Prevalence, Incidence and Prognosis of Chronic Kidney Disease in Rheumatoid Arthritis Patients
Rheumatoid Arthritis (RA) is a systemic disorder primarily affecting s the joints; however, it is also known to affect renal system as well. There are several potential causes of nephropathy in RA patients such as drug-related renal disease, where drugs such as NSAIDs and DMARDs are used, secondary renal amyloidosis and various types of glomerulonephritis (GN). There are limited studies available that evaluate and discuss the renal function and histological renal status in RA patients. Patients with RA often experience other types of kidney diseases also. LaTonya Hickson, a nephrologist at Mayo Clinic said that “ Most patients with RA and chronic kidney disease (CKD) do not undergo a kidney biopsy.” While those who did get biopsies, reported a variety of renal diseases including amyloidosis, membranous glomerulonephritis and other glomerular diseases.
Since the prevalence, incidence and prognosis of CKD are still unclear among RA patients, Tokoroyama T et al., conducted a study to describe the prevalence among RA patients. It was a retrospective cohort study including 1077 RA patients, screened through July 2004 to June 2014 . According to the current CKD classification, CKD can be defined as either proteinuria ≥1+ or estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 or both. The cumulative incidence of mortality and CKD were analyzed by Kaplan- Meier method. The association of each outcome with known risk factors was assessed using multivariate Cox proportional hazards regression models. Hazard ratios with 95% confidence intervals for mortality and incidence of CKD were calculated.
The mean follow-up period evaluated was 51.5±39.6 months and the cumulative mortality reported was 20.6% over 10 years. While the prevalence of any CKD reported was 24.5% at the enrollment. Pre-existing CKD was reported to be strongly associated with future death and this association seemed to be the most robust in very high risk CKD. However, the cumulative incidence of CKD over time was 59.5% in 813 patients who did not had prior CKD. The use of prednisolone and NSAIDs increased the likelihood of death.
O summarize, the incidence of CKD gradually increases over the time in RA patients and prevalent CKD may be an potential risk factor linked to the increased mortality in RA patients.