Features of glomerular filtration rate evaluation for kidney function assessment in patients with rheumatoid arthritis

The development of renal dysfunction in patients with rheumatoid arthritis (RA) is due to the presence and severity of autoimmune disorders, chronic systemic inflammation, a multiplicity of comorbid conditions, and pharmacotherapy features. The most important parameter that describes the general condition of the kidneys is glomerular filtration rate (GFR). This review presents the data on the possibilities of modern methods for determining estimated GFR (e-GFR) and the specificity of their use in various clinical situations that accompany the course of RA. For the initial assessment of GFR in patients with RA it is advisable to use the measurement of e-GFR based on serum creatinine concentration using the CKD-EPI equation (2009) (with or without indexing by body surface area). In cases where the e-GFR equations are not reliable enough or the results of this test are insufficient for clinical decision making, the serum cystatin C level should be measured and the combined GFR calculation based on creatinine and cystatin C should be used.