Production of platelet-activating factor in patients with sepsis-associated acute renal failure

Background. Studies in experimental animals have suggested that platelet-ac tivating factor (PAF) is a mediator of sepsis-associated acute renal failur e (ARF). In the present study we have evaluated whether an increased concen tration of PAF within circulation or urine of septic patients correlated wi th the worsening of renal function. Methods. The concentration of PAF and selected cytokines (TNF, IL-1, IL-6, IL-8) was evaluated in blood and urine of 12 patients with septic shock and ARF for 4 consecutive days. Results. The data obtained indicate that blood and urinary concentrations o f PAF and of IL-1, IL-6 and IL-8 were significantly higher in septic patien ts than in controls subjects and in patients with chronic renal failure. Th e concentration of TNF was significantly increased only in urine. A signifi cantly positive correlation was found among blood concentration of PAF and heart rate (r =0.4193. P<0.017), serum creatinine (1 =0.3671, P<0.038), ser um IL-6 (r=0.5475, P<0.005) and urine excretion of IL-8 (r=0.3984, P<0.044) , whereas a negative correlation was present with the number of circulating platelets (r=-0.4285, P<0.018). Moreover, a positive correlation among the concentration of PAF in urine and the serum concentration of IL-6 (r=0.565 4, P<0.006) and urine excretion of IL-6 (r=0.6589, P<0.0008) and IL-8 (r=0. 6371, P<0.0004) were found. Conclusions. These results demonstrate in humans during ARF associated with septic shock the production of PAF, a mediator that has been previously im plicated in the pathogenesis of experimental endotoxin-induced shock and re nal injury. The observation that blood and urinary concentrations of PAF co rrelated with some of the clinical and laboratory parameters related to the severity of ARF and sepsis suggests that PAF may contribute to the develop ment of renal injury in septic patients.