Decreased chronic kidney disease in rheumatoid arthritis in the era of biologic disease-modifying anti-rheumatic drugs

Background: We investigated the incidence of chronic kidney disease (CKD) progression and its factors relevant to patients with stable rheumatoid arthritis (RA). Methods: We enrolled consecutive patients with RA who had initiated treatment with a biologic disease-modifying anti-rheumatic drug (bDMARD) at our institution and continued the same drug for >5 years between 2001 and 2016. Patients with CKD at bDMARD initiation were excluded. C-reactive protein (CRP) level, Clinical Disease Activity Index (CDAI) score and estimated glomerular filtration rate were measured every 6 months. Results: We included 423 patients, with 196 on tumour necrosis factor inhibitors, 190 on tocilizumab and 37 on abatacept. Among these patients, 34 (8.0%) progressed to CKD within 5 years. The mean CRP level and CDAI score over 5 years were significantly lower in patients without CKD progression than in those with CKD progression (P <. 001 and P =. 008, respectively). Multivariable analysis revealed that age at bDMARD initiation [odds ratio (OR) 1.05, P =. 002], non-steroidal anti-inflammatory drug use (OR 3.47, P =. 004) and mean CRP >0.14 mg/dL (OR 5.89, P =. 015) were independently associated with CKD progression, while tocilizumab use was associated with a decreased risk of CKD progression (OR 0.31, P =. 027). Conclusions: Controlling inflammation contributes to the inhibition of CKD progression in RA patients.