Direct and indirect immunofluorescence as a diagnostic adjunct in the interpretation of nonneoplastic medical lung disease.

Fresh open lung biopsy material from 57 patients was incubated with fluoresceinated complement and immunoglobulin antisera. An indirect immunofluorescent assay using neonatal lung as substrate was conducted as well. Direct immunofluorescent patterns could be categorized into interalveolar septal capillary deposition, large vessel wall localization, alveolar basement membrane localization, or a pauci-immune immunofluorescence pattern.