Membrane and soluble forms of Fas (CD95) in peripheral blood lymphocytes and in serum from burns patients

Burn trauma results in disorders of regulation of programmed cell death cal led apoptosis. Apoptosis of immunocytes is associated with the expression o f Fas antigen. There are two major forms of Fas molecule, membranous Fas (m Fas) and soluble Fas (sFas). The last form is generated by alternative spli cing and differs from mFas by lacking 21 amino acid residues containing the transmembrane domain. We determined the expression of mCD3, mCD4, mCD8 and mFas in peripheral blood lymphocytes and the level of the soluble form of Fas in serum in patients with acute thermal trauma (n = 32). As the control blood of healthy volunteers (n = 25) was investigated, Compared to healthy volunteers, burn patients showed a remarkable reduction in number of CD3lymphocytes in the 24 h following injury, which was accompanied by a decrea se in CD4+ but not CD8+ subsets by indirect immunofluorescence method. The decrease of expression of mFas in the patients with acute thermal trauma at all burn disease time was determined simultaneously. We established the de crease of level of sFas during the first (404 +/- 25 U/ml) and second (352 +/- 38 U/ml) postburn 10-day periods by the ELISA method. The contents of s Fas in serum of healthy volunteers was 534 +/- 31.8 U/ml. There were no rel ations between the level of membrane Fas expression and contents of the sol uble Fas in serum both in clinical manifestation and survival. We suppose t hat it is impossible to predict outcomes of burn disease by quantity of CD9 5+ cells and contents of sFas in serum. However, it is probable that signif icant deviations from the level of sFas may be attributes of non-revealed a ccompanying pathology. (C) 2001 Elsevier Science Ltd and ISBI. All rights r eserved.