Pancreatic stone protein is highly increased during posttraumatic sepsis and activates neutrophil granulocytes. Crit Care Med. 2009;37:1642-1648. [PMID: 19325491 DOI: 10.1097/ccm.0b013e31819da7d6]

The Possible Pathophysiological Role of Pancreatic Stone Protein in Sepsis and Its Potential Therapeutic Implication

According to the current understanding of the pathophysiology of sepsis, key host dysregulated responses leading to organ failure are mediated by innate immunity, through interactions between pathogen-associated molecular patterns (PAMPs) and damaged-associated molecular patterns (DAMPs) binding to four types of pattern recognition receptors (PRRs). PRRs activation triggers the protein kinase cascade, initiating the cellular response seen during sepsis. Pancreatic stone protein (PSP), a C-type lectin protein, is a well-defined biomarker of sepsis. Studies have shown that stressed and immune-activated pancreatic β-cells secrete PSP. Animal studies have shown that PSP injection aggravates sepsis, and that the disease severity score and mortality were directly correlated with the doses of PSP injected. In humans, studies have shown that PSP activates polymorphonuclear neutrophils (PMNs) and aggravates multiple organ dysfunction syndrome. Clinical studies have shown that PSP levels are correlated with disease severity, vasopressor support, progression to organ failure, mechanical ventilation, renal replacement therapy, length of stay, and mortality. As PSP is a C-type lectin protein, it may have a role in activating innate immunity through the C-type lectin receptors (CLRs), which is one of the four PRRs. Herein, we review the literature on PSP and its possible role in the pathophysiology of sepsis, and we discuss its potential therapeutic role.

Serial monitoring of pancreatic stone protein for the detection of sepsis in intensive care unit patients with complicated abdominal surgery: A prospective, longitudinal cohort study

PURPOSE

The objective of this study was to assess the performance of pancreatic stone protein (PSP) monitoring for the detection of sepsis, prediction of outcome and distinction between bacterial and fungal infections in intensive care unit (ICU) patients with complicated abdominal surgery.

MATERIALS AND METHODS

In this prospective multicenter cohort study, patients with complicated abdominal surgery had serial PSP measurements during their ICU stay. Infectious episodes were classified as bacterial, fungal or mixed. PSPmax (maximal PSP value within 48 h of the diagnosis of infection) and ΔPSP (difference between PSPmax and the preceding PSP value) were used for analyses.

RESULTS

PSPmax was obtained for 118 infectious episodes (68 patients). ΔPSP was available for 73 episodes (48 patients). Both PSPmax and ΔPSP were significantly higher in patients with sepsis and in patients with a fatal outcome. A PSPmax ≥124 ng/ml and a ΔPSP ≥34 ng/ml could detect sepsis with a sensitivity/specificity of 84%/54% and 69%/76%, respectively. There was no significant difference of PSPmax or ΔPSP between patients with bacterial/mixed versus fungal infections.

CONCLUSIONS

Serial PSP monitoring may be an additional tool for the early detection of sepsis in patients with complicated abdominal surgery who are at high risk of severe infections.

Development and validation of an ELISA to measure regenerating island-derived protein 3E in canine blood

BACKGROUND

Regenerating island-derived proteins (REG) are upregulated in people with sepsis, pancreatitis, and gastrointestinal diseases. One member of the REG family, namely REG3E, was recently identified in pancreatic tissue and plasma of dogs, with high expression in pancreatitis and sepsis.

OBJECTIVES

We aimed to develop and validate an ELISA to measure REG3E concentrations in canine blood.

METHODS

An indirect sandwich ELISA was developed using recombinant canine REG3E protein and polyclonal anti-canine REG3E antibodies raised in guinea pigs and rabbits. Antibody specificity was assessed using western blot and mass spectrometric analysis of protein purified from canine plasma. Assay validation included evaluation of dilutional linearity, parallelism, spiking recovery, repeatability and reproducibility, stability, interferences, and comparison of serum and heparinized plasma.

RESULTS

Antibodies bound specifically to REG3E with no evidence of cross-reactivity with other proteins. The limit of detection of the ELISA was 15 ng/mL, and the lower limit of quantification was 30 ng/mL. The assay demonstrated good to excellent linearity, dilutional and mixing parallelism, and recovery, with mean observed-to-expected ratios of 104%, 107%, 102%, and 92%, respectively, and no evidence of a hook effect. Coefficients of variation were ≤8.5% for repeatability and ≤14.3% for reproducibility at three different levels. Measurements of REG3E in plasma were not significantly influenced by different storage conditions, freeze-thawing cycles, hemolysis, lipemia, or icterus. There was no significant difference between REG3E concentrations in heparinized plasma and serum samples.

CONCLUSIONS

The canine REG3E ELISA has acceptable precision, accuracy, linearity, and reproducibility for the measurement of REG3E in canine plasma and serum.

Diagnostic and Prognostic Ability of Pancreatic Stone Protein: A Scoping Review

Pancreatic stone protein (PSP) is an acute-phase reactant mainly produced in response to stress. Its diagnostic and prognostic accuracy for several types of infection has been studied in several clinical settings. The aim of the current review was to assess all studies examining a possible connection of pancreatic stone protein levels with the severity and possible complications of patients diagnosed with infection. We performed a systematic search in PubMed, Scopus, the Cochrane Library and Clinicaltrials.gov to identify original clinical studies assessing the role of pancreatic stone protein in the diagnosis and prognosis of infectious diseases. We identified 22 eligible studies. Ten of them provided diagnostic aspects, ten studies provided prognostic aspects, and another two studies provided both diagnostic and prognostic information. The majority of the studies were performed in an intensive care unit (ICU) setting, five studies were on patients who visited the emergency department (ED), and three studies were on burn-injury patients. According to the literature, pancreatic stone protein has been utilized in patients with different sites of infection, including pneumonia, soft tissue infections, intra-abdominal infections, urinary tract infections, and sepsis. In conclusion, PSP appears to be a useful point-of-care biomarker for the ED and ICU due to its ability to recognize bacterial infections and sepsis early. Further studies are required to examine PSP's kinetics and utility in specific populations and conditions.

Examining pancreatic stone protein response in ICU-acquired bloodstream infections: a matched event analysis

BACKGROUND

Pancreatic stone protein (PSP) exhibits potential as a plasma biomarker for infection diagnosis and risk stratification in critically ill patients, but its significance in nosocomial infection and intensive care unit (ICU)-acquired bloodstream infection (BSI) remains unclear. This study explores the temporal responses of PSP in ICU-acquired BSI caused by different pathogens.

METHODS

From a large cohort of ICU patients, we selected episodes of ICU-acquired BSI caused by Gram-negative rods (GNRs), enterococci, or Candida species. Events were matched on length of ICU stay at infection onset, Severe Organ Failure Assessment (SOFA) score, presence of immune deficiency, and use of renal replacement therapy. PSP concentrations were measured at infection onset (T0) and at 24, 48 and 72 h prior to infection onset as defined by the first occurrence of a positive blood culture. Absolute and trend differences in PSP levels between pathogen groups were analysed using one-way analysis of variance. Sensitivity analyses were performed in events with a new or worsening systematic inflammatory response based on C-reactive protein, white cell count and fever.

RESULTS

We analysed 30 BSI cases per pathogen group. Median (IQR) BSI onset was on day 9 (6-12). Overall, PSP levels were high (381 (237-539) ng/ml), with 18% of values exceeding the assay's measurement range. Across all 90 BSI cases, there was no clear trend over time (median change 34 (- 75-189) ng/ml from T-72 to T0). PSP concentrations at infection onset were 406 (229-497), 350 (223-608), and 480 (327-965) ng/ml, for GNR, enterococci, and Candida species, respectively (p = 0.32). At every time point, absolute PSP levels and trends did not differ significantly between pathogens. PSP values at T0 correlated with SOFA scores. Eighteen (20%) of 90 BSI events did not exhibit a systemic inflammatory response, primarily in Candida species. No clear change in PSP concentration before BSI onset or between-group differences were found in sensitivity analyses of 72 cases.

CONCLUSIONS

Against a background of overall (very) high plasma PSP levels in critically ill patients, we did not find clear temporal patterns or any pathogen-specific differences in PSP response in the days preceding onset of ICU-acquired BSI.

