What is the diagnosis and management of vasculitis in a patient undergoing dialysis (renal replacement therapy)?

From the Guidelines

Vasculitis in dialysis patients should be treated with a minimum of 6 months of induction immunosuppression, considering the high risk of infection and related mortality, and low relapse risk, as suggested by the 2023 KDOQI US commentary 1.

Key Considerations

• The decision to discontinue induction immunosuppression in patients with renal-limited vasculitis who remain on dialysis should be made with caution, weighing the risks of infection and treatment-related complications against the benefits of continued therapy.
• Patients should be monitored closely for the emergence of extrarenal disease or treatment-related complications.
• Rituximab-treated patients may have B-cell depletion for more than 8 to 12 months, which should be taken into account when planning treatment duration and monitoring.

Treatment Approach

• The recommended approach includes corticosteroids (prednisone 1 mg/kg/day, maximum 60-80 mg daily) as initial therapy, often combined with cyclophosphamide (2 mg/kg/day orally or 15 mg/kg IV pulse every 2-3 weeks) for severe disease.
• Rituximab (375 mg/m² weekly for 4 weeks) is an alternative for ANCA-associated vasculitis.
• Treatment duration typically involves 3-6 months of induction therapy followed by maintenance with lower-dose steroids and either azathioprine (2 mg/kg/day), methotrexate (15-25 mg weekly), or mycophenolate mofetil (1-2 g daily).

Important Considerations for Dialysis Patients

• Medication doses must be adjusted for renal function and dialysis schedule.
• Dialysis patients with vasculitis face unique challenges, including increased infection risk, drug clearance issues during dialysis, and potential disease flares triggered by dialysis membranes.
• Close monitoring for treatment complications is essential, including complete blood counts, liver function tests, and signs of infection.
• Plasma exchange may be considered for severe presentations with pulmonary hemorrhage or rapidly progressive glomerulonephritis, as noted in the 2014 Canadian Society of Nephrology commentary 1.

Underlying Cause Investigation

• The underlying cause of vasculitis should be investigated, as some forms may be secondary to medications, infections, or malignancies that require specific management approaches.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Vasculitis in Patients on Dialysis

• Vasculitis can present as rapidly progressive glomerulonephritis, characterized by acute kidney injury, hematuria, and proteinuria 2, 3, 4.
• Treatment of renal vasculitis involves the use of steroid and non-steroid agents, with or without adjunctive plasma exchange 2, 3, 4.
• Plasma exchange as adjunctive therapy can significantly reduce the risk of end-stage kidney disease at 12 months 2, 3, 4.
• Induction therapy with rituximab or cyclophosphamide can be effective, with rituximab being non-inferior to cyclophosphamide for remission-induction in severe ANCA-associated vasculitis 5.
• Maintenance therapy with azathioprine, mycophenolate mofetil, or rituximab can be effective in preventing relapses 3, 4.

Treatment Options

• Cyclophosphamide is a standard induction treatment, but rituximab and mycophenolate mofetil are also effective 2, 3, 4.
• Azathioprine, methotrexate, and leflunomide are effective as maintenance therapy 3, 4.
• Plasma exchange is effective in patients with severe acute kidney injury secondary to vasculitis 2, 3, 4.
• Pulse cyclophosphamide may result in an increased risk of relapse compared to continuous oral use, but with a reduced total dose 2, 3, 4.

Clinical Spectrum

• The frequency of renal involvement in vasculitis varies among different syndromes, with Wegener's granulomatosis and microscopic polyarteritis being more common 6.
• The clinical expression of renal vasculitis depends on the size of the affected vessels and can include renovascular hypertension, isolated non-nephrotic proteinuria, interstitial nephritis, and glomerulonephritis 6.
• Diagnosis is established by a combination of history, clinical manifestations, laboratory findings, imaging techniques, and renal biopsy 6.
• Prognosis varies from unfavorable in rapidly progressive glomerulonephritis to benign, as in the case of Henoch-Schonlein purpura 6.