sPD‐L1 Expression is Associated with Immunosuppression and Infectious Complications in Patients with Acute Pancreatitis

Abstract

Acute pancreatitis (AP) with infectious complications has high mortality because of early-stage immunosuppression. The programmed cell death-1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway is an important host immunosuppression mechanism. Soluble PD-L1 (sPD-L1) expression regulates co-inhibitory signals in malignancies or autoimmune disorders; however, its effects in AP are unknown. Here, we evaluated whether serum sPD-L1 is involved in immune dysfunction and assessed its relationship with infectious complications in early AP. Blood samples were obtained from 56 patients with acute pancreatitis and 21 healthy individuals in this prospective study. Serum sPD-L1 levels within 48 h after AP onset were tested by enzyme-linked immunosorbent assays. Relevant immune parameters (human leucocyte antigen-DR, lymphocyte count) and inflammatory markers (C-reactive protein, white blood cell count) were analysed. sPD-L1 was significantly upregulated in patients with early AP, especially those with infectious complications, compared to healthy controls. Significant negative correlations were observed among monocyte HLA-DR expression, lymphocyte count and sPD-L1 levels in AP. Multivariate regression indicated that sPD-L1 was an independent risk factor for infectious complications in AP. The findings suggest that increased sPD-L1 expression appears to be involved in the development of immunosuppression in the early stage of AP and that sPD-L1 might be an early parameter for prediction of infectious complications in patients with AP.

Is high serum programmed death ligand 1 level a risk factor for poor survival in patients with gastric cancer?

“…The other limitation was that there were no age‐matched healthy controls to compare their serum PD‐L1 level with those of patients with gastric cancer. Using the same ELISA kit as that used in the present study, Chen et al reported that the median serum PD‐L1 level in healthy controls was 48.15 pg/mL, which is very similar to the median serum PD‐L1 level reported in our series of patients with gastric cancer. Therefore, we suspect that there is no statistically significant difference in serum PD‐L1 level between healthy controls and patients with gastric cancer.…”

Are preoperative high soluble programmed death ligand 1 levels responsible for patients’ poor prognoses in hepato-biliary-pancreatic cancer?

“…One of the limitations of the present study was the lack of healthy controls to compare sPD-L1 levels with those of patients with HBP cancer. Using the same ELISA kit that was used in the present study, Chen et al reported that the median serum PD-L1 level in healthy controls was 48.15 pg/ml [18]. The median serum PD-L1 level reported in our present study was slightly higher than this value.…”

Are preoperative high soluble programmed death ligand 1 levels responsible for patients’ poor prognoses in hepato-biliary-pancreatic cancer?

“…To conclude and validate this observation without a shadow of doubt, a larger cohort with control group is needed. Using the same ELISA kit that was used in the present study, Chen et al reported that the median serum PD-L1 level in healthy controls was 48.15 pg/ml [18]. The median serum PD-L1 level reported in our present study was slightly higher than this value.…”