Diagnostic accuracy of pancreatic stone protein in patients with sepsis: a systematic review and meta-analysis

BACKGROUND

Sepsis is a common syndrome of multiorgan system dysfunction secondary to the dysregulated inflammatory response to infection. The role of pancreatic stone protein (PSP) in diagnosing sepsis has been investigated in previous studies. The meta-analysis aimed to comprehensively investigate the diagnostic value of PSP in identifying sepsis.

METHODS

PubMed, Web of Science, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI), were systematically searched. Studies investigating the diagnostic performance of PSP were included. Pooled sensitivity, specificity, positive Likelihood Ratio (+ LR) and negative Likelihood Ratio (-LR), diagnostic odds ratio (DOR), and area under the curve (AUC) of summary receiver operating characteristic (SROC) were calculated.

RESULTS

The sensitivity of PSP was 0.88 (95% CI: 0.77-0.94), and the pooled specificity was 0.78 (95% CI: 0.65-0.87). Pooled + LR, -LR, and DOR were 4.1 (2.3, 7.3), 0.16 (0.07, 0.34), and 26 (7, 98). The AUC value for the SROC of PSP was 0.90 (0.87, 0.92). The pooled sensitivity, specificity, + LR and - LR, and DOR for PSP among neonates were 0.91 (95% CI: 0.84, 0.96), 0.66 (95% CI: 0.58, 0.74), 3.97 (95% CI: 0.53, 29.58), 0.13 (95% CI: 0.02, 1.00), and 31.27 (95% CI: 0.97, 1004.60).

CONCLUSIONS

This study indicates that PSP demonstrated favorable diagnostic accuracy in detecting sepsis. Well-designed studies are warranted to ascertain the value of PSP measurement to guide early empirical antibiotic treatment, particularly in neonates.

Accuracy of Pancreatic Stone Protein for diagnosis of sepsis in children admitted to pediatric intensive care or high-dependency care: a pilot study

BACKGROUND

Pancreatic Stone Protein (PSP) is one of the most promising diagnostic and prognostic markers. The aim of the study was to assess the accuracy of PSP, compared to C-Reactive Protein (CRP), and Procalcitonin (PCT) for sepsis diagnosis in pediatric patients. Furthermore, we explored the correlation of PSP levels with sepsis severity and organ failure measured with PELOD-2 score.

METHODS

Forty pediatric patients were enrolled following admission to pediatric intensive care, high dependency care or pediatric ward. PSP blood levels were measured in Emergency Department (nanofluidic point-of-care immunoassay; abioSCOPE, Abionic SA, Switzerland) on day 1, 2, 3, 5 and 7 from the onset of the clinical signs and symptoms of sepsis or SIRS. Inclusion criteria were: 1) patient age (1 month to 18 years old), 2) signs and symptoms of SIRS, irrespective of association with organ dysfunction. Exclusion criteria were: 1) hemato-oncological diseases and/or immunodeficiencies, 2) pancreatic diseases.

RESULTS

Septic patients showed higher PSP levels than those with non-infectious systemic inflammation. The optimal cut-off in diagnosis of sepsis for PSP at day 1 was 167 ng/ml resulted in a sensitivity of 59% (95% IC 36%-79%) and a specificity of 83% (95% IC 58%-96%) with an AUC of 0.636 for PSP in comparison to AUC of 0.722 for PCT and 0.503 for C-RP. ROC analysis for outcome (survival versus no survival) has showed AUC 0.814 for PSP; AUC 0.814 for PCT; AUC of 0.657 for C-RP.

CONCLUSIONS

PSP could distinguish sepsis from non-infectious systemic inflammation; however, our results need to be confirmed in larger pediatric population.

Point-of-care pancreatic stone protein measurement in critically ill COVID-19 patients

INTRODUCTION

Pancreatic stone protein (PSP) is a novel biomarker that is reported to be increased in pneumonia and acute conditions. The primary aim of this study was to prospectively study plasma levels of PSP in a COVID-19 intensive care unit (ICU) population to determine how well PSP performed as a marker of mortality in comparison to other plasma biomarkers, such as C reactive protein (CRP) and procalcitonin (PCT).

METHODS

We collected clinical data and blood samples from COVID-19 ICU patients at the time of admission (T0), 72 h later (T1), five days later (T2), and finally, seven days later. The PSP plasma level was measured with a point-of-care system; PCT and CRP levels were measured simultaneously with laboratory tests. The inclusion criteria were being a critical COVID-19 ICU patient requiring ventilatory mechanical assistance.

RESULTS

We enrolled 21 patients and evaluated 80 blood samples; we found an increase in PSP plasma levels according to mixed model analysis over time (p < 0.001), with higher levels found in the nonsurvivor population (p < 0.001). Plasma PSP levels achieved a statistically significant result in terms of the AUROC, with a value higher than 0.7 at T0, T1, T2, and T3. The overall AUROC of PSP was 0.8271 (CI (0.73-0.93), p < 0.001). These results were not observed for CRP and PCT.

CONCLUSION

These first results suggest the potential advantages of monitoring PSP plasma levels through point-of-care technology, which could be useful in the absence of a specific COVID-19 biomarker. Additional data are needed to confirm these results.

The Role of Pancreatic Stone Protein (PSP) as a Biomarker of Pregnancy-Related Diseases

Background: Pancreatic stone protein (PSP) is a biochemical serum marker that contains levels that are elevated in various inflammatory and infectious diseases. The role of PSP in the diagnosis of these diseases seems to be more important compared to clinically established biochemical serum markers in discriminating the severity of the same diseases. Standard values for PSP in pregnant women in relation to gestational age have been reported recently. Additionally, increased PSP levels have been observed to be associated with renal dysfunction in pregnant women. The aim of this study is to evaluate the diagnostic role of PSP in pregnancy-related diseases, such as pre-eclampsia (PE), hemolysis-elevated liver enzymes, and low platelet (HELLP) syndrome. In addition, the study aims to assess its diagnostic role in inflammation-triggered diseases as preterm premature rupture of membranes (PPROM) or COVID-19-positive pregnant women. Materials and Methods: In this single-centred prospective study performed at a tertiary university hospital between 2013 and 2021, we included 152 pregnant women who were diagnosed with either PE, HELLP syndrome, or PPROM. In December 2020, in the context of the COVID-19 pandemic, the Independent Ethics Committee (IEC) approved an amendment to the study protocol. Depending on the underlying disease, single or serial-serum PSP measurements were assessed. These PSP values were compared to PSP levels of women with normal pregnancies. Results: Pregnant women diagnosed with pre-eclampsia or HELLP syndrome had significantly increased PSP values (mean 9.8 ng/mL, SD 2.6) compared to healthy singleton pregnant women (mean 7.9 ng/mL, SD 2.6, p ≤ 0.001). There was no difference in serum PSP in pregnant women with PPROM compared to women with uncomplicated singleton pregnancies (mean in PPROM: 7.9 ng/mL; SD 2.9 versus mean in healthy pregnancies: 7.9 ng/mL; SD 2.6, p = 0.98). Furthermore, no difference in the PSP values in women with or without intra-amniotic infection was observed (infection: mean 7.9 ng/mL; SD 2.8 versus no infection: mean 7.8 ng/mL; SD 3, p = 0.85). The mean value of PSP in COVID-19-infected women during pregnancy (8.5 ng/mL, SD 2.3) was comparable to healthy singleton pregnancies (mean 7.9 ng/mL, SD 2.6), p = 0.24. Conclusions: The novel serum biomarker PSP is significantly upregulated in pregnant women with pre-eclampsia and HELLP syndrome. Our observations call for the further evaluation of PSP in randomized controlled clinical trials to demonstrate the actual role of PSP in pregnancy-related diseases and whether it may provide new approaches for the management and discrimination of the severity of these gestational conditions.

The critical role of pancreatic stone protein/regenerating protein in sepsis-related multiorgan failure

Introduction

Multiple organ dysfunction syndrome (MODS) is common in patients with sepsistic admitted to an intensive care unit (ICU) and greatly increases mortality. Pancreatic stone protein/regenerating protein (PSP/Reg) is a type of C-type lectin protein that is overexpressed during sepsis. This study aimed to evaluate the potential involvement of PSP/Reg in MODS development in patients with sepsis.

