E PAN1, J CHUA1
1Peninsula Health, Frankston, Australia
Background: Atypical haemolytic uraemic syndrome (aHUS) is a rare condition that presents with a triad of microangiopathic haemolytic anaemia, thrombocytopenia and acute kidney injury. Diagnosis can be difficult due to other conditions which present similarly, including malignant hypertension. We present a patient who had severe hypertension and the triad of features seen with aHUS, where it was difficult to differentiate between aHUS and malignant hypertension as the primary cause.
Case report: A 53-year-old female presented with severe hypertension and was found to have the triad features of aHUS with microangiopathic haemolytic anaemia (haemoglobin 65g/L, raised LDH 512units/L and fragments seen on blood film), thrombocytopenia (platelets 115×10^9/L) and severe acute kidney injury (serum creatinine 890micromol/L). ADAMS-TS-13 level was normal (78.2%). A renal biopsy demonstrated changes consistent with thrombotic microangiopathy (TMA) and severe hypertension with small renal arteries containing focal thrombi and having wall thickening with “onion-skin” appearance.
The patient was commenced on haemodialysis and had her anti-hypertensive therapy significantly increased. Eculizumab was commenced for suspected aHUS. During the acute admission there was improvement in haemolysis markers and blood pressure control, however she remained dialysis dependent. Four months since her initial presentation, the patient remains on dialysis. She has persistent hypertension despite treatment, but there is no evidence of haemolysis. She continues eculizumab therapy.
Conclusions: Many clinical features of aHUS and malignant hypertension overlap and it remains a diagnostic challenge to identify the primary cause of patients who present with kidney failure and hypertension, and have TMA. It is difficult to know the utility of eculizumab in these cases, particularly as the diagnosis of aHUS is uncertain and has a significant cost burden to the healthcare system.
Dr Eugenie Pan is a Basic Physician Trainee currently training at Peninsula Health. She is planning to specialise in nephrology in the future.