Background. Pathogenetic features of the development of diseases and treatment of rheumatoid arthritis (RA) and psoriatic arthritis (PsA) suggest the possibility of developing kidney damage.
Objective. The assessment of the presence and severity of tubular dysfunction in female patients with RA and PsA, and detection of the features of tubular damage depending on the characteristics of the disease.
Material and methods. The study included 61 female patients with RA and 39 patients with PsA aged 18 to 60 years who were treated in the Rheumatology Department of the Regional Clinical Hospital (Saratov). The following exclusion criteria were applieed: the presence of concomitant kidney diseases, stage III hypertension, diseases accompanied by the development of secondary nephropathy, pregnancy, chronic diseases in the acute stage. Tubular dysfunction was assessed by the α1-microglobulin, microalbumin and fermenturia levels. The comparison group consisted of 30 healthy women.
Results. In patients with RA and PsA, an increase in the levels of α1-microglobulin, microalbumin and enzymes in the urine was revealed (p<0.05). The highest severity of tubular dysfunction and albuminuria was detected in patients with PsA and RA with a disease duration of more than 10 years, a high degree of activity of the process, in the presence of pronounced structural changes in the joints, low functional status of the patient, and a high frequency of taking non-steroidal anti-inflammatory drugs.
Conclusion. Tubular dysfunction was revealed in female patients with PsA and RA, and the markers studied can be used as early markers of kidney damage in patients with arthritis. Apparently, α1-microglobulin is the earliest of the parameters studied.

Keywords: ревматоидный артрит, псориатический артрит, тубулярная дисфункция