Monoclonal immunoglobulin as a prognostic factor for the severity of bone damage in paraproteinemic hemoblastoses and Waldenström’s macroglobulinemia

Aim. Identify risk factors for the development of osteodestructive syndrome. To determine the relationship between the types of secreted monoclonal immunoglobulin (paraprotein) and the severity of osteodestructive syndrome in patients with paraproteinemic hemoblastoses (PH) and Waldenström’s macroglobulinemia (WM).Materials and methods. A retrospective analysis of data from 116 patients with PH and WM was performed. 104 patients (89.6 %) were diagnosed with multiple myeloma. Less commonly observed were WM (in 8 patients – 6.9 %), plasma cell leukemia (in 2 patients – 1.8 %), solitary plasmacytoma and monoclonal gammopathy of unknown significance were diagnosed in one case (0.9 %) each. According to the severity of osteodestructive syndrome, all patients were divided into 4 groups. The first group (0) included patients who did not have osteodestructive changes in the bones. In patients of the second group, a mild degree (I) osteodestructive process was observed, and in patients from the third and fourth groups – moderate (II) and severe (III) degrees, respectively. All patients underwent protein electrophoresis followed by immunofixation to determine the type of paraprotein and its concentration in serum and urine.Results. In the majority of patients, paraproteins were detected in the blood – Gκ (35.1 %), Gλ (24.6 %), Bence Jones protein λ-type (BJλ) (14.9 %); in urine – BJλ protein (14.9 %) and Bence Jones protein κ-type (BJκ) (28.1 %). Secretion of other types of paraproteins in the blood was less frequently detected – Aκ (9.6 %), Aλ (7.0 %), Mκ (3.5 %), Mλ (3.5 %), Dλ (2.6 %), BJκ (4.4 %). Osteodestructive syndrome of I and II severity was diagnosed in 43 (37.1 %) and 40 (34.5 %) patients, respectively; lytic destruction of III degree was less frequently detected in 20 (17.2 %) patients, in 13 (11.2 %) patients osteodestruction was not detected (degree 0). It was noted that a higher degree of destruction (II, III) was observed in patients with multiple myeloma occurring with paraproteinemia Dλ and BJλ in the blood, as well as hypercalcemia. Osteodestructive syndrome of the lowest degree (0, I) was diagnosed in patients with the secretion of monoclonal proteins Ak and Mλ. There was no statistically significant relationship between the type of secretion of paraproteins Gκ, Gλ, Aλ, Mκ, BJκ in the blood, as well as proteins BJκ and BJλ in the urine and the severity of the osteodestructive process.Conclusion. The results obtained in the study make it possible to identify risk groups, and parameters such as the type of paraprotein, the concentration of calcium in the blood serum can be considered as prognostic factors when assessing the severity of osteodestructive syndrome in patients with PH and WM.