Platelet Soluble NOX2 as a New Biomarker in Patients with Sepsis

Background: Substantial evidence supports the view that NOX2 may function as a pivotal regulator in various physiological and pathological processes. However, to date, the interplay between platelet soluble NOX2 levels and sepsis remains unclear. The overall aim of this work is to obtain a better insight into whether or not platelet NOX2 is involved in sepsis. Methods: The levels of platelet soluble NOX2, from 31 patients diagnosed with Gram-positive sepsis, 36 patients with Gram-negative sepsis and 45 healthy individuals, were measured with sandwich ELISA kits that we developed. Results: In this work, we showed that platelet NOX2 concentrations were significantly lower in healthy individuals compared to patients with sepsis (P<0.01), and that platelet NOX2 values were significantly correlated with the platelet activation markers, including soluble CD40L and soluble P-selectin. Interestingly, we also found that platelet NOX2 values in patients with Gram-positive sepsis were higher than those in patients with Gram-negative sepsis. Conclusions: Platelet NOX2 levels maybe an important indicator of the pathogenesis of sepsis-induced platelet activation.

CD40/CD40L Signaling as a Promising Therapeutic Target for the Treatment of Renal Disease

The cluster of differentiation 40 (CD40) is activated by the CD40 ligand (CD40L) in a variety of diverse cells types and regulates important processes associated with kidney disease. The CD40/CD40L signaling cascade has been comprehensively studied for its roles in immune functions, whereas the signaling axis involved in local kidney injury has only drawn attention in recent years. Clinical studies have revealed that circulating levels of soluble CD40L (sCD40L) are associated with renal function in the setting of kidney disease. Levels of the circulating CD40 receptor (sCD40), sCD40L, and local CD40 expression are tightly related to renal injury in different types of kidney disease. Additionally, various kidney cell types have been identified as non-professional antigen-presenting cells (APCs) that express CD40 on the cell membrane, which contributes to the interactions between immune cells and local kidney cells during the development of kidney injury. Although the potential for adverse CD40 signaling in kidney cells has been reported in several studies, a summary of those studies focusing on the role of CD40 signaling in the development of kidney disease is lacking. In this review, we describe the outcomes of recent studies and summarize the potential therapeutic methods for kidney disease which target CD40.

AB0844 SERUM sCD40L LEVEL CAN PREDICT SHORT-TERM CLINICAL OUTCOMES IN PATIENTS WITH PSORIATIC ARTHRITIS ON TREATMENT WITH APREMILAST.

Background:The pathogenesis of Psoriatic Arthritis (PsA) involves several pathways simultaneously, including the CD40/CD40L interaction. In vitro evidence suggests that the cleavage of soluble CD40L (sCD40L) may happen as a Phosphodiesterase 4- (PDE4) dependent reaction [1-3].Objectives:Here we investigate whether apremilast, a PDE4 inhibitor, could modify circulating level of soluble CD40L (sCD40L) in PsA patients, and the possible associations of these changes with clinical response.Methods:Consecutive patients with PsA starting apremilast in routine clinical practice between October 2018 and September 2019 in a single center were longitudinally observed. Sera were collected at baseline and at the 6-month follow up visit. Demographics and clinical characterstics at different observation times were recorded. Samples were ran in a Bio-Plex ProTM plate for sCD40L level. To investigate the association of sCD40L level with DAPSA minor response and DAPSA Low Disease Activity (LDA) and/or Remission (ie DAPSA ≤14) at 6 months of treatment, multivariate logistic regression models with backward selection (p <0.05) were built.Results:We studied n.27 patients (16/27 women, 59.6%) with PsA with mean age (± SD) of 58.4 ± 10.4 years. A significant reduction of the mean values of DAPSA, LEI and PASI was evidenced at 6 months. Mean serum level of sCD40L decreased from 5364.02 ± 2025.70 to 4412.14 ± 2629.81 pg/ml after 6 months of apremilast treatment (p=0.01, Figure 1). Baseline sCD40L was an independent predictor of DAPSA minor response (OR 1.0006, 95% CI 1.0001-1.0012; AUC 0.76 (95% CI 0.55-0.97)). Moreover baseline DAPSA (OR 0.80, 95% CI 0.65-0.98) and baseline sCD40L (OR 1.001, 95%CI 1.0001-1.0028; AUC 0.85 95% CI 0.69-0.98, Figure 2) were independently associated with DAPSA LDA/Remission.Conclusion:Apremilast may decrease sCD40L level in PsA patients. Higher baseline serum sCD40L level may predict short-term clinical response to apremilast.References:[1]Davidson DC, Jackson JW, Maggirwar SB. Targeting platelet-derived soluble CD40 ligand: a new treatment strategy for HIV-associated neuroinflammation? J Neuroinflammation 2013;10:144.[2]Vanichakarn P, Blair P, Wu C, Freedman JE, Chakrabarti S. Neutrophil CD40 enhances platelet-mediated inflammation. Thromb Res 2008;122(3):346-58.[3]Totani L, Amore C, Di Santo A, et al. Roflumilast inhibits leukocyte-platelet interactions and prevents the prothrombotic functions of polymorphonuclear leukocytes and monocytes. J Thromb Haemost 2016;14(1):191-204.Disclosure of Interests:Vincenzo Venerito: None declared, Dorotea Natuzzi: None declared, Rita Bizzoca: None declared, Nunzia Lacarpia: None declared, Marco Fornaro: None declared, maria giannotta: None declared, giulia righetti: None declared, Giuseppe Lopalco: None declared, Florenzo Iannone Consultant of: Speaker and consulting fees from AbbVie, Eli Lilly, Novartis, Pfizer, Roche, Sanofi, UCB, MSD, Speakers bureau: Speaker and consulting fees from AbbVie, Eli Lilly, Novartis, Pfizer, Roche, Sanofi, UCB, MSD

