sPD-L1 Levels Research Articles

Changes in soluble PD-L1 levels in patients with advanced non-small cell lung cancer

Abstract Soluble programmed death-1 ligand (sPD-L1) in the serum of non-small cell lung cancer (NSCLC) patients is a crucial factor in disease prognosis and an indicator for immunotherapy response. This study aimed to evaluate changes in sPD-L1 levels in advanced NSCLC patients. Between May 2018 and October 2022, 80 patients with advanced-stage NSCLC and 30 healthy volunteers participated in a prospective study. The findings revealed a significant rise in sPD-L1 concentration in the lung cancer group compared to the normal control group (1.08 vs. 0.42, p < 0.001). No apparent correlation was found between sPD-L1 concentration and membrane-bound programmed death-1 ligand (mPD-L1) expression. The optimal diagnostic threshold for sPD-L1 was set at 0.92 ng/mL, showing a sensitivity of 56.25% and specificity of 77.33%, with an area under the curve (AUC) of 0.743 (p = 0.001). Although increased sPD-L1 levels were prevalent in individuals with advanced age, prolonged disease duration, large tumor size, and finger clubbing, these associations did not reach statistical significance (p > 0.05). In conclusion, sPD-L1 levels significantly increased in advanced NSCLC patients compared to controls (p < 0.05), with no association observed with mPD-L1 (p = 0.304). The study suggests that sPD-L1 concentration can be a specific biomarker for guiding the diagnosis of advanced NSCLC, with a recommended cutoff value of 0.92 ng/mL, demonstrating a sensitivity of 56.25% and specificity of 77.33% (p = 0.001). Importantly, no apparent relationship was established between sPD-L1 levels and clinical or paraclinical characteristics in advanced NSCLC patients.

Soluble immune checkpoints associated with disease activity and treatment response in GD and TED.

Soluble immune checkpoints play an important role in peripheral tolerance that has seldom been investigated in Graves' disease (GD) and thyroid eye disease (TED). The objective of this work is to examine the alteration of soluble immune checkpoints in GD and TED. We performed a quantitative multiplex analysis of 17 immune checkpoint proteins in serum from 50 GD patients without TED, 28 GD patients with TED and 40 healthy controls. The association with demographical, serological, clinical features and 27 cytokines was analyzed. A follow-up was conducted in GD patients without TED. Functional outcomes of sLAG-3 and sGITR were assessed in cell cultures using rh-LAG3, rh-GITR, an antagonistic LAG-3 antibody and an antagonistic GITR antibody. GD patients with TED had distinct sICP and cytokine profiles compared with GD patients without TED. Active TED patients exhibited elevation in the levels of sBTLA, sLAG-3, sGITR, sCD80, sCD86 and sPD-L1. Further, GD patients without TED with high sBTLA, sCD27 and sCD40 levels at baseline showed a better improvement in thyrotropin receptor antibody (TRAb) titers after antithyroid drug (ATD) treatment. Adding recombinant human GITR and LAG-3 to PBMC cultures resulted in increased inflammatory cytokine secretion and decreased anti-inflammatory cytokine secretion. The present study uncovers disturbed soluble immune checkpoints and cytokines in GD patients with and without TED, and may pave the way for novel immunological screening, allowing for identification of TED patients at higher risk of developing active disease and GD patients with better treatment response after ATD treatment.

Expression of sPD-L1 levels in an ex vivo liver perfusion model.

The programmed cell death protein 1 (PD-1) acts as a central inhibitory immune checkpoint receptor. The soluble form of its primary ligand, sPD-L1, was found to be elevated in serum of patients with cancer, infectious diseases and chronic inflammation. So far, the hepatic origin of sPD-L1 has received relatively little attention and is therefore subject of this study in the context of normothermic machine perfusion (NMP) of liver grafts. sPD-L1 concentrations as well as several well-established clinically relevant laboratory parameters were determined in the perfusate of 16 donor liver grafts undergoing normothermic machine perfusion (NMP) up to 30 hours (h). sPD-L1 levels continuously increased during NMP and significantly correlated with markers of hepatic synthesis (cholinesterase), acute-phase proteins (von Willebrand factor, procalcitonin, antithrombin, interleukin-6, fibrinogen) and liver decay markers (gamma-glutamyltransferase, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase). Perfusate leukocytes were in the lower reference range, and decreased after 12h. Mean sPD-L1 levels in the perfusate correlated with donor levels of gamma-glutamyltransferase, alanine aminotransferase, creatinine and blood urea nitrogen. Our study reveals a significant increase of concentration of sPD-L1 following ischemia-reperfusion injury in a hepatic ex vivo model. sPD-L1 concentrations during NMP correlate with established acute-phase proteins and liver cell decay markers suggesting that hepatic sPD-L1 synthesis or shedding increases during the acute phase and cell decay. Furthermore, sPD-L1 correlates with established liver function and synthesis parameters as well as with donor laboratory values and might therefore be a potential biomarker for hepatic function of liver grafts.