Materials and methods

The relationship between circulating PSP/Reg levels, patient prognosis, and progression to MODS was analyzed in patients with sepsis admitted to the ICU of a general tertiary hospital. Furthermore, to examine the potential involvement of PSP/Reg in sepsis-induced MODS, a septic mouse model was established per the cecal ligation and puncture procedure, randomized into three groups, and subjected to a caudal vein injection of recombinant PSP/Reg at two different doses and phosphate-buffered saline. Survival analyses and disease severity scoring were performed to evaluate the survival status of the mice; enzyme-linked immunosorbent assays were performed to detect the levels of inflammatory factors and organ-damage markers in murine peripheral blood; terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to measure apoptosis levels in lung, heart, liver, and kidney tissue sections and to visualize the degree of organ damage in the mouse model; myeloperoxidase activity assay, immunofluorescence staining, and flow cytometry were performed to detect neutrophil infiltration levels in vital murine organs and the activation indexes of neutrophils.

Results and discussion

Our findings indicated that Circulating PSP/Reg levels were correlated with patient prognosis and sequential organ failure assessment scores. Furthermore, PSP/Reg administration increased disease severity scores, shortened survival time, increased the TUNEL-positive staining rate, and increased the levels of inflammatory factors, organ-damage markers, and neutrophil infiltration in the organs. Neutrophils can be activated by PSP/Reg to an inflammatory state, both in vivo and in vitro, which is characterized by the increased levels of intercellular adhesion molecule 1 and CD29.

Conclusion

Patient prognosis and progression to MODS can be visualized by monitoring PSP/Reg levels upon ICU admission. Additionally, PSP/Reg administration in animal models exacerbates the inflammatory response and severity of multiorgan damage, which may be accomplished by promoting the inflammatory state of neutrophils.

Serum Pancreatic Stone Protein Reference Values in Healthy Pregnant Women: A Prospective Cohort Study

BACKGROUND

In non-pregnant populations, pancreatic stone protein (PSP) has been reported to have a higher diagnostic performance for identifying severe inflammatory and infectious disease than other established biomarkers.

OBJECTIVE

To generate reference values for serum PSP in pregnancy and compare them to the values of the general healthy population.

DESIGN

A prospective cohort study.

SETTING

A single center.

POPULATION

Healthy women with singleton and multiple pregnancies.

METHODS

This is a prospective single-center cohort study. Between 2013 and 2021, samples of 5 mL peripheral blood were drawn from 440 healthy pregnant women. Therein, 393 cases were singletons and 47 were multiple pregnancies. Serum PSP levels were measured by specific enzyme-linked immunosorbent assay. The main outcome measures were serum PSP level (ng/mL) reference values in healthy pregnant women.

RESULTS

The mean PSP reference values in women with singleton pregnancies were 7.9 ± 2.6 ng/mL (95% CI; 2.69-13.03 ng/mL). The PSP values in women with multiple pregnancies (9.17 ± 3.06 ng/mL (95% CI; 3.05-15.28 ng/mL)) were significantly higher (p = 0.001). The PSP values in the first trimester (6.94 ± 2.53 ng/mL) were lower compared to the second (7.42 ± 2.21 ng/mL) and third trimesters (8.33 ± 2.68 ng/mL, p = 0.0001). Subgroup analyses in singletons revealed no correlations between PSP values, maternal characteristics, and pre-existing medical conditions.

CONCLUSION

The PSP values in healthy pregnant women (4-12 ng/mL) were in the range of the reference values of the general healthy population (8-16 ng/mL). This insight blazes a trail for further clinical studies on the use of PSP as a potential novel biomarker for the early detection of pregnancy-related diseases such as chorioamnionitis.

Pediatric sepsis diagnostic and prognostic biomarkers: pancreatic stone protein, copeptin, and apolipoprotein A-V

BACKGROUND

We assessed serum concentrations of pancreatic stone protein (PSP), copeptin, and apolipoprotein A-V (APOA5) biomarkers for the diagnosis and prognosis of pediatric sepsis, a condition associated with high mortality.

METHODS

This prospective study included 180 children admitted to the Pediatric Intensive Care Unit and 100 healthy controls at Menoufia University Hospital. Pediatric Risk of Mortality (PRISM), Pediatric Index of Mortality-2 (PIM2), and Pediatric Sequential Organ Failure Assessment (pSOFA) scores were calculated. Serum PSP, copeptin and APOA5 were measured once within 24 h of admission.

RESULTS

PSP, copeptin, and APOA5 were significantly higher in the patients than in the controls (p < 0.001). PSP and copeptin were increased among children who required mechanical ventilation (MV), had multiple organ dysfunctions, and were non-survivors, but APOA5 was decreased in those children. Logistic regression analyses showed that high pSOFA, high PSP and copeptin, low APOA5, and use of MV were associated with mortality. The receiver operating characteristic revealed that the area under the curve (AUC) for APOA5, copeptin, and PSP (0.965, 0.960, and 0.868, respectively) demonstrated high sensitivity (96%, 94%, and 80%) for sepsis diagnosis. The AUC values for PSP, copeptin, and APOA5 were 0.709, 0.705, and 0.571, respectively, with sensitivities of 74%, 58%, and 58% for mortality prediction.

CONCLUSIONS

PSP, copeptin, and APOA5 are promising diagnostic biomarkers for pediatric sepsis but inadequate predictors of mortality.

IMPACT

Apolipoprotein A-V (APOA5), copeptin, and pancreatic stone protein (PSP) are acute-phase proteins with diagnostic value in evaluating critically ill pediatric patients with sepsis and detecting sepsis severity. PSP and copeptin had the power to discriminate non-survivors from survivors. APOA5 was less powerful than the other biomarkers in discriminating between survivors and non-survivors.

Monitoring of the Forgotten Immune System during Critical Illness-A Narrative Review

Immune organ failure is frequent in critical illness independent of its cause and has been acknowledged for a long time. Most patients admitted to the ICU, whether featuring infection, trauma, or other tissue injury, have high levels of alarmins expression in tissues or systemically which then activate innate and adaptive responses. Although necessary, this response is frequently maladaptive and leads to organ dysfunction. In addition, the counter-response aiming to restore homeostasis and repair injury can also be detrimental and contribute to persistent chronic illness. Despite intensive research on this topic in the last 40 years, the immune system is not routinely monitored in critical care units. In this narrative review we will first discuss the inflammatory response after acute illness and the players of maladaptive response, focusing on neutrophils, monocytes, and T cells. We will then go through commonly used biomarkers, like C-reactive protein, procalcitonin and pancreatic stone protein (PSP) and what they monitor. Next, we will discuss the strengths and limitations of flow cytometry and related techniques as an essential tool for more in-depth immune monitoring and end with a presentation of the most promising cell associated markers, namely HLA-DR expression on monocytes, neutrophil expression of CD64 and PD-1 expression on T cells. In sum, immune monitoring critically ill patients is a forgotten and missing piece in the monitoring capacity of intensive care units. New technology, including bed-side equipment and in deep cell phenotyping using emerging multiplexing techniques will likely allow the definition of endotypes and a more personalized care in the future.

Identification of regenerating island-derived protein 3E in dogs

Regenerating islet-derived protein (REG) 1A (aka pancreatic stone protein) and REG3A (aka pancreatitis-associated protein) are upregulated in humans with sepsis, pancreatitis, and gastrointestinal diseases, but little is known about this protein family in dogs. Our aim was to identify REG1 and REG3 family members in dogs. REG-family genes were computationally annotated in the canine genome and proteome, with verification of gene expression using publicly available RNA-seq data. The presence of the protein in canine pancreatic tissue and plasma was investigated with Western blot and immunohistochemistry, using anti-human REG1A and REG3A antibodies. Protein identity was confirmed with mass spectrometry. Two members of the REG3 subfamily were found in the canine genome, REG3E1 and REG3E2, both encoding for the same 176 AA protein, subsequently named REG3E. Anti-human REG3A antibodies demonstrated cross-reactivity with the canine REG3E protein in pancreas homogenates. In canine plasma, a protein band of approximately 17 kDa was apparent. Mass spectrometry confirmed this protein to be the product of the two annotated REG3E genes. Strong immunoreactivity to anti-human REG3A antibodies was found in sections of canine pancreas affected with acute pancreatitis, but it was weak in healthy pancreatic tissue. Recombinant canine REG3E protein underwent a selective trypsin digestion as described in other species. No evidence for the presence of a homolog of REG1A in dogs was found in any of the investigations. In conclusion, dogs express REG3E in the pancreas, whose role as biomarker merits further investigations. Homologs to human REG1A are not likely to exist in dogs.

Development and application of a novel aldehyde nanoparticle-based amplified luminescent proximity homogeneous assay for rapid quantitation of pancreatic stone protein

BACKGROUND

Timely diagnosis of bacterial infections is important to prevent sepsis. Classical infection biomarkers have some flaws, and common detection methods are time-consuming. Thus, we aimed to establish an efficient detection method that precisely detects pancreatic stone protein (PSP) in human plasma for the timely diagnosis of bacterial infections.

