sPD-1 Levels Research Articles

Preliminary observations on soluble programmed cell death protein-1 as a prognostic and predictive biomarker in patients with metastatic melanoma treated with patient-specific autologous vaccines

Because of its role as an immune checkpoint, levels of soluble programmed cell death protein-1 (sPD-1) could be useful as a prognostic biomarker or predictive biomarker in cancer patients treated with vaccines. Very low levels of sPD-1 may indicate lack of an existing anti-cancer immune response; very high levels may indicate an active immune response that is suppressed. In between these extremes, a decrease in PD-1 following injections of an anti-cancer vaccine may indicate an enhanced immune response that has not been suppressed. Blood samples obtained during a randomized trial in patients with metastatic melanoma were tested from 22 patients treated with a tumor cell vaccine (TCV) and 17 treated with a dendritic cell vaccine (DCV). Survival was better in DCV-treated patients. sPD-1 was measured at week-0, one week before the first of three weekly subcutaneous injections, and at week-4, one week after the third injection. The combination of a very low baseline sPD-1, or absence of a very high PD-1 at baseline followed by a decline in sPD-1 at week-4, was predictive of surviving three or more years in DCV-treated patients, but not TCV-treated. Among DCV-treated patients, these sPD-1 criteria appropriately classified 8/10 (80%) of 3-year survivors, and 6/7 (86%) of patients who did not survive three years. These preliminary observations suggest that sPD-1 might be a useful biomarker for melanoma patients being considered for treatment with this DCV vaccine, and/or to predict efficacy after only three injections, but this would have to be confirmed in larger studies.

Unbalanced expression of membrane-bound and soluble inducible costimulator and programmed cell death 1 in patients with myasthenia gravis

This study aimed to investigate the possible functions and mechanisms of positive and negative costimulatory molecules in the pathological process of myasthenia gravis (MG). The expression levels of membrane-bound inducible costimulator (ICOS) and programmed cell death 1 (PD-1) in peripheral blood T cells, their corresponding ligands ICOSL and PDL-1 on B cells, and their soluble forms (sICOS, sPD-1, sICOSL, and sPDL-1) in plasma were detected in patients with untreated-stage MG (USMG) and remission-stage MG (RSMG). The results showed that the expression levels of membrane-bound ICOS and PD-1 in the peripheral blood T cells of the USMG group and their corresponding ligands ICOSL and PD-L1 on B cells were significantly increased compared to those in the RSMG group and healthy controls (HCs). The levels of sICOSL and sPD-1 were significantly upregulated in USMG patients compared to those in the RSMG and HC groups, while the levels of sICOS and sPD-L1 were not different. The expression of PD-L1 on CD19+ B cells was positively correlated with the concentrations of AchR Ab in the USMG group. The expression of ICOS and PD-1 in CD4+ T cells and the expression of ICOSL and PD-L1 on CD19+ B cells were positively correlated with the quantitative myasthenia gravis (QMG) scores in the USMG group. Also, in the USMG group, the plasma levels of sICOSL and sPD-1 were positively correlated with the QMG scores. In addition, the percentage of peripheral blood follicular helper T (Tfh) cells in the USMG group was positively correlated with ICOS and PD-1 expression on CD4+ T cells and ICOSL and PD-L1 expression on CD19+ B cells. There were positive correlations between sICOSL and sPD-1 levels and the percentage of peripheral blood Tfh cells and plasma interleukin-21 (IL-21) levels in the USMG group. The results suggest that the positive ICOS/ICOSL and negative PD-1/PD-L1 costimulatory molecule pairs participate in the pathological process of MG. Abnormal sICOSL and sPD-1 expression might interfere with the normal signal transduction of ICOS and PD-1 on Tfh cells, causing excessive activation of Tfh cells and promotion of disease progression. sICOSL and sPD-1 have potential value in monitoring MG disease states.

Abstract 4107: Predictive value of soluble PD-1, PD-L1, VEGFA, CD40 ligand and CD44 for nivolumab efficacy in advanced non-small cell lung cancer

