TLR4 expression correlated with PD-L1 expression indicates a poor prognosis in patients with peripheral T-cell lymphomas.

Toll-like receptor 4 (TLR4), a member of the pattern recognition receptors, has been reported to be involved in carcinogenesis. However, the clinical impact of TLR4 in peripheral T-cell lymphomas (PTCL) remains unclear. The current study, using immunohistochemical staining, first examined TLR4 and programmed cell death-ligand 1 (PD-L1) expression in patients with PTCL, to correlate TLR4 and PD-L1 expression with clinicopathological parameters. It was found that the rates of high expression of TLR4 and PD-L1 were 41.7% and 45.8%, respectively. TLR4 expression was closely associated with PD-L1 expression. The expression of TLR4 was closely related to primary extranodal site involvement, increased Ann Arbor stage, and low hemoglobin expression, while the expression of PD-L1 was closely related to a low platelet count and multiple extranodal organ involvements (>1). High expression of either TLR4 or PD-L1 indicated a poor survival rate for patients with PTCL. Multivariate analyses further confirmed that increased expression levels of TLR4 and PD-L1 are unfavorable prognostic factors for PTCL. This study demonstrates that the expressions of TLR4 and PD-L1 are independent predictors of survival time for patients with PTCL. Thus, TLR4 and PD-L1 may serve as potential therapeutic targets in PTCL patients.