosis accuracy of EBV
DNA copies. After comparing the area under the curve, EBV
DNA loads in plasma had significantly higher accuracy in distinguishing disease activation than in PBMCs. Therefore, we propose redefining CAEBV-NK diagnosis criteria as increased EBV
DNA copies in plasma (over 7.1 × 102 copies/ml) instead of in peripheral blood. In ANKL and ENKTL cohorts, patients who received effective
therapy had significantly lower EBV
DNA copies in plasma & PBMCs than in those with ineffective
therapy. The significant and consistent decline indicated EBV
DNA loads in plasma being a more sensitive
biomarker in monitoring EBV-NK-LPDs
therapy responses.
Hemophagocytic lymphohistiocytosis (HLH) can occur secondary to EBV-NK-LPDs, mostly associated with a poor prognosis, so we try to estimate the combination of HLH by monitoring EBV
DNA copies. When comparing the Receiver operating characteristic curves of EBV
DNA copies, EBV
DNA loads in plasma had higher diagnosis accuracy. When the copies level over 4.16 × 103 copies/ml, it might indicate combining with HLH.