A case of multicentric Castleman's disease demonstrating severe eosinophilia and enhanced production of interleukin-5.

Introduction: Castleman's disease (CD), idiopathic lymph-node hyperplasia, is a heterogeneous disease of unknown origin. Although the pathophysiology is yet to be elucidated, interleukin (IL)-6 produced by swollen lymph nodes has been reported to play a crucial role in CD. Case report: This report presents a case of a 37-yr-old man with CD showing marked elevation of IL-6, hypereosinophilia, and also IL-5 elevation. To date, IL-5 has not been reported to influence CD. However, because in this case the serum concentration of IL-5 produced from swollen lymph nodes paralleled the general symptoms, IL-5, in addition to IL-6, may have played an important role in the disease. Discussion: Although in CD the serum IL-5 level is generally within the normal range, mild eosinophilia is a common complication of the disease. This case indicates that IL-5 can also influence eosinophilia. Taken together, this suggests that there may be a more general association between local production of IL-5 and the pathology of CD.