Prognostic value of soluble programmed death-1 and soluble programmed death ligand-1 in severe traumatic brain injury patients

Patients with traumatic brain injury (TBI) frequently exhibit concomitant immunosuppression. In this study, we evaluated the predictive values of soluble programmed death-1 (sPD-1) and soluble programmed death ligand-1 (sPD-L1) in patients with severe TBI. Peripheral blood sPD-1 and sPD-L1 levels were measured within 48 h of patient admission. A total of 20 healthy volunteers and 82 patients were enrolled in this study. The levels of sPD-1 and sPD-L1 were upregulated in patients with severe TBI (P < 0.001). They were significantly increased in the post-TBI severe pneumonia group and among non-survivors (P < 0.001). The area under the curves (AUCs) for sPD-1 and sPD-L1 levels to predict severe pneumonia were 0.714 and 0.696, respectively, and the AUCs to predict mortality were 0.758 and 0.735. The levels of sPD-1 and sPD-L1 are correlated with the GCS scores at admission, APACHE II scores, length of MV, and time elapsed to mortality. The levels of sPD-1 and sPD-L1 emerged as independent predictive factors for severe pneumonia and mortality. This study demonstrates that upregulation of sPD-1 and sPD-L1 in severe TBI patients is significantly associated with severe pneumonia and mortality, suggesting their potential as predictive biomarkers for these outcomes.

Changes in the level of immune checkpoints in patients with various forms of autoimmune thyroiditis

Background. Autoimmune thyroiditis (AIT) affects more than 5 % of the world’s population.The aim. To determine the level of sPD-1, sPD-L1, sCTLA-4 and sB7.2 molecules in individuals suffering from various forms of autoimmune thyroiditis.Methods. The study included 31 individuals aged 18 to 40 years. They were divided into four groups: group I – healthy individuals (n = 10); group II – carriers of antibodies to thyroid peroxidase (n = 11); group III – individuals with AIT accompanied with subclinical form of hypothyroidism (n = 6); group IV – individuals with AIT complicated by compensated hypothyroidism (n = 4). Venous blood was collected to determine the level of antibodies to thyroid peroxidase using enzyme immunoassay, the concentration of thyroid stimulating hormone and free thyroxine – using chemiluminescence immunoassay, and the levels of sPD-1, sPD-1L, sCTLA-4, and sB7.2 – using flow cytofluorometry. Statistical processing was performed using the Kruskal – Wallis one-way analysis of variance.Results. When comparing the level of sPD-1L in groups I (54.1 (28.7; 67.6) pg/ml) and II (4.36 (2.36; 18.0) pg/ml), the decreased in this indicator was 91.94 % (p = 0.001). When comparing the sPD-1 level in the group of healthy individuals (16.6 (13.6; 37.2) pg/ml) and group IV (7.28 (5.18; 11.1) pg/ml), werecorded a decrease of 56.14 % (p = 0.001). The sB7.2 concentration decreased by 65.03 % in group II (16.4 (15.6; 32.7) pg/ml) compared to the control group (46.9 (39.3; 54.4) pg/ml) (p = 0.001). In group III, the sCTLA-4 level was 3.22 (3.06; 3.33) pg/ml and decreased by 88.66% compared to the control group (p = 0.001).Conclusion. The development of autoimmune thyroiditis is accompanied with the decrease in the concentration of sPD-1, sPD-1L, sCTLA-4 and sB7.2.

