[Levels of inflammatory cytokines and plasma cortisol in respiratory syncytial virus bronchiolitis].

BACKGROUND An increased inflammatory innate response may play a role in pathogenesis of respiratory syncytial virus (RSV) infection. AIM To quantify pro-inflammatory cytokines (IL-6-IL-8, ÍL-2-P and TNF-a) in nasopharyngeal aspirate (NPA) and plasma, and plasma cortisol in previously healthy infants with RSV bronchiolitis. PATIENTS AND METHODS We studied 49 infants aged less than one year of age with RSV bronchiolitis and 25 healthy controls. Severity was defined using a previously described modified score. We quantified interleukins in NPA and plasma by flow cytometry and plasma cortisol by radioimmunoanalysis. RESULTS Among patients with RSV bronchiolitis, 25 were classified as severe and 24 as moderate or mild. Significantly higher levels of IL-6 and IL-8 in NPA and plasma and IL-lfi in NPA were found in children classified as severe, when compared to those with moderate or mild disease and controls. There was a positive correlation between IL-6 and cortisol in plasma (r = 0,55; p < 0,0001) and both were correlated with the severity of the disease. CONCLUSIONS RSV bronchiolitis severity was associated with higher levéis of inflammatory interleukins and plasma cortisol.