[Renal involvement in POEMS syndrome]

We described a patient with a POEMS syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal grammapathy and Skin changes) who was found to have renal involvement with peculiar renal pathological findings. Hitherto, 17 other cases, most of them from Japan, of POEMS syndrome with renal involvement, have been published. Clinical features are variable: acute renal failure with anasarca or moderate chronic renal insufficiency with mild proteinuria. This latter presentation often passes unnoticed. There is no severe HTA, no microangiopathic hemolytic anemia. Renal biopsy shows prominent glomerular changes which are unusual and distinct from membranoproliferative glomerulonephritis (MPGN) and from glomerular thrombotic microangiopathy (TMA). Mesangial proliferation and thickening of the capillary wall with double contour evoke by light microscopy a MPGN. By immunofluorescent microscopy, no immunoglobulins or complement deposits are found. The finding of mesangiolytic lesions has led to the term of "mesangiolytic glomerulonephritis". The presence, on electron microscopy, of lucent subendothelial space could evoke TMA. But there is neither thrombi, nor arteriolar changes. We are inclined to presume that microangiopathic lesions are due to chronic injury of glomerular endothelial cells, exacerbated at outbreaks of the disease. An increased production of IL-6 could support the efficacity of corticosteroid therapy, particularly in acute clinical situations.