Soluble PD-L1 shows no association to relapse and overall survival in early stage non-small cell lung cancer (NSCLC)

BackgroundCancer immune evasion is critical in non-small cell lung cancer (NSCLC) and has been targeted by immunotherapy. High soluble (s)PD-L1 is associated with reduced survival and treatment failure in advanced stages. Here we evaluated the effects of sPD-L1 on T cells, relapse free survival, and overall survival in early stage NSCLC. MethodsIn vitro T cell stimulation was performed in the presence of sPD-L1 to evaluate its immunomodulatory activity. Data from The Cancer Genome Atlas (TCGA) were investigated for PD-L1 splice variants and enzymes involved in proteolytic cleavage (i.e. ADAM10). Plasma from 74 NSCLC (stage IA-IIIB), as well as an additional 73 (control cohort) patients was collected prior to curative surgery. Thereafter sPD-L1 levels from an immunosorbent assay were correlated with patient outcome. ResultsIn vitro sPD-L1 inhibited IFN-γ production and proliferation of T cells and induced a terminal effector CD4 T cell subtype expressing CD27. Data from the TCGA demonstrated that elevated mRNA levels of ADAM10 is a negative predictor of outcome in NSCLC patients. To investigate the clinical relevance of these in vitro and TCGA findings, we quantified sPD-L1 in the plasma of early-stage NSCLC patients. In the first cohort we found significantly higher sPD-L1 levels in relapsing NSCLC patients, with a multivariate analysis revealing high sPD-L1 (>1000 pg/mL) as an independent predictor of survival. However, these findings could not be validated in two independent control cohorts. DiscussionAlthough in vitro and TCGA data support the suppressive effect of sPD-L1 we were unable to translate this in our clinical setting. These results may be due to the small patient number and their heterogeneity as well as the lack of a standardized sPD-L1 ELISA. Our inconclusive results regarding the value of sPD-L1 in early stage NSCLC warrant assay validation and further investigation in larger (neo-)adjuvant trials.

297. ASSESSING BLOOD-BASED BIOMARKERS IN OESOPHAGEAL CANCER PATIENTS RECEIVING NEOADJUVANT CHEMORADIOTHERAPY

Abstract Background Oesophageal cancer is the sixth most common cause of cancer-related deaths globally. It has a significant rate of mortality despite the multimodal approach to treatment. Neo-adjuvant chemoradiotherapy is standard of care but there is a clinical need for new therapies. HER2-targeted therapies and immune checkpoint inhibitors targeting the PD-1/PD-L1 axis have emerged as treatment strategies of significant interest in recent years. This study focuses on exploring potential plasma-based biomarkers (growth factors, cytokines, soluble (s) PD-L1) in patients (pts) with oesophageal cancer receiving standard of care neo-adjuvant therapy and stratified based on HER2 expression and pathological complete response (pCR). Methods 50 pts with oesophageal cancer who are eligible for neoadjuvant therapy were recruited. Blood samples were taken pre-treatment, on the first day of the 2nd cycle and post-neoadjuvant treatment. Plasma was extracted within four hours of blood draw and stored at -800C. 20 matched pre- and post-treatment samples were included in this analysis. HER2 status (IHC 3+ (n=3), IHC 2+ (n=5), IHC 1+ (n=3), IHC 0 (n=6) was available for 17 pts. 3 pts achieved a pCR but no HER2 IHC data was available. The levels (pg/ml) of 21 analytes were assessed using the Human Growth Factor Luminex Performance Assay and a Luminex MagPix system. Changes were significant if p&amp;lt;0.05, paired student’s t test. Results Twenty-one biomarkers of response were assessed in the final analysis. Platelet-derived growth factor (PDGF)-AA and PDGF AA/BB displayed the highest concentration levels of the tested analytes but levels did not change pre-and post-treatment. GRO-b (CXCL2) and vascular endothelial growth factor (VEGF) displayed a numerical increase post-treatment but this did not prove significant (p&amp;lt;0.05). Tumour-necrosis factor-related apoptosis-inducing ligand (TRAIL) protein decreased significantly post-therapy (p=0.038). PD-L1 levels significantly increased in the post-treatment cycles (paired t-test p=0.0029), especially in pts with HER2+ status. TRAIL or sPD-L1 levels were not significantly different when categorised by HER2 IHC or pCR status. Conclusion The increase in sPD-L1 and reduction in TRAIL levels in the peripheral blood of oesophageal cancer patients following neoadjuvant therapy suggests treatment alters factors associated with immune-suppression and the induction of tumour cell death. Further investigation in a larger cohort is warranted.

Prognostic and predictive significance of soluble programmed death ligand 1 in bronchoalveolar lavage fluid in stage IV non-small cell lung cancer.

