From the Guidelines
Rheumatoid arthritis can cause several kidney complications, primarily due to the systemic inflammatory nature of the disease and its treatments, with the most common complications being secondary amyloidosis, glomerulonephritis, and drug-induced nephrotoxicity. The kidney complications associated with rheumatoid arthritis include:
- Secondary amyloidosis, where inflammatory proteins deposit in kidney tissues, impairing function and potentially leading to proteinuria and kidney failure
- Glomerulonephritis, with mesangial proliferative glomerulonephritis being the most frequent type
- Drug-induced nephrotoxicity from medications used to treat the disease, particularly NSAIDs which can cause acute kidney injury, and disease-modifying antirheumatic drugs (DMARDs) like methotrexate and cyclosporine which may cause various forms of kidney damage 1, 2
- Renal vasculitis, where blood vessels in the kidneys become inflamed
- Membranous nephropathy, which may occur as an associated autoimmune condition Additionally, RA patients have an increased risk of developing chronic kidney disease due to ongoing inflammation, medication effects, and comorbidities like hypertension and diabetes 3. Regular kidney function monitoring through blood tests (creatinine, BUN) and urinalysis is essential for RA patients, especially those on nephrotoxic medications, to detect complications early and adjust treatment accordingly. According to the 2015 American College of Rheumatology guideline for the treatment of rheumatoid arthritis, laboratory monitoring for traditional DMARDs is crucial to prevent kidney damage 3. Furthermore, the British Association of Dermatologists' guidelines for the safe and effective prescribing of methotrexate for skin disease 2016 recommend evaluation of renal function with eGFR at baseline and avoiding MTX in those with a creatinine clearance of < 20 mL min-1 2.
From the Research
Kidney Complications of Rheumatoid Arthritis
The kidney complications of rheumatoid arthritis (RA) can be significant and may worsen the course and mortality of the primary disease 4. Some of the common kidney complications associated with RA include:
- Glomerulonephritis and amyloidosis, which are the most frequent renal lesions, accounting for 60-65% and 20-30% of cases, respectively 4
- Acute or chronic interstitial nephritis 4
- Secondary renal amyloidosis, which affects survival, increases morbidity, and is the main cause of end-stage renal disease in patients with RA and nephropathy 4
- Nephrotoxic effects of antirheumatic drugs, such as NSAIDs and DMARDs 4, 5
- Mesangial glomerulonephritis, which is the most frequent histological lesion in RA nephropathies, followed by minimal change glomerulopathy and p-ANCA positive necrotizing crescentic glomerulonephritis 4
- IgA nephropathy, FSGS, and membranous nephropathy, which have also been reported in patients with RA 5, 6
Renal Manifestations and Treatment
The renal manifestations of RA can be improved with advances in treatment strategies, including the use of biologic agents and methotrexate 7. These treatments can reduce the risk of renal complications and improve outcomes in patients with RA. However, certain medications, such as NSAIDs and DMARDs, may need to be adjusted or avoided in patients with renal dysfunction to prevent adverse events 8. Regular monitoring of renal function and performance of renal biopsy in patients with suspected renal disorder are essential for early detection and treatment of kidney complications in RA 5.