Eculizumab for Atypical Hemolytic Uremic Syndrome Recurrence in Renal Transplantation

Eculizumab (anti-C5) has been sporadically reportedas an efficient therapy for atypical hemolytic uremicsyndrome (aHUS). However, the lack of series pre-cludes any firm conclusion about the optimal use ofanti-C5 for preventing or treating aHUS posttrans-plant aHUS recurrence. We thoroughly studied 22 re-nal transplant recipients with aHUS who received off-label therapy with anti-C5, including 12 cases, whichhave not been reported yet. Nine patients, all car-rying a complement genetic abnormality associatedwith a high risk of aHUS recurrence, received pro-phylactic anti-C5 therapy to prevent posttransplantrecurrence. Eight of them had a successful recurrence-free posttransplant course and achieved a satisfac-tory graft function, while the remaining patient expe-rienced early arterial thrombosis of the graft. Thirteenrenal transplant recipients were given anti-C5 for post-transplant aHUS recurrence. A complete reversal ofaHUSactivitywasobtainedinallofthem.Importantly,the delay of anti-C5 initiation after the onset of theaHUS episode inversely correlated with the degree ofrenal function improvement. Three patients in whomanti-C5 was subsequently stopped experienced a re-lapse. Altogether these data suggest that long-termeculizumab is highly effective for preventing and treat-ing posttransplant aHUS recurrence. Our study alsoindicates that anti-C5 should be promptly started if arecurrence occurs.Key words: Atypical hemolytic uremic syndrome,eculizumab, renal transplant recipientAbbreviations: aHUS, atypical hemolytic uremic syn-drome; C3, complement component 3; C5, comple-ment component 5; CFB, complement factor B; CFH,complement factor H; CFHR1, CFH-related protein 1;CFI,complementfactorI; SCR,shortconsensusrepeatdomain.Received 02 April 2012, revised 05 July 2012 andaccepted for publication 23 July 2012