METHODS

Based on the novel amplified luminescent proximity homogeneous assay (AlphaLISA) method, donor and acceptor beads modified with aldehyde groups were directly coupled to the anti-PSP antibodies. PSP was quickly detected by a double-antibody sandwich method. Plasma samples from healthy individuals, bacterially infected patients, and acute-phase response patients were tested.

RESULTS

The detection time of the developed method is only 5 min. The results of PSP-AlphaLISA and time-resolved fluorescence were consistent (ρ = 0.9722). The plasma PSP levels of patients with bacterial infection were significantly higher than those of acute-phase response patients and healthy individuals (P < 0.05). PSP levels in patients with bacterial infection with sepsis were significantly higher than those in patients with bacterial infection without sepsis (P < 0.05).

CONCLUSIONS

The PSP-AlphaLISA exhibited excellent performance and may be applied to the differential diagnosis between bacterial infection and sepsis in patients without interference from patients with acute-phase response.

Pancreatic Stone Protein as a Biomarker for Sepsis at the Emergency Department of a Large Tertiary Hospital

Early recognition of sepsis is essential for improving outcomes and preventing complications such as organ failure, depression, and neurocognitive impairment. The emergency department (ED) plays a key role in the early identification of sepsis, but clinicians lack diagnostic tools. Potentially, biomarkers could be helpful in assisting clinicians in the ED, but no marker has yet been successfully implemented in daily practice with good clinical performance. Pancreatic stone protein (PSP) is a promising biomarker in the context of sepsis, but little is known about the diagnostic performance of PSP in the ED. We prospectively investigated the diagnostic value of PSP in such a population for patients suspected of infection. PSP was compared with currently used biomarkers, including white blood cell count (WBC) and C-reactive protein (CRP). Of the 156 patients included in this study, 74 (47.4%) were diagnosed with uncomplicated infection and 26 (16.7%) patients with sepsis, while 56 (35.9%) eventually had no infection. PSP was significantly higher for sepsis patients compared to patients with no sepsis. In multivariate regression, PSP was a significant predictor for sepsis, with an area under the curve (AUC) of 0.69. Positive and negative predictive values for this model were 100% and 84.4%, respectively. Altogether, these findings show that PSP, measured at the ED of a tertiary hospital, is associated with sepsis but lacks the diagnostic performance to be used as single marker.

Pancreatic Stone Protein: Review of a New Biomarker in Sepsis

Sepsis is a life-threatening syndrome characterized by a dysregulated host response to an infection that may evolve rapidly into septic shock and multiple organ failure. Management of sepsis relies on the early recognition and diagnosis of infection and the providing of adequate and prompt antibiotic therapy and organ support. A novel protein biomarker, the pancreatic stone protein (PSP), has recently been studied as a biomarker of sepsis and the available evidence suggests that it has a higher diagnostic performance for the identification of infection than the most used available biomarkers and adds prognostic value. This review summarizes the clinical evidence available for PSP in the diagnosis and prognosis of sepsis.

[Which biomarkers for diagnosis and guidance of anti-infection treatment in sepsis?]

To date no biomarker has been identified bringing together perfect sensitivity and specificity to discriminate between inflammation and infections. Since the 1930s new markers of tissue damage and endothelial damage have been identified but which are incapable of identifying infections in every clinical setting to enable initiation of early antibiotic treatment. In this review the most important classical biomarkers and upcoming new PCR-based approaches are addressed. These markers are highlighted with respect to special clinical settings and to control the success of antibiotic treatment. The issue of discrimination between inflammation and infection is not yet solved. Based on one single biomarker it is impossible to decide whether infection is the reason for the patient's worsening condition but the combination of biomarkers or the integration of new biomarkers may be a meaningful supplement. The measurement of different biomarkers of infection or inflammation is part of the routine in critical care and will be essential in the future.

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.

Accuracy of pancreatic stone protein for the diagnosis of infection in hospitalized adults: a systematic review and individual patient level meta-analysis

Background

Accurate biomarkers to diagnose infection are lacking. Studies reported good performance of pancreatic stone protein (PSP) to detect infection. The objective of the study was to determine the performance of PSP in diagnosing infection across hospitalized patients and calculate a threshold value for that purpose.

Methods

A systematic search across Cochrane Central Register of Controlled Trials and MEDLINE databases (1966–March 2019) for studies on PSP published in English using ‘pancreatic stone protein’, ‘PSP’, ‘regenerative protein’, ‘lithostatin’ combined with ‘infection’ and ‘sepsis’ found 44 records. The search was restricted to the five trials that evaluated PSP for the initial detection of infection in hospitalized adults. Individual patient data were obtained from the investigators of all eligible trials. Data quality and validity was assessed according to PRISMA guidelines. We choose a fixed-effect model to calculate the PSP cut-off value that best discriminates infected from non-infected patients.

Results

Infection was confirmed in 371 of 631 patients. The median (IQR) PSP value of infected versus uninfected patients was 81.5 (30.0–237.5) versus 19.2 (12.6–33.57) ng/ml, compared to 150 (82.70–229.55) versus 58.25 (15.85–120) mg/l for C-reactive protein (CRP) and 0.9 (0.29–4.4) versus 0.15 (0.08–0.5) ng/ml for procalcitonin (PCT). Using a PSP cut-off of 44.18 ng/ml, the ROC AUC to detect infection was 0.81 (0.78–0.85) with a sensitivity of 0.66 (0.61–0.71), specificity of 0.83 (0.78–0.88), PPV of 0.85 (0.81–0.89) and NPV of 0.63 (0.58–0.68). When a model combining PSP and CRP was used, the ROC AUC improved to 0.90 (0.87–0.92) with higher sensitivity 0.81 (0.77–0.85) and specificity 0.84 (0.79–0.90) for discriminating infection from non-infection. Adding PCT did not improve the performance further.

Conclusions

PSP is a promising biomarker to diagnose infections in hospitalized patients. Using a cut-off value of 44.18 ng/ml, PSP performs better than CRP or PCT across the considered studies. The combination of PSP with CRP further enhances its accuracy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03609-2.

Serial measurement of pancreatic stone protein for the early detection of sepsis in intensive care unit patients: a prospective multicentric study

Background

The early recognition and management of sepsis improves outcomes. Biomarkers may help in identifying earlier sub-clinical signs of sepsis. We explored the potential of serial measurements of C-reactive protein (CRP), procalcitonin (PCT) and pancreatic stone protein (PSP) for the early recognition of sepsis in patients hospitalized in the intensive care unit (ICU).

Methods

This was a multicentric international prospective observational clinical study conducted in 14 ICUs in France, Switzerland, Italy, and the United Kingdom. Adult ICU patients at risk of nosocomial sepsis were included. A biomarker-blinded adjudication committee identified sepsis events and the days on which they began. The association of clinical sepsis diagnoses with the trajectories of PSP, CRP, and PCT in the 3 days preceding these diagnoses of sepsis were tested for markers of early sepsis detection. The performance of the biomarkers in sepsis diagnosis was assessed by receiver operating characteristic (ROC) analysis.

Results

Of the 243 patients included, 53 developed nosocomial sepsis after a median of 6 days (interquartile range, 3–8 days). Clinical sepsis diagnosis was associated with an increase in biomarkers value over the 3 days preceding this diagnosis [PSP (p = 0.003), PCT (p = 0.025) and CRP (p = 0.009)]. PSP started to increase 5 days before the clinical diagnosis of sepsis, PCT 3 and CRP 2 days, respectively. The area under the ROC curve at the time of clinical sepsis was similar for all markers (PSP, 0.75; CRP, 0.77; PCT, 0.75).

Conclusions

While the diagnostic accuracy of PSP, CRP and PCT for sepsis were similar in this cohort, serial PSP measurement demonstrated an increase of this marker the days preceding the onset of signs necessary to clinical diagnose sepsis. This observation justifies further evaluation of the potential clinical benefit of serial PSP measurement in the management of critically ill patients developing nosocomial sepsis.

Trial registration The study has been registered at ClinicalTrials.gov (no. NCT03474809), on March 16, 2018. https://www.clinicaltrials.gov/ct2/show/NCT03474809?term=NCT03474809&draw=2&rank=1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03576-8.