Patients with non-small cell lung cancer (NSCLC) have been shown to exhibit elevated levels of soluble programmed death-ligand 1 (sPD-L1) in the blood, associated with poor survival in NSCLC. The bronchoalveolar lavage fluid (BALF) composition reflects the tumor microenvironment of lung cancer. In this study, we investigated sPD-L1 levels in BALF and its role as a prognostic and predictive marker in patients with stage IV NSCLC. We prospectively obtained BALF from lung cancer patients who underwent bronchoscopy between January 2020 and September 2022 at Chungnam National University Hospital (CNUH). Finally, 94 NSCLC stage IV patients were included in this study. Soluble PD-L1 levels in BALF were measured using a human PD-L1 Quantikine ELISA kit. The correlation between PD-L1 expression in tumor cells and sPD-L1 in BALF was weakly positive (rho =0.314, P=0.002). The median overall survival (OS) of the low sPD-L1 in BALF group was 16.47 months [95% confidence interval (CI): 11.15-21.79 months], which is significantly longer than 8.87 months (95% CI: 0.0-19.88 months, P=0.001) in the high sPD-L1 in BALF group. In 64 patients treated with or without immune checkpoint inhibitors (ICIs), sPD-L1 in BALF was significantly associated with progression-free survival (PFS) and OS. In the subgroup analysis of 31 patients treated with ICI, the objective response rate (ORR) in the low sPD-L1 BALF group was significantly higher than in high sPD-L1 in BALF group (ORR: 60.9% vs. 12.5%, P=0.02). Soluble PD-L1 in BALF is a potential prognostic indicator for patients with stage IV NSCLC and a predictive marker for ICI treatment response.

Effect of Follicular T Helper and T Helper 17 Cells-Related Molecules on Disease Severity in Patients with Myasthenia Gravis.

Contribution of T helper 1 and 2 cells-related cytokines to pathogenesis of myasthenia gravis (MG) is well known. Recently, the contribution of follicular T helper (Tfh) and T helper 17 cells-related molecules to the pathogenesis has gained importance. In this study, we aimed to evaluate the changes in Tfh- and Th17-related molecules before and after rescue therapy in patients with myasthenic crisis (cMG) and to reveal the molecular differences between stable MG and cMG patients. Patients with stable generalized MG (gMG) and cMG were classified according to Myasthenia Gravis Foundation of America (MGFA) classification. Serum samples were collected from cMG patients both before and after rescue therapy (plasmapheresis or intravenous immunoglobulin [IVIg]). Serum levels of Tfh- and selected Th17-related molecules (IL-22, IL-17A, CXCL13, sPD-L1, sICOSLG, and sCD40L) were analyzed by commercial ELISA kits. Twelve cMG (6 for IVIg, 6 for plasmapheresis) and 10 gMG patients were included in the study. A decrease in serum sPD-L1 and CXCL13 levels was observed in cMG patients after treatment, regardless of the treatment modality (p &lt; 0.05). In contrast, serum sICOSLG levels decreased only in patients treated with IVIg (p &lt; 0.05) and serum IL-22 levels increased in patients receiving plasmapheresis (p &lt; 0.05). cMG patients had higher serum IL-17A levels compared to stable patients (p &lt; 0.001) and its level was positively correlated with disease severity (r = 0.678, p = 0.001). Our results confirm the contribution of Tfh- and Th17-related cell pathways to MG pathogenesis. Both IVIg and plasmapheresis appear to be effective in reducing Tfh- and Th17-related cytokine/molecule levels in cMG patients. Increased serum IL-17A levels may contribute to disease severity.

Dual-signal output biosensor for the detection of program death-ligand 1 and therapy progress monitoring of cancer

A disposable dual-output biosensor to detect program death-ligand 1 (PD-L1) was developed for immunotherapy progress monitoring and early cancer detection in a single experimental setup. The aptamer probe was assembled on rGO composited with carboxylated terthiophene polymer (rGO-pTBA) to specifically capture PD-L1 protein labeled with a new redox mediator, ortho-amino phenol para sulphonic acid, for amperometric detection. Each sensing layer was characterized through electrochemical and surface analysis experiments, then confirmed the sensing performance. The calibration plots for the standard PD-L1 protein detection revealed two dynamic ranges of 0.5–100.0 pM and 100.0–500.0 pM, where the detection limit was 0.20 ± 0.001 pM (RSD ≤5.2%) by amperometry. The sensor reliability was evaluated by detecting A549 lung cancer cell-secreted PD-L1 and clinically relevant serum levels of soluble PD-L1 (sPD-L1) using both detection methods. In addition, therapeutic trials were studied through the quantification of sPD-L1 levels for a small cohort of lung cancer patients. A significantly higher level of sPD-L1 was observed for patients (221.6–240.4 pM) compared to healthy individuals (16.2–19.6 pM). After immunotherapy, the patients’ PD-L1 level decreased to the range of 126.7–141.2 pM. The results indicated that therapy monitoring was successfully done using both the proposed methods. Additionally, based on a comparative study on immune checkpoint-related proteins, PD-L1 is a more effective biomarker than granzyme B and interferon-gamma.

