Significance of PD-L1 in the diagnosis and treatment of B-cell malignant lymphoma

The present study explored the significance of programmed death-ligand 1 (PD-L1) molecules in the diagnosis and treatment of B-cell malignant lymphoma. A total of 92 patients with B-cell malignant lymphoma (experimental group), admitted to the Quanzhou First Hospital Affiliated to Fujian Medical University from February 2014 to May 2017, and 60 healthy subjects (control group) were enrolled in this study and their clinical data were retrospectively analyzed. Plasma levels of PD-L1 before treatment and at 5, 10, and 15 days after treatment were measured by ELISA. Correlation between PD-L1 expression levels and treatment time was analyzed. Levels of PD-L1 in different pathological types were compared. ROC curve was used to analyze the efficacy of PD-L1 in the treatment of B-cell lymphoma. The expression level of PD-L1 in experimental group was 272.86±48.21 pg/ml, significantly higher than that in control group (18.24±3.62 pg/ml) (P<0.01). In patients with B-cell lymphoma, PD-L1 expression was highest in diffuse large B-cell lymphoma, followed by small lymphocyte lymphoma, mucosa-associated lymphoid tissue lymphoma, mantle cell lymphoma, and the lowest PD-L1 expression level was observed in follicular lymphoma (P<0.05). Linear correlation analysis showed that the expression level of PD-L1 was negatively correlated with treatment time (r=−0.683, P<0.01). The highest Youden index (51.24) was set as cut-off score, the sensitivity of the diagnosis of B-cell lymphoma was 81.66%, and the specificity was 90.24%. PD-L1 is highly expressed in B-cell malignant lymphomas and negatively correlated with treatment time. It has high diagnostic efficiency for B-cell lymphoma and is expected to be an effective immunotherapeutic target for B-cell lymphoma.