Abstract: PUB224
An Unusual Presentation of Atypical Hemolytic Uremic Syndrome in a Patient with Skin Ulcerations
Session Information
Category: Trainee Case Report
- 1500 Onco-Nephrology
Authors
- Blau, Ira H., University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
- Palmer, Matthew, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
- Lohani, Sadichhya, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
Introduction
Atypical hemolytic uremic syndrome (aHUS), characterized by microangiopathic anemia and acute kidney injury (AKI), is a rare and debilitating disease, but its diagnosis can be difficult because of potential overlap with several other autoimmune conditions. We present a case of aHUS-induced acute renal failure with skin ulcerations as initial presentation.
Case Description
A 61-year-old female presented with progressively worsening skin ulcerations on her hands after two cycles of rituximab and bendamustine for B-Cell chronic lymphocytic leukaemia. She also reported cocaine use. On presentation, her physical exam was notable for bilateral ulcers on her knuckles and ankles. She was treated empirically for osteomyelitis without improvement. Skin biopsy was non-diagnostic. She was noted to have anemia, thrombocytopenia and AKI with nephrotic-range proteinuria. Other remarkable labs included a low haptoglobin and a high LDH. Urinalysis revealed dysmorphic red blood cells, and peripheral smear showed schistocytes. An autoimmune process was suspected; thus, pulse steroids was initiated. A renal biopsy was suggestive of thrombotic microangiopathy (TMA). A full immunological work-up eventually returned unremarkable. Plasmapheresis was initiated before her ADAMTS13 activity resulted at > 10%. She was then started on eculizumab. After one session of plasmapheresis and four doses of weekly eculizumab 900 mg, her platelet counts improved. However, she required initiation of renal replacement therapy. TMA panel and genetic testing showed a low factor H level and dysregulated complement cascade consistent with aHUS despite negative CFH-CFHR5 mutation. She had some improvement in urine output but continued to require hemodialysis on discharge. Biweekly eculizumab 1200 mg was continued with plan to closely monitor for renal recovery.
Discussion
Although a rare disease with features that may overlap with other autoimmune processes, aHUS can cause rapid decline in renal function, thus requiring early recognition and treatment. CHF-CFHR5 mutation can be negative in ~40% of the patients. In the presence of the dysregulated complement cascade, microangiopathic process and renal failure, early treatment with eculizumab is crucial in renal recovery, but the renal response to treatment can be delayed compared to the hematologic response.