Sarcoidosis. An updated review.

Sarcoidosis, a multisystem disease of unknown cause characterized by the formation of noncaseating granulomas, may involve any organ of the body, but the commonest sites of predilection are the lungs, lymph nodes, skin, and eyes. Sarcoidosis can be associated with polyclonal hyperglobulinemia, hypercalcemia, hypercalciuria, circulating immune complexes, cutaneous anergy, and in vitro depressed cell-mediated immunity. Recent studies of the cellular composition and cellular interactions of sarcoid-involved tissue have resulted in some insight into the pathophysiology of the disease. In early stages the predominance of activated T-helper cells in affected sites may account for many of the immunologic aberrations. The production of macrophage chemotactic substances by these cells may be the initial stimulus for the formation of the granuloma. The natural history of the disease is highly variable; the acute forms tend to resolve spontaneously, whereas the chronic forms rarely involute. Although multiple therapeutic modalities have been used and some have reportedly been effective, systemic corticosteroids remain the most effective available therapeutic agents.