POS-538 KIDNEY DISEASE IN MULTIPLE MYELOMA

Abstract

Multiple myeloma (MM) is characterized by a proliferation of malignant plasma cells and a subsequent overabundance of monoclonal paraprotein invading the hematopoietic marrow and other organs such as bone.Kidney disease is a common complication of MM. It can be indicative of the disease, or appear during its course. The objective of our work was to determine the incidence and clinical-biological aspects of renal involvement in multiple myeloma It was a retrospective and descriptive study including patients hospitalized in nephrology department of Sahloul Hospital in Sousse with multiple myeloma and renal disease, during the period from December 2007 to June 2019. We collected 53 patients with an average incidence of 4.8 new cases / year. The average age of our patients was 63.53 years +/- 11.49 years with extremes ranging from 41 years to 85 years. There was a slight male predominance with a sex ratio M / F = 1.2. In more than 50% of cases, MM was hitherto unrecognized and the diagnosis was made during the exploration of renal failure in nephrology department. Only 24.5% of patients were already diagnosed and treated for MM in hematology department and renal failure had occurred during the course of the disease. The circumstances of discovery of renal disease were represented by bone pain and odematous syndrome with urine dipstick proteinuria. General manifestations were dominated by the presence of general deterioration in 35 patients (67.3%) followed by signs of extracellular dehydration which was objectified in 23 patients (34.4%). Acute renal injury (ARI) was found in 43 patients (81.1%). This acute renal failure was secondary to myelomatous tubulopathy in 79.1% of cases; functional in 7% of cases. A functional ARI associated with myelomatous tubulopathy was found in 14% of cases. Myelomatous tubulopathy confirmed by renal puncture biopsy (RPB) in 11 cases. AL amyloidosis was found in 10 cases (18.9%) of which 7 cases were confirmed by RPB and in 3 cases the diagnosis was established by accessory salivary gland biopsy. Histologically unproven chronic glomerular nephropathy was found in 2 cases. Myelomatous tubulopathy is by far the most common renal complications of myeloma and a major cause of acute renal injury, hence the value of screening for renal involvement in any patient followed for myeloma.