In this review, the role of innate and adaptive immunity in the pathogenesis of inflammatory bowel diseases (IBD) is reported. In IBD, an altered innate immunity is often found, with increased Th17 and decreased Treg cells infiltrating the intestinal mucosa. An associated increase in inflammatory cytokines, such as IL-1 and TNF-α, and a decrease in anti-inflammatory cytokines, such as IL-10, concur in favoring the persistent inflammation of the gut mucosa. Autoinflammation is highlighted with insights in the role of inflammasomes, which activation by exogenous or endogenous triggers might be favored by mutations of NOD and NLRP proteins. Autoimmunity mechanisms also take place in IBD pathogenesis and in this context of a persistent immune stimulation by bacterial antigens and antigens derived from intestinal cells degradation, the adaptive immune response takes place and results in antibodies and autoantibodies production, a frequent finding in these diseases. Inflammation, autoinflammation and autoimmunity concur in altering the mucus layer and enhancing intestinal permeability, which sustains the vicious cycle of further mucosal inflammation.

Background: The sensitivities and specificities of C-reactive protein (CRP) and faecal calprotectin (fCal), as recommended for inflammatory bowel diseases (IBD) diagnosis and monitoring, are low. Our aim was to discover new stool protein/peptide biomarkers for diagnosing IBD. Methods: For peptides, MALDI-TOF/MS (m/z 1000–4000) was performed using stools from an exploratory (34 controls; 72 Crohn’s disease [CD], 56 ulcerative colitis [UC]) and a validation (28 controls, 27 CD, 15 UC) cohort. For proteins, LTQ-Orbitrap XL MS analysis (6 controls, 5 CD, 5 UC) was performed. Results: MALDI-TOF/MS spectra of IBD patients had numerous features, unlike controls. Overall, 426 features (67 control-associated, 359 IBD-associated) were identified. Spectra were classified as control or IBD (absence or presence of IBD-associated features). In the exploratory cohort, the sensitivity and specificity of this classification algorithm were 81% and 97%, respectively. Blind analysis of the validation cohort confirmed 97% specificity, with a lower sensitivity (55%) paralleling active disease frequency. Following binary logistic regression analysis, IBD was independently correlated with MALDI-TOF/MS spectra (p < 0.0001), outperforming fCal measurements (p = 0.029). The IBD-correlated m/z 1810.8 feature was a fragment of APC2, homologous with APC, over-expressed by infiltrating cells lining the surface in UC or the muscularis-mucosae in CD (assessed by immunohistochemistry). IBD-associated over-expressed proteins included immunoglobulins and neutrophil proteins, while those under-expressed comprised proteins of the nucleic acid assembly or those (OLFM4, ENPP7) related to cancer risk. Conclusions: Our study provides evidence for the clinical utility of a novel proteomic method for diagnosing IBD and insight on the pathogenic role of APC. Moreover, the newly described IBD-associated proteins might become tools for cancer risk assessment in IBD patients.

Combined approaches based on immunotherapy and drugs supporting immune effector cell function might increase treatment options for pancreatic ductal adenocarcinoma (PDAC), vitamin D being a suitable drug candidate. In this study, we evaluated whether treatment with the vitamin D analogue, calcipotriol, counterbalances PDAC induced and SMAD4-associated intracellular calcium [Ca²⁺]_i alterations, cytokines release, immune effector function, and the intracellular signaling of peripheral blood mononuclear cells (PBMCs). Calcipotriol counteracted the [Ca²⁺]_i depletion of PBMCs induced by SMAD4-expressing PDAC cells, which conditioned media augmented the number of calcium flows while reducing whole [Ca²⁺]_i. While calcipotriol inhibited spontaneous and PDAC-induced tumor necrosis factor alpha (TNF-α) release by PBMC and reduced intracellular transforming growth factor beta (TGF-β), it did not counteract the lymphocytes proliferation induced in allogenic co-culture by PDAC-conditioned PBMCs. Calcipotriol mainly antagonized PDAC-induced apoptosis and partially restored PDAC-inhibited NF-κB signaling pathway. In conclusion, alterations induced by PDAC cells in the [Ca²⁺]_i of immune cells can be partially reverted by calcipotriol treatment, which promotes inflammation and antagonizes PBMCs apoptosis. These effects, together with the dampening of intracellular TGF-β, might result in an overall anti-tumor effect, thus supporting the administration of vitamin D in PDAC patients.

Objective: Salivary alpha-amylase (sAA) has been recently proposed as biomarker of stress responsiveness within the sympathetic nervous system, preferable to cortisol, since limitations related to cortisol measurement (e.g. diurnal and seasonal rhythms, drugs interferences). Several factors, as age, collection device and analytical methods, also influence sAA levels and interpretation. This study aims to assess whether sAA could be useful to evaluate the stress response, also verifying some sources of variability. Methods: To identify any sources of sAA variability, saliva samples were collected from eight healthy subjects at five different times (8:00, 10:00, 12:00, 14:00 and 16:00) over five consecutive days using two different collection devices. Saliva was then collected from 35 obstetric residents before and after a simulated shoulder dystocia scenario, one of the most traumatic birth events in the professional life of gynecologists, to assess the stress levels. Samples were analysed throughout two different assays. Heart rate (HR) of residents was also measured before and after simulation scenario. Residents self-collected two saliva samples 10 min apart on a typical day. Results: Overall, sAA levels increased significantly from morning to afternoon. Levels varied between subjects, but no differences were found between days or sampling devices. sAA activity levels in samples from 35 residents were significantly higher than those obtained before the scenario took place (about ten minutes later). These results were confirmed by two different assays. Moreover, a similar trend was observed when HR was considered. No differences were observed between samples collected 10 minutes apart on a typical day. Conclusions: Salivary alpha-amylase activity is a reliable, quick, and efficient marker for stress response, then its measurement will be of potential interest in the field of stress-related disorders. However, it is important to consider the timing of sample collection before introducing sAA in a clinical setting.