Evaluation of soluble co‐inhibitors and co‐stimulators levels of the immune response in gastric cancer

AbstractBackgroundCo‐inhibitor and co‐stimulator mediators trigger actions that result in immunological homeostasis and are being evaluated as potential therapeutic targets in gastric cancer (GC).ObjectiveTo evaluate the soluble levels of sPD‐1, sPD‐L1, sPD‐L2, sTIM‐3, sGal9, sGITR, and sGITRL in GC patients.MethodsThe cross‐sectional study was carried out at the Hospital de Cancer de Pernambuco, Brazil between 2017 and 2018. A total of 74 GC patients and 30 healthy controls were included.ResultsLow levels of sPD1 (p = 0.0179), sPDL2 (p = 0.0003), and sGal9 (p &lt; 0.0001), and higher levels of sPDL1 (p = 0.004), sTIM‐3 (p = 0.0072), sGITR (p = 0.0179), and sGITRL (p = 0.0055) compared to the control group. High sPD‐1, sTIM‐3, and sGal9 levels in stage IV compared I/II and III (p &lt; 0.05). High sPDL1, sGal9, and sGITRL levels in esophagogastric junction compared to body and Pylorus/Antrum groups (p &lt; 0.05). No significant differences were observed in sPD1, sPDL1, sPDL2, sTIM3, sGal9, sGITR, and sGITRL levels between the intestinal, diffuse, and mixed GC groups. Low sGITR levels in GC patients who died within the first 24 months compared to the who survived (p = 0.0332).ConclusionsThere is an association of sPD1, sTIM‐3, and sGal9 with disease progression and sGITR with death, these mediators may be potential prognostic biomarkers in GC.

Serum sPD-1 and sPD-L1 as predictive biomarkers for HBsAg clearance in HBeAg-negative CHB patients undergoing IFN-based therapy.

For chronic hepatitis B (CHB) patients, there is still a need to improve hepatitis B surface antigen (HBsAg) clearance rates. This study aimed to assess the predictive effectiveness of soluble programmed cell death-1 (sPD-1) and soluble programmed cell death ligand-1 (sPD-L1) for HBsAg clearance in HBeAg-negative CHB patients undergoing peginterferon (Peg-IFN)-based antiviral treatment. This study encompassed 280 patients undergoing treatment with Peg-IFNα. Serum levels of sPD-1 and sPD-L1 were measured using ELISA kits at baseline, as well as at 12, 24 and 48 weeks. The primary endpoint of the study was the determination of HBsAg clearance at 48 weeks. Logistic regression analysis was employed to identify predictors of HBsAg clearance. The clearance group demonstrated significantly lower serum sPD-L1 levels compared to the non-clearance group. While both groups exhibited an increase in sPD-1 levels, only the clearance group showed a rise in sPD-L1 levels. Multivariate analysis identified sPD-L1 increase at 24 weeks, and HBsAg decline at 24 weeks as predictors for HBsAg clearance at 48 weeks. The combined use of these indicators showed a predictive performance for HBsAg clearance with an AUROC of 0.907 (95% CI: 0.861-0.953, p < 0.001). The study revealed an inverse relationship between the trends of sPD-1/sPD-L1 and HBsAg clearance during combined IFN and NAs treatment. Moreover, the magnitude of HBsAg reduction and sPD-L1 increase emerged as significant predictors for HBsAg clearance.

First-line immunochemotherapy modulates peripheral immune landscape in advanced gastric cancer and gastroesophageal junction cancer (GC/GEJC): Prediction of response to combination therapy.

