Development and implementation of the International AIDA Network Castleman's disease registry.

Castleman's disease (CD) consists of a wide spectrum of rare disorders classified into unicentric CD and multicentric CD (MCD), based on the diffusion of disease distribution and the severity of clinical manifestations. While unicentric CD is characterized by a single lymph node involvement, MCD is defined by multiple lymph node station involvement with more prominent systemic symptoms. MCD is further subdivided into HHV-8 associated MCD, polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS)-associated MCD, and idiopathic MCD (iMCD), which is also subdivided into iMCD-TAFRO (thrombocytopenia, anasarca, fever, reticulin fibrosis, organomegaly) and iMCD-NOS (not otherwise specified). The rarity of the disease makes it still poorly understood, as current insight is largely based on case reports and relatively small patient cohorts. Therefore, knowledge about the clinical details of the disease, histological correlations, complications, prognostic factors, and optimal treatment management remains incomplete. The potential offered by the creation of online data sharing makes the development of a registry specifically dedicated to CD a necessary step to conduct solid research on this condition. Building on the experience and widespread international reach of the AutoInflammatory Disease Alliance (AIDA) Network, the development of this registry can allow the recruitment of a sufficient number of patients to conduct robust research in all the fields of the disease. Moreover, the AIDA Network itself will enable multidisciplinary and integrated collaboration among the various figures necessary for the optimal diagnostic, clinical, and therapeutic management of patients affected by CD in its different forms.