Role of beta 2 microglobulin in chronic kidney disease

The aim : to study the relationship of beta-2-microglobulin (beta-2 MG) with clinical and laboratory manifestations of chronic kidney disease (CKD). Patients and Methods. The results of a comprehensive examination of 284 people (118 males and 166 females) aged 18 to 86 years with various types of socially significant diseases were studied. All patients underwent thorough collection of clinical and anamnestic data, laboratory monitoring with the determination of the level of systolic and diastolic blood pressure (BP), body mass index, red blood, beta-2-microglobulin (B2M), lipid profile and proteinuria. Kidney function was assessed according to the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formula using serum creatinine. The main group included 113 patients (55 men and 58 women, mean age 50.9±15.8 years), diagnosed with chronic kidney disease (CKD). The control group consisted of 171 people (63 men and 108 women) with various forms of socially significant diseases, but without signs of CKD. Statistical analysis was carried out using the programs Statistica 10.0 (StatSoft Inc., USA) and Microsoft Office Excel 2010 (Microsoft Corp., USA). Results . In the subgroup of patients with CKD, signs of renal failure were observed in 46 people in 40.7 % of cases. As CKD progressed, the signs of impaired metabolism of B2M were more severe: its serum level was 8.646 (7.892; 12.231) mg/l at C4 and 18.444 (11.225; 23.717) mg/l at C5 stages of CKD, and urinary excretion was 2.502 (0.305; 6.313) mg/l at C4 and 2.614 (1.535; 25.812) mg/l at C5 stages of CKD. Regardless of renal dysfunction, the median serum B2M level was clinically significantly higher in females (p>0.05). Single-factor one-way correlation analysis showed statistically highly significant relationship was between serum B2M and creatinine levels both in the subgroup of patients with CKD (r = 0.905; p = 0.001) and in the total sample (r = 0.749; p = 0.001). There was a strong negative relationship between serum B2M levels and estimated glomerular filtration rate (GFR) (r = -0.717; p = 0.001). In individuals without CKD, an increase in serum creatinine was closely associated with an increase in urinary excretion of B2M (r=0.252; p=0.005). Simultaneously, in this category of patients, there was a close correlation between estimated GFR with serum B2M level (r= -0.433; p=0.002) and its urinary excretion (r= -0.247; p=0.005). A direct relationship between an increase in serum B2M and an increase in diastolic blood pressure (r=0.274; p=0.034) among CKD patients was established. In the total sample, a direct relationship between the value of systolic BP and serum B2M level (r= 0.223; p=0.01) was registered, as well as between diastolic BP (r= 0.268; p=0.01) and urinary excretion of B2M. Conclusion . As a result of the study, metabolism of B2M and its relationship with the clinical and laboratory manifestations of CKD were evaluated. The data obtained show high prognostic potential of changes in metabolism of B2M in the population of patients with various forms of socially significant diseases, as well as CKD, which allows to identify among them groups of patients with high and/or very high renal and cardiovascular risk, in order to take timely targeted therapy.