e14540 Background: The use of immunochemotherapy has brought about a change in the treatment of advanced or metastatic GC/GEJC, but only a subset of patients could benefit substantially. Therefore, seeking efficacious biomarkers to identify favorable populations for the regimen is imperative. This study aims to explore predictive markers and potential mechanism of combination therapy for GC/GEJC in real-world settings based on blood proteomic biopsy. Methods: This is a prospective, single-center trial in which all patients are adults with advanced or metastatic GC/GEJC confirmed by pathology or imaging. 30 eligible patients will receive PD-1 mab (sintilimab/nivolumab (NIVO) Q3W) and chemotherapy (SOX/XELOX Q3W) regardless of programmed death ligand-1 status. Blood samples were collected before treatment and after every two treatment cycles for Olink Target 96 IO analysis. CT scans were performed after every two cycles and will be categorized as responding (complete response plus primary response) or non-responding (progress disease plus stable disease) according to RECIST 1.1. Results: As of January 17, 2024, a total of 21 patients were enrolled. Eight of these patients received 16 samples before and after treatment, with 4 each of the 8 patients responding and non-responding. By analyzing the baseline samples comparing the responding and non-responding groups, it was found that patients in the responding group had lower expression of serum PD-L1 (sPD-L1) ( p=0.015). In the post-treatment samples, angiopoietin 1 was found to be poorly expressed in the responding patients ( p&lt;0.001). In contrast, high expression of angiopoietin 2 in post-treatment blood samples was more pronounced in non-responders compared to pre-treatment ( p=0.020). Additionally, we observed that immunotherapy can modify the immune microenvironment by up-regulating the T cell receptor signaling and NK cell-mediated toxic effects pathways. These pathways may be potential targets for treatment. Conclusions: In summary, low sPD-L1 level before treatment may be a predictive biomarker for better efficacy of immuno-combination chemotherapy in advanced GC/GEJC; whereas elevation of angiopoietin after treatment predicts poor efficacy and suggests that antiangiogenic therapy may subsequently be added in non-responding patients. We are further recruiting more patients to obtain more accurate conclusions. Clinical trial information: ChiCTR2300078000 .

A digital microfluidic device integrated with electrochemical sensor and 3D matrix for detecting soluble PD-L1

PD1/PD-L1 checkpoint inhibitors are at the forefront of cancer immunotherapies. However, the overall response rate remains only 10–30%. Even among initial responders, drug resistance often occurs, which can lead to prolonged use of a futile therapy in the race with the fatal disease. It would be ideal to closely monitor key indicators of patients’ immune responsiveness, such as circulating PD-L1 levels. Traditional PD-L1 detection methods, such as ELISA, are limited in sensitivity and rely on core lab facilities, preventing their use for the regular monitoring. Electrochemical sensors exist as an attractive candidate for point-of-care tool, yet, streamlining multiple processes in a single platform remains a challenge. To overcome this challenge, this work integrated electrochemical sensor arrays into a digital microfluidic device to combine their distinct merits, so that soluble PD-L1 (sPD-L1) molecules can be rapidly detected in a programmed and automated manner. This new platform featured microscale electrochemical sensor arrays modified with electrically conductive 3D matrix, and can detect as low as 1 pg/mL sPD-L1 with high specificity. The sensors also have desired repeatability and can obtain reproducible results on different days. To demonstrate the functionality of the device to process more complex biofluids, we used the device to detect sPD-L1 molecules secreted by human breast cancer cell line in culture media directly and observed 2X increase in signal compared with control experiment. This novel platform holds promise for the close monitoring of sPD-L1 level in human physiological fluids to evaluate the efficacy of PD-1/PD-L1 immunotherapy.

Lysosomal degradation of PD-L1 is associated with immune-related adverse events during anti-PD-L1 immunotherapy in NSCLC patients.

Background: Immune checkpoint inhibitors (ICIs) can induce immune-related adverse events (irAEs). Liquid biomarkers to predict irAE occurrence are urgently needed. We previously developed an ELISA system to specifically detect soluble PD-L1 (sPD-L1) with PD-1-binding capacity (bsPD-L1). Here, we investigated the relationship between sPD-L1 and bsPD-L1 in gastric cancer (GC) and non-small cell lung cancer (NSCLC) treated with PD-1/PD-L1 blockade and their association with irAEs. Methods: We examined sPD-L1, bsPD-L1, matrix metalloproteinases (MMPs), and proinflammatory cytokine levels by ELISA in plasma samples from 117 GC patients prior to surgery and 72 NSCLC patients prior to and at 2 months after ICI treatment (anti-PD-1, n = 48; anti-PD-L1, n = 24). In mice treated with anti-PD-1/PD-L1 antibodies (Abs), sPD-L1 levels and localization of Abs were examined by ELISA and immunohistochemistry, respectively. Results:sPD-L1 was detected with higher frequency in GC patients than in NSCLC patients, whereas bsPD-L1 was detected with similar frequencies in GC and NSCLC patients. sPD-L1 levels were correlated with IL-1α, IL-1β, TNF-α, and IL-6 levels, while bsPD-L1 levels were correlated with MMP13, MMP3, and IFN-γ levels. In NSCLC patients, anti-PD-L1, but not anti-PD-1, treatment increased sPD-L1, which was associated with irAE development, but not with clinical outcomes. In mice, trafficking of anti-PD-L1 Abs to lysosomes in F4/80+ macrophages resulted in sPD-L1 production, which was suppressed by treatment with lysosomal degradation inhibitor chloroquine and macrophage depletion. Conclusion: Anti-PD-L1-mediated lysosomal degradation induces sPD-L1 production, which can serve as an indicator to predict irAE development during anti-PD-L1 treatment.

