Growth factors and proinflammatory cytokines in the renal involvement of POEMS syndrome.

The POEMS syndrome is a multisystemic syndrome associated with plasma cell dyscrasia, characterized by the combination of polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes. Renal involvement in POEMS syndrome is rare (26 reported cases). It has been described as membranoproliferative glomerulonephritis-like lesions (MPGN-like), mesangiolytic glomerulonephritis, or thrombotic microangiopathy. Proinflammatory cytokines (TNF-alpha, IL-1, IL-6) have been implicated in the physiopathogenesis of POEMS syndrome, particularly when there is renal involvement. Growth factors (FGF-beta, TGF-beta, PDGF) have been implicated in renal lesions of the same histological type but of different origins. An increase in serum vascular endothelial growth factor (VEGF) has been reported in POEMS syndrome (20 of 22 cases). Circulating levels of these factors were determined in 4 patients with POEMS and renal involvement (3 MPGN-like, 1 MPGN-like, and mesangiolysis) and compared with those obtained in 4 patients with POEMS without clinical renal involvement and in 4 patients with primitive membranoproliferative glomerulonephritis (MPGN). TNF-alpha, IL-1beta, and IL-6 were determined with an immunoradiometric assay, and VEGF, PDGF, FGF-beta, and TGF-beta with an enzyme-linked immunosorbent assay. Among the patients with POEMS syndrome, there was no difference in proinflammatory cytokines and growth factors between those with or without renal involvement. VEGF is the only growth factor that differentiates MPGN in POEMS syndrome from primitive MPGN.