Castleman's disease and mesangial proliferative glomerulonephritis: the role of interleukin-6.

Renal complications of Castleman's disease (angiofollicular lymph node hyperplasia) are uncommon. The reported cases are very heterogeneous and their renal pathology ranged from minimal change disease, mesangial proliferative glomerulonephritis, to amyloidosis. We have previously reported two cases of Castleman's disease with renal complications. We now present two more such cases. In contrast to other reports, all our cases are of the plasma cell type and their renal pathology showed remarkable similarities, namely mesangial proliferation, interstitial plasma cell infiltration and negative immunofluorescence. The level of serum interleukin-6 (IL-6) in both patients was elevated at presentation and came down with immunosuppressive therapy.