Background Haemolytic uraemic syndrome (HUS) is a clinical entity defined as the triad of nonimmune haemolytic anaemia, thrombocytopaenia, and acute renal failure, in which the underlying lesions are mediated by systemic thrombotic microangiopathy (TMA). Atypical HUS (aHUS) is a consequence of the insufficient regulation of the activation of the complement on cell surfaces, leading to endotelial damage mediated by C5 and the complement terminal pathway. Eculizumab is a monoclonal antibody that inhibits the activation of C5 and blocks the formation of the cell membrane attack complex. It has been associated with significant long-term improvements in renal function and important reductions in the need for dialysis.

Purpose To describe a case of aHUS in which eculizumab is used as prophylactic therapy to prevent post-transplant aHUS recurrence.

Material and methods Retrospective case report of a 36-years-old female diagnosed with aHUS who carried the heterozygous mutation c.2557T>C in the CFH gene (Complement Factor H).

Results In 2010, the patient presented haemolytic anaemia, acute renal failure, hypertension and cardiorespiratory arrest, secondary to aHUS. She was treated with losartan 100 mg, 30 plasmapheresis sessions, prednisone and dialysis. Moreover, she received two doses of eculizumab, but previously was vaccinated against haemophilus influenzae, pneumococcus and meningococcus. She recovered from haemolytic anaemia but continued her chronic kidney disease needing dialysis, calcium acetate, cholecalciferol 0.266 mg/bimonthly and losartan 100 mg/daily. In May 2016, she started with losartan 25 mg/daily, paricalcitol 1 mcg instead of cholecalciferol, darbepoetin alpha 20 mcg/weekly and iron sucrose 50 mg/weekly as well. On 6 July 2017, she underwent kidney transplantation. It was scheduled with an induction using thymoglobulin, prednisone, mycophenolate-mofetil, tacrolimus and prophylactic eculizumab. The regimen consisted of the administration of the first dose of eculizumab 1200 mg 6 hours pre-transplant, then within 24 hours, then three weekly doses and subsequently, doses of 900 mg in fortnightly cycles. After 16 weeks, this patient has an adequate renal function (creatinine 0.78 mg/dl and glomerular filtration 90 ml/min/1.73 m²). She takes prophylactic penicillin and valganciclovir (450 mg/daily), iron sulphate 100 mg/daily, darbepoetin 40 mcg