Castleman's disease is a benign lymphoproliferative disorder in which interleukin-6 (IL-6), a pleiotropic proinflammatory cytokine, is thought to play a pathogenetic role. Presented is the case of a 72-year-old man with Castleman's disease who exhibited progressive renal dysfunction with proteinuria. Renal biopsy revealed mesangial hypercellularity and matrix expansion in most glomeruli and peritubular inflammatory cell infiltration. Immunofluorescence studies showed intense deposition of IgG in a granular pattern along the glomerular basement membrane. Histological features were compatible with membranoproliferative glomerulonephritis accompanied by interstitial inflammatory cell infiltration. Immunohistological analysis showed that IL-6 was abundantly expressed by tubular cells and interstitial macrophages, suggesting involvement of IL-6 in the renal injury. As a result of administration of tocilizumab, a humanized anti-IL-6 receptor antibody, the patient experienced clinical and biochemical improvement of Castleman's disease, including marked reduction of proteinuria and stabilization of renal function. These findings suggest the efficacy of tocilizumab against Castleman's disease and its renal complications.
CEN case reports. 2012 Mar 17 [Epub]
Akito Maeshima, Masao Nakasatomi, Daizo Henmi, Shin Yamashita, Yoriaki Kaneko, Takashi Kuroiwa, Keiju Hiromura, Yoshihisa Nojima