Initial Treatment of Patients with Suspected aHUS
We recommend that all patients with a potential new diagnosis of complement mediated primary aHUS are offered treatment with eculizumab. The earlier treatment with eculizumab is initiated the greater the chance of recovery of renal function. Although all investigations on the diagnostic checklist must be undertaken at initial presentation in adults only the ADAMTS13 activity must be available prior to authorisation of Eculizumab. Until this is available we recommend that plasma therapy is undertaken where appropriate.
In children due to the rarity of TTP and the difficulty of plasma exchange Kidney Disease: Improving Global Outcomes (KDIGO) recommended that Eculizumab can be commenced prior to the ADAMTS13 result with the caveat that clinical deterioration on eculizumab should necessitate immediate plasma therapy.
Thrombotic microangiopathy occurring in the post-transplant period can be due to several factors including acute antibody mediated rejection and calcineurin inhibitor toxicity. Currently Eculizumab is not licenced for treatment of secondary TMAs. However, there is evidence that some cases of post-transplant TMA may be due to defective complement regulation. These patients may therefore benefit from treatment with Eculizumab. We are happy to discuss any patient with evidence of a post-transplant TMA and can arrange testing for complement activation and for abnormalities in complement regulation.