Abstract Context Anti-PD1 therapy nivolumab has been approved for the treatment of advanced non-small cell lung cancer (NSCLC). However, a large inter-individual variability in its efficacy has been observed. Thus, the search for reliable factors to predict anti-PD1 efficacy represents a major challenge, particularly in NSCLC patients. The aim of this prospective study was to assess the correlation of five immunity-related plasmatic biomarkers, soluble PD-1 (sPD-1), soluble PD-L1 (sPD-L1), VEGFA, soluble CD40L and soluble CD44, with survival in nivolumab-treated metastatic NSCLC patients. Method This study included patients from the CERTIM prospective cohort (Immuno-modulatory Therapies Multidisciplinary Study group, Cochin Hospital, Paris, France), treated with nivolumab for a metastatic NSCLC between July 2015 and June 2017. Plasma levels of the five biomarkers were assayed at baseline and after two cycles of nivolumab using commercial ELISA kits. Due to their inconsistent expression, a cut-off of positivity for sPD-1, sPD-L1 and sCD40L expressions was defined as a plasma level above the lower limit of quantification (0.156ng/mL). The primary and secondary endpoints were progression-free survival (PFS) and overall survival (OS), respectively. Results Fitfty-one patients were included (43% female, median age 66 years old): 40 patients (78%) had an adenocarcinoma, and 35 (69%) received nivolumab as a second-line regimen. Median [interquartile range] follow-up was 804 days [553 - 1112]. Baseline sPD-1, sPD-L1 and sCD40L were positive for 15 (29.4%), 27 (52.9%) and 18 patients (50%), respectively. Baseline positivity of sPD-1 and sPD-L1 did not independently correlate with PFS and OS in multivariate analysis. We defined a composite criteria (sCombo) corresponding to the positivity of sPD-1 and/or sPD-L1 for each patient. Patients exhibiting baseline sCombo positivity experienced shorter PFS (median [95% confidence interval]: 78 days [55-109] vs. 658 days [222-not reached]; HR 4.12, 95%CI [1.95-8.71], p=0.0002) and OS (median [95% CI]: 367 days [167 - 501] vs. not reached [402 - not reached]; HR: 3.99, 95%CI [1.63-9.80], p=0.003). The multivariate analysis including clinical factors and tumor cell PD-L1 expression showed that positivity of baseline sCombo was independently associated with a shorter PFS (HR: 2.66, 95%CI [1.17-6.08], p=0.02) but not with OS (HR: 2.17,95%CI [0.86-5.45], p=0.10). An increased or stable sPD-1 level after two cycles of nivolumab independently correlated with longer PFS (HR: 0.23, 95%CI [0.09-0.62], p=0.004) and OS (HR: 0.16, 95%CI [0.05-0.52], p=0.002). VEGFA, sCD40L and sCD44 did not correlate with patients’ survival in this cohort. Conclusion We propose a composite biomarker using soluble PD1 and soluble PDL1, predictive of nivolumab efficacy in NSCLC patients. A larger prospective validation study is warranted to confirm these results. Citation Format: Manuela Tiako Meyo, Anne Jouinot, Etienne Giroux-Leprieur, Elizabeth Fabre, Pascaline Boudou-Rouquette, Audrey Bellesoeur, Jennifer Arrondeau, Hélène Blons, Audrey Mansuet-Lupo, Diane Damotte, Michel Vidal, François Goldwasser, Jérôme Alexandre, Benoit Blanchet. Predictive value of soluble PD-1, PD-L1, VEGFA, CD40 ligand and CD44 for nivolumab efficacy in advanced non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4107.

Clinical significance of soluble forms of immune checkpoint molecules in advanced esophageal cancer.

Immune checkpoint molecules are expressed on cancer cells and regulate tumor immunity by binding to ligands on immune cells. Although soluble forms of immune checkpoint molecules have been detected in the blood of patients with some types of tumors, their roles have not been fully elucidated. Soluble PD-L1, PD-1, CD155, LAG3, and CD226 (sPD-L1, sPD-1, sCD155, sLAG3, and sCD226, respectively) were measured in the sera of 47 patients with advanced esophageal cancer and compared with those of 24 control subjects. Pretreatment levels of sPD-1 and sCD155 were significantly higher in the patients with cancer than in the control subjects (P = 0.023, P = 0.001). The sPD-1 levels tended to be higher in the patients with lymph node metastasis, a large tumor diameter, and higher levels of serum SCC antigen (P = 0.150, P = 0.189, and P = 0.078, respectively). However, higher levels of sCD155 were associated with a better response to chemotherapy and favorable overall survival (P = 0.111 and P = 0.068, respectively). After 2 courses of chemotherapy, the levels of sCD155 and sCD226 were significantly increased (P < 0.001 and P = 0.002, respectively). Moreover, the increase in sCD226 during chemotherapy was associated with poor treatment response (P = 0.019). sPD-1 levels are possibly dependent on the tumor aggressiveness of the esophageal cancer. Furthermore, the pretreatment levels of sCD155 and kinetic change of sCD226 after chemotherapy may be used as biomarkers of the treatment response and prognosis in patients with esophageal cancer.

Analysis of Plasma EBV-DNA and Soluble Checkpoint Proteins in Nasopharyngeal Carcinoma Patients after Definitive Intensity-Modulated Radiotherapy.

