Lactate dehydrogenase isoenzymes and alveolar inflammation in acute severe bronchiolitis in infants

: The authors have tried to value in 17 children (age: 1-11 months) affected by a severe acute viral bronchiolitis, if the measurement of Lactate Dehydrogenase (LD) isoenzymes could have been used to reveal alveolar injury. In the 76.4% (13/17) of subjects areas of consolidation were demonstrated by chest's radiographic examination due either to atelectasis secondary to obstruction or to inflammation of the alveoli. These coincided with a significant increase respect to a check's group (18 children) of LD4 in 70.5% (12/17), LD3 in 35.2% (6/17) and LD5 in 29.4% (5/17) of children. The presence of an analogous electrophoretic pattern and macrophages degenerated in pulmonary alveolar proteinosis lavage effluent associated with increases in lymphocytes and mononuclear phagocytes in lung specimens from children dead for bronchiolitis help to understand the inflammatory origin of pathological modification of LD isoenzymes observed in this series of cases.