Inhibitor of differentiation 1 is a candidate prognostic marker in multicentric Castleman's disease

Castleman's disease (CD) is a benign lymphoproliferative disorder characterized by dysfunctional lymphatic node hyperplasia. Lymphatic node hyperplasia is associated with elevated levels of inhibitor of differentiation 1 (ID1) in many human tumors. To assess the possible role of ID1 expression as a prognostic marker in multicentric CD (MCD), intra-lymph node ID1 expression was analyzed and related to clinical characteristics and outcomes in 48 patients. Furthermore, the correlation between ID1 and possible signaling molecules such as interleukin-6 (IL6), phosphorylated extracellular response kinase (p-ERK), and vascular endothelial growth factor C (VEGFC) was explored on six fresh MCD surgical specimens. Immunohistochemistry revealed that the patients with extensive ID1 expression had significantly poorer prognosis, compared to those with localized ID1. In addition, ID1 was positively associated with levels of IL6, p-ERK, and VEGFC. We conclude that ID1 may ultimately be a prognostic marker in MCD and that the IL6/ERK/VEGFC pathway is involved in the progress of this disease.