Hypocomplementemic Urticarial Vasculitis Syndrome With Crescentic Glomerulonephritis

Hypocomplementemic urticarial vasculitis syndrome (HUVS) is a rare autoimmune disease characterized by multiple organ system involvement, including renal disease, with low complement levels. We report the case of a 31-year-old woman who presented with nonspecific symptoms including fatigue, diarrhea, macular rash and abdominal pain with acute renal failure leading to end-stage kidney disease. Laboratory results showed hematuria, nephrotic range proteinuria, worsening creatinine and low C1q levels. Left kidney biopsy showed proliferative glomerulonephritis with crescent formation. She was treated with 6 months of intravenous cyclophosphamide, followed by 2 doses of intravenous rituximab (1 g each), thereafter maintained on mycophenolate mofetil and glucocorticoid-based therapy. She experienced a full recovery of renal function after 12 months of dialysis dependence. Hypocomplementemic urticarial vasculitis syndrome with crescentic glomerulonephritis is a rare disease with only 5 other reported cases in literature. In our case, we document a delayed but excellent renal recovery during a 2-year follow-up.