A retrospective analysis of 76 patients with severe acute pancreatitis (36 patients with ACS and 40 with intra-abdominal hypertension) revealed that proportions of CD4+ T lymphocytes on days 1, 3, and 7 were significantly lower in ACS patients than in IAH patients, whereas proportions of CD8+ T cells did not differ significantly between the two groups on any of the three days [88]. This evidence concerns the gene CD4 and acute pancreatitis.