Renal dysfunction in patients taking fumaric acid esters - a retrospective cross-sectional study

Area of Science:

• Dermatology
• Nephrology
• Pharmacology

Background:

• Fumaric acid esters (FAE) have been a long-standing treatment for psoriasis.
• Case reports suggest a link between FAE and nephrotoxicity, including acute renal injury and Fanconi syndrome.
• Contradictory findings exist, with some studies showing no evidence of renal dysfunction with FAE.

Purpose of the Study:

• To assess the incidence of significant proteinuria and renal dysfunction in patients treated with FAE at our institution.
• To identify potential risk factors associated with FAE-induced renal complications.

Main Methods:

• A single-center, retrospective study was conducted.
• Data from 127 patients on FAE therapy were analyzed over an 18-week period.
• Recorded variables included demographics, comorbidities, FAE dosage and duration, proteinuria, renal function, and biochemical markers.

Main Results:

• Eighty-two patients (64.6%) experienced proteinuria during FAE treatment, with 18 (14.2%) showing persistent proteinuria.
• Six patients (4.7%) developed proximal tubular dysfunction (PTD).
• Lower body weight, higher dose per weight, and longer treatment duration were identified as risk factors for PTD. Renal function improved upon FAE dose reduction or discontinuation.

Conclusions:

• Fumaric acid esters are commonly associated with transient or persistent proteinuria.
• Significant renal dysfunction due to FAE is uncommon and typically reversible.
• Screening for proteinuria is essential, and higher FAE doses/longer treatment duration may increase the risk of PTD.