Identification of a novel antibody associated with autoimmune pancreatitis.

BACKGROUND: Autoimmune pancreatitis is characterized by an inflammatory process that leads to organ dysfunction. The cause of the disease is unknown. Its autoimmune origin has been suggested but never proved, and little is known about the pathogenesis of this condition. METHODS: To identify pathogenetically relevant autoantigen targets, we screened a random peptide library with pooled IgG obtained from 20 patients with autoimmune pancreatitis. Peptide-specific antibodies were detected in serum specimens obtained from the patients. RESULTS: Among the detected peptides, peptide AIP(1-7) was recognized by the serum specimens from 18 of 20 patients with autoimmune pancreatitis and by serum specimens from 4 of 40 patients with pancreatic cancer, but not by serum specimens from healthy controls. The peptide showed homology with an amino acid sequence of plasminogen-binding protein (PBP) of Helicobacter pylori and with ubiquitin-protein ligase E3 component n-recognin 2 (UBR2), an enzyme highly expressed in acinar cells of the pancreas. Antibodies against the PBP peptide were detected in 19 of 20 patients with autoimmune pancreatitis (95%) and in 4 of 40 patients with pancreatic cancer (10%). Such reactivity was not detected in patients with alcohol-induced chronic pancreatitis or intraductal papillary mucinous neoplasm. The results were validated in another series of patients with autoimmune pancreatitis or pancreatic cancer: 14 of 15 patients with autoimmune pancreatitis (93%) and 1 of 70 patients with pancreatic cancer (1%) had a positive test for anti-PBP peptide antibodies. When the training and validation groups were combined, the test was positive in 33 of 35 patients with autoimmune pancreatitis (94%) and in 5 of 110 patients with pancreatic cancer (5%). CONCLUSIONS: The antibody that we identified was detected in most patients with autoimmune pancreatitis but also in some patients with pancreatic cancer, making it an imperfect test to distinguish between these two conditions.

Exocrine and endocrine pancreatic function in 21 patients suffering from autoimmune pancreatitis before and after steroid treatment.

BACKGROUND/AIM: Autoimmune pancreatitis (AIP) responds rapidly and dramatically to steroid therapy. The aim of this study was to evaluate pancreatic exocrine and endocrine function in patients suffering from AIP both before and after steroid therapy. PATIENTS AND METHODS: Fecal elastase 1 and diabetes were evaluated before steroid therapy and within 1 month of its suspension in 21 patients (13 males and 8 females, mean age 43 +/- 16.5 years) diagnosed as having AIP between 2006 and 2008. RESULTS: At clinical onset, fecal elastase 1 was 107 +/- 126 microg/g stool. Thirteen patients (62%) showed severe pancreatic insufficiency (<100 microg/g stool), 4 (19%) had mild insufficiency (100-200 microg/g stool), while 4 (19%) had normal pancreatic function (>200 microg/g stool). Before steroids, diabetes was diagnosed in 5 patients (24%), all of whom had very low levels of fecal elastase 1 (<19 microg/g stool). Following steroids, fecal elastase 1 increased in all patients (237 +/- 193 microg/g stool) and observed levels were significantly higher than those seen before steroids (p = 0.001). CONCLUSIONS: Patients suffering from AIP display exocrine and/or endocrine pancreatic insufficiency at clinical onset. These insufficiencies improve after steroid therapy.

Autoimmune pancreatitis: differences between the focal and diffuse forms in 87 patients.

