[Crow-Fukase (POEMS) syndrome].

Crow-Fukase syndrome is also called POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes) syndrome and is a rare cause of demyelinating and axonal mixed neuropathy with multiorgan involvement. The pathogenesis of Crow-Fukase syndrome is not well understood, but overproduction of vascular endothelial growth factor (VEGF), probably mediated by monoclonal proliferation of plasma cells, is likely to be responsible for most of the characteristic symptoms. However, other cytokines are also upregulated and could contribute to the pathophysiology of this syndrome. The etiopathophysiology of peripheral neuropathy is unclear, but VEGF may affect the blood-nerve barrier and allow some neurotoxic substances in the serum to access the nerve parenchyma, resulting in nerve demyelination. Moreover, microangiopathy due to proliferative endothelial cells and hypercoagulability may contribute to the development of neuropathy. A recent molecular biological study has shown oligoclonal usage of V(lambda) subfamily in light chain of the M-protein, suggesting that particular patterns of V(lambda) gene are associated with the development of Crow-Fukase syndrome. There is no established treatment regimen for this syndrome. In appropriate candidates, high-dose chemotherapies with autologous peripheral blood stem cell transplantation is highly recommended, because this treatment can cause obvious improvement in neuropathy as well as other symptoms, with a significant decrease in serum VEGF levels. The indication for this treatment has not yet been established, and the long-term prognosis is unclear. Potential future therapies include the administration of thalidomide or lenalidomide, and anti-VEGF monoclonal antibody (bevacizumab).