Background Tumor immunotherapy and immunological checkpoint-related proteins are research hotspots. Intensity-modulated radiotherapy (IMRT) is the main treatment for nasopharyngeal carcinoma (NPC). Hence, the evaluation of its effect is very important. The aim of this study was to assess the relationship between the concentrations of soluble checkpoint proteins, plasma EBV-DNA, and cytokines in NPC patients treated with IMRT. Methods In this study, the plasma samples of 37 NPC patients and 40 healthy controls were collected. Luminex MAGPIX was used to detect the concentrations of 32 plasma targets, including soluble programmed cell death 1 (sPD-1). RT-qPCR was used to measure EBV-DNA. Results The concentrations of 33 plasma targets were detected in NPC patients before and after IMRT to explore the changes after IMRT. The results showed that IMRT could increase the expression of sPD-1 and significantly reduce the level of EBV-DNA in the plasma of NPC patients. The expression level of sPD-1 in TNM I/II patients was significantly higher than that in III/IV patients. Besides, the concentrations of 12 other targets were significantly different after IMRT, including LAG-3, PD-L1, TIM-3, IFN-γ, IL-12p70, IL-1β, IL-5, IL-6, TNF-α, IL-10, IL-17A, and IL-22. High sPD-1 patients had longer survival than those with low sPD-1. Also, patients with lower EBV-DNA and TNM grades I and II/III had longer survival than those with higher EBV-DNA or TNM IV. Conclusions This study demonstrated that the concentration of sPD-1 was significantly increased and EBV-DNA was significantly reduced in the NPC patients after IMRT. Plasma EBV-DNA level was a highly specific and sensitive biomarker for NPC diagnosis. Both sPD-1 expression and EBV-DNA concentration in plasma were related to the survival of patients.

Serum sPD-1 and sPD-L1 as Biomarkers for Evaluating the Efficacy of Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer Patients

BackgroundNeoadjuvant chemotherapy (NAC) is widely administered in the primary treatment of triple-negative breast cancer (TNBC). However, serum biomarkers for evaluating or monitoring the curative efficacy of NAC have not been established. Accumulating data have shown that soluble programmed death 1 (sPD-1) and its ligand (sPD-L1) might be potential biomarkers for evaluating the curative efficacy of chemotherapy and patient prognosis in several cancers but not yet in breast cancer. Patients and MethodsBlood specimens were obtained from 66 TNBC patients who received NAC and 59 healthy women. The serum concentrations of sPD-1 and sPD-L1 were measured by enzyme-linked immunosorbent assay. ResultsCompared to healthy women, the serum concentration of sPD-1 was significantly elevated in TNBC patients before NAC (549.3 ± 58.76 pg/mL vs. 379.2 ± 17.30 pg/mL, P = .007), but there was only an increase tendency for sPD-L1 (227.7 ± 23.99 pg/mL vs. 195.0 ± 8.49 pg/mL, P = .22). The serum levels of sPD-1 and sPD-L1 before NAC in TNBC patients increased with tumor stage (P = .038 and .030, respectively). Patients who experienced complete or partial remission after NAC had significantly decreased serum levels of sPD-1 and sPD-L1 compared to patients with a poor response to NAC (P = .019 and .021, respectively). ConclusionSerum levels of sPD-1 and sPD-L1 could be used as noninvasive biomarkers for evaluating the malignancy of TNBC before NAC and for predicting the NAC response in TNBC patients.

Soluble forms of the immune check-point receptor PD-1 and its ligand PD-L1 in blood serum of patients with renal cell carcinoma: clinical and pathologic correlations

Background. Renal cancer is one of the most immunosensitive oncologic diseases. A prominent breakthrough in this field was gained with the development of medications directed to the suppression of PD-1/PD-L immune check-point signaling pathway that in normal physiologic conditions controls autoimmune reactions. Tumor PD-1 and/or PD-L1 expression is investigated both as a predictor of corresponding immunotherapy efficiency, and as molecular markers of overall prognosis and patients’ survival. This goal could be also attained by the measure­ment of soluble forms of these proteins (sPD-1 и sPD-L1) in blood serum. Objective of the study — comparative evaluation ofsPD-1 and sPD-L1 content in blood serum of practically healthy persons and patients with renal cancer and benign kidney tumors; analysis of the associations between these markers and clinical and pathologic characteristics of renal cancer. Materials and methods . 106 renal cancer (64 male and 42 female; age 33—81 years) and 11 patients with benign kidney tumors (3 male and 8 female; age 29—84 years) were included in the study. Control group comprised 19 men and 18 women of matching age. 57patients had stage I, 12 — II, 15 — III and 22 — stage IVrenal cancer. Serum sPD-L1 and sPD-1 concentrations were measured using standard enzyme immunoassay kits (Affimetrix, eBioscience, USA). Results. sPD-L1 levels in blood serum of patients with primary renal cancer and benign tumors were significantly higher than in control (p <0.0001 and p <0.05 respectively). sPD-L1 level significantly increased with disease stage (p <0.001), with T index increase from 1 to 3 declining at T4, was significantly higher in patients with lymph node metastases (both N1, and N2) than in those without such lesions (N0); it was also increased in М + patients, and in patients with grade III—IVin comparison to grade I—II tumors. sPD-1 levels did not differ sig­nificantly between study groups, did not depend on disease stage, presence of lymph node or distant metastases, but were decreased in patients with Т 4 as compared to those with less advanced primary tumor, and were significantly lower in patients with clear-cell than in those with chromophobic or papillary histologic variants. Conclusion . Serum sPD-L1 in renal cancer patients correlates with disease progression and tumor grade, and can be regarded as promising marker for monitoring of anti-PD1/PD-L1 treatment efficiency. Potential clinical implications of sPD-1 require further investigations and analysis.

