Serum leptin, but not adiponectin and receptor for advanced glycation end products, is able to distinguish autoimmune pancreatitis from both chronic pancreatitis and pancreatic neoplasms

OBJECTIVE: Serum leptin and adiponectin determinations have been proposed as markers for distinguishing pancreatic cancer and chronic pancreatitis from autoimmune pancreatitis; however, no studies exist in patients with autoimmune pancreatitis and in those with intraductal papillary mucinous tumors of the pancreas. The aim of this paper was to evaluate the circulating concentrations of receptor for advanced glycation end products (RAGE), leptin and adiponectin in patients with chronic pancreatic diseases. MATERIAL AND METHODS: Seventy-five consecutive patients with chronic pancreatic diseases (47 males, 28 females; mean age 67.0 +/- 13.2 years; range 37-97 years) were studied: six (8.0%) had autoimmune pancreatitis, 23 (30.7%) had chronic pancreatitis, 34 (45.3%) had pancreatic cancer and the remaining 12 (16.0%) had intraductal papillary mutinous tumors of the pancreas. Leptin, adiponectin and RAGE were determined in serum using commercially available kits. The leptin concentrations were normalized to the lower and upper reference limits because of the different gender reference ranges. RESULTS: Normalized leptin concentrations were significantly lower in chronic pancreatitis patients (0.53 +/- 1.28; p = 0.008) and in those with pancreatic cancer (0.12 +/- 0.33; p < 0.001) compared to the overall population (0.58 +/- 1.23), whereas autoimmune pancreatitis patients had significantly higher concentrations of this protein (2.18 +/- 2.56; p = 0.004) compared to the overall population. RAGE and adiponectin concentrations were similar among the four groups of patients studied. Among the clinical variables considered, only pain was significantly related to leptin concentrations (patients with pain 0.18 +/- 0.54, patients without pain 1.07 +/- 1.64; p = 0.001). CONCLUSION: Serum leptin seems to be a good serum marker for differentiating autoimmune pancreatitis patients from those with chronic pancreatitis and pancreatic cancer.