Value of measurement of neutrophil elastase-alpha 1 proteinase inhibitor levels in the early diagnosis of neonatal infection.

In a case-control study in 398 neonates the value of measuring the levels of neutrophil elastase-alpha 1 proteinase inhibitor (EPI) for early diagnosis of neonatal infection was studied in comparison to the commonly used parameters of leukocyte count, ratio of immature to total granulocytes and C-reactive protein levels. Investigations were performed on day 1 or day 6 of life. On the basis of the clinical findings patients were allocated to one of the three following groups: healthy neonates (group A), neonates with local infections such as pneumonia or skin infection (group B) or neonates with septicemia as demonstrated by a positive blood culture (group C). The median EPI levels (with range) measured on day 1 were: group A 40 (15-65) micrograms/l, group B 120 (80-260) micrograms/l, group C225 (140-355) micrograms/l. The levels on day 6 were: group A 27.5 (5-55) micrograms/l, group B 105 (65-370) micrograms/l, group C 182.5 (74-450) micrograms/l. EPI thus discriminated well between healthy neonates and neonates with infection, but not between neonates with infection and neonates with septicemia.