Patient stratification and therapy in atypical haemolytic uraemic syndrome (aHUS).

Approximately 50% of aHUS patients have an underlying inherited and/or acquired abnormality of complement which predisposes to excessive activation of the alternative pathway. Use of complement inhibitors such as eculizumab to treat aHUS is therefore logical. Anecdotal reports and subsequent open-label trials demonstrated the efficacy of eculizumab in aHUS leading to approval by both the FDA and EMA. NHS England established in 2013 an interim national service for aHUS including funding for eculizumab for both new patients and those undergoing transplantation. NICE guidance now also recommends eculizumab for funding within the NHS in England under the coordination of an expert centre. The investigation and response to treatment in this cohort provides a unique resource for patient stratification.