P0332DIAGNOSTIC, THERAPEUTIC AND EVOLUTIONARY FEATURES OF KIDNEY DISEASE IN MULTIPLE MYELOMA

Abstract Background and Aims Multiple myeloma (MM) is a malignant disease of plasma cells. It’s is characterized by clonal proliferation of malignant plasma cells producing monoclonal proteins and causing organ damage. Kidney injury is a common complication of multiple myeloma. Multiple pathogenic mechanisms can contribute to kidney injury in the patient with myeloma, some of which are the result of nephrotoxic monoclonal immunoglobulin and some of which are independent of paraprotein deposition. Method We conducted a retrospective study, from January 1974 to June 2019, including all cases of multiple myeloma with renal impairment treated in our Department. The objective of this study is to analyze the epidemiological and clinico-biological characteristics of MM with renal impairment and to identify the predictive factors of mortality. Results We collected 196 cases. The average age was 63.47 years (31-86 years) with a male predominance (sex ratio 1.27). The circumstances of discovery was dominated by asthenia, anorexia and weight loss in 150 cases (76.5%). Renal involvement was present at the time of diagnosis of myeloma in 138 patients (70.4%) with an average serum creatinine level of 686.42 μmol/l (92-2960 μmol/L). The average hemoglobin level was 8.05 ± 2.4 g/dl. The average 24-hour proteinuria was 2.62 ± 2.11 g/24h. The renal biopsy puncture was performed in 48 patients (24.4%), revealing myelomatous tubulopathy in 16.32% of cases, AL amyloidosis in 5.1% of patients, Randall disease in 3.06% of patients, nodular glomerulosclerosis in 1% of cases and membranous nephropathy in one patient. In our series, 170 patients received chemotherapy. Of the patients, 25.5% required hemodialysis at the time of diagnosis of MM. In our series, 66.83% progressed to the end stage renal disease, 25.5% were in partial remission and 2.05% in total remission. The causes of death were dominated by infectious complications (14.97%). The average renal survival was 4 months. The prognostic factors correlated with poor renal survival were tobacco (p = 0.01), serum uric acid> 600 μmol/l (p = 0.04) and 24-hour proteinuria> 5g/24h (p = 0.009). Conclusion Renal involvement is frequent in multiple myeloma. The spectrum of renal lesions is heterogeneous, and it determines the management and prognosis of MM so the factors associated with renal recovery should be studied further.