The value of modern morphological methods (histochemistry, immunopathology) in sarcoidosis

Correlative studies concerning the value of modern of morphological methods in correlation to the clinical picture were undertaken in patients with sarcoidosis. The investigations comprised immunopathological and histochemical studies of mediastinal lymph nodes, normal lymph nodes and lymphnodes by inflammatory lung diseases. The metabolic state of the granulomas in sarcoidosis is expressed by enzymehistochemical investigations and shows a strong activity of enzymes of the pentose cycle, cancer cycle, anaerobic glycolysis, respiratory chain and of hydrolytic enzymes. Of special interest is the activity of aminopeptidase in the granulomas, found only positive in progressive stage of the disease. With the aid of some hydrolases (acid phosphatase, nonspecific esterase) information is given about phagocytotic activity in granulomas. Antibody formation (anti-human-IgG, -IgA and -IgM) is visible in fresh cases around granulomas in the cytoplasms of large lymphoid cells, in some cases also in the walls of vessels. With longer duration of the disease immunoglobulins were found extracellulary first in little focal areas and later as a dense homogen material around the granulomas. In long existing cases only a weak or negative fluorescence was observed in this material, expressed by light microscopy as hyaline transformation. The value of this methods is given in additional information concerning the metabolic activity (especially phagozytosis) and immunological state (antibody formation) of the disease as an important factor for a well-timed and effective therapy.