THE ROLE OF MARKERS OF SYSTEMIC INFLAMMATORY RESPONSE IN THE POSTOPERATIVE PERIOD. REVIEW

Despite all the achievements of modern surgery, the number of postoperative infectious complications in the world remains high. Their occurrence leads to a longer period of patients’ hospitalization, requires the use of additional medical and diagnostic measures, which ultimately leads to higher treatment costs and significant financial losses in the health care system. Therefore, it is important to identify postoperative complications at an early stage, even before the development of pronounced clinical symptoms, and to predict their possible development in a certain category of patients. For these purposes, scientists try to use various laboratory markers. In this paper, we analyzed both well-known indicators of the inflammatory response, such as: C-reactive protein, albumin, their ratio, procalcitonin and interleukin-6, and relatively new parameters that research teams are trying to apply for these purposes: neutrophil granularity intensity and neutrophil reactivity intensity, pancreatic stone protein and pancreatitis-associated protein. We tried to collect the most complete information available at the moment, evaluate the opinions of researchers, identify contradictions in their works and try to explain their cause. As a result, it turned out that even the markers of inflammation known for many years are not absolutely specific for postoperative infectious complications. We concluded that most of the laboratory parameters described in this article can be used to some extent in the early diagnosis of postoperative infectious complications, but if we want to obtain more complete information in this area of knowledge, it is necessary to conduct new largescale studies.

Faecal regenerating 1B protein concentration is not associated with child growth in rural Malawi

AIM

This study was designed to determine whether faecal regenerating 1B protein (REG1B) concentration is associated with physical growth among 6-30-month-old children in rural Malawi.

METHODS

This was a secondary analysis from a randomised controlled trial in rural Malawi in which we followed-up 790 live-born infants from birth to 30 months of age. We collected anthropometric data at the age of 6, 12, 18, 24 and 30 months. We measured faecal REG1B concentration by enzyme-linked immunosorbent assay (ELISA) technique using stool samples collected at 6, 18 and 30 months of age. We assessed the association between faecal REG1B concentration and children's physical growth using linear regression and longitudinal data analysis.

RESULTS

Of 790 live-born infants enrolled, 694 (87%) with at least one faecal REG1B concentration measurement were included in the analysis. Faecal REG1B concentration was not associated with the children's concurrent length-for-age z-score (LAZ), weight-for-age z-score (WAZ), weight-for-length z-score (WLZ) and mid-upper arm circumference-for-age z-score (MUACZ) at any time point (P > 0.05), nor with a change in their anthropometric indices in the subsequent 6-month period (P > 0.05).

CONCLUSIONS

Faecal REG1B concentration is not associated with LAZ, WAZ, WLZ and MUACZ among 6-30-month-old infants and children in rural Malawi.

Expression of Pancreatic Stone Protein is Unaffected by Trauma and Subsequent Surgery in Burn Patients

BACKGROUND

Altered levels of pro-inflammatory markers secondary to trauma or surgery present a major problem to physicians in being prone to interfere with the clinical identification of infectious events.

METHODS

Patients admitted to Zurich Burn Center between May 2015 and October 2018 with burns ≥10% total body surface area (TBSA) and without infection. Longitudinal analysis of the time course of PSP and routine inflammatory biomarkers [procalcitonin (PCT), C-reactive protein (CRP) and white blood cells (WBC)] over two days after (a) trauma with initial debridement and (b) subsequent burn surgeries was performed. The influence of TBSA, abbreviated burn severity index (ABSI), age and length of operation was investigated using a linear mixed effect regression model.

RESULTS

Sixty-six patients (15 female) were included with a mean age of 45.5 ± 18.3 years, median TBSA of 22% (IQR 17) and mean ABSI score 6.8 ± 2.7. PSP was the only biomarker that showed no association with any of the baseline characteristics. Additionally, PSP serum levels did not change over time neither after the burn trauma (p = 0.832) nor after secondary procedures (p = 0.113), while PCT levels increased significantly after the trauma (p < 0.001). Similarly, CRP serum levels were elevated significantly after both trauma and surgery (p < 0.001), whereas WBC values demonstrated a significant decline after the trauma (p < 0.001).

CONCLUSION

Established biomarkers (WBC, CRP and PCT) demonstrate decisive alterations after tissue destruction caused by burn injuries and subsequent surgical interventions. The robustness of PSP serum levels toward these inflammatory insults is a quality criterion for an upcoming sepsis biomarker.

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.

Serum REG Iα as a potential novel biomarker in cancer: An observational study

The regulation of the gene-regenerating family member 1 alpha (REG Iα) played important roles in cancer cell biology. However, the correlation between its gene product serum REG Iα and cancer has not been evaluated. In this observational study, 130 hospitalized patients from the department of internal medicine in Zhongda Hospital Southeast University were included and assigned to cancer or noncancer groups. History, clinical, and laboratory data were obtained. Serum REG Iα levels and alanine aminotransferase were found significantly higher in patients with cancer (P < .001 and P < .05 respectively). Logistic regression analysis indicated that REG Iα was an independent risk factor for cancer (P < .001). The area under the curve of REG Iα was 0.764 and the optimal cut-off point of REG Iα was 46.97 ng/mL. Besides, the cancer patients with metastasis had significantly higher serum REG Iα levels than those in nonmetastasis cancer group (P < .05). In conclusion, serum REG Iα was significantly elevated in patients with cancer, and it might be a potential biomarker in predicting cancer occurrence and development.

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.

Response of routine inflammatory biomarkers and novel Pancreatic Stone Protein to inhalation injury and its interference with sepsis detection in severely burned patients

BACKGROUND

Inhalation of thermal and chemical products of combustion evokes an immune response measurable at a systemic level. Inhalation injury related kinetics of currently available inflammatory biomarkers and novel Pancreatic Stone Protein (PSP) as well as their interference with septic events has not been addressed to literature yet.

METHODS

Analysis of the influence of inhalation injury and ARDS on biomarker kinetics (PSP, procalcitonin (PCT), C-reactive Protein (CRP), white blood cells (WBC)) in 90 patients admitted to Zurich Burn Center between May 2015 and October 2018 with burns ≥15% total body surface area (TBSA) over 14 days.

RESULTS

Twenty-five (27%) of 90 included patients presented with inhalation injury (median age 52 years [IQR 27], median TBSA 31.5% [IQR 21], mean ABSI-Score 7±3). At admission, only WBC demonstrated significantly higher values in the inhalation injury group (p=0.011). Acute respiratory distress syndrome (ARDS) was present in 32% without association to the severity of inhalation injury (p=0.11). WBC, CRP and PCT failed to delineate inhalation injury related inflammation from septic progression at most time points. PSP was the strongest marker to identify septic patients both by its higher values and steeper increase over time (p<0.001).

CONCLUSION

Inhalation injury leads to an inflammatory response at a systemic level with alterations of biomarkers. While routine inflammatory markers demonstrated strong interferences between inhalation injury with its associated ARDS and evolving sepsis, PSP reliably identified septic patients in a setting of inflammatory turbulences secondary to inhalation injury.

A 2020 review on the role of procalcitonin in different clinical settings: an update conducted with the tools of the Evidence Based Laboratory Medicine

Biomarkers to guide antibiotic treatment decisions have been proposed as an effective way to enhancing a more appropriate use of antibiotics. As a biomarker, procalcitonin (PCT) has been found to have good specificity to distinguish bacterial from non-bacterial inflammations. Decisions regarding antibiotic use in an individual patient are complex and should be based on the pre-test probability for bacterial infection, the severity of presentation and the results of PCT serum concentration. In the context of a high pre-test probability for bacterial infections and/or a high-risk patient with sepsis, monitoring of PCT over time helps to track the resolution of infection and decisions regarding early stop of antibiotic treatment. As outlined by the Evidence Based Laboratory Medicine (EBLM), not only the pre-test probability but also the positive likelihood ratio influence the performance of a test do be really diagnostic. This aspect should be taken into account in the interpretation of the results of clinical trials evaluating the performance of PCT in guiding antibiotic therapy.

Pancreatic stone protein - sepsis and the riddles of the exocrine pancreas

Pancreatic stone protein (PSP), discovered in the 1970ies, was first associated with stone formation during chronic pancreatitis. Later, the same protein was independently detected in islet preparations and named regenerating protein 1 (REG1). Additional isoforms of PSP, including pancreatitis-associated protein (PAP), belong to the same protein family. Although the names indicate a potential function in stone formation or islet regeneration, involvements in cellular processes were only suggestive and never unequivocally proven. We established an association between PSP levels in patient blood samples and the development of sepsis. In this review, written in connection with receiving the Lifetime Achievement Award of the European Pancreatic Club, the evolution of the sepsis aspect of PSP is described. We conclude that the true functional properties of this fascinating pancreatic protein still remain an enigma.

