OBJECTIVETo explore the diagnostic value of serum levels of BamHI-W fragment, latent membrane protein-1 (LMP-1), BZLF1 and ZEBRA protein in patients with natural killer (NK)/T-cell lymphomas (NKTCLs), and to evaluate their relationship with clinical features.

METHODSA total of 144 cases were analyzed in this study, including 48 NKTCLs patients, 48 other types of non-Hodgkin's lymphomas (NHL) patients and 48 healthy individuals as controls. Fluorescent quantitative real-time polymerase chain reaction (RQ-PCR) was used to measure the copy number of BamHI-W, LMP-1 and BZLF1 in serum. Enzyme linked immunosorbent assay (ELISA) was applied to measure the serum levels of ZEBRA protein. The relative operating characteristic (ROC) curve was applied in the evaluation of the tested markers in diagnosis of NKTCL patients, and the correlations among the tested markers and clinical feature were analyzed.

RESULTSCompared with the controls, NKTCL group showed significantly higher levels of all the tested markers (P < 0.01). The median values of serum BamHI-W, LMP-1 and BZLF1 DNAs level were 1870, 394 and 499 copies/ml, respectively. And the median value of ZEBRA protein level was 73.3 µg/L. Furthermore, the ROC curves analysis revealed that all the area under curve (AUC) of LMP-1, BZLF1 and ZEBRA were more than 0.70, which were probably helpful in the diagnosis of NKTCL. To predict the presence of NKTCL, BamHI-W showed a high sensitivity of 81.3%, while BZLF1 showed a high specificity of 81.2%. Untreated patients seemed to have a significantly higher level of serum LMP1 DNA than that of treated patients (median value 898 copies/ml vs 0 copies/ml, P = 0.050). Correlation analysis showed that serum BamHI-W DNA level was correlated with the presence of B symptoms. All the three genes expressed in 94.4% of the untreated cases. On the other hand, none of them expressed in treated cases.

CONCLUSIONSIt suggested that combined measurements of BamHI W, LMP1 and BZLF1 DNA levels might be helpful to the diagnosis and therapeutic monitor of NKTCL.