Circulating lymphocyte numbers and activation together with granulocyte function were measured in 20 patients in the early stages of an attack of acute pancreatitis and in 20 healthy controls. Circulating lymphocytes, T lymphocytes, and CD4 and CD8 T lymphocyte subsets were decreased in both mild pancreatitis (67-80 per cent of controls) and severe pancreatitis (22-40 per cent of controls). CD4: CD8 ratios were unchanged and median (interquartile range) interleukin 2 receptor expression was increased from less than 1 per cent in controls to 14(6) per cent in severe pancreatitis, suggesting lymphocyte activation. Median granulocyte chemiluminescence was increased to 293 per cent of controls in severe pancreatitis and random motility was reduced to 77 per cent of controls, indicating increased metabolic activity. Complement-mediated antibody-independent opsonization and chemotaxis toward endotoxin were normal. Immune function is not reduced early in acute pancreatitis. Granulocyte hyperactivity may be important in the development of multiple organ failure.
Pancreatic infection is a leadin cause of morbidity and mortality in acute pancreatitis ,2. Pathogens may arise from several sources, including the colon and biliary tract, and they reach the pancreas by different route^^,^. However, contamination of the healthy gland does not lead to infection5. Infection may develop as a complication in patients with acute pancreatitis. Understanding of the factors responsible for this increased risk may lead to improved treatment.
The risk of infection is proportional to the severity of pancreatitis and the extent of pancreatic necrosis5-'". Several lines of evidence, however, suggest that host immune function may also be important. Reduced delayed hypersensitivity skin test response to recall antigens (anergy) early in acute pancreatitis is associated with increased risk of sepsis and death". Circulating T helper cell numbers are decreased early in acute pancreatitisI2, a finding that may be associated with immune deficiency. The rate of clearance of bacteria and proteases is suggesting impaired reticuloendothelial system function. It was hypothesized that immune function is reduced in acute pancreatitis. The aim of this study was to investigate immune function early in acute pancreatitis. Changes within the first 48 h of admission to hospital were measured before the effects of infection, starvation and multiple organ failure became important16.".