Pancreatic stone protein (PSP) and pancreatitis-associated protein (PAP): a protocol of a cohort study on the diagnostic efficacy and prognostic value of PSP and PAP as postoperative markers of septic complications in patients undergoing abdominal surgery (PSP study)

The Potential Role of REG Family Proteins in Inflammatory and Inflammation-Associated Diseases of the Gastrointestinal Tract

Regenerating gene (REG) family proteins serve as multifunctional secretory molecules with trophic, antiapoptotic, anti-inflammatory, antimicrobial and probably immuno-regulatory effects. Since their discovery, accumulating evidence has clarified the potential roles of the REG family in the occurrence, progression and development of a wide range of inflammatory and inflammation-associated diseases of the gastrointestinal (GI) tract. However, significant gaps still exist due to the undefined nature of certain receptors, regulatory signaling pathways and possible interactions among distinct Reg members. In this narrative review, we first describe the structural features, distribution pattern and purported regulatory mechanisms of REG family proteins. Furthermore, we summarize the established and proposed roles of REG proteins in the pathogenesis of various inflammation-associated pathologies of the GI tract and the body as a whole, focusing particularly on carcinogenesis in the ulcerative colitis—colitic cancer sequence and gastric cancer. Finally, the clinical relevance of REG products in the context of diagnosis, treatment and prognostication are also discussed in detail. The current evidence suggests a need to better understanding the versatile roles of Reg family proteins in the pathogenesis of inflammatory-associated diseases, and their broadened future usage as therapeutic targets and prognostic biomarkers is anticipated.

Nanotools for Sepsis Diagnosis and Treatment

Sepsis is one of the leading causes of death worldwide with high mortality rates and a pathological complexity hindering early and accurate diagnosis. Today, laboratory culture tests are the epitome of pathogen recognition in sepsis. However, their consistency remains an issue of controversy with false negative results often observed. Clinically used blood markers, C reactive protein (CRP) and procalcitonin (PCT) are indicators of an acute-phase response and thus lack specificity, offering limited diagnostic efficacy. In addition to poor diagnosis, inefficient drug delivery and the increasing prevalence of antibiotic-resistant microorganisms constitute significant barriers in antibiotic stewardship and impede effective therapy. These challenges have prompted the exploration for alternative strategies that pursue accurate diagnosis and effective treatment. Nanomaterials are examined for both diagnostic and therapeutic purposes in sepsis. The nanoparticle (NP)-enabled capture of sepsis causative agents and/or sepsis biomarkers in biofluids can revolutionize sepsis diagnosis. From the therapeutic point of view, currently existing nanoscale drug delivery systems have proven to be excellent allies in targeted therapy, while many other nanotherapeutic applications are envisioned. Herein, the most relevant applications of nanomedicine for the diagnosis, prognosis, and treatment of sepsis is reviewed, providing a critical assessment of their potentiality for clinical translation.

Role of regenerating islet-derived proteins in inflammatory bowel disease

Inflammatory bowel disease (IBD) is an inflammatory disorder of the gastrointestinal tract that affects millions of patients worldwide. It has a complex and multifactorial etiology leading to excessive exposure of intestinal epithelium to microbial antigens, inappropriate activation of the immune system and ultimately to the damage of intestinal tissues. Although numerous efforts have been made to improve the disease management, IBD remains persistently recurring and beyond cure. This is due largely to the gaps in our understanding of the pathogenesis of IBD that hamper the development of timely diagnoses and effective treatment. However, some recent discoveries, including the beneficial effects of interleukin-22 (IL-22) on the inflamed intestine, have shed light on a self-protective mechanism in IBD. Regenerating islet-derived (REG/Reg) proteins are small secretory proteins which function as IL-22's downstream effectors. Mounting studies have demonstrated that IBD patients have significantly increased REG expressions in the injured intestine, but with undefined mechanisms and roles. The reported functions of REG/Reg proteins in intestinal homeostasis, such as those of antibacterial, anti-inflammatory and tissue repair, lead us to discuss their potential mechanisms and clinical relevance in IBD in order to advance IBD research and management.

Normal values for pancreatic stone protein in different age groups

Background

Pancreatic stone protein (PSP) has been identified as a promising sepsis marker in adults, children and neonates. However, data on population-based reference values are lacking. This study aimed to establish age-specific reference values for PSP.

Methods

PSP was determined using a specific ELISA. PSP serum concentrations were determined in 372 healthy subjects including 217 neonates, 94 infants and children up to 16 years, and 61 adults. The adjacent categories method was used to determine which age categories had significantly different PSP concentrations.

Results

PSP circulating levels were not gender-dependent and ranged from 1.0 to 99.4 ng/ml with a median of 9.2 ng/ml. PSP increased significantly between the age categories, from a median of 2.6 ng/ml in very preterm newborns, to 6.3 ng/ml in term newborns, to 16.1 ng/ml in older children (p < 0.001). PSP levels were higher on postnatal day three compared to levels measured immediately post delivery (p < 0.001). Paired umbilical artery and umbilical vein samples were strongly correlated (p < 0.001). Simultaneously obtained capillary heel-prick versus venous samples showed a good level of agreement for PSP (Rho 0.89, bias 19 %).

Conclusions

This study provides age-specific normal values that may be used to define cut-offs for future trials on PSP. We demonstrate an age-dependent increase of PSP from birth to childhood.

Pancreatic stone protein as a postmortem biochemical marker for the diagnosis of sepsis

Pancreatic stone protein/regenerating protein has recently emerged as an interesting diagnostic and prognostic marker of inflammation and sepsis in the clinical field. Increased blood concentrations have been described in patients with sepsis. Moreover, a high accuracy in predicting fatal outcomes in septic patients admitted to intensive care units has been reported. In this study, we investigated pancreatic stone protein/regenerating protein in postmortem serum in a series of sepsis-related fatalities, local infections and non-infectious cases that underwent medico-legal investigations. Procalcitonin, C-reactive protein, interleukin 6, soluble triggering receptor expressed on myeloid cells-1 and pancreatic stone protein/regenerating protein were measured in the postmortem serum collected during autopsy in a group of sepsis-related deaths, local infections and non-septic intensive care unit patients. Statistically significant differences in pancreatic stone protein/regenerating protein concentrations were observed between sepsis and control patients. A significant positive correlation was found between procalcitonin and pancreatic stone protein/regenerating protein values in septic cases. Pancreatic stone protein/regenerating protein is measurable in postmortem serum from femoral blood collected during autopsy. Additionally, as in the clinical field, pancreatic stone protein/regenerating protein can be used as a postmortem biochemical marker for the diagnosis of sepsis.