HISTOPATHOLOGICAL STUDY OF SAUROPUS ANDROGYNUS-ASSOCIATED CONSTRICTIVE BRONCHIOLITIS OBLITERANS - A NEW CAUSE OF CONSTRICTIVE BRONCHIOLITISOBLITERANS

The development of constrictive bronchiolitis obliterans in patients w ho have ingested Sauropus androgynus juice has not been previously rep orted. We describe four patients with S. androgynus-associated constri ctive bronchiolitis obliterans who underwent open lung biopsies for hi stopathological analysis. This article aims to recognize the possible pathogenesis of the disease. The spectrum of histologic changes ranged from slight bronchiolar inflammation and fibrosis to marked submucosa l fibrosis causing complete cicatricial obliteration of the lumen. A d ense eosinophil infiltrate was noted in the bronchiolar submucosa or f ibrotic tissue of the completely obliterated bronchioles in two patien ts. Immunohistochemical studies revealed that lymphocytic infiltrate c onsisted mainly of T lymphocytes in all patients. Immunofluorescent st ains for immunoglobulin (Ig)G, IgA, IgM, C1q, C3, and C4 were negative . Electron microscopy disclosed no immune complex deposition in the sp ecimens examined. Although the role of antibody- and complement-mediat ed reaction is not supported by the negative results of immunofluoresc ent and electron microscopic studies, the common finding of the predom inant T-lymphocytic infiltrate suggests that a T-cell mediated immune response is involved in the pathogenesis of the disease. Furthermore, the finding of a heavy lymphocytic infiltrate in many bronchioles with out significant collagen deposition suggests that the lymphocytic infi ltrate may precede the tissue fibrosis. In addition, the presence of a dense eosinophil infiltrate may combine with lymphocytes and other im munologic and mesenchymal cells to promote antigen-specific stimulatio n of lymphocytes and induction of fibrosis.