Pancreatic Stone Protein Predicts Sepsis in Severely Burned Patients Irrespective of Trauma Severity: A Monocentric Observational Study

OBJECTIVE

The burn victim's inherent state of hyperinflammation frequently camouflages septic events delaying the initiation of targeted intensive care therapy. Accurate biomarkers are urgently needed to support sepsis detection before patients' clinical deterioration.

SUMMARY OF BACKGROUND DATA

Evidence on the usefulness of pancreatic stone protein (PSP) as a powerful diagnostic and prognostic marker in critically ill patients has recently accumulated.

METHODS

Analysis of biomarker kinetics (PSP, routine markers) was performed on 90 patients admitted to the Zurich Burn Center between May 2015 and October 2018 with burns ≥15% total body surface area with regard to infection and sepsis (Sepsis-3) over a 14-day time course.

RESULTS

PSP differentiated between sepsis, infection and sterile inflammation from day 3 onward with an area under the curve of up to 0.89 (P < 0.001), therefore, competing with procalcitonin (area under the curve = 0.86, P < 0.001). Compared to routine inflammatory biomarkers, only PSP demonstrated a significant interaction between time and presence of sepsis - signifying a steeper increase in PSP levels in septic patients as opposed to those exhibiting a nonseptic course (interaction P < 0.001). Event-related analysis demonstrated tripled PSP serum levels within 72 hours and doubled levels within 48 hours before a clinically apparent sepsis.

CONCLUSION

PSP is able to differentiate between septic and nonseptic patients during acute burn care. Its steep rise up to 72 hours before clinically overt deterioration has the potential for physicians to timely initiate treatment with reduced mortality and costs.

The prognostic value of serum procalcitonin measurements in critically injured patients: a systematic review

Background

Major trauma is associated with high incidence of septic complications and multiple organ dysfunction (MOD), which markedly influence the outcome of injured patients. Early identification of patients at risk of developing posttraumatic complications is crucial to provide early treatment and improve outcomes. We sought to evaluate the prognostic value of serum procalcitonin (PCT) levels after trauma as related to severity of injury, sepsis, organ dysfunction, and mortality.

Methods

We searched PubMed, MEDLINE, EMBASE, the Cochrane Database, and references of included articles. Two investigators independently identified eligible studies and extracted data. We included original studies that assessed the prognostic value of serum PCT levels in predicting severity of injury, sepsis, organ dysfunction, and mortality among critically injured adult patients.

Results

Among 2015 citations, 19 studies (17 prospective; 2 retrospective) met inclusion criteria. Methodological quality of included studies was moderate. All studies showed a strong correlation between initial PCT levels and Injury Severity Score (ISS). Twelve out of 16 studies demonstrated significant elevation of initial PCT levels in patients who later developed sepsis after trauma. PCT level appeared a strong predictor of MOD in seven out of nine studies. While two studies did not show association between PCT levels and mortality, four studies demonstrated significant elevation of PCT levels in non-survivors versus survivors. One study reported that the PCT level of ≥ 5 ng/mL was associated with significantly increased mortality (OR 3.65; 95% CI 1.03–12.9; p = 0.04).

Conclusion

PCT appears promising as a surrogate biomarker for trauma. Initial peak PCT level may be used as an early predictor of sepsis, MOD, and mortality in trauma population.

Prognostic performance of pancreatic stone protein in critically ill patients with sepsis

Aim: To assess the prognostic value for 28-day mortality of PSP in critically ill patients with sepsis. Material & methods: 122 consecutive patients with sepsis were enrolled in this study. Blood samples were collected on admission and day 2. Results: On admission, the combination of PSP and lactate achieved an area under the receiver operating characteristic (AUC-ROC) of 0.796, similar to sequential organ failure assessment score alone (AUC-ROC: 0.826). On day 2, PSP was the biomarker with the highest performance (AUC-ROC: 0.844), although lower (p = 0.041) than sequential organ failure assessment score (AUC-ROC: 0.923). Conclusion: The combination of PSP and lactate and PSP alone, on day 2, have a good performance for prognosis of 28-day mortality and could help to identify patients who may benefit most from tailored intensive care unit management.

Association of Serum PSP/REG Iα with Renal Function in Pregnant Women

Pancreatic stone protein/regenerating protein Iα (PSP/REG Iα) is a secretory protein produced in the pancreas, but its expression has also been observed in the kidney. It may be associated with kidney dysfunction. This study investigates the possible association between PSP/REG Iα and kidney function in pregnant women. Serum PSP/REG Iα levels were measured by a specific ELISA enzyme-linked immunosorbent assay. Maternal information and clinical and biochemical parameters were collected. Estimated glomerular filtration rate (eGFR) was calculated for all individuals to evaluate their renal function. Spearman's correlation and multiple linear regression analyses were performed to assess the associations between PSP/REG Iα and eGFR, serum creatinine (Cr), blood urea nitrogen (BUN), and uric acid (UA). A total of 595 pregnant women were enrolled in the study. Participants with mildly reduced eGFR had higher PSP/REG Iα levels [50.49 (35.02, 58.64)] than in the general population [26.84 (21.02, 33.07)] (p < 0.001). Included participants were stratified into PSP/REG Iα quartiles; significant differences were observed in the levels of eGFR, serum Cr, BUN, and UA. PSP/REG Iα was negatively correlated with eGFR (r = −0.402, p < 0.001) and positively associated with serum Cr (r = 0.468, p < 0.001), BUN (r = 0.166, p < 0.001), and UA (r = 0.207, p < 0.001). The linear regression analysis indicated that PSP/REG Iα was associated with UA, BUN, and eGFR. High PSP/REG Iα concentrations were closely associated with renal dysfunction in pregnant women. Our study provides clinical evidence that serum PSP/REG Iα levels could be a novel biomarker for assessment of renal function in pregnant women.

Measurement of pancreatic stone protein in the identification and management of sepsis

Sepsis is a life-threatening syndrome characterized by a dysregulated host response to an infection resulting in multiple organ dysfunctions. Early diagnosis and management of sepsis is key to improve patient outcome but remains challenging. Despite extensive research, only few biomarkers have so far proven to be helpful in the diagnosis of sepsis. A novel protein biomarker, the pancreatic stone protein (PSP), is showing great promises. Several lines of evidences suggest that PSP has a higher diagnostic performance for the identification of sepsis than procalcitonin and C-reactive protein, and a strong prognostic value to predict unfavorable outcome at admission to intensive care unit. This review summarizes the current knowledge on the molecular mechanisms of PSP function and the clinical evidences available to highlight the relevance of this protein in the diagnosis and prognosis of sepsis.

Analyzing the capability of PSP, PCT and sCD25 to support the diagnosis of infection in cancer patients with febrile neutropenia

Background

Early diagnosis of infection is essential for the initial management of cancer patients with chemotherapy-associated febrile neutropenia (FN). In this study, we have evaluated two emerging infection biomarkers, pancreatic stone protein (PSP) and soluble receptor of interleukin 2, known as soluble cluster of differentiation 25 (sCD25), for the detection of an infectious cause in FN, in comparison with other commonly used infection biomarkers, such as procalcitonin (PCT).

Methods

A total of 105 cancer patients presenting to the emergency department were prospectively enrolled. We observed 114 episodes of chemotherapy-associated FN. At presentation, a blood sample was collected for the measurement of PCT, PSP and sCD25. In order to evaluate the discriminatory ability of these markers for the diagnosis of infection, the area under the curve (AUC) of the receiver operating characteristic curves was calculated.

Results

Infection was documented in 59 FN episodes. PCT, PSP and sCD25 levels were significantly higher in infected patients. PCT was the biomarker with the highest diagnostic accuracy for infection (AUC: 0.901), whereas PSP and sCD25 showed a similar performance, with AUCs of 0.751 and 0.730, respectively. In a multivariable analysis, PCT and sCD25 were shown to be independently associated with infection.

Conclusions

Two novel biomarkers, PSP and sCD25, correlated with infection in cancer patients with chemotherapy-associated FN, but neither PSP nor sCD25 improved the performance of PCT. Based on the results obtained, the introduction of these novel biomarkers as a tool for the diagnosis of infection in this patient group is not recommended.

