Aim: comparative analysis of factors influencing the course and prognosis of multiple myeloma, depending on the involvement of the kidneys.
Material and methods. Clinical and laboratory parameters of 100 patients with multiple myeloma were studied: 50 patients with renal involvement (I group) and 50 patients without it (II group). Demographic, constitutional indicators, and treatment regimens were comparable in both groups.
Results. In patients with kidney damage, the diagnosis was established on average after 12,8±2,9 months from the onset of complaints, and in patients without kidney damage – 7,9±1,2 months (t=1,5; p>0,05). Patients with multiple myeloma and kidney damage had significantly lower hemoglobin levels and more often destructive skeletal lesions. By the myelograms, the average percentage of plasma cells in patients with kidney damage is higher than in patients without kidney damage (39,9±2,7% vs 27,6±3,1%, t=3; р<0,01). 13 (26%) patients of the first group required hemodialysis sessions, and in 9 (~70%) of them dialysis treatment was started at the time of diagnosis. In 74% of patients with kidney damage, renal function improved during chemotherapy.
Conclusion. Timely diagnosis of MM will avoid severe kidney damage, promote better renal response and improve the prognosis of the disease.

Keywords: free light chains, kidney damage, multiple myeloma, hemodialysis