Subclinical atypical haemolytic uremic syndrome relapse following discontinuation of eculizumab.

A 25-year-old man presented with microangiopathic haemolytic anaemia and acute kidney injury. With a normal ADAMTS-13 level, negative faecal shiga-toxin test and strong family history of atypical haemolytic uremic syndrome, he was commenced on eculizumab to good clinical response. Subsequent genetic testing revealed a heterozygous complement factor H mutation. Eculizumab was discontinued after 44 months of treatment, and he relapsed within 6 months, with the first sign being downtrending haptoglobin levels, with no other markers of haemolysis or thrombocytopaenia, 5 weeks prior to development of acute kidney injury. He was recommenced on eculizumab and to date still remains on it. This case highlights the unusual pattern of relapse and discusses the considerations for eculizumab discontinuation in patients with stable atypical haemolytic uremic syndrome receiving maintenance therapy.