Elevated serum level of pancreatic stone protein/regenerating protein (PSP/reg) is observed in diabetic kidney disease

Diabetic kidney disease (DKD) is a major complication of diabetes, and serves as an important cause of end-stage renal disease (ESRD). The role of chronic inflammation in DKD is becoming widely accepted. Pancreatic stone protein/regenerating protein (PSP/reg) is a secretory protein, which is elevated in blood during infected conditions and organ failure. The aim of this study was to investigate the relationship between serum PSP/reg and DKD in patients with type 2 diabetes (T2DM). A total of 120 subjects which includes newly diagnosed T2DM patients, diabetes patients without DKD, DKD patients, as well as healthy controls were enrolled in this study. Serum PSP/reg levels were significantly higher in DKD subjects compared with those of healthy controls (p < 0.001), newly diagnosed T2DM (p < 0.001) and diabetes patients without DKD (p < 0.001). PSP/reg levels correlated positively with glycated hemoglobin (HbA1c) (p < 0.001) and serum creatinine (p < 0.001). Meanwhile, serum PSP level was negatively correlated with estimated glomerular filtration rate (eGFR) (p < 0.001). The area under the curve (AUC) for presence of DKD was 0.854. In conclusion: PSP/reg levels are significantly up-regulated in DKD patients and might be related to renal injury. A follow-up study with a large cohort is needed.

Status and Challenges of Predicting and Diagnosing Sepsis in Burn Patients

Burns are a common form of trauma that account for more than 300,000 deaths each year worldwide. Survival rates have improved over the past decades because of improvements in nutritional and fluid support, burn wound care, and infection control practices. Death, however, remains unacceptably high. The primary cause of death has changed over the last decades from anoxic causes to now predominantly infections and sepsis. Sepsis and septic complications are not only major contributors to poor outcomes, but they further result in longer hospital stay and higher healthcare costs. Despite the importance of infections and sepsis, the diagnosis and prediction remain a major challenge. To date, no clear diagnostic criteria or predictive formula exist that can predict reliably the occurrence of sepsis and infections. This review will highlight and discuss current definitions and criteria for diagnosis as well as predictive biomarkers of sepsis in patients with burns. It will also present the diagnostic tools employed, such as procalcitonin, C-reactive protein, and cytokines. We will discuss the benefits and shortcomings of different treatment modalities in the context of sepsis prevention. Last, we identify new therapeutic strategies for sepsis prediction and present future considerations to prevent sepsis in patients with burns. Minimizing and preventing septic complications through early detection would significantly benefit patients and necessitate continued research to unravel new biomarkers and mechanisms. Subsequent studies need to take a fresh perspective and consider the implementation of patient-centered therapeutic strategies.

Procalcitonin and Pancreatic Stone Protein Function as Biomarkers in Early Diagnosis of Pediatric Acute Osteomyelitis

Background

High plasma levels of procalcitonin (PCT) are typically seen in children with severe bacterial infection, particularly in cases of septic shock or bacteremia. Similarly, pancreatic stone protein (PSP) is associated with inflammation, infection, and other disease-related stimuli. However, the prognostic value of PSP in critically ill pediatric patients is unknown. This study investigated the early diagnostic value of PCT and PSP in pediatric acute osteomyelitis.

Material/Methods

A total of 187 patients with suspected acute osteomyelitis and 80 healthy control children were enrolled. The serum expression of PTC and PSP was measured. Pearson correlation analysis was conducted to correlate PTC with PSP. ROC analysis was used to test the value of PTC and PSP in early diagnosis of pediatric acute osteomyelitis.

Results

Acute osteomyelitis was diagnosed in 49.2% of the patients (n=92) based on the layered bone puncture. The serum levels of PTC and PSP in pediatric acute osteomyelitis were higher than in the non-acute osteomyelitis group (P<0.01). Serum PTC concentrations showed a significantly positive correlation with PSP levels (P<0.001). ROC analysis showed that the AUC values of PTC and PSP were 0.767 (95% CI, 0.700–0.826), and 0.796 (95% CI, 0.731–0.855), respectively. The AUC value of PTC & PSP was 0.903 (95% CI: 0.851–0.941), which was markedly increased compared with PTC or PSP (P<0.01).

Conclusions

Serum levels of PCT and PSP are promising biomarkers for early diagnosis of pediatric acute osteomyelitis.

Interleukin-17 as a predictor of sepsis in polytrauma patients: a prospective cohort study

Sepsis is one of the most serious complications after major trauma, and may be associated with increased mortality. We sought to determine whether there is an association between serum levels of interleukin-17 (IL-17) at the time of admission to the intensive care unit (ICU) and the development of sepsis. We evaluated 100 adult patients with major trauma admitted to the surgical ICU over a 6-month period. Serum levels of IL-17, IL-6, and TNF-α were determined by enzyme-linked immunosorbent assays (ELISA). The IL-17 rs1974226 genotype was determined by real-time PCR. In both non-adjusted and adjusted analyses, IL-17 was the only biomarker significantly associated with sepsis [median serum IL-17 of 72 pg/mL in sepsis versus 37 pg/mL in those without sepsis, P = 0.0001; adjusted odds ratio (OR) 3.2, P = 0.02]. No significant association was found among IL-17 rs1974226 genotypes and related serum cytokine levels. These data suggest that elevated serum IL-17 may increase the susceptibility for septic complications in polytrauma patients and so could be a useful biomarker for trauma patient management.

The pancreas responds to remote damage and systemic stress by secretion of the pancreatic secretory proteins PSP/regI and PAP/regIII

INTRODUCTION

In patients with infection and sepsis serum levels of Pancreatic Stone protein/regenerating protein I (PSP) are highly elevated. The origin of PSP during these conditions is presumably the pancreas, however, an intestinal origin cannot be excluded. Similarly, pancreatitis-associated protein (PAP) was identified in the pancreas. These proteins were also localized in intestinal organs. Here we aim to elucidate the bio-distribution of PSP and PAP in animal models of sepsis and in healthy humans.

RESULTS

PSP and PAP responded to remote lesions in rats although the pancreatic response was much more pronounced than the intestinal. Tissue distribution of PSP demonstrated a 100-fold higher content in the pancreas compared to any other organ while PAP was most abundant in the small intestine. Both proteins responded to CLP or sham operation in the pancreas. PSP also increased in the intestine during CLP. The distribution of PSP and PAP in human tissue mirrored the distribution in the murine models.

MATERIALS AND METHODS

Distribution of PSP and PAP was visualized by immunohistochemistry. Rats and mice underwent midline laparotomies followed by mobilization of tissue and incision of the pancreatic duct or duodenum. Standard cecum-ligation-puncture (CLP) procedures or sham laparotomies were performed. Human tissue extracts were analyzed for PSP and PAP.

CONCLUSIONS

The pancreas reacts to remote lesions and septic insults in mice and rats with increased PSP synthesis, while PAP is selectively responsive to septic events. Furthermore, our results suggest that serum PSP in septic patients is predominantly derived through an acute phase response of the pancreas.

Pancreatic stone protein and soluble CD25 for infection and sepsis in an emergency department

BACKGROUND

Infection is a common problem in emergency departments (EDs) and is associated with high mortality, morbidity and costs. Identifying infection in ED patients can be challenging. Biomarkers can facilitate its diagnosis, enabling an early management and improving outcomes. In the critical care setting, two emerging biomarkers, pancreatic stone protein (PSP) and soluble CD25 (sCD25), have demonstrated to be useful for diagnosis of sepsis. We aimed to assess the diagnostic value of these biomarkers, in comparison with procalcitonin (PCT), for infection and sepsis in an ED population with suspected infection.

MATERIALS AND METHODS

Through a prospective, observational study, we investigated the utility of serum PCT, PSP and sCD25 levels, measured on admission, for diagnosis of infection and sepsis, defined according to the recently updated for sepsis (Sepsis-3), in patients presenting to the ED for suspected infection. Diagnostic accuracy was evaluated by using receiver operating characteristic curves (ROC) analysis.

RESULTS

Of the 152 patients enrolled in this study, 129 had a final diagnosis of infection, including 82 with noncomplicated infection and 47 with sepsis. Median PCT, PSP and sCD25 levels were significantly higher in patients with infection and sepsis. The ROC curve analysis revealed a similar diagnostic accuracy for infection (ROC area under the curve (AUC) PCT: 0·904; sCD25: 0·869 and PSP: 0·839) and for sepsis (ROC AUC: PCT: 0·820; sCD25: 0·835 and PSP: 0·872).

