Immunohistological Assessment of Constituents of the ExtracellularMatrix in Granuloma Annulare

Overview

Background.
The histological diagnosis of granuloma annulare is based on assessment of a palisade-likegranuloma and necrobiosis. The authors attempt to make a more accurate diagnosis of the disease based onimmunohistological assessment of components of the extracellular matrix.Methods and Results. In a group of 15 patients with granuloma annulare the authors assessed, using theimmunoperoxidase method, collagens type I, III and V and fibronectin. An increased amount of collagens type IIIand V was found within the palisade-like granuloma and its neighbourhood resp. In the area of the necrobiosis thefindings of the mentioned collagens depended on the degree of necrobiotic changes (12 of 15 patients). An increasedoccurrence of collagen type I was only indicated in the vicinity of granulomas or within the palisade-like granulomain 7 of 15 patients. Larger amounts of fibronectin were found in the area of the necrobiosis and in the area of thegranulomatous palisade-like infiltrate resp. (12 of 15 patients).Conclusions. In the author’s opinion the higher incidence of collagens types III and V in the neighbourhood ofthe palisade-like granulomatous infiltrate and its size resp. as well as the finding of fibronectin in the area ofnecrobiosis and the granulomatous infiltrate justify the use of immunohistological assessment of the aboveconstituents of the extracellular matrix as a supplementary examination in the diagnosis of the above disease.

Key words:
granuloma annulare, interstitial collagens, fibronectin, immunohistological assessment.