OBJECTIVES: Autoimmune pancreatitis (AIP) is a particular type of chronic pancreatitis that can be classified into diffuse and focal forms. The aim of this study was to analyze clinical and instrumental features of patients suffering from the diffuse and focal forms of AIP. METHODS: AIP patients diagnosed between 1995-2008 were studied. RESULTS: A total of 87 AIP patients (54 male and 33 female patients, mean age 43.4+/-15.3 years) were studied. Focal-type AIP was diagnosed in 63% and diffuse-type in 37%. Association with autoimmune diseases was observed in 53% of cases, the most common being ulcerative colitis (30%). Serum levels of IgG4 exceeded the upper normal limits (135 mg/dl) in 66% of focal AIP and in 27% of diffuse AIP (P=0.006). All patients responded to steroids. At recurrence non-steroid immunosuppressive drugs were successfully used in six patients. Recurrences were observed in 25% of cases, and were more frequent in focal AIP (33%) than in diffuse AIP (12%) (P=0.043), in smokers than in non-smokers (41% vs. 15%; P=0.011), and in patients with pathological serum levels of IgG4 compared to those with normal serum levels (50% vs. 12%; P=0.009). In all, 23% of the patients underwent pancreatic resections. Among patients with focal AIP, recurrences were observed in 30% of operated and in 34% of not operated patients. CONCLUSIONS: Focal-type and diffuse-type AIP differ as regards clinical symptoms and signs. Recurrences occur more frequently in focal AIP than in diffuse AIP. The use of non-steroid immunosuppressants may be a therapeutic option in relapsing AIP.

Clinical and radiological outcome of patients suffering from chronic pancreatitis associated with gene mutations.

OBJECTIVES: Cystic fibrosis transmembrane conductance regulator (CFTR), cationic trypsinogen gene (PRSS1), and serine protease inhibitor kazal type 1 (SPINK1) gene mutations have been associated with chronic pancreatitis (CP). The aim of this study was to compare clinical and radiological findings in sporadic CP with (CPgm) and without (CPwt) gene mutations. METHODS: Data from patients observed between 2001 and 2006 were collected. All patients were tested for 25 CFTR gene mutations, for R122H and N29I on the PRSS1 gene, and for N34S mutation on the SPINK1 gene. RESULTS: We found 34 (17.2%) of 198 patients with CPgm, 23 (11.6%) of them on the CFTR gene, 11 (5.6%) on the SPINK1, and none on the PRSS1 gene. The age at clinical onset was younger in CPgm (36.2 +/- 17.2 years) than in CPwt (44 +/- 12.6 years; P = 0.005). There were more heavy drinkers among CPwt (33%) than among CPgm (9%; P = 0.003), and the same applied to smokers (69% vs 33%, respectively; P < 0.0001). In CPgm group, the onset of pancreatic calcifications was observed more frequently in drinkers and/or smokers. Exocrine and endocrine insufficiency occurred less frequently and later in CPgm than in CPwt patients. CONCLUSIONS: Clinical and radiological outcome differ in CPgm compared with CPwt. Alcohol, even in small quantities, and cigarette smoking influence the onset of pancreatic calcifications.

A randomized trial of consensus interferon in combination with ribavirin as initial treatment for chronic hepatitis C.

BACKGROUND/AIMS: The aim of the present, open-labeled, randomized study was to determine the efficacy and safety of different doses of consensus interferon plus ribavirin in the initial treatment of chronic hepatitis C. METHODS: One hundred and one genotype 2/3 patients were randomized to receive 9 mcg (group A, n=48) or 18 mcg (group B, n=53) of consensus interferon thrice weekly plus ribavirin (1000/1200 mg/daily) for 24 weeks and 92 genotype 1 patients to receive 9 mcg (group C, n=47) or 18 mcg (group D, n=45) of consensus interferon plus ribavirin for 48 weeks. RESULTS: In an intention-to-treat analysis, the sustained virologic response at 24-week follow-up was 69% and 66% for group A and B (P=0.77) and 40% and 36% for group C and D (P=0.63). The overall sustained response was 67% and 38% in patients with genotype 2/3 and 1, respectively. Among genotype 1 patients the sustained virologic response was 39% and 41% for high or low baseline viremia levels. CONCLUSIONS: Higher consensus interferon dose does not increase sustained virologic response. Naive genotype 1 patients may achieve significant response rate of approximately 40% if treated with 9 mcg of consensus interferon plus ribavirin for 48 weeks.