Pancreatitis associated protein as an early marker of acute pancreatitis

Proteomic research on new urinary biomarkers of renal disease in canine leishmaniosis: Survival and monitoring response to treatment

The objective of our study was to search for survival biomarkers (SB) and treatment response monitoring biomarkers (TRMB) in the urinary proteome of dogs with renal disease secondary to canine leishmaniosis (CanL), using UHPLC-MS/MS. The proteomic data are available via ProteomeXchange with identifier PXD042578. Initially, a group of 12 dogs was evaluated and divided into survivors (SG; n = 6) and nonsurvivors (NSG; n = 6). A total of 972 proteins were obtained from the evaluated samples. Then, bioinformatic analysis reduced them to 6 proteins like potential SB increased in the NSG, specifically, Haemoglobin subunit Alpha 1, Complement Factor I, Complement C5, Fibrinogen beta chain (fragment), Peptidase S1 domain-containing protein, and Fibrinogen gamma chain. Afterwards, SG was used to search for TRMB, studying their urine at 0, 30, and 90 days, and 9 proteins that decreased after treatment were obtained: Apolipoprotein E, Cathepsin B, Cystatin B, Cystatin-C-like, Lysozyme, Monocyte differentiation CD14, Pancreatitis-associated precursor protein, Profilin, and Protein FAM3C. Finally, enrichment analysis provided information about the biological mechanisms in which these proteins are involved. In conclusion, this study provides 15 new candidate urinary biomarkers and an improved understanding of the pathogenesis of kidney disease in CanL.

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.

Risk factors for gastrointestinal upset and evaluation of outcome following surgical resection of canine pancreatic β-cell tumors

The objective of this study was to determine risk factors for vomiting and inappetence and evaluate long-term outcome after surgical treatment of pancreatic β-cell tumors in dogs. Records of 33 dogs that underwent surgery for such tumors were retrospectively evaluated. Inappetence and vomiting occurred in 27.3% and 24.2% of dogs, respectively. Risk factors for postoperative vomiting were longer duration of clinical signs before surgery, higher preoperative total protein concentration, and lack of liver metastasis. No significant risk factors for inappetence or survival were identified. Median survival time was 723 days. Dogs with a longer duration of clinical signs before surgery may have had greater pancreatic involvement or more pronounced systemic perturbations. Higher preoperative total protein concentration may reflect preoperative dehydration or inflammation. Significance of lack of liver metastasis is unknown. The long survival time indicates a good overall prognosis with surgical treatment, justifying surgical intervention in patients with advanced disease.

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

INTRODUCTION

Major abdominal surgery leads to a postoperative systemic inflammatory response, making it difficult to discriminate patients with systemic inflammatory response syndrome from those with a beginning postoperative infectious complication. At present, physicians have to rely on their clinical experience to differentiate between the two. Pancreatic stone protein (PSP) and pancreatitis-associated protein (PAP), both secretory proteins produced by the pancreas, are dramatically increased during pancreatic disease and have been shown to act as acute-phase proteins. Increased levels of PSP have been detected in polytrauma patients developing sepsis and PSP has shown a high diagnostic accuracy in discriminating the severity of peritonitis and in predicting death in intensive care unit patients. However, the prognostic value of PSP/PAP for infectious complications among patients undergoing major abdominal surgery is unknown.

METHODS AND ANALYSIS

160 patients undergoing major abdominal surgery will be recruited preoperatively. On the day before surgery, baseline blood values are attained. Following surgery, daily blood samples for measuring regular inflammatory markers (c-reactive protein, procalcitonin, interleukin-6, tumour necrosis factor-α and leucocyte counts) and PSP/PAP will be acquired. PSP/PAP will be measured using a validated ELISA developed in our research laboratory. Patient's discharge marks the end of his/her trial participation. Complication grade including mortality and occurrence of infectious postoperative complications according to validated diagnostic criteria will be correlated with PSP/PAP values. Total intensive care unit days and total length of stay will be recorded as further outcome parameters.

ETHICS AND DISSEMINATION

The PSP trial is a prospective monocentric cohort study evaluating the prognostic value of PSP and PAP for postoperative infectious complications. In addition, a comparison with established inflammatory markers in patients undergoing major abdominal surgery will be performed to help evaluate the role of these proteins in predicting and diagnosing infectious and other postoperative complications.

