The role of paraproteins in kidney damage in patients with lymphoproliferative diseases
Authors: Pysarevskaya O. N. , Kotelnikova A. N. , Kazakov S. P. , Potekhin N. P. , Rukavitsyn O. A. 
Published: October 2019

Background.The course of lymphoproliferative diseases, in which the proliferation of a malignant clone is accompanied by the secretion of paraproteins, is often complicated by kidney damage. Perhaps kidney damage is associated with the physicochemical properties of monoclonal proteins.The objective of the studywas to determine the relationship between the type of monoclonal paraprotein, its level of secretion, and kidney damage in lymphoproliferative diseasesMaterials and methods.A retrospective analysis of the data of 108 patients with lymphoproliferative diseases accompanied by paraproteinemia and kidney damage was performed. The age of the patients was 31–86 years (median 62.5 years). 78 out of 108 patients were diagnosed with chronic kidney disease (CKD). CKD was diagnosed in accordance with the clinical guidelines of KDIGO 2012.Results.In patients with multiple myeloma, stage III CKD was diagnosed in 28 (35.9 %) cases, stage IV – in 14 (17.9 %), stage V – in 19 (24.4 %). High risk group for CKD included 10 (9.3 %) of 30 patients without CKD. 91 patients were diagnosed with concomitant diseases predisposing to the development of kidney damage. In the group of patients with paraproteinemic hemoblastosis in combination with CKD, the vast majority were patients with the presence of IgGκ and IgGλ blood paraproteins, free light chains (FLC), and Bence-Jones protein (BJ) in the urine. At the same time, patients with the secretion of IgDλ, IgAλ, IgAκ and IgMκ paraproteins were much less common. The highest level of pathological Ig of all classes and their structural components and fragments was observed in patients with stage III CKD, which is also characteristic of other laboratory markers in CKD. A negative correlation of glomerular filtration rate (GFR) with FLCκ in the blood (r = –0.21), GFR with BJκ (r = –0.35), GFR with FLCλ in the blood (r = –0.13), GFR c BJλ, which indicates a tendency to damage the kidneys of FLC and protein BJ.Conclusion.In patients with lymphoproliferative diseases accompanied by monoclonal secretion of paraprotein and kidney damage with the development of CKD, in most cases IgGκ, IgGλ, FLCκ and FLCλ were determined in the blood, and protein BJ in urine. IgAκ, IgAλ, IgMκ, IgMλ, IgDλ paraproteins were determined much less frequently in serum. The highest level of pathological Ig and their structural components was observed in patients with stage III CKD. No association with quantitative level, type of paraprotein, and kidney damage was found. The role of FLC and BJ protein in the development of nephropathy is noted. The results of the study also show that with the development of the disease and kidney damage with subsequent progression of the stage of CKD in patients with lymphoproliferative diseases and proteinemia, there is a tendency to a temporary decrease in proteinuria and a compensatory increase in the number of paraproteins in the blood. This can be considered as one of the compensatory pathophysiological mechanisms of the protective function of the kidneys.