CONCLUSIONS

Pancreatic stone protein and sCD25 perform well as infection and sepsis biomarkers, with a similar performance than PCT, in ED patients with suspected infection. Further larger studies investigating use of PSP and sCD25 are needed.

Predictive value of cytokines for developing complications after polytrauma

AIM: To investigate posttraumatic cytokine alterations and their value for predicting complications and mortality in polytraumatized patients.

METHODS: Studies on the use of specific cytokines to predict the development of complications and mortality were identified in MEDLINE, EMBASE, Web of Science and the Cochrane Library. Of included studies, relevant data were extracted and study quality was scored.

RESULTS: Forty-two studies published between 1988 and 2015 were identified, including 28 cohort studies and 14 “nested” case-control studies. Most studies investigated the cytokines interleukin (IL)-6, IL-8, IL-10 and tumor necrosis factor (TNF-α). IL-6 seems related to muliorgan dysfunction syndrome, multiorgan failure (MOF) and mortality; IL-8 appears altered in acute respiratory distress syndrome, MOF and mortality; IL-10 alterations seem to precede sepsis and MOF; and TNF-α seems related to MOF.

CONCLUSION: Cytokine secretion patterns appear to be different for patients developing complications when compared to patients with uneventful posttraumatic course. More research is needed to strengthen the evidence for clinical relevance of these cytokines.

Prognostication of Mortality in Critically Ill Patients With Severe Infections

BACKGROUND

The purpose of this study was to confirm the prognostic value of pancreatic stone protein (PSP) in patients with severe infections requiring ICU management and to develop and validate a model to enhance mortality prediction by combining severity scores with biomarkers.

METHODS

We enrolled prospectively patients with severe sepsis or septic shock in mixed tertiary ICUs in Switzerland (derivation cohort) and Brazil (validation cohort). Severity scores (APACHE [Acute Physiology and Chronic Health Evaluation] II or Simplified Acute Physiology Score [SAPS] II) were combined with biomarkers obtained at the time of diagnosis of sepsis, including C-reactive-protein, procalcitonin (PCT), and PSP. Logistic regression models with the lowest prediction errors were selected to predict in-hospital mortality.

RESULTS

Mortality rates of patients with septic shock enrolled in the derivation cohort (103 out of 158) and the validation cohort (53 out of 91) were 37% and 57%, respectively. APACHE II and PSP were significantly higher in dying patients. In the derivation cohort, the models combining either APACHE II, PCT, and PSP (area under the receiver operating characteristic curve [AUC], 0.721; 95% CI, 0.632-0.812) or SAPS II, PCT, and PSP (AUC, 0.710; 95% CI, 0.617-0.802) performed better than each individual biomarker (AUC PCT, 0.534; 95% CI, 0.433-0.636; AUC PSP, 0.665; 95% CI, 0.572-0.758) or severity score (AUC APACHE II, 0.638; 95% CI, 0.543-0.733; AUC SAPS II, 0.598; 95% CI, 0.499-0.698). These models were externally confirmed in the independent validation cohort.

CONCLUSIONS

We confirmed the prognostic value of PSP in patients with severe sepsis and septic shock requiring ICU management. A model combining severity scores with PCT and PSP improves mortality prediction in these patients.

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.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Pancreatic stone protein/regenerating protein (PSP/reg): a novel secreted protein up-regulated in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) has insulin resistance (IR) or reduced β-cell mass, partially due to an increased β-cell apoptosis rate. Pancreatic stone protein/regenerating protein (PSP/reg) is a secretory protein produced in the pancreas and up-regulated dramatically during pancreatic disease. Recent studies revealed that β-cells undergoing apoptosis induce PSP/reg expression in surviving neighboring cells. Further experiments demonstrated that PSP/reg was elevated during disease progression in type 1 diabetes mellitus (T1DM). However, the association between PSP/reg and T2DM patients is unknown. The aim of this pilot study was to investigate PSP/reg in different clinical stages of T2DM and evaluate its correlation with chronic complications of diabetes. A total of 1,121 participants (479 males, 642 females; age range 23-80 years) were enrolled in this study. PSP/reg serum values were measured by a newly developed enzyme-linked immunosorbent assay (ELISA). We analyzed its correlation with clinical and biochemical parameters in subjects with T2DM at different clinical phases. Statistical analyses were conducted using SPSS 17.0 software. Correlations of PSP/reg and clinical parameters were performed using Spearman's rank correlation coefficient. Differences between groups were determined by Nemenyi test. PSP/reg was elevated in high-risk and impaired glucose regulation (IGR) patients (p<0.05). PSP/reg was significantly up-regulated in newly diagnosed T2DM patients and long-term diabetes patients with complications (p<0.001). PSP/reg levels correlated with the duration of diabetes (p<0.001). The area under the curve (AUC) for presence of diabetes-onset and its chronic complications was 0.640 and 0.754, respectively. PSP/reg is significantly up-regulated in T2DM patients, and PSP/reg levels are related to the duration of diabetes. Therefore, PSP/reg might be useful as a predictor of T2DM and disease progression.

Pancreatic stone protein predicts postoperative infection in cardiac surgery patients irrespective of cardiopulmonary bypass or surgical technique

Introduction

We investigated the role of pancreatic stone protein (PSP) in predicting the occurrence of infection in the postoperative course of cardiac surgery patients. Several biomarkers indicating the presence of inflammation and infection are available in the clinical routine; yet, their utility in the postoperative course of patients following cardiac surgery remains uncertain. Moreover, cardiopulmonary bypass, also referred to as “on-pump surgery”, increases the susceptibility to an exaggerated inflammatory state. However, the impact of such extracorporeal circulation on circulating PSP levels remains poorly understood.

Methods

In a prospective cohort of unselected patients undergoing cardiac surgery, we set out to elucidate the diagnostic accuracy of serum PSP levels as opposed to canonical biomarkers (CRP, WBC) of inflammation to discriminate between the presence of infection and surgical trauma,. In addition, we investigated whether the biomarkers were influenced by the surgical technique employed, i.e. on-pump vs. off-pump and minimally invasive surgery vs. sternotomy. Levels of circulating PSP and routine inflammatory biomarkers (CRP, WBC) were measured in samples taken from 120 patients at baseline as well as at postoperative day 1–3.

Results

Univariate analysis showed that among the biomarkers investigated, only PSP levels had discriminatory power to differentiate infection from surgical trauma in the postoperative course of the entire cohort of patients following cardiac surgery. With regard to cardiac surgical interventions, there was no significant association between the absence or presence of extracorporeal circulation and PSP levels. However, there was a significant difference in the slope of the rise of postoperative PSP between minimally invasive surgery as opposed to patients subjected to sternotomy.

Conclusion

In an unselected population of cardiac surgery patients, post-operative serum PSP levels were significantly associated with the presence of infection in both the on-pump and off-pump setting. Of note, the surgical technique employed (sternotomy vs. minimally invasive approach) had a significant impact on postoperative PSP levels.

Expression of REG Iα gene in type 2 diabetics in Pakistan

BACKGROUND

The escalating rate of diabetes' has prompted researchers around the world to explore for early markers. A deficit of functional β-cell mass plays a central role in the pathophysiology of type 2 diabetes. The REG (Regenerating) gene, encoding a 166 amino acid REG protein was discovered in rats and humans which is released in response to β-cells damage and play a role in their regeneration. The objective of this study was to characterize serum levels of REG Iα proteins in type 2 diabetic patients as indicator of β-cell apoptosis as well as regeneration.

METHODS

Unrelated type 2 diabetic patients (n = 55) of different age groups and disease duration were recruited from the Medical OPD of PNS Shifa Hospital. Age and sex matched non diabetic controls (n = 20) without family history of diabetes were selected from the same setting. Demographical details were recorded on a structured questionnaire. Biochemical parameters like FBG, HbA1c, TC and TG levels were measured. Serum levels of REG Iα protein were determined by ELISA.

RESULTS

Levels of REG Iα protein were found significantly raised in type 2 diabetic patients compared to controls (p < 001). Patients with short duration of the disease had higher levels of REG Iα as compared to patients with longer duration of the disease. Although the patients were on anti hyperglycemic agents, a positive correlation was found between REG Iα serum levels, FBG and HbA1c levels. Patients with higher BMI had higher levels of serum REG Iα levels. Serum TC, TG and Hb levels showed no correlation.

CONCLUSION

REG Iα may be used as a marker/predictor of type 2 diabetes especially in the early stages of the disease.