INSTITUTION ETHICS BOARD APPROVAL ID

KEKZH-Nr. STV 11-2009.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01258179.

Differential HMG-CoA lyase expression in human tissues provides clues about 3-hydroxy-3-methylglutaric aciduria

3-Hydroxy-3-methylglutaric aciduria is a rare human autosomal recessive disorder caused by deficiency of 3-hydroxy-3-methylglutaryl CoA lyase (HL). This mitochondrial enzyme catalyzes the common final step of leucine degradation and ketogenesis. Acute symptoms include vomiting, seizures and lethargy, accompanied by metabolic acidosis and hypoketotic hypoglycaemia. Such organs as the liver, brain, pancreas, and heart can also be involved. However, the pathophysiology of this disease is only partially understood. We measured mRNA levels, protein expression and enzyme activity of human HMG-CoA lyase from liver, kidney, pancreas, testis, heart, skeletal muscle, and brain. Surprisingly, the pancreas is, after the liver, the tissue with most HL activity. However, in heart and adult brain, HL activity was not detected in the mitochondrial fraction. These findings contribute to our understanding of the enzyme function and the consequences of its deficiency and suggest the need for assessment of pancreatic damage in these patients.

Time frames for analysis of inflammatory mediators in acute pancreatitis: improving admission triage

Improving the outcome of acute pancreatitis through prognostic markers has been a matter of ample research. We evaluate the clinical usefulness of four serum markers in comparison to Ranson's score. Serum measurements of C-reactive protein (CRP), interleukin-6, -10 (IL-6, IL-10), and pancreatitis-associated protein (PAP) were performed. The usefulness of each marker for predicting severity was compared with that of Ranson's score. Time of evolution was considered for improving their usefulness. Seventy-one patients were studied. Severe cases had higher levels of all markers, although only IL-10 had better accuracy than Ranson's. In patients admitted during the first 48 h, IL-6, IL-10, and PAP had improved accuracy over Ranson's; however, after this time frame, only CRP outperformed Ranson's score. Analysis of time frames improved the accuracy of all markers. Therefore, time of evolution should be considered when using these parameters for a better prognosis.

Pancreatitis-associated protein 2 modulates inflammatory responses in macrophages

Pancreatitis-associated proteins (PAP) are stress-induced secretory proteins that are implicated in immunoregulation. Previous studies have demonstrated that PAP is up-regulated in acute pancreatitis and that gene knockdown of PAP correlated with worsening severity of pancreatitis, suggesting a protective effect for PAP. In the present study, we investigated the effect of PAP2 in the regulation of macrophage physiology. rPAP2 administration to clonal (NR8383) and primary macrophages were followed by an assessment of cell morphology, inflammatory cytokine expression, and studies of cell-signaling pathways. NR8383 macrophages which were cultured in the presence of PAP2 aggregated and exhibited increased expression of IL-1, IL-6, TNF-alpha, and IL-10; no significant change was observed in IL-12, IL-15, and IL-18 when compared with controls. Chemical inhibition of the NFkappaB pathway abolished cytokine production and PAP facilitated nuclear translocation of NF-kappaB and phosphorylation of IkappaB alpha inhibitory protein suggesting that PAP2 signaling involves this pathway. Cytokine responses were dose dependent. Interestingly, similar findings were observed with primary macrophages derived from lung, peritoneum, and blood but not spleen. Furthermore, PAP2 activity was inhibited by the presence of serum, inhibition which was overcome with increased PAP2. Our results demonstrate a new function for PAP2: it stimulates macrophage activity and likely modulates the inflammatory environment of pancreatitis.

Risk and markers of severe acute pancreatitis

Acute pancreatitis begins with pancreatic injury, elicits an acute inflammatory response, and encompasses a variety of potential complications in a subset of patients. Early determination of severity and risk of complications is crucial for instituting immediate interventions to improve outcome. The severity of acute pancreatitis is a function of the amount of pancreas that is injured and the intensity of the inflammatory response. Early death is mainly linked to an overwhelming inflammatory response leading to cardiovascular collapse or acute respiratory distress syndrome, whereas late death is associated with infected pancreatic necrosis and sepsis. This article reviews recent advancements in understanding the pathogenesis, immunology, and genetics of severe acute pancreatitis, and the literature on laboratory-based markers, which predict a severe clinical course and pancreatic necrosis.

