Sakhawat H. Rahman

Intestinal hypoperfusion contributes to gut barrier failure in severe acute pancreatitis.

Intestinal barrier failure and subsequent bacterial translocation have been implicated in the development of organ dysfunction and septic complications associated with severe acute pancreatitis. Splanchnic hypoperfusion and ischemia/reperfusion injury have been postulated as a cause of increased intestinal permeability. The urinary concentration of intestinal fatty acid binding protein (IFABP) has been shown to be a sensitive marker of intestinal ischemia, with increased levels being associated with ischemia/reperfusion. The aim of the current study was to assess the relationship between excretion of IFABP in urine, gut mucosal barrier failure (intestinal hyperpermeability and systemic exposure to endotoxemia), and clinical severity. Patients with a clinical and biochemical diagnosis of acute pancreatitis were studied within 72 hours of onset of pain. Polyethylene glycol probes of 3350 kDa and 400 kDa were administered enterally, and the ratio of the percentage of retrieval of each probe after renal excretion was used as a measure of intestinal macromolecular permeability. Collected urine was also used to determine the IFABP concentration (IFABP-c) and total IFABP (IFABP-t) excreted over the 24-hour period, using an enzyme-linked immun-osorbent assay technique. The systemic inflammatory response was estimated from peak 0 to 72-hour plasma C-reactive protein levels, and systemic exposure to endotoxins was measured using serum IgM en-dotoxin cytoplasmic antibody (EndoCAb) levels. The severity of the attack was assessed on the basis of the Atlanta criteria. Sixty-one patients with acute pancreatitis (severe in 19) and 12 healthy control subjects were studied. Compared to mild attacks, severe attacks were associated with significantly higher urinary IFABP-c (median 1092 pg/ml vs. 84 pg/ml; P < 0.001) and IFABP-t (median 1.14 μg vs. 0.21 |μg; P = 0.003). Furthermore, the control group had significantly lower IFABP-c (median 37 pg/ml; P = 0.029) and IFABP-t (median 0.06 μg; P = 0.005) than patients with mild attacks. IFABP correlated positively with the polyethylene glycol 3350 percentage retrieval (r = 0.50; P < 0.001), CRP (r = 0.51; P < 0.001), and inversely with serum IgM EndoCAb levels (r = —0.32; P = 0.02). The results of this study support the hypothesis that splanchnic hypoperfusion contributes to the loss of intestinal mucosal integrity associated with a severe attack of pancreatitis.

Serum Macrophage Migration Inhibitory Factor Is an Early Marker of Pancreatic Necrosis in Acute Pancreatitis

Objective:To determine if 24-hour blood concentrations of macrophage migration inhibitory factor (MIF), soluble CD14, and CD163 receptors could predict complications associated with acute pancreatitis (AP). Summary Background Data:Soluble receptor proteins derived from the macrophage-monocyte lineage potentiate the inflammatory cytokine response early in AP. Understanding the temporal expression of these molecules could afford better measures for therapeutic intervention. Methods:Patients with AP (amylase >5 times normal) were recruited within 24-hour of onset of pain. Peripheral blood was analyzed for MIF, sCD163, and sCD14 levels and levels correlated with CRP, APACHE-II score, and clinical disease severity (Atlanta criteria); subclassified as multiorgan dysfunction (MOF), pancreatic necrosis (PN >30% on contrast CT), and death. Results:In total, 64 patients with AP (severe, 19: 8 had MOF alone, 7 both PN and MOF, 2 PN without MOF, and 2 single-organ failures with local septic complications) were recruited. Both sCD14 and MIF concentrations were elevated in patients with severe attacks (P = 0.004 and P < 0.001 respectively), and patients who developed MOF (P = 0.004 and P < 0.001). However, only serum MIF was significantly raised in patients who subsequently developed PN (median, 92.5 ng/mL; IQR, 26–181 vs. 31.1 ng/mL; IQR, 5–82, P < 0.001), independently of MOF (P = 0.01). Multivariate analysis demonstrated serum MIF as an independent predictor of PN (P = 0.01; OR = 2.73; 95% CI, 2.72–2.74). Conclusion:The prognostic utility of 24-hour plasma MIF concentration in predicting PN has major clinical and healthcare resource implications. Its mechanistic pathway may afford novel therapeutic interventions in clinical disease by using blocking agents to ameliorate the systemic manifestations of AP.

Genetic Polymorphisms of GSTT1, GSTM1, GSTP1, MnSOD, and Catalase in Nonhereditary Chronic Pancreatitis: Evidence of Xenobiotic Stress and Impaired Antioxidant Capacity