Predictive Value of Soluble Programmed Death-1 for Severe Sepsis and Septic Shock During the First Week in an Intensive Care Unit.

Programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) exists in both membrane-bound and soluble forms. In this study, we evaluated the predictive value of soluble PD-1 (sPD-1) for severity and 28-day mortality in patients with severe sepsis and septic shock during the first week in an intensive care unit (ICU). In this prospective cohort study, patients were classified into the severe sepsis group or the septic shock group according to the severity of their condition on ICU admission. All patients were also separated into the survivor or nonsurvivor groups according to their 28-day outcomes. Peripheral blood sPD-1 and soluble PD-L1 (sPD-L1) levels, PD-1 expression on CD4 and CD8 T cells, and PD-L1 expression on monocytes were measured and compared between the groups on days 1 and 7 after ICU admission. In all, 45 healthy volunteers and 112 patients were recruited. Serum sPD-1 levels were positively correlated with the severity of sepsis, sPD-L1 levels, PD-1 expression on CD4 or CD8 T cells, and PD-L1 expression on monocytes. The sPD-1 was an independent predictive factor for 28-day mortality both on day 1 and day 7. The area under the curve (AUC) of the sPD-1 on day 7 (0.871) was higher than that on day 1 (0.785) (P < 0.05), and better than the AUC of the percentages of PD-L1 on monocytes (0.770) on day 7 (P < 0.05). Serum sPD-1 shows valuable predictive ability for the severity and 28-day mortality of severe sepsis and septic shock during the first week of ICU treatment.

Clinical significance of soluble programmed cell death-1 and soluble programmed cell death-ligand 1 in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy.

BackgroundInhibition of the programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) axis in combination with radiotherapy may be a promising approach to treat cancer. In the present study, we aimed to evaluate serum soluble PD-1/PD-L1 levels in patients with advanced rectal cancer treated with neoadjuvant chemoradiotherapy (CRT).MethodsSerum soluble PD-L1 and PD-1 levels were measured using an enzyme-linked immunosorbent assay before and after CRT in 117 patients with low rectal cancer. Changes in the levels of sPD-L1/PD-1 after CRT, and the correlation between sPD-L1/PD-1 level and clinicopathological characteristics or disease-free survival (DFS) were evaluated.ResultssPD-L1 levels significantly increased after CRT (p < 0.0001), whereas sPD-1 levels did not change significantly (p = 0.1050). High sPD-L1 before CRT was significantly associated with younger age (p = 0.044), and after CRT, with lymphovascular invasion (p = 0.021). High sPD-1 before and after CRT was significantly associated with a longer distance of the tumor from the anal verge (both p < 0.001). There was no correlation between sPD-L1 level and local PD-L1 expression on stromal immune cells. High sPD-L1 level after CRT tended to be associated with worse DFS (p = 0.0752). The multivariate analysis could not demonstrate an independent association for sPD-L1 levels after CRT with DFS.ConclusionsSignificant increase of sPD-L1 levels after CRT suggests that anti-PD-L1 therapy might be a potential treatment strategy in combination with CRT in advanced rectal cancer.

Elevated Soluble PD-L1 in Pregnant Women's Serum Suppresses the Immune Reaction.

Background: Programmed death-ligand 1 (PD-L1) is expressed not only on some cancer cells, but also on the outer surface of placental syncytiotrophoblasts, which is assumed to induce maternal immune tolerance to fetal tissue via programmed death-1 (PD-1) receptors on T cells. Recently, levels of soluble forms of PD-L1 (sPD-L1) were reported to be higher in the serum of pregnant women (PW) than in non-pregnant women (non-PW). However, there have been no reports of the functional significance of PW's serum containing high sPD-L1 levels. Therefore, the aim of the present study was to clarify the role of sPD-L1 in the sera of PW as an immunosuppressive molecule by in vitro assays.Methods: As a post-hoc analysis of our previous cohort study, 330 pairs of serum from PW during the third trimester and cord blood (CB) from paired offspring without major complications were examined. Serum levels of sPD-L1 and sPD-1 were measured by ELISA. On mixed lymphocyte culture (MLC), 3H-thymidine uptakes in the presence of PW's, offspring's, or non-PW's serum were compared. Peripheral blood mononuclear cells (PBMCs) were cultured in the presence of PW's serum stimulated with PHA, and then cytokine levels were measured in supernatants by multiple cytokine analysis with or without anti-PD-L1blocking antibody.Results: The median sPD-L1 level was 8.3- and 6.9-fold higher in PW than in offspring and non-PW, respectively, whereas sPD-1 levels were lower in PW and offspring than in non-PW. On MLC, 3H-thymidine uptake in the presence of autoantigen was strongly reduced by co-culture with serum of both PW and offspring, compared with serum of non-PW. In contrast, uptake in the presence of alloantigen was moderately inhibited by PW's serum, whereas it was less suppressed by offspring's serum, compared with non-PW's serum. In the culture of PBMCs, tumor necrosis factor-α, interferon gamma, interleukin (IL)-2, and IL-4 levels were significantly higher in the presence of anti-PD-L1 blocking antibody than in culture not treated with antibody (all P < 0.05) or culture treated with isotype control antibody (all P < 0.05).Conclusion: The levels of sPD-L1 are elevated in PW's serum, which may, at least in part, suppress maternal immunity.