Pancreatitis-associated protein: From a lectin to an anti-inflammatory cytokine

Pancreatitis-associated protein (PAP) was discovered in the pancreatic juice of rats with acute pancreatitis. PAP is a 16 kDa secretory protein structurally related to the C-type lectins although classical lectin-related function has not been reported yet. Then, it was demonstrated that PAP expression may be activated in some tissues in a constitutive or injury- and inflammation-induced manner. More recently, it has been found that PAP acts as an anti-inflammatory factor in vitro and in vivo. PAP expression can be induced by several pro- and anti-inflammatory cytokines and by itself through a JAK/STAT3-dependent pathway. PAP is able to activate the expression of the anti-inflammatory factor SOCS3 through the JAK/STAT3-dependent pathway. The JAK/STAT3/SOCS3 pathway seems to be a common point between PAP and several cytokines. Therefore, it is reasonable to propose that PAP is a new anti-inflammatory cytokine.

Inflammatory Markers of Disease Severity in Acute Pancreatitis

To date, CRP remains the single standard biochemical marker for predicting the severity of AP. Because the combination of clinico-physiological scores and CRP provides good information at 48 hours, research has focused on the predictive ability of various markers when applied in the initial 24 hours after admission to the hospital. After detailed review of the literature, the authors conclude that there is no single tool that serves as the optimal predictor of severity. There are, however, data supporting the use of certain tests to improve upon the clinician's early predictive ability on the subsequent course of AP. These include an APACHE II score greater than seven, IL-6 at the time of admission, and urine TAP, urine trypsinogen-2,and serum PMN-elastase at 24 hours (Box 1). These markers will only be able to help the clinician's predictive ability if they can be performed locally and if the results can be available in a timely manner. Future research should focus on markers such as procalcitonin, IL-8, IL-I ra, sTNFR,CAPAP, PLA-2, novel markers, and the combined use of more than one marker. The conventional research approach in predicting severity used in the last15 years has limitations and appears to have reached its maximal potential. Novel conceptions and approaches, such as identification of genetic polymorphisms that predispose to severe course and complications of AP, are needed for a quantum step forward.

Predictors of severity and necrosis in acute pancreatitis

C-reactive protein remains the single standard biochemical marker for predicting the severity of AP. Because the combination of clinical-physiological scores and CRP provide good information at 48 hours, research has focused on the predictive ability of various markers when applied in the initial 24 hours after admission to the hospital. After detailed review of the literature, the authors conclude that there is no single tool that serves as the optimal predictor of severity. There are, however, data that support the use of certain tests to improve upon the clinician's early predictive ability on the subsequent course of AP. These include an APACHE II score greater than 7 and IL-6 at the time of admission, and urine TAP, urine trypsinogen-2, and serum PMN elastase at 24 hours (Table 4). These markers only will be able to help the clinician's predictive ability if they can be performed locally and if the results can be available ina timely manner. Future research should focus on promising markers such as procalcitonin, IL-8, IL-I ra, sTNFR, CAPAP, PLA-2, novel markers, and the combined use of more than one marker. The conventional research approach in predicting severity used in the last 15 years has limitations and appears to have reached its maximal potential. Novel conceptions and approaches, such as identification of genetic polymorphisms that predispose to severe course and complications of AP or other approaches are needed for a quantum step forward.

Trends in the management of severe acute pancreatitis: interventions and outcome

BACKGROUND

Severe acute pancreatitis (SAP) in the intensive care unit (ICU) is a complex and challenging problem. The aim of the present study was to identify trends in management of SAP patients admitted to a tertiary level ICU, and to relate these to changes in interventions and outcome.

METHODS

Patients admitted to the Department of Critical Care Medicine (DCCM), Auckland Public Hospital with SAP from 1988 to 2001 (inclusive) were identified from the DCCM prospective database, and data were extracted from several sources.