Abstract PO3-15-11: Soluble sFas, sFasL, sPD1, and sPD-L1 analyses in the blood peripheral of locally advanced breast cancer women before and after neoadjuvant chemotherapy

Abstract Assess soluble sFAS, sFASL, sPD1, and sPD-L1 levels in patients with HER2 or triple-negative (TN) breast cancer submitted to neoadjuvant chemotherapy. A prospective cohort study was performed with TN and HER2+ breast cancer patients between 2015 and 2018. Soluble levels of sFasL, sFas, sPD-L1, and sPD1 were collected before and after neoadjuvant chemotherapy (NAC). NAC regimens included a dense dose of Adriablastin and cyclophosphamide during four cycles, followed by Paclitaxel for 12 weeks. No clinical evidence of tumor in the breast and axillary lymph nodes was defined as a pathological complete response (pCR). Twenty-one women with TN (56,7%) and 16 (43,3%) HER2+ breast cancer were included. Twenty-one women (56.7%) presented complete pathological response (pCR) after neoadjuvant chemotherapy (NAC), defined as the absence of invasive disease in the breast and lymph nodes. High sPD1 and sFas levels in the TN and HER2+ patients compared to the control group (P&amp;lt; 0.05). In paired analysis, statistical differences of sFas and sFasL levels in TN and HER2+ patients before and after NAC (P&amp;lt; 0.05). Low levels of sPDL1 in HER2+ patients with pCR compared to non-pCR (P&amp;lt; 0.05). High sFasL levels in TN patients with pCR compared to the non-pCR group (P&amp;lt; 0.05). Conclusion: soluble sFas, sFas-L, sPD1, and sPD-L1 levels were apoptosis-related markers with potential predictive value of neoadjuvant chemotherapy response in TN and HER2+ breast cancer. Keywords: breast cancer; FAS receptor; Programmed death 1, HER2+, Triple negative Citation Format: Carolina Vasconcelos, Marcelo Salgado, Carlos Eduardo Anunciação, Denise Viana, Leuridan Torres, Nathália Valois Montarroyos de Moraes. Soluble sFas, sFasL, sPD1, and sPD-L1 analyses in the blood peripheral of locally advanced breast cancer women before and after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-15-11.

Correlation of Systemic Inflammation Parameters and Serum SLFN11 in Small Cell Lung Cancer-A Prospective Pilot Study.

The objective of this research was to analyze the correlation of the neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), soluble programmed cell death ligand 1 (sPD-L1), and Schlafen 11 (SLFN11) with the response to first-line chemotherapy in a cohort of small cell lung cancer (SCLC) patients, and to determine their potential as predictive serum biomarkers. A total of 60 SCLC patients were included. Blood samples were taken to determine CRP, sPD-L1, and SLFN11 levels. The first sampling was performed before the start of chemotherapy, the second after two cycles, and the third after four cycles of chemotherapy. The patients who died earlier during the study had NLR and SLFN11 concentrations significantly higher compared to the survivor group. In the group of survivors, after two cycles of chemotherapy, the NLR ratio decreased significantly (p < 0.01), but after four cycles, the NLR ratio increased (p < 0.05). Their serum SLFN11 concentration increased significantly (p < 0.001) after two cycles of chemotherapy, but after four cycles, the level of SLFN11 fell significantly (p < 0.01). CRP, NLR, and SLFN11 were significant predictors of patient survival according to Kaplan-Meier analysis. The combination of inflammatory parameters and SLFN11 with a cutoff value above the 75th percentile of the predicted probability was associated with significantly lower overall survival in SCLC patients (average survival of 3.6 months vs. 4.8 months). The combination of inflammatory markers and the levels of two specific proteins (sPD-L1, SLFN11) could potentially serve as a non-invasive biomarker for predicting responses to DNA-damaging therapeutic agents in SCLC.

