Background: Castleman disease (CD), or angiofollicular lymph-node hyperplasia, is an atypical lymphoproliferative disorder with heterogeneous clinical manifestations. Renal involvement in CD has been described in only single-case reports, which have included various types of renal diseases.
Methods: Nineteen patients with histologically documented CD and renal biopsies available were included. Clinical features and renal histological findings were reviewed, and the available samples were immunolabelled with anti-vascular endothelial growth factor (VEGF) antibody.
Results: Nineteen CD cases were identified: 89% were multicentric, and 84% were of the plasma-cell or mixed type. Four cases (21%) were associated with human immunodeficiency virus (HIV) infection. Among HIV-negative patients, two main patterns of renal involvement were found: (i) a small-vessel lesions group (SVL) (60%) with endotheliosis and glomerular double contours in all patients and with superimposed glomerular/arteriolar thrombi or mesangiolysis in most; and (ii) AA amyloidosis (20%). Renal histology was more heterogeneous among HIV-positive patients. Decreases in glomerular VEGF were observed only in some patients with SVL, whereas VEGF staining was normal in all other histological groups. Interestingly, glomerular VEGF loss associated with SVL was correlated with plasma C-reactive protein levels, a marker of CD activity.
Conclusions: Small-vessel lesions are the most frequent renal involvement in CD, whereas loss of glomerular VEGF is correlated with CD activity and could have a role in SVL pathophysiology.