Peanut lectin binding to the alveolar lining layer in hyaline membrane disease

The authors have studied the histochemical pattern of Peanut lectin (PNA) binding sites in lungs of seven newborns with hyaline membrane disease (HMD) and ten controls. The alveolar lining layer was positive in HMD and no changes in the PNA pattern was noted after neuraminidase digestion. Hyaline membranes were generally unstained but occasional reactivity was encountered in some parts. No reaction with PNA was observed in control lungs, but positivity was seen after neuraminidase pretreatment. Our histochemical data document the presence of accessible galactosyl residues with absence of terminal sialic acid in the alveolar lining layer of newborns with HMD. The authors suggest that PNA reactivity in HMD reflects an histochemical feature described in fetal lungs at the pseudoglandular and canalicular stages.