Background/Aim: Cancer immune therapy by immune checkpoint inhibitors (ICIs) is a promising therapeutic strategy for various cancer types. Among ICIs, anti-programmed cell death protein-1 (PD1) and antiprogrammed death-ligand 1 (PD-L1) antibodies have shown a remarkable clinical benefit. The present study aimed to address the functional and clinical significance of serum levels of soluble PD-L1 (sPD-L1) in patients. Materials and Methods: A total of 21 patients, 11 with NSCLC, nine with gastric cancer and one with bladder cancer, who underwent anti-PD-1 therapy were evaluated for sPD-L1 concentration by ELISA analyses at diagnosis and after treatment. Results: Pretreatment levels of sPD-L1 in patients who received ICIs were not remarkably correlated with the overall survival of these patients (r=0.3394, p=0.1323). Reduction of plasma sPD-L1 level was significantly correlated with tumor regression in patients administered four cycles of treatment (p<0.05). Conclusion: sPD-L1 might be derived and secreted from tumors and might be useful to identify primary responders to ICIs at a relatively early treatment timepoint.Programmed death protein (PD1) and its ligand PD-L1 are central components in immune suppression, comprising the so-called 'immune checkpoint' (1, 2). Accumulating evidence revealed that the PD1/PD-L1 pathway is closely involved in resistance to antitumor immunity in multiple cancer types. Therefore, targeting immune checkpoints using immune checkpoint inhibitors (ICIs), such as those against PD1/PD-L1, has contributed to recent advances in cancer therapeutics (3, 4). However, many patients failed to respond or developed resistance after an initial response to ICIs. Predictive biomarkers for identifying potential responders to ICIs are currently under debate (5). Notably, several lines of evidence suggest a correlation between tumor PD-L1 expression and response to ICIs in variable malignancies including lung adenocarcinoma, melanoma, refractory Hodgkin's lymphoma, and other solid tumor types (6-10). Intriguingly, such correlation was reported for the expression level of membrane-bound PD-L1 (mPD-L1) on tumor tissues and plasma level of soluble PD-L1 (sPD-L1) in the blood of patients with cancer, highlighting the importance of their prognostic value. Several studies showed that high expression of sPD-L1 was associated with a poor prognosis in multiple types of malignant tumor. This suggests that sPD-L1 might be a predictive marker for low treatment responses to conventional chemotherapy and patients with high expression of sPD-L1 might be suitable for ICI therapy (11)(12)(13)(14)(15)(16)(17)(18)(19)(20). However, it remains unclear whether the plasma sPD-L1 level is derived from malignant tumors pre-existing in patients and reflects a potential response to ICIs. Here, we measured the plasma level of sPD-L1 collected from patients with non-small cell lung cancer (NSCLC) and those with gastric cancer who underwent anti-PD1 therapy and analyzed 5195

Rapid immune recovery following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is important for clinical outcome prediction. In most studies, immune recovery after allo-HSCT is monitored via peripheral blood. However, few reports regarding the status of absolute lymphocyte subsets in the bone marrow (BM) microenvironment have been undertaken. Therefore, we evaluated the clinical impact of immune recovery in the early period following allo-HSCT using BM samples. We showed that delayed natural killer cell recovery was independently associated with a poor prognosis for overall survival (hazard ratio [HR], 3.07; 95% confidence interval [CI], 1.37- 6.89; P = .007), progression-free survival (HR, 3.42; 95% CI, 1.47-7.94; P = .004), and nonrelapse mortality (HR, 6.68; 95% CI, 1.82-25.0; P = .004) by multivariate analysis. In addition, low NK cell counts were associated with the presence of 1 or more bacterial, viral, or fungal infections. Our results indicate that investigating absolute lymphocyte subsets in BM in the early phase following allo-HSCT can be useful for predicting and improving survival outcomes.

