Alarmins as biomarkers of gastrointestinal surgical injury - a pilot study

S100A8 and S100A9 in Cancer

S100A8 and S100A9 are Ca²⁺ binding proteins that belong to the S100 family. Primarily expressed in neutrophils and monocytes, S100A8 and S100A9 play critical roles in modulating various inflammatory responses and inflammation-associated diseases. Forming a common heterodimer structure S100A8/A9, S100A8 and S100A9 are widely reported to participate in multiple signaling pathways in tumor cells. Meanwhile, S100A8/A9, S100A8, and S100A9, mainly as promoters, contribute to tumor development, growth and metastasis by interfering with tumor metabolism and the microenvironment. In recent years, the potential of S100A8/A9, S100A9, and S100A8 as tumor diagnostic or prognostic biomarkers has also been demonstrated. In addition, an increasing number of potential therapies targeting S100A8/A9 and related signaling pathways have emerged. In this review, we will first expound on the characteristics of S100A8/A9, S100A9, and S100A8 in-depth, focus on their interactions with tumor cells and microenvironments, and then discuss their clinical applications as biomarkers and therapeutic targets. We also highlight current limitations and look into the future of S100A8/A9 targeted anti-cancer therapy.

Methylomic and transcriptomic characterization of postoperative systemic inflammatory dysregulation

In this study, we define and validate a state of postoperative systemic inflammatory dysregulation (PSID) based on postoperative phenotypic extremes of plasma C-reactive protein concentration following major abdominal surgery. PSID manifested clinically with significantly higher rates of sepsis, complications, longer hospital stays and poorer short, and long-term outcomes. We hypothesized that PSID will be associated with, and potentially predicted by, altered patterns of genome-wide peripheral blood mononuclear cell differential DNA methylation and gene expression. We identified altered DNA methylation and differential gene expression in specific immune and metabolic pathways during PSID. Our findings suggest that dysregulation results in, or from, dramatic changes in differential DNA methylation and highlights potential targets for early detection and treatment. The combination of altered DNA methylation and gene expression suggests that dysregulation is mediated at multiple levels within specific gene sets and hence, nonspecific anti-inflammatory treatments such as corticosteroids alone are unlikely to represent an effective therapeutic strategy.

Intraoperative Peritoneal Interleukin-6 Concentration Changes in Relation to the High-Mobility Group Protein B1 and Heat Shock Protein 70 Levels in Children Undergoing Cholecystectomy

The aim was the evaluation of IL-6 concentration in peritoneal lavage fluid of children which underwent cholecystectomy to ascertain if there is a difference in early inflammatory response depending on the type of surgical approach (open vs. laparoscopy). The analysis of high-mobility group protein B1 (HMGB1) and heat shock protein 70 (HSP70) was performed to find out if the source of IL-6 was related to tissue damage. IL-6 concentration in peritoneal lavage fluid samples, obtained at the beginning and at the end of the laparoscopic (N = 23) and open cholecystectomy (N = 14), was tested with a routinely used electrochemiluminescence assay. The concentrations of HMGB1 and HSP70 were analyzed with the use of an ELISA method. Statistical analysis was performed using the STATISTICA PL release 12.5 Program. The differences were assessed using the Mann-Whitney U test and Wilcoxon matched pairs test. Correlations were studied by using the Spearman correlation test. Our results demonstrated significant peritoneal lavage fluid IL-6 concentration growth measured at the end of the cholecystectomy as compared to the beginning, regardless of the type of the procedure. IL-6 growth during open cholecystectomy was greater compared to laparoscopic cholecystectomy (62.51-fold vs. 3.19-fold). IL-6 concentration did not correlate with HMGB1 and HSP70, which indicate that the significant growth of this cytokine was not related to mechanical tissue damage due to surgical procedure. A clinical significance of the study could be related to the fact that the evaluation of IL-6 concentration in peritoneal lavage fluid may be useful to assess an early local inflammatory response.

