Prevention of recurrence of atypical hemolytic uremic syndrome post renal transplant with the use of higher-dose eculizumab .

Eculizumab, a terminal complement inhibitor, has recently been used successfully to both prevent and treat the recurrence of atypical hemolytic uremic syndrome (aHUS) post renal transplantation. We describe a case that highlights the need to monitor the effects of eculizumab on the complement system and in this case alter the dosage. Despite taking the standard recommended dose of eculizumab for an adult, this aHUS patient developed a low-grade thrombotic microangiopathy on biopsy within months of renal transplantation. Complement assays (trough CH50) showed small amounts of residual terminal pathway activity suggesting inadequate complement blockade on 1,200 mg eculizumab every 2 weeks. Following an increase in the dose of eculizumab to 1,500 mg every 2 weeks, lactate dehydrogenase (LDH), proteinuria, and creatinine decreased, and CH50 assay showed 0%. This case emphasizes the need to monitor clinical parameters and complement activity to ensure that adequate therapeutic blockade is achieved.
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