Association Between Activation of the Programmed Cell Death-1 (PD-1)/Programmed Death-Ligand 1 (PD-L1) Pathway and Pain in Patients with Cancer.

BackgroundThe aim of this study was to investigate the clinical correlation between sPD-1 (soluble programmed cell death-1) and PD-1 (programmed cell death-1) expression and cancer pain.Material/MethodssPD-1 content in peripheral blood was determined by enzyme-linked immunosorbent assay (ELISA). T cell surface-positive rate was determined by flow cytometry, and the correlation of clinical characteristics of patients with cancer pain was analyzed.ResultsThe positive expression rate of PD-1 in sPD-1 and T cells of patients with cancer pain was higher than that in normal patients. There was a significant correlation between sPD-1 and PD-1 positivity on T cell surface with tumor type, differentiation degree, and VAS scores of patients with cancer pain (P<0.05). Peripheral blood sPD-1 level and PD-1 positivity in patients with liver cancer and melanoma cancer were higher than those in patients with renal cell carcinoma and breast cancer. In addition, peripheral blood sPD-1 level and PD-1 positivity in patients with poorly-differentiated cancer pain were higher than those in patients with intermediately- to well-differentiated cancer. The sPD-1 content was lower and PD-1 positivity rate was higher in cancer pain patients with low VAS scores.ConclusionsThe positive expression rate of sPD-1 and PD-1 in patients with cancer pain is higher than that in normal people. The activation rate of the PD-1/PD-L1 pathway was mediated by sPD-1 and PD-1 positive expression, age, tumor type, and differentiation. There are correlations between clinical characteristics such as degree and pain level as shown by VAS score.

Soluble forms of immune checkpoint receptor PD-1 and its ligand PD-L1 in plasma of patients with ovarian neoplasms

Background:Ovarian cancer is one of the most common oncologic diseases holding the frst place in mortality related to neoplasms of female genitalia. Along with active surgical intervention, contemporary ovarian cancer treatment includes various chemotherapeutic regimens which in many cases are quite effective, but relapse and death rates still remain high. In the recent years, major attention has been paid to the possibility of ovarian cancer immunotherapy associated with the discovery of the so-called “immune checkpoint” signaling, i.e. programmed cell death-1 / programmed death-ligand 1 (PD-1/PD-L) pathway, controlling intensity and duration of autoimmune response at physiologic conditions. Tumor PD-1 and/or PD-L1 expression is being actively studied as a predictor of anti-PD-1/PD-L treatment efficacy; however, this approach has certain limitations and problems that might be probably bypassed by determination of soluble PD-1 (sPD-1) and its ligand (sPD-L1) in serum or plasma.Aim:Comparative evaluation of sPD-1 and sPD-L1 content in plasma of healthy women and of patients with benign or borderline ovarian tumors and ovarian cancer, as well as the analysis of associations between these markers and main clinical and pathologic characteristics of ovarian cancer.Materials and methods:Sixty two (62) patients with ovarian neoplasms aged 32 to 77 (median, 56.5) years were enrolled into the study. Fifteen (15) patients had benign tumors, 9 had borderline, and 38, ovarian cancer. The control group included 17 healthy women aged 24 to 67 (median, 49) years. Plasma sPD-L1 and sPD-1 concentrations were measured with standard enzyme immunoassay kits (Afmetrix, eBioscience, USA).Results:Plasma sPD-L1 and sPD-1 levels in ovarian cancer patients (median, 41.3 and 48.0 pg/ml, respectively) did not differ significantly from those in the control group (49.5 and 43.8 pg/ml). sPD-L1 level in the patients with benign tumors (median, 22.2 pg/ml) was signifcantly lower than in the control (p &lt; 0.01). The lowest sPD-1 level in plasma was found in the patients with borderline ovarian neoplasms, the difference with the ovarian cancer group being statistically signifcant (p &lt; 0.05). No correlations between sPD-L1 and sPD-1 plasma levels were found in any of the study groups. sPD-L1 level signifcantly increased with disease stage (R = 0.44; p &lt; 0.01), the most signifcant increase being observed at the most advanced IIIC stage (p &lt; 0.05 as compared to all other stages). sPD-L1 was also signifcantly higher in the patients with ascites than in those without ascites. Plasma sPD-1 concentration was not associated with the indices of ovarian cancer progression, though its median was 1.3–1.44 times lower in the stage I than in the stage II–III patients, and decreased in those with the tumor size above 10 cm (assessed by ultrasound examination) and in the patients with ascites. No statistically signifcant associations of the markers' levels with tumor histological type and differentiation grade of ovarian cancer were found.Conclusion:sPD-L1 level in ovarian cancer patients correlates with disease progression and can be considered as a promising marker for monitoring of anti-PD-1/PD-L1 treatment efficacy. Potential clinical implications of sPD-1 require further studies.