Immune checkpoint inhibitors (ICIs) confer remarkable therapeutic benefits to patients with various cancers. However, many patients are non-responders or develop resistance following an initial response to ICIs. There are no reliable biomarkers to predict the therapeutic effect of ICIs. Therefore, this study investigated the clinical implications of plasma levels of soluble anti-programmed death-1 (sPD-1) in patients with cancer treated with ICIs. In total, 22 patients (13 with non-small-cell lung carcinoma, 8 with gastric cancer, and 1 with bladder cancer) were evaluated for sPD-1 concentration using enzyme-linked immunosorbent assays for diagnostic and anti-PD-1 antibody analyses. sPD-1 levels were low before the administration of anti-PD-1 antibodies. After two and four cycles of anti-PD-1 antibody therapy, sPD-1 levels significantly increased compared with pretreatment levels (p = 0.0348 vs. 0.0232). We observed an increased rate of change in plasma sPD-1 concentrations after two and four cycles of anti-PD-1 antibody therapy that significantly correlated with tumor size progression (p = 0.024). sPD-1 may be involved in resistance to anti-PD-1 antibody therapy, suggesting that changes in sPD-1 levels can identify primary ICI non-responders early in treatment. Detailed analysis of each cancer type revealed the potential of sPD-1 as a predictive biomarker of response to ICI treatment in patients with cancer.

Studies showed red cell distribution width (RDW) can improve the detection of morphological changes in red blood cells and the understanding of their contribution to dyserythropoiesis in myelodysplastic syndrome (MDS). The purpose of the study was to evaluate dyserythropoiesis in MDS by RDW analysis and to explore the utility of RDW in clinical practice. We retrospectively analyzed laboratory and clinical data of 101 patients (59 patients was refractory anemia (RA) according to the French-American-British (FAB) classification). In patients with RA, RDW was showed weak inverse correlation with both hemoglobin concentration (Hb) (r = -0.37, P = 0.0035) and mean corpuscular hemoglobin concentration (MCHC) (r = -0.36, P = 0.0047). On the other hand, RDW was showed weak correlation with the number of ringed sideroblasts in bone marrow (r = 0.31, P = 0.023). The increased RDW (≥15.0%) was associated with shorter overall survival (OS) (P = 0.0086). In patients with refractory anemia with excess blasts (RAEB) and RAEB in transformation (RAEB-t), effect of RDW on OS was less evident. These results suggested that increased RDW might reflect dyserythropoiesis, associated with deregulated hemoglobin synthesis and iron metabolism in MDS. Furthermore, increased RDW may have potential to be a prognostic significance in RA.

Pancreatic cancer has an extremely poor prognosis, and identification of novel predictors of therapeutic efficacy and prognosis is urgently needed. Chemoresistance-related molecules are correlated with poor prognosis and may be effective targets for cancer treatment. Here, we aimed to identify novel molecules correlated with chemoresistance and poor prognosis in pancreatic cancer. We established 10 patient-derived xenograft (PDX) lines from patients with pancreatic cancer and performed next-generation sequencing (NGS) of tumor tissues from PDXs after treatment with standard drugs. We established a gene-transferred tumor cell line to express chemoresistance-related molecules and analyzed the chemoresistance of the established cell line against standard drugs. Finally, we performed immunohistochemical (IHC) analysis of chemoresistance-related molecules using 80 pancreatic cancer tissues. From NGS analysis, we identified olfactomedin-4 (OLFM4) as having high expression in the PDX group treated with anticancer drugs. In IHC analysis, OLFM4 expression was also high in PDXs administered anticancer drugs compared with that in untreated PDXs. Chemoresistance was observed by in vitro analysis of tumor cell lines with forced expression of OLFM4. In an assessment of tissue specimens from 80 patients with pancreatic cancer, Kaplan-Meier analysis showed that patients in the low OLFM4 expression group had a better survival rate than patients in the high OLFM4 expression group. Additionally, multivariate analysis showed that high expression of OLFM4 was an independent prognostic factor