[Immunohistologic determination of extracellular matrix components in granuloma annulare]

The histological diagnosis of granuloma annulare is based on assessment of a palisade-like granuloma and necrobiosis. The authors attempt to make a more accurate diagnosis of the disease based on immunohistological assessment of components of the extracellular matrix.

In a group of 15 patients with granuloma annulare the authors assessed, using the immunoperoxidase method, collagens type I, III and V and fibronectin. An increased amount of collagens type III and V was found within the palisade-like granuloma and its neighbourhood resp. In the area of the necrobiosis the findings of the mentioned collagens depended on the degree of necrobiotic changes (12 of 15 patients). An increased occurrence of collagen type I was only indicated in the vicinity of granulomas or within the palisade-like granuloma in 7 of 15 patients. Larger amounts of fibronectin were found in the area of the necrobiosis and in the area of the granulomatous palisade-like infiltrate resp. (12 of 15 patients).

In the author's opinion the higher incidence of collagens types III and V in the neighbourhood of the palisade-like granulomatous infiltrate and its size resp, as well as the finding of fibronectin in the area of necrobiosis and the granulomatous infiltrate justify the use of immunohistological assessment of the above constituents of the extracellular matrix as a supplementary examination in the diagnosis of the above disease.