Soluble programmed death ligand 1 as prognostic biomarker in non-small cell lung cancer patients receiving nivolumab, pembrolizumab or atezolizumab therapy

Many studies have focused on the prognostic role of soluble programmed death ligand 1 (sPD-L1) in non-small cell lung cancer (NSCLC), but outcomes are ambiguous and further investigations are needed. We addressed the matter by studying sPD-L1 in baseline samples and in longitudinal samples taken prior to three subsequent cycles of anti-PD-1/anti-PD-L1 treatments. Eighty patients with NSCLC were enrolled. Median sPD-L1 level at baseline was 52 pg/mL [95% confidence interval (CI) 49–57]. In patients treated with pembrolizumab and nivolumab, the concentration of sPD-L1 remained rather stable throughout treatment. In contrast, sPD-L1 rose by 50-fold following the first cycle of atezolizumab therapy. We found the baseline level of sPD-L1 to be related to overall survival (OS) after two years of follow-up in simple Cox analysis (p = 0.006) and multiple Cox Regression, hazard ratio 1.02 (95% CI 1.00–1.03) (p = 0.033). There was no association between sPD-L1 and tissue PD-L1 expression, overall response rate, or progression free survival. In conclusion, sPD-L1 measured in baseline serum samples may be associated with OS in NSCLC patients receiving anti-PD1/anti-PD-L1 treatment. Importantly, the results signify that further research is warranted to explore the clinical utility of sPD-L1 in patients treated with anti-PD-L1.

Soluble PD-L1 predicts tumor response and immune-related adverse events in patients with advanced melanoma treated with anti-PD-1 antibodies.

Immune checkpoint inhibitors (ICIs) bring prognostic benefits to patients with malignancies. However, there is a substantial number of patients whose lesions are not improved by ICIs. In addition, ICIs may cause immune-related adverse events (irAEs), which could lead to an unfavorable prognosis with fatal consequences. Therefore, we conducted a retrospective study to evaluate the utility of circulating sPD-L1 (soluble programmed cell death 1 ligand 1) as a biomarker in patients with advanced melanoma treated with anti-PD-1 (programmed cell death 1 protein) antibodies. Sera from 31 consecutive patients were prospectively collected before and after anti-PD-1 antibody treatment and the serum level of sPD-L1 was evaluated. We found that high sPD-L1 levels before treatment were associated with better prognosis, and this association was observed only in patients with a low tumor burden. We also found that sPD-L1 levels were elevated in patients who developed severe irAEs after treatment, and the patients with severe irAEs had significantly higher fluctuations in sPD-L1 (delta sPD-L1) than those without severe irAEs. Our study suggests that serum sPD-L1 level is a useful biomarker to predict tumor response and irAE development in patients with advanced melanoma treated with anti-PD-1 antibodies.

Correlation between PD-1 and sPD-L1 expression levels in peripheral blood of DLBCL patients and their clinicopathological characteristics.

Molecular pathology and clinical characteristics play a crucial role in guiding treatment selection and predicting the prognosis of diffuse large B-cell lymphoma (DLBCL). The programmed cell death protein 1 (PD-1) and its ligand (PD-L1), have emerged as pivotal regulators of immune checkpoints in cancer. The objectives of this study are to investigate the correlation between the expression levels of PD-1 and soluble PD-L1 (sPD-L1) in the peripheral blood of DLBCL patients, analyze their clinicopathological characteristics, and identify the optimal beneficiary group for PD-1/PD-L1 blockade. Peripheral blood samples were collected from 36 DLBCL patients before their initial treatment at Shandong Cancer Hospital between December 2018 and July 2019. The expression levels of PD-1 and sPD-L1 were measured using flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. The clinicopathological characteristics, including age, sex, Ann Arbor stage, International Prognostic Index (IPI) score, response to treatment, etc., were recorded for each patient. The surface expression of PD-1 on peripheral blood T cells was significantly higher in DLBCL patients compared to healthy controls. There was a significant association between elevated PD-1 expression levels and the advanced Ann Arbor stage (P=0.0153) as well as the B group (P=0.0184). Higher sPD-L1 levels were associated with the GCB subtype according to Hans's classification (P=0.0435). The expression levels of PD-1 and sPD-L1 in the peripheral blood of DLBCL patients are significantly correlated with advanced disease stage, B group, and GCB subtype according to Hans's classification. This suggests that the PD-1/PD-L1 axis play a critical role in specific subgroups of DLBCL. Targeting this axis could serve as a potential therapeutic strategy to enhance the clinical outcomes of DLBCL patients. Further studies are necessary to explore the prognostic implications of PD-1 and sPD-L1 expression levels in DLBCL patients.