Vitamin D Supplementation Regulates Postoperative Serum Levels of PD-L1 in Patients with Digestive Tract Cancer and Improves Survivals in the Highest Quintile of PD-L1: A Post Hoc Analysis of the AMATERASU Randomized Controlled Trial.

Because vitamin D responsive elements have been found to be located in the PD-L1 gene, vitamin D supplementation was hypothesized to regulate serum PD-L1 levels and thus alter survival time of cancer patients. A post hoc analysis of the AMATERASU randomized, double-blind, placebo-controlled trial of postoperative vitamin D3 supplementation (2000 IU/day) in 417 patients with stage I to stage III digestive tract cancer from the esophagus to the rectum was conducted. Postoperative serum PD-L1 levels were measured by ELISA and divided into quintiles (Q1-Q5). Serum samples were available for 396 (95.0%) of the original trial. Vitamin D supplementation significantly (p = 0.0008) up-regulated serum PD-L1 levels in the lowest quintile (Q1), whereas it significantly (p = 0.0001) down-regulated them in the highest quintile (Q5), and it did not either up- or down-regulate them in the middle quintiles (Q2-Q4). Significant effects of vitamin D supplementation, compared with placebo on death (HR, 0.34; 95% CI, 0.12-0.92) and relapse/death (HR, 0.37; 95% CI, 0.15-0.89) were observed in the highest quintile (Q5) of serum PD-L1, whereas significant effects were not observed in other quintiles (Pinteraction = 0.02 for death, Pinteraction = 0.04 for relapse/death). Vitamin D supplementation significantly reduced the risk of relapse/death to approximately one-third in the highest quintile of serum PD-L1.

Circulating PD-L1 levels change during bevacizumab-based treatment in recurrent glioma.

PURPOSE: In primary brain tumors, the efficacy of immune-modulating therapies is still under investigation as inflammatory responses are restricted by tight immunoregulatory mechanisms in the central nervous system. Here, we measured soluble PD-L1 (sPD-L1) in the plasma of patients with recurrent glioblastoma (GBM) and recurrent WHO grade II-III glioma treated with bevacizumab-based salvage therapy. METHODS: Thirty patients with recurrent GBM and 10 patients with recurrent WHO grade II-III glioma were treated with bevacizumab-based salvage therapy at the Medical University of Vienna. Prior to each treatment cycle, EDTA plasma was drawn and sPD-L1 was measured applying a sandwich ELISA with a lower detection limit of 0.050 ng/ml. Leukocyte counts and C-reactive protein (CRP) levels were measured according to institutional practice. RESULTS: Median number of sPD-L1 measurements was 6 per patient (range: 2-24). At baseline, no significant difference in sPD-L1 concentrations was observed between WHO grade II-III glioma and GBM. Intra-patient variability of sPD-L1 concentrations was significantly higher in WHO grade II-III glioma than in GBM (p = 0.014) and tendentially higher in IDH-mutant than in IDH-wildtype glioma (p = 0.149) In WHO grade II-III glioma, sPD-L1 levels were significantly lower after one administration of bevacizumab than at baseline (median: 0.039 ng/ml vs. 0.4855 ng/ml, p = 0.036). In contrast, no significant change could be observed in patients with GBM. CONCLUSIONS: Changes in systemic inflammation markers including sPD-L1 are observable in patients with recurrent glioma under bevacizumab-based treatment and differ between WHO grade II-III glioma and GBM.

Clinical significance of circulating soluble immune checkpoint proteins in sorafenib-treated patients with advanced hepatocellular carcinoma.

In hepatocellular carcinoma (HCC), the clinical significance of soluble immune checkpoint protein levels as predictors of patient outcomes or therapeutic responses has yet to be defined. This study profiled the baseline levels of sixteen soluble checkpoint proteins and their changes following sorafenib treatment for HCC. Plasma samples were obtained from 53 patients with advanced HCC at baseline, week 1, 2 and 4 of sorafenib treatment and tested the concentrations of 16 soluble checkpoint proteins using multiplexed fluorescent bead-based immunoassays. Multivariate analysis showed high sBTLA levels at baseline were an independent predictor of poor overall survival (p = 0.038). BTLA was highly expressed in T cells and macrophages in peritumoral areas. At week 2, sCD27 levels were decreased compared to baseline. By contrast, the concentrations of most inhibitory proteins, including sBTLA, sLAG-3, sCTLA-4, sPD-1, sCD80, sCD86 and sPD-L1, had significantly increased. The fold-changes of soluble checkpoint receptors and their ligands, including sCTLA-4 with sCD80/sCD86, sPD-1 with sPD-L1; and the fold-changes of sCTLA-4 with sBTLA or sPD-1 were positively correlated. sBTLA may be a good biomarker for predicting overall survival in HCC patients. Sorafenib treatment in patients with advanced HCC revealed dynamic changes of soluble checkpoint protein levels.

Influence of total glucosides of paeony on PD-1/PD-L1 expression in primary Sjögren's syndrome.

AIM: To study the influence of total glucosides of paeony (TGP) on the expression of peripheral blood programmed cell death protein 1 (PD-1) and its ligand (PD-L1) in patients with primary Sjögren's syndrome (pSS). METHOD: Ten patients with new-onset pSS were selected as the experimental group and were treated with 1.8 g of TGP (the main ingredient is Radix Paeoniae Alba) daily for 3 months; furthermore, 10 physically healthy individuals were selected as the control group. Peripheral blood mononuclear cells were isolated, and flow cytometry was used to detect PD-1 expression on the surface of CD4+ T and CD8+ T lymphocytes and PD-L1 expression on the surface of CD14+ monocytes and CD19+ B cells before and after treatment in the experimental and control groups. Furthermore, plasma levels of soluble PD-1 (sPD-1), interleukin (IL)-10, and IL-17A were also determined using enzyme-linked immunosorbent assay. RESULTS: The PD-1 expression on the surface of CD4+ T and CD8+ T lymphocytes in the peripheral blood of patients with pSS were significantly higher than in the control group (P < 0.001). However, PD-L1 expression on the surface of CD14+ monocytes declined but not significantly (P > 0.05), and PD-L1 expression on the surface of CD19+ B cells increased significantly (P < 0.001). Moreover, sPD-1 and IL-17A levels in the plasma of the experimental group were significantly higher than in the control group (P < 0.001), but the IL-10 level was significantly lower than in the control group (P < 0.001). After TGP treatment, PD-1 expression on the surface of CD4+ T and CD8+ lymphocytes in the peripheral blood of patients with pSS had decreased significantly (P < 0.001); the PD-L1 expression on the surface of CD19+ cells had decreased significantly (P < 0.001); and the PD-L1 expression on the surface of CD14+ monocytes did not differ significantly (P > 0.05). Furthermore, the levels of sPD-1 and IL-17A in plasma had decreased (P < 0.01) and IL-10 levels had increased after TGP treatment (P < 0.01). CONCLUSION: PD-1/PD-L1 molecules expressed on the surface of T cells, B cells, and monokaryon participated in the pathogenesis and development of SS through interactions. Therefore, TGP, which may increase the expression of PD-1 and its relevant ligand PD-L1 in the peripheral blood mononuclear cells, may play a role in the pathogenesis and development of SS through the PD-1/PD-L1 pathway by regulating regulatory T cells/T helper cell 17.