Pilot Investigation of the Association Between Serum Stress Neuropeptide Levels and Lymphocyte Expression of Fas and Fas Ligand in Critical Illness

Introduction:In critical illness, apoptotic loss of immunocytes is associated with immunosuppression.Aim:To explore expression of Fas/Fas ligand (FasL) on B and T cells from critically ill patients without sepsis compared to matched controls and associations with disease severity and neuropeptide Y (NPY), cortisol, adrenocorticotropic hormone (ACTH), and prolactin (PRL) levels.Methods:Repeated-measures correlational design with 36 critically ill patients (14-day follow-up) and 36 controls. Disease severity was assessed using the Multiple Organ Dysfunction Score (MODS) and Multi Organ Failure scale. Fas/FasL values were standardized for viable cell counts. An enzyme-linked immunosorbent assay (NPY) and electrochemiluminescence immunoassay (cortisol, ACTH, and PRL) were employed.Results:Fas and FasL expression on T-helper (p < .0001–.03) and T-cytotoxic cells (p < .0001–.002) and Fas expression on B cells (p < .0001–.03) were higher in patients. MODS severity was associated with FasL expression on cytotoxic...