Bronchoalveolar interleukin-1 beta in infants on day 1 of life

Interleukin-1 beta (IL-1 beta) a proinflammatory cytokine associated with adult lung diseases, may play a role in the development of bronchopulmonary dysplasia (BPD). Concentrations of IL-1 beta were measured in bronchoalveolar lavage fluid from 17 infants on day 1 of life and in 18 infants intubated until day 14. IL-1 beta was detected in 31 of 35 samples. Day 14 concentrations were significantly higher than those obtained on day 1. The four infants who had BPD had significantly higher IL-1 beta levels than those who received oxygen for less than a week or for 1 to 4 weeks. Day 1 IL-1 beta concentration was related to the neutrophil count and inversely to gestational age. IL-1 beta is present in the majority of newborn infants intubated on day 1 or at 2 weeks of life and is elevated during the first 24 hours in infants who will subsequently require longer ventilatory support. It is also elevated in infants who have a stronger pulmonary inflammatory response.