Objectives: In severe acute pancreatitis (SAP), immunologic impairment in the early phase may be linked to subsequent infectious complications. Immunosuppressive acidic protein (IAP) is an immunosuppressive factor to be present in serum and ascites of cancer patients, and it is used as a tumor marker and an index of immune status of cancer hosts.
Methods: We measured serum IAP levels in 42 patients with SAP (Japanese severity score [JSS] > or = 2) on admission and analyzed the relationships with disease severity, pancreatic necrosis, blood biochemical parameters on admission, and clinical outcome (infection and death).
Results: Serum IAP level increased 791 +/- 285 microg/mL (range, 159-1430 microg/mL) on admission and recognized abnormal high level (normal range, < 500 microg/mL) in 37 patients (88.1%). Serum IAP level was significantly lower in patients of stages 3 and 4 (JSS > or = 9) (678 +/- 187 microg/mL) than that in patients of stage 2 (2 < or = JSS < or = 8) (848 +/- 311 microg/mL). It was also significantly lower in patients whose Ranson score was 5 or higher (674 +/- 287 microg/mL) than that in patients whose Ranson score was 4 or less (910 +/- 287 microg/mL). Moreover, it was significantly lower in patients with pancreatic necrosis (693 +/- 194 microg/mL) than that in patients without pancreatic necrosis (922 +/- 336 microg/mL). Among the blood biochemical parameters on admission, serum IAP was significantly negatively correlated with hematocrit, serum lipase, and serum interferon gamma and was significantly positively correlated with serum total protein. Serum IAP levels in patients of stage 2 reached higher peak at 7 days after admission and decreased more rapidly than those in patients of stages 3 and 4.
Conclusions: Serum IAP levels were elevated in patients with SAP but were significantly lower in patients with higher grade of severity or pancreatic necrosis. These results suggest that serum IAP levels may be related to systemic inflammatory response and reflect the immunoresponsiveness in patients with SAP.