The correlation and prognostic value of serum levels of soluble programmed death protein 1 (sPD-1) and soluble programmed death-ligand 1 (sPD-L1) in patients with hepatocellular carcinoma

BackgroundBlocking the programmed death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway in hepatocellular carcinoma (HCC) is a very promising approach in immunotherapy. However, the correlation and prognostic values of serum soluble PD-1 and PD-L1 (sPD-1/sPD-L1) have not been explored conjointly in HCC patients.MethodsThis study retrospectively included 120 HCC patients receiving radical resection. The serum levels of sPD-1/sPD-L1 and inflammatory cytokines were measured by antibody array assay. Immunohistochemistry was applied to assess both the expression of membrane-bound PD-L1, and the number of CD4+ tumor-infiltrating lymphocytes (TILs) and CD8+ TILs.ResultsThe best cut-off values of sPD-1 and sPD-L1 for predicting disease-free survival (DFS) were 33.0 µg/ml and 11.2 µg/ml, respectively. Multivariable analysis showed that sPD-L1 was a negative independent prognostic factor [DFS, Hazard Ratio (HR) 2.58, 95% CI 1.14–5.84, P = 0.023; overall survival (OS), HR 1.77, 95% CI 1.01–3.12, P = 0.048], while sPD-1 was a favorable independent prognostic factor (DFS, HR 0.32, 95% CI 0.14–0.74, P = 0.007; OS, HR 0.54, 95% CI 0.30–0.98, P = 0.044) in HCC patients. We also observed some similar associations between inflammatory cytokines (IL-10, IL-17, TNF-α) and sPD-1 or sPD-L1, as well as a close positive association between sPD-1 and sPD-L1. No significant associations of sPD-1/sPD-L1 with either intra-tumoral PD-L1 expression, or the numbers of CD4+ TILs and CD8+ TILs were determined.ConclusionsOur findings indicate that sPD-1 and sPD-L1 are independent prognostic factors with opposite prognostic roles in predicting both DFS and OS in HCC patients.

Characterization of Soluble Immune Checkpoint Protein PD-1, PD-L1 and PD-L2 Levels in Different Types of Lymphoid Malignancies

BackgroundCheckpoint proteins regulate the immune system and their down-regulation of effector mechanisms is exploited by malignant cells to evade antitumor immune response. Membrane bound programmed death 1 protein (PD-1) and its ligands 1 and 2 (PD-L1 and PD-L2) are pivotal members of the immune checkpoint family. The significance of the PD-1 pathway have been demonstrated in a variety of malignant diseases and suppressing the pathway with targeting antibodies can re-establish antitumor immunity.Soluble forms of the proteins (sPD-1, sPD-L1 and sPD-L2) are detectable in the peripheral blood, but their biological and clinical significance are still largely unknown. To our knowledge, this is the first study to simultaneously characterize sPD-1, sPD-L1 and sPD-L2 in different types of lymphoma.AimsThe aim of the present study was to measure the pre-therapeutic sPD-1, sPD-L1 and sPD-L2 levels in different lymphoid malignancies and correlate them with clinico-pathological features and outcome.MethodsWe established and validated a Time Resolved Immunoflourometric assay (TRIFMA) to determine levels of sPD-1 and sPD-L2. Soluble PD-L1 levels were measured using a commercially available enzyme-linked immunosorbent assay (ELISA) applied according to manufacturer's instructions.In total, archival serum samples from 102 patients were analysed in duplicate for each protein. This single-institution study population consisted of patients with chronic lymphocytic leukemia (CLL; n=42), diffuse large B cell lymphoma (DLBCL; n=33), follicular lymphoma (FL; 15) and Hodgkin lymphoma (HL; n=12). In addition, 22 and 17 healthy controls were included for analysis of sPD-1/sPD-L1 and sPD-L2, respectively. Information on clinical parameters, response to treatment and outcome was obtained from medical records. Measured levels were compared between patient subgroups and controls using a non-parametric test (Mann-Whitney). P-values below 0.05 were considered statistically significant.ResultsSoluble PD-1 levels were higher in patients, taken as one group, compared to controls (p=0.0002). When analyzed according to lymphoma type, patients with DLBCL, CLL and FL still had significantly elevated sPD-1 levels as compared to controls (p=0.0089, p=0.0008 and p<0.0001, respectively). Highest sPD-1 levels were observed in FL and these were also significantly higher than in any of the other lymphoma subtypes analyzed.Soluble PD-L1 levels were similar in patients, taken as one group, and controls. Interestingly, patients with FL had lower sPD-L1 levels than patients from all the other lymphoma subtypes and it was the only histology whose sPD-L1 levels differed significantly (lower values) from healthy controls (p=0.0017, see table 1). Moreover, we identified a reverse expression pattern of sPD-1/sPD-L1 in FL as compared to other lymphoma subtypes, as FL had significantly higher sPD-1 and lower sPD-L1 than all other remaining patients (see table 1).Soluble PD-L2 levels were generally higher than those of sPD-1 and sPD-L1, and the highest values were found in healthy controls. When analyzed according to histological subtype, patients with CLL, DLBCL and FL had all significantly lower sPD-L2 levels than healthy controls (see table 1).Interestingly, the sPD-1, sPD-L1 and sPD-L2 levels measured in HL patients did not differ significantly from controls, however, this may be due to limited sample size.ConclusionWe simultaneously characterized sPD-1, sPD-L1 and sPD-L2 in selected lymphomas subtypes and found varying levels across the investigated lymphoma entities. In particular, we identified a reverse expression pattern of sPD-1 and sPD-L1 in FL compared to other lymphoid malignancies. We were the first to also characterize sPD-L2 levels in the same patients and found its levels to be generally high throughout lymphoma entities, but highest in healthy controls. A correlation analysis with outcome-related parameters is ongoing. DisclosuresNo relevant conflicts of interest to declare.