RESULTS

One hundred and twelve patients (men 69, women 43, mean age (+/-SD) 57.3 years +/- 14.3) were admitted with SAP to DCCM in the 13-year period. Aetiology was gallstones (42%), alcohol (29%), or idiopathic (29%). At admission to DCCM the median duration of symptoms was 7 days (range 1-100) and the mean (+/-SD) Acute Physiology and Chronic Health Evaluation II score was 19.9 +/- 8.2. Ninety-nine patients (88%) had respiratory failure and 79 (71%) had circulatory failure. The number of necrosectomies peaked between 1991 and 1995 (17/35 patients (49%) compared to 4/22 (18%) prior 1991; chi(2) = 6.90, P = 0.032). Abdominal decompression, enteral nutrition, percutaneous tracheostomy, and the use of stents in endoscopic retrograde cholangiopancreatography were introduced over the study period. The length of stay in DCCM did not alter (median 4 days, range 1-60) but there was a reduction in the length of hospital stay (median 36 days to 15 days; anova= 6.16, P = 0.046). The overall mortality was 31% (35/112) and did not alter over the study period.

CONCLUSIONS

SAP remains a formidable disease with a high mortality despite a number of changes in intensive care and surgical management.

The usefulness of laboratory tests in the early assessment of severity of acute pancreatitis

Acute pancreatitis is a disorder that affects approximately 200,000 individuals in the U.S. annually. While most cases are mild, up to 30% of patients will have a complicated course with prolonged hospitalization and significant morbidity and mortality. Early institution of several therapeutic interventions, such as enteral nutrition, prophylactic antibiotics, endoscopic retrograde cholangiopancreatography (ERCP) and intensive care monitoring, have been shown to decrease the morbidity associated with severe acute pancreatitis. However, the ability of clinicians to predict, upon presentation, which patient will have mild or severe pancreatitis has remained poor over the years, thus leading to a delay in the institution of such treatments. Researchers have focused on markers that might improve upon clinical prediction alone. While data have shown the predictive value of tools such as Ranson's and Glasgow's criteria, C-reactive protein (CRP) and the APACHE score, their application in clinical practice has been limited by a time delay of at least 48 h in the former two and by being cumbersome in the latter. Thus, our focus is to critically appraise the evidence available for various biochemical markers in their ability to distinguish mild and severe acute pancreatitis early and more accurately than currently available tools.

Pancreatitis-associated protein levels in pancreatic juice from patients with pancreatic diseases

BACKGROUND

Pancreatitis-associated protein (PAP), the acute-phase protein of the pancreas, is overexpressed in acute pancreatitis. Serum PAP levels were reported to be useful as an indicator of the severity, prognosis and healing of acute pancreatitis. Although PAP was originally identified in pancreatic juice, there has been no clinical report on PAP levels in pancreatic juice. This study was conducted to determine levels of PAP in pancreatic juice (PJ-PAP) in various human pancreatic diseases.

METHODS

PAP levels in endoscopically aspirated PJ were measured by enzyme-linked immunosorbent assay in 86 patients with pancreatic diseases.

RESULTS

55% of 22 patients with pancreatic cancer (PC) and 25% of 49 patients with chronic pancreatitis (CP) were positive (> 350 ng/ml) for PJ-PAP. PJ-PAP levels were significantly higher in PC than in CP, in which PJ-PAP was also significantly higher than in 15 control subjects. There was no significant correlation between PJ-PAP and serum PAP, and combination assay of serum PAP and/or PJ-PAP detected 80% of PC cases and 44% of CP cases.

CONCLUSIONS

We have demonstrated that human PAP could be detected in pancreatic juice from patients with pancreatic diseases. Determination of PAP in pancreatic juice might be helpful for early detection of pancreatic injury.

Serum levels of pancreatitis-associated protein in digestive diseases with special reference to gastrointestinal cancers

The serum levels of pancreatitis-associated protein (PAP) were measured in 196 patients with digestive diseases and 15 healthy subjects by an enzyme-linked immunosorbent assay. The serum PAP levels were significantly elevated in the patients with gastric, colorectal, biliary tract, hepatocellular, or pancreatic cancers compared with the healthy subjects. After curative resection of the tumor, serum PAP levels were significantly decreased. The serum PAP levels were not related to clinicopathological factors except for the tumor size of pancreatic cancer. There were some cases of PAP-positive and carcinoembryonic antigen (CEA) or carbohydrate antigen (CA) 19-9 -negative gastric and colorectal cancers. The serum PAP levels were also significantly elevated in the patients with acute pancreatitis compared with those in not only the healthy subjects but also the patients with chronic pancreatitis. The peak PAP levels were significantly correlated with the severity of acute pancreatitis and reflected the clinical healing of the disease. The peak of serum PAP was significantly delayed compared with those of other pancreatic enzymes. These results suggest that the increase of serum PAP levels in patients with gastrointestinal cancers reflects an ectopic expression of PAP in cancer cells and that increased serum levels of PAP in acute pancreatitis are correlated with the disease severity and are prolonged than those of other pancreatic markers.