Calprotectin and Calgranulin C as Biomarkers of Pancreatic Tumors: Baseline Levels and Level Changes after Surgery

Pancreatic tumors and their surgical resection are associated with significant morbidity and mortality, and the biomarkers currently used for these conditions have limited sensitivity and specificity. Because calprotectin and calgranulin C serum levels have been demonstrated to be potential biomarkers of certain cancers and complications of major surgery, the levels of both proteins were tested in the current study in patients with benign and malignant pancreatic tumors that were surgically removed. The baseline serum levels and kinetics of calprotectin and calgranulin C during the 7-day postoperative period were evaluated with immunoassays in 98 adult patients who underwent pancreatic surgery. The baseline serum levels of calprotectin and calgranulin C in patients with malignant (n = 84) and benign tumors (n = 14) were significantly higher (p < 0.01) when compared to those in the healthy controls (n = 26). The serum levels of both proteins were also significantly (p < 0.05) higher in patients with benign tumors than in those with malignant tumors. After surgery, the serum levels of calprotectin and calgranulin C were significantly (p < 0.01) higher than their baseline values, and this elevation persisted throughout the seven days of the follow-up period. Interestingly, starting on day 1 of the postoperative period, the serum levels of both proteins were significantly (p < 0.05) higher in the 37 patients who developed postoperative pancreatic fistulas (POPFs) than in the patients who had uneventful recoveries (n = 61). Moreover, the serum levels of calprotectin and calgranulin C demonstrated a significant predictive value for the development of POPF; the predictive values of these two proteins were better than those of the serum level of C-reactive protein and the white blood cell count. Taken together, the results of this study suggest that calprotectin and calgranulin C serum levels are potential biomarkers for pancreatic tumors, surgical injury to the pancreatic tissue and the development of POPFs.

Expression of Toll-like receptors 2 and 4 on peripheral mononuclear cells (PBMCs) after laparoscopic cholecystectomy

Increasing evidence suggests that the course and intensity of inflammation, as well as repair processes, developed in response to stress, injury, and trauma, depend on the interaction between immediately released endogenous molecules, called alarmins or danger/damage-associated molecular patterns (DAMPs) and cellular pattern recognition receptors (PRR) including Toll-like receptors (TLRs) and activation of inflammatory/immune cells. Therefore, the aim of this study was to examine the expression of TLRs in peripheral blood mononuclear cells (PBMCs), CD3⁺, and CD14⁺ cells in control group and in patients before the laparoscopic cholecystectomy, and three and seven days after surgery. Flow cytometry was used to evaluate expression of TLR2 and TLR4. TLR2 and especially TLR4 expression levels on PBMCs were significantly lower in patients with asymptomatic cholelithiasis than in the control group. Laparoscopic surgery did not induce the significant changes in the expression of TLR2, both on PBMCs and CD3⁺ and CD14⁺ cell subpopulations. On the contrary, TLR4 expression level on PBMCs was significantly lower on the third and seventh postoperative day than before surgery. Collectively, the expression levels of cellular TLRs, and especially TLR2 and TLR4, might strongly influence the responsiveness of cells to DAMP activation, and in this way can regulate the intensity of inflammatory response to surgical injury.

Surgical injury: comparing open surgery and laparoscopy by markers of tissue damage

Background

Major abdominal surgery (MAS) is high-risk intervention usually accompanied by tissue injury leading to a release of signaling danger molecules called alarmins. This study evaluates the surgical injury caused by two fundamental types of gastrointestinal surgical procedures (open surgery and laparoscopy) in relation to the inflammation elicited by alarmins.

Patients and methods

Patients undergoing MAS were divided into a mixed laparoscopy group (LPS) and an open surgery group (LPT). Serum levels of alarmins (S100A8, S100A12, HMGB1, and HSP70) and biomarkers (leukocytes, C-reactive protein [CRP], and interleukin-6 [IL-6]) were analyzed between the groups. The secondary objectives were to compare LPT and LPS cancer subgroups and to find the relationship between procedure and outcome (intensive care unit length of stay [ICU-LOS] and hospital length of stay [H-LOS]).

Results

A total of 82 patients were analyzed. No significant difference was found in alarmin levels between the mixed LPS and LPT groups. IL-6 was higher in the LPS group on day 2 (p=0.03) and day 3 (p=0.04). Significantly higher S100A8 protein levels on day 1 (p=0.02) and day 2 (p=0.01) and higher S100A12 protein levels on day 2 (p=0.03) were obtained in the LPS cancer subgroup. ICU-LOS and H-LOS were longer in the LPS cancer subgroup.

Conclusion

The degree of surgical injury elicited by open MAS as reflected by alarmins is similar to that of laparoscopic procedures. Nevertheless, an early biomarker of inflammation (IL-6) was higher in the laparoscopy group, suggesting a greater inflammatory response. Moreover, the levels of S100A8 and S100A12 were higher with a longer ICU-LOS and H-LOS in the LPS cancer subgroup.