OUTCOME OF METASTATIC RENAL CELL CARCINOMA (MRCC) PATIENTS TREATED BY ANTI-PD-1 THERAPY IN EXPANDED ACCESS PROGRAM: CLINICAL EFFICACY AND POTENTIAL BIOMARKERS FOR NIVOLUMAB THERAPY

Therapy with immune checkpoints inhibitors (anti-PD-1 therapy) has become the standard of care for metastatic renal cell carcinoma (mRCC) patients with resistance to tyrosine kinase inhibitors (TKI). Identification of reliable predictive markers for anti-PD-1 therapy would help to select patients who are most likely to respond to checkpoints inhibitors. This article represents the results of treatment of 23 mRCC patients who received nivolumab as part of the expanded access program in Russia. All patients demonstrated resistance to previous lines of TKI therapy. Overall response rate for nivolumab was 21.7 % with median progression-free survival of 4 months (95%CI=1.37–10.04). The median overall survival was not reached with the median follow-up of 10 months (3–14 months). The grade 3–4 toxicity was observed in 3 (13 %) pts. Favorable MSKCC prognosis before treatment, the initial level of sPD-1 exceeding the estimated threshold value and the development of any grade hypothyroidism after treatment initiation were associated with greater progression free survival. The number of preceding lines of TKI therapy, the level of PD-L1 and FOXP3 expression on tumor-infiltrating leukocytes (TILs) did not significantly affect progression-free survival in this group of mRCC patients. The ef ficacy and toxicity profile of nivolumab corresponded to the results of phase 2–3 trials.

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

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). 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. 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). 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.

Imbalance of circulating Tfr/Tfh ratio in patients with rheumatoid arthritis.

Follicular helper T(Tfh) cells and follicular regulatory T(Tfr) cells are critical for the development and maintenance of germinal center and humoral immune responses. Accumulating evidence has demonstrated that the dysregulation of either Tfh or Tfr cells contributes to the pathogenesis of autoimmune diseases. The aim of this study was to examine the numbers of Tfh and Tfr cells in patients with rheumatoid arthritis (RA). Twenty-four patients with RA patients and 20 health controls (HCs) were enrolled in this study. We analyzed the numbers of Tfh (CD4+ CXCR5+ PD-1hi) cells and Tfr (CD4+ CXCR5+CD127lo) cells in 24 RA patients via flow cytometry. The level of the soluble PD-1 and its ligands (sPD-L1 and sPDL-2) were examined by ELISA. Flow cytometry revealed that both circulating Tfh and Tfr cells were increased in RA patients compared with HCs. More importantly, the ratio of Tfr/Tfh was decreased, indicating a disruption of the balance between Tfh and Tfr. The Tfr/Tfh ratio was inversely correlated with level of serum CRP, ESR, RF, anti-CCP, IgG and DAS28 index. We also found that the serum level of sPD-1 was significantly elevated in the RA patients, which was positively correlated with CRP, ESR and the number of Tfh cells. These results indicate that an imbalance of circulating Tfr and Tfh cells may be involved in the immunopathogenesis of RA and may provide novel insight for the development of RA therapies.

