Plasma cytokine levels in necrotizing enterocolitis.

Plasma concentrations of tumour necrosis factor (TNF) and interleukin-6 (IL-6) were measured by ELISA in samples taken from 24 infants with necrotizing enterocolitis (NEC) between 0 and 306 h from diagnosis. TNF was detected (> 10 pg/ml) in 71% samples with a mean of 48 pg/ml (95% CI 42 to 55 pg/ml) and did not vary with either time from diagnosis or severity of disease. IL-6 was raised during the first 48 h with a significant difference between stage II (mean 127 pg/ml, 95% CI 10 to 329 pg/ml) and stage III (mean 3127 pg/ml, 95% CI 1809 to 4445 pg/ml, p = 0.001). Postoperative plasma IL-6 concentration fell to similar levels seen in stage II (mean 150 pg/ml, 95% CI 37 to 283 pg/ml, p = 0.79). We conclude that plasma concentration of IL-6 rather than TNF reflects the clinical severity of necrotizing enterocolitis and that the relative level of these cytokines has important implications for the use of anti-cytokine therapy in NEC.