The Many Faces of Sarcoidosis : Novel insights into pathogenesis, diagnostics and therapy

Sarcoidosis is a granulomatous disorder of unknown cause affecting multiple organs and is characterized by non-caseating granulomas. Usually sarcoidosis develops before the age of 50 years, with an incidence peaking at 20 to 39 years. The worldwide prevalence varies from 2 to 80 per 100,000. In the Netherlands the prevalence is estimated to be 50 per 100,000. However, in 30-60% of the cases the prevalence may be underestimated by the asymptomatic signs of the disease.
Although sarcoidosis was first described in 1877, the pathophysiology and what triggers the disease remains still a question. It is presumed that granulomas play a central role in the pathogenesis of sarcoidosis. The hypothesis in sarcoidosis is that granulomas are formed by an interaction between antigen presenting cells and activated T-lymphocytes, mainly CD4+ T cells. This leads to a release of cytokines which triggers macrophages to produce TNF-α and strengthen the local inflammation response by releasing a cascade of several cytokines. In this thesis aspects of sarcoidosis on areas pathophysiology, diagnostics and new treatment modalities will be highlighted.