Pancreatitis-associated proteins: experimental and clinical studies

Various novel biochemical markers indicate pancreatic cellular injury more accurately than serum amylase or lipase. One of these is a non-enzymatic secretory protein called pancreatitis-associated protein (PAP).The main function of PAP is unclear at present but it may be an acute phase protein in the defence reactions of pancreatic cells. The protein was characterized in 1984 as a serum marker of pancreatitis. The serum PAP is expressed 6 hours after the induction of pancreatitis, and it increases to maximal levels within 2-4 days: PAP is not sufficiently sensitive for the diagnosis of acute pancreatitis in the emergency room. The sensitivity and specificity of PAP in the differentiation of severe from mild pancreatitis is between 60-70%. This is not superior to serum CRP assays or CT scans. PAP increases in pancreatic cellular injury without pancreatitis (subclinical cell damage, graft rejection) where PAP may have a diagnostic role.

Alcohol and the pancreas

Alcoholic pancreatitis may be one of the most serious adverse consequences of alcohol abuse. Its diagnosis, as it has for many years, depends primarily on clinical acumen in interpreting properly the symptoms and signs of abdominal distress, buttressed by elevated pancreatic enzymes (amylase and lipase). More recently, the use of computerized tomography (CT) in selected situations has been both of confirmatory and prognostic value. Severity of abnormality by CT correlates reasonably well with a variety of clinical-laboratory clusters (APACHE system, Ranson's criteria, etc.) and aids in therapy. The pathogenesis of alcoholic pancreatitis is not fully defined. The ultimate picture is one of tissue autolysis by activated proteolytic enzymes. The triggers for such activation, however, are still not known. They are represented by three main theories: (1) large duct obstruction and/or increased permeability relative to pancreatic secretion, (2) small duct obstruction due to proteinaceous precipitates, and (3) a direct toxic-metabolic effect of ethanol on pancreatic acinar cells. While not mutually exclusive, we favor the last hypothesis as being most consistent with the effects of ethanol on other organ systems. The direct effects of ethanol and/or its metabolites may be mediated, at least in part, via oxidative stress or the generation of fatty acid ethyl esters. Autolysis (regardless of proximate mechanism(s)) leads to inflammation likely mediated via release of various cytokines. It also should be appreciated that "acute" pancreatitis (the topic of this chapter) likely represents an acute process within a chronic pancreatic exposure and injury from alcoholic abuse. The key question of why pancreatitis develops in only a small number of alcohol abusers is not resolved. Therapy depends on the severity of alcoholic pancreatitis, which is defined by clinical-laboratory and often CT criteria. Mild pancreatitis usually resolves acutely with alcohol abstention and supportive therapy. Severe pancreatitis has a significant morbidity and mortality, mainly related to the degree of pancreatic necrosis and infection. It requires meticulous combined medical-surgical care.

Advances in the laboratory diagnostics of acute pancreatitis

Acute pancreatitis is a rather common abdominal disorder. In most patients the disease is mild, but about 20% of cases develop a severe necrotizing form of the disease with complications. In an emergency setting, the diagnosis of acute pancreatitis remains problematic and several patients with severe disease are diagnosed only at autopsy. Measurements of amylase or lipase are the principal laboratory methods for diagnosing acute pancreatitis. However, their sensitivity and specificity are generally considered unsatisfactory. Recent advances in the knowledge of the pathogenesis of acute pancreatitis and advances in laboratory technology have revealed new diagnostic possibilities. Especially assays based on trypsin pathophysiology have brought new alternatives for diagnostics and severity grading of the disease. Additionally, development of phospholipase A2 determinations and discovery of a new pancreatic protein, pancreatitis-associated protein, are very interesting. This article summarizes the value of new methods in the laboratory diagnostics of acute pancreatitis.