Epidemiological studies have demonstrated a variety of potential environmental factors that may alter susceptibility to chronic pancreatitis (CP) through oxidative/xenobiotic stress; however, a direct causal and mechanistic role has not been established. We aimed (1) to determine the prevalence of functional genetic polymorphisms in the antioxidant enzymes, glutathione S-transferase GSTM-1, GSTP-1, and GSTT-1, manganese superoxide dismutase, and catalase in CP and (2) to reveal evidence of oxidative stress in patients with CP by measuring whole-blood glutathione redox status. In total, 122 patients with CP (75 alcohol-induced [AlCP], 33 idiopathic [ICP], and 13 hereditary) and 245 age- and sex-matched controls were recruited. The prevalence of the functional GSTT-1 genotype (GSTT-1*A) was significantly higher in CP (88.5%) compared to healthy controls (76%; χ2 = 7.26, P = 0.007). Stratification to disease etiology demonstrated that the GSTT-1*A genotype was also significantly more prevalent among patients with ICP (94%; P = 0.02; 95% CI, 0.04–9.16) but not in those with AlCP. In 22 patients with stable CP, the whole-blood glutathione concentration (median [IQR]: 72 μmol/L [21–181 μmol/L]) and the glutathione redox ratio (GSH/GSSG) (median [IQR]: 9 (3–77]) were significantly reduced compared to those in 20 healthy volunteers (median [IQR]: 815 μmol/L [679–1148 μmol/L], P < 0.001, and 96 [52–347], P = 0.005, respectively). We conclude that the GSTT-1 functional genotype is associated with ICP. Evidence of altered glutathione redox status suggests that this disease modification may be a consequence of oxidative stress or the bioactivation of xenobiotics.

The SPINK1 N34S variant is associated with acute pancreatitis

Objective Acute pancreatitis (AP) is a disease whose pathogenesis remains largely obscure. Genetic research has focussed attention upon the role of the pancreatic protease/protease inhibitor system. The aim of this study was to investigate the prevalence of genetic variants of the trypsin inhibitor, SPINK1, in acute pancreatitis. Methods We genotyped 468 patients with AP and 1117 healthy controls for SPINK1 alterations by single-strand conformation polymorphism analysis and by melting curve analysis using fluorescence resonance energy transfer probes. Results The c.101A>G (p.N34S) variant was detected in 24/936 alleles of patients and in 18/2234 alleles of healthy controls (odds ratio=3.240; 95% confidence interval: 1.766–5.945; P<0.001). In the UK patients, the mean age of patients with N34S was 11.9 years younger compared with N34S negative patients (P=0.023), but this was not apparent in the German patients. Allele frequencies for the c.163C>T (p.P55S) variant did not differ between patients and controls. Conclusion The SPINK1 N34S variant is associated with acute pancreatitis. This supports the importance of premature protease activation in the pathogenesis of AP and suggests that mutated SPINK1 may predispose certain individuals to develop this disease.

Clinical Presentation and Delayed Treatment of Cholangitis in Older People

Acute cholangitis is more common in older people, and increasing age is a determinant of morbidity and mortality, as is early biliary decompression by ERCP. This study aims to identify factors that may contribute to delays in the diagnosis and treatment of older people with acute cholangitis. Case notes of 122 patients (45 aged < 75 years, 77 > 75 years) with a final diagnosis of acute cholangitis who underwent ERCP were reviewed for presenting clinical features (pain, jaundice, rigors, fever, falls, incontinence, confusion), liver function tests, blood count, and the interval from admission to diagnosis, ultrasonography, and ERCP. The most common symptom at presentation was abdominal pain (81%), followed by jaundice (55%). These symptoms were no less common in older patients. Charcots triad was present in only 15.6% of young and 18.8% of older patients. Jaundice was not detected in 16% of significantly hyperbilirubinemic older patients, but only the presence of functional symptoms was associated with significant diagnostic delay (median, 1 day [range: 0–11] vs. 9.5 days [3–25]; P< 0.001) and delay in performing ERCP (median: 4 days [0–24] vs. 16.5 days [2–29], P< 0.001). Overall mortality was 10%, and the incidence of septic shock was similar in both groups. Charcots classical triad is infrequent in patients suffering from acute cholangitis. Given the greater difficulty assessing jaundice in older people and the confounding effect of falls, incontinence, and confusion, a routine policy of liver function tests, with further investigation of abnormal results in such presentations, may reduce delays in diagnosing and treating acute cholangitis.

Transsulfuration Pathway Defects and Increased Glutathione Degradation in Severe Acute Pancreatitis

Glutathione depletion is a consistent feature of the progression of mild to severe acute pancreatitis. In this study, we examined the temporal relationship between cysteine, homocysteine, and cysteinyl-glycine levels; total reduced erythrocyte glutathione; gamma-glutamyl transpeptidase activity; and disease severity. Initially, cysteine concentration was low, at levels similar to those of healthy controls. However, glutathione was reduced whilst cysteinyl glycine and gamma-glutamyl transpeptidase activity were increased in both mild and severe attacks. As the disease progressed, glutathione and cysteinyl glycine were further increased in mild attacks and cysteine levels correlated with homocysteine (r = 0.8, P < 0.001) and gamma-glutamyl transpeptidase activity (r = 0.75, P < 0.001). The progress of severe attacks was associated with glutathione depletion, reduced gamma-glutamyl transpeptidase activity, and increased cysteinyl glycine that correlated with glutathione depletion (r = 0.99, P = 0.01). These results show that glutathione depletion associated with severe acute pancreatitis occurs despite an adequate cysteine supply and could be attributed to heightened oxidative stress coupled to impaired downstream biosynthesis.