Interferon-gamma activates monocyte function in patients with severe pancreatitis

Background: Sepsis and infection are important prognostical factors in the therapy course of patients with severe pancreatitis. Secondary infections w ith subsequent sepsis are probably induced by a suppression of the immune s ystem. Our former results suggest that decreased HLA-DR expression of surfa ce antigens on monocytes represent the disturbed immune system in severe pa ncreatitis. In vivo and in vitro studies propose that the application of In terferon-gamma (IFN-gamma) may improve monocyte function. Patients and Methods: In a prospective study 12 patients with severe pancre atitis and a continuous decrease of HLA-DR expression < 150 MFI (mean fluor escence intensity) on monocytes (CD(+)14) received daily subcutaneous injec tions of 100 mu g Interferon-gamma-1b. The daily immunomonitoring included measurements of HLA-DR expression on monocytes (CD(+)14), Procalcitonin (PC T), soluble (s)-TNF-alpha-receptors and Neopterin. Results: In all patients the HLA-DR expression on monocytes increased signi ficantly after the third day (median) of IFN-gamma application. The cellula r parameter PCT showed a significant decline as a sign of improved immune r esponse. Representing the activated cellular immune status, s-TNF-alpha-rec eptors and neopterin levels increased significantly. Conclusion: We assume a central role of IFN-gamma in the regulation of the immune system. For confirmation of IFN-gamma as an immunomodulating cytokin e, further controlled, randomized studies are necessary.