Could soluble levels of CD40L and galectin-9 be possible prognostic biomarkers and therapeutic targets in NSCLC?

e21508 Background: Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all cases of lung cancer. The immune system is now recognized to have the potential to destroy cancer cells. TIM-3 binds to Galectin-9 (GAL9) causing suppression of cytokine production, cell cycle arrest and cell death. Soluble CD40L (sCD40L) that is released by activated T lymphocytes and platelets. Therefore, we hypothesized that soluble forms immune checkpoint receptors and their ligands, such as TIM-3, GAL9 and CD40L may also prognostic implications of NSCLC. Objectives: Evaluate the soluble levels of CD40L, TIM-3 and GAL9 in patients with NSCLC in III and IV stages of disease. Methods: Samples of blood were collected from a cohort prospective involving 32 patients between 50 and 80 years old (65 + 8,6 years). Enzyme-linked immunosorbent assay was used to quantify expression these receptors. A non-parametric test was used to compare all groups (Mann-Whitney U-test). Statistical significance was defined as p<0.05. Data analysis was performed using GraphPadPrism v8.3. Results: Our results showed higher levels GAL-9 and TIM3 in patients with stage III and IV than controls ( p<0.05). As also, higher expression of CD40L was identified in patients stage III than stage IV ( p<0.0001) and controls ( p=0.007). It wasn’t seen significant different expression of CD40L between stage IV patients and controls. Analyzing GAL9, it was identified higher level in patients stage III than stage IV ( p<0.0001). Expression of TIM-3 wasn’t significant difference between patients with stage III and IV. When analysing in ratio between CD40L/TIM3, TIM3/GAL9 and CD40L/GAL9 in all groups, only TIM-3/GAL9 ratio had a positive correlation in patients stage IV (r=0.688; p<0.0001). By histology, patients with squamous cell carcinoma had higher levels of CD40L than adenocarcionoma ( p=0.01), but no significant difference was identified between expression of TIM3 e GAL9 and histological subtypes. Conclusions: This study showed expression sCD40L and GAL9 were higher stage III than stage IV in patients NSCLC. It can be inferred that soluble CD40L and GAL9 receptors are possible prognostic biomarkers and potential therapeutic targets in NSCLC.

Evaluation of the in vitro Function of Platelet Concentrates from Pooled Buffy Coats or Apheresis

Background: Platelet concentrates play an important role in transfusion medicine. Their short lifespan and lack of robustness require efforts to ensure adequate product quality. In this study, we compared the in vitro quality of the main concentrate types, pooled platelet concentrate (PPC) from whole blood donations, and platelet concentrate from single-donor apheresis (APC). Methods: Twenty PPCs and 20 APCs prepared in plasma were analyzed on days 2, 4, and 7 of storage. Variables related to metabolism, degranulation, platelet aggregation, P-selectin expression, and annexin V binding were analyzed. Morphology was assessed by transmission electron microscopy of ultrathin sections. A microfluidic device was applied to test the effects of shear stress on platelet function. Results: The metabolic parameters indicated stable storage conditions throughout the 7-day period. The resting discoid form was the prevailing morphology on days 2 and 4 in the PPCs and APCs. Chemokine release and receptor shedding of soluble P-selectin and soluble CD40L equally increased in PPCs and APCs. Aggregation responses to ADP and collagen were heterogeneous, with marked losses in collagen responsiveness on day 4 in individual concentrates. Baseline expression of P-selectin in PPCs and APCs was low, and inducibility of P-selectin was well preserved until day 4. Under shear stress, equal adhesiveness and stability were found with platelets from PPCs and APCs. Conclusions: Platelets from PPCs and APCs showed similar in vitro function and stability parameters. However, platelet concentrates presented a high variability and individual concentrates an impaired functional capability. Identifying the factors contributing to this would help increase product reliability.