Assessment of Renal Involvement in an Iraqi Cohort of Rheumatoid Arthritis

Abstract

Background: Rheumatoid arthritis (RA) is an autoimmune chronic systemic inflammatory disease involves synovial joints but may involveextra‑articular organ as well. Objectives: to determine the prevalence of indicators of renal involvement in patients with RA with implicationsof impact of related drugs on the kidney. Materials and Methods: This cross‑sectional study was conducted from May 1, 2019, to November1, 2019, in the Outpatient Rheumatology Clinic of Hawler teaching hospital, Erbil, Iraq. One hundred and seventy‑six patients with seropositiveRA were enrolled, other 13 were dropped because of missing data. Participant’s characteristics and data regarding drug history were collected.Body mass index (BMI), erythrocyte sedimentation rate (ESR), and serum creatinine were measured; renal function was assessed from theestimated glomerular filtration rate (eGFR) using the modification of diet in renal disease formula. Urine examined for proteinuria, microscopichematuria, and noninfectious leucocyturia. When eGFR <60 ml/min/1.73 m² regarded as renal impairment, impact of RA medicationsnon‑steroidal anti‑inflammatory drug, disease‑modifying anti‑rheumatic drugs, and biological agents on renal function and urine sedimentswere studied. Results: Out of a total 176 RA patients, 56.8% were females, their mean age 50.4 (±10.4) years, BMI 28.7 (±3.6) kg/m²,with disease duration 8.3(±4.5) years. Renal impairment was detected in 20 (11.4%) participants. Proteinuria, hematuria, and uninfectiousleucocyturia were observed in 10.2%, 23.9%, and 25%, respectively. Renal dysfunction was significantly associated with old ages, BMI ≥30,long duration of disease and proteinuria (P = 0.004, 0.002, 0.014, and 0.009, respectively). Renal impairment was not significantly associatedwith sex, smoking status, ESR level, RA medications, hematuria, and uninfectious leucocyturia (P > 0.5). Conclusions: Renal disorder iscommon in RA patients. Regular monitoring of renal involvement by using eGFR and urinary dipstick is crucial, especially in the elderlyobese RA patients with a long duration of the disease and proteinuria. Early identification of renal disease can facilitate the early interventionand achieve the better management of RA patients.