[Renal involvement in monoclonal gammopathy and multiple myeloma]

Lymphoproliferative disorders often involve the kidney either by direct cell infiltration (lymphoma) or by deposition of paraproteins (monoclonal gammopathy, multiple myeloma, LCDD, amyloidosis). Nowadays the latter phenomenon seems to be the most common as a result of the growing number of elderly people affected by monoclonal gammopathies. The nephrotoxic potential of monoclonal immunoglobulins and amyloidogenic proteins make monoclonal gammopathies clinical entities of considerable interest in nephrology. Renal involvement presents different clinicomorphological patterns depending on the qualitative and quantitative characteristics of the paraproteins. Tubulointerstitial toxicity is frequent, while vascular and glomerular lesions resulting from non-inflammatory reactions due to immunoglobulin deposition are less common. Acute kidney failure may complicate the clinical course; this could be due to tubular obstruction by paraproteins or to hypovolemia induced by chemotherapy in association with diuretics. Early diagnosis of renal involvement will allow prophylactic interventions to prevent renal complications. At the same time, the increased number of therapeutic tools has enabled better management of kidney complications in lymphoproliferative disorders.