CIRCULATING IL-1RA AND IL-10 LEVELS ARE INCREASED BUT DO NOT PREDICT THE DEVELOPMENT OF ACUTE RESPIRATORY-DISTRESS SYNDROME IN AT-RISK PATIENTS

Although numerous cytokines, including interleukin (IL)-1, IL-8, and t umor necrosis factor, circulate in critically ill patients at risk for acute respiratory distress syndrome (ARDS), none clearly predict the development of the syndrome. We hypothesized that cytokines, such as I L-1ra, IL-10, and IL-4, which modulate inflammation, might contribute to or reflect the development of acute lung injury. Accordingly, seria l levels of IL-1ra and IL-10 were measured in 77 patients who were ide ntified as being at risk for the development of ARDS. Initial IL-1ra l evels were significantly higher (p < 0.0001) in the patients (7.82 [2. 29-38.01] ng/ml) than in normal control subjects (0.24 [0.24-0.34] ng/ ml) but did not predict the development of ARDS. Initial IL-1ra levels , however, were greater (p = 0.038) in the patients who died (31.95 [3 .02-65.06] ng/ml) compared with survivors (6.61 [1.86-29.33] ng/ml). S imilarly, IL-10 levels were increased in patients (155 [53.75-318.75] ng/ml) compared with normal control subjects (0 ng/ml) but did not pre dict the development of ARDS. Like IL-1ra levels, initial IL-10 levels were significantly higher (p = 0.005) in patients who died compared w ith survivors. IL-4 was not detectable in any of the patient plasma sa mples measured. Thus, modulators of inflammation are increased in pati ents at risk for ARDS who die, but do not predict the development of t he syndrome.