Idiopathic multicentric Castleman disease: pathogenesis, clinical presentation and recommendations for treatment based on the Castleman Disease Collaborative Network (CDCN)

Castleman disease is a very rare, lymphoproliferative disease, driven by dysregulation of the cytokine interleukin 6 (IL-6) and other proinflammatory cytokines with the development of symptoms of systemic inflammation, reactive proliferation of lymphocytes, and damage to numerous organs. HHV-8 infection plays a major role in the pathogenesis of human immunodeficiency virus (HIV+) multicentric Castleman disease (MCD). The aetiology of the idiopathic form of MCD (HIV/HHV-8 negative) is unknown. In 2017, a panel of Castleman Disease Collaborative Network (CDCN) experts developed unified diagnostic criteria necessary for the diagnosis of idiopathic MCD. The disease has a diverse course, with a broad spectrum from mild to severe. The drug of choice according to the CDCN recommendation of 2018 for patients requiring treatment is anti-IL-6 monoclonal antibody, siltuximab. Immunomodulatory and immunosuppressive drugs are an alternative first-line treatment when anti-IL-6/IL-6R drugs are unavailable, and in subsequent lines of treatment after the failure of anti-IL-6 antibodies. Chemotherapy is reserved for the treatment of severe forms of the disease. The prognosis in most patients is moderately good. Unfortunately, the availability of the new therapies remains limited.