Surgical Delay is associated with Improved Survival in Patients with Hepatocellular Carcinoma

To evaluate the efficacy of soluble programmed death-1 (sPD-1) for risk stratification and prediction of 28-day mortality in patients with sepsis, we compared serum sPD-1 with procalcitonin (PCT), C-reactive protein (CRP), and the Mortality in Emergency Department Sepsis (MEDS) score.A total of 60 healthy volunteers and 595 emergency department (ED) patients were recruited for this prospective cohort study. According to the severity of their condition on ED arrival, the patients were allocated to the systemic inflammatory response syndrome group (130 cases), sepsis group (276 cases), severe sepsis group (121 cases), and septic shock group (68 cases). In addition, all patients with sepsis were also divided into the survivor group (349 cases) and nonsurvivor group (116 cases) according to the 28-day outcomes.When the severity of sepsis increased, the levels of sPD-1 gradually increased. The levels of sPD-1, PCT, CRP and the MEDS score were also higher in the nonsurvivor group compared to the survivor group. Logistic regression suggested that sPD-1, PCT, and the MEDS score were independent risk factors for 28-day mortality of patients with sepsis. Area under the curve (AUC) of sPD-1, PCT and the MEDS score for 28-day mortality was 0.725, 0.693, and 0.767, respectively, and the AUC was improved when all 3 factors were combined (0.843).Serum sPD-1 is positively correlated with the severity of sepsis, and it is valuable for risk stratification of patients and prediction of 28-day mortality. Combining sPD-1 with PCT and the MEDS score improves the prognostic evaluation.

Abstract 5540: Clinical significance of soluble forms of immune checkpoint molecules in advanced esophageal cancer

Abstract Background: Immune checkpoint molecules such as PDL1 and CD155 are expressed on cancer cells and regulate tumor immunity by binding to ligands on immune cells. Although soluble forms of immune checkpoint molecules have been detected in the blood, the roles of these soluble forms have not been fully elucidated. In this study, the clinical significance of soluble forms of immune checkpoint molecules in advanced esophageal cancer was examined. Methods: Soluble PDL1 (sPDL1), PD1(sPD1), CD155(sCD155), and LAG3 (sLAG3) were measured by ELISA in 47 patients who were diagnosed with advanced esophageal cancer and planned to receive multidisciplinary treatment in our department from April 2015 to March 2017. The levels of these molecules in cancer patients were compared with those of 24 control subjects. Results: The mean age of the tumor group was 66 years (41 years to 78 years), the ratio of males and females was 42: 5. Based on TNM-UICC stage grouping, 8, 24 and 15 patients were in clinical stage II, III and IV, respectively. All patients underwent chemotherapy, 25 patients underwent radiation therapy in combination with chemotherapy, and 26 underwent surgical therapy after chemotherapy. There was no difference in age between two groups, but the proportion of male was significantly higher in the cancer group than in the tumor group (P = 0.014). Regarding sPDL1 and sLAG3, there was no significant difference between two groups, but the levels of sPD1 and sCD155 were significantly higher in the tumor group than the control group (sPD1: P = 0.0225; sCD155: P = 0.0006). In subgroup analysis of patients with esophageal cancer, there was a tendency for higher levels of sPD1 in patients with lymph node metastasis (P = 0.150), large tumor diameter (P = 0.189), and higher levels of serum SCC (P = 0.078). The level of sPD1 was related to neither response rate nor overall survival. On the other hand, we did not find any association between clinical characteristics and the level of sCD155. However, the level of sCD155 tended to be higher in patients with response to chemotherapy (CR / PR) (P = 0.111) and in patients with a longer survival (P = 0.183). Discussion: We confirmed that sPD1 and sCD155 are elevated in advanced esophageal cancer. In addition, results in this study suggested that sCD155 may be a biomarker for therapeutic effect or prognostic prediction of esophageal cancer. Large-scale studies are needed to confirm our findings. Citation Format: Juichiro Yoshida, Takeshi Ishikawa, Takayuki Ohta, Tomoyo Yasuda, Osamu Dohi, Tetsuya Okayama, Naohisa Yoshida, Kazuhiro Kamada, Kazuhiko Uchiyama, Osamu Handa, Tomohisa Takagi, Hideyuki Konishi, Yuji Naitoh, Yoshito Itoh. Clinical significance of soluble forms of immune checkpoint molecules in advanced esophageal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5540.

Changes of serum sPD-1 levels in HBeAg-positive chronic hepatitis B patients with entecavir treatment and correlation with curative effect

Background/aim: This study aimed to assess expression changes of serum sPD-1 levels in HBeAg-positive chronic hepatitis B patients with entecavir treatment and explore the correlation with the curative effect. Materials and methods: A total of 220 HBeAg-positive CHB patients and 207 healthy individuals were included. sPD-1 levels and virological and biochemical responses were assessed at baseline and at 12, 24, and 48 weeks in CHB patients after antiviral therapy. Results: sPD-1 levels in HBeAg-positive CHB patients before treatment were significantly lower than those of healthy controls. After entecavir treatment, sPD-1 levels increased gradually over time. At 48 weeks after entecavir treatment, sPD-1 amounts in the HBeAg seroconversion group were significantly higher than the values of the HBeAg-negative and HBeAg-positive groups. sPD-1 levels in patients with alanine aminotransferase (ALT) returning to normal were significantly higher than in those with ALT not returning to normal. sPD-1 levels in treated patients with no HBV-DNA were significantly higher than in those with HBV-DNA remaining positive. sPD-1 was negatively correlated with ALT and HBV-DNA at 12, 24, and 48 weeks after entecavir treatment. Conclusion: sPD-1 may play a certain role in chronic hepatitis B and has a close relationship with the curative effect of entecavir.