Renal involvement in Behçet´s Disease: a rare clinical challenge.

Although Behçet´s disease (BD) is a systemic inflammatory disease, renal involvement is uncommon and ranges from mild asymptomatic urinary abnormalities to severe disease with progressive renal failure. We describe the case of a 30 years-old woman with multiorgan BD, under ustekinumab, who presented with proteinuria, hematuria and impaired renal function. Kidney biopsy revealed histological findings of active renal vasculitis in the context of IgA nephropathy and tubulointerstitial nephritis and the patient was treated with corticosteroids and cyclophosphamide with excellent response. Our case highlights the importance of recognizing a possible renal involvement in BD patients, reinforcing the need for monitoring renal function and urinalysis in these patients.