Evaluation of monoclonal antibody against human pulmonary surfactant apoprotein

Lung sections of 104 newborn infants stored for 20 to 25 years and of seven cases of paraquat (PQ) intoxication were examined to detect the pulmonary surfactant apoprotein with the monoclonal antibody PE10 by immunoperoxidase staining technique. Specific peroxidase staining was observed in alveolar Type II cells and on alveolar walls of normal adult lungs. In the lungs of liveborn infant up to 28 weeks' gestation, peroxidase staining was negative. However, faint positive staining was observed in a specimen of 29 weeks' gestation, and the rate of positive staining increased with gestational age. Fifteen cases of newborn lungs with hyaline membranes revealed no positive staining except one. In the lungs of stillborn infants, peroxidase staining was weak and the rate of negative staining was more than that of liveborn infants. The specimens of PQ intoxication up to 5 days survival showed positive staining on alveolar walls, while those of 10 days or more survival, in which fibrotic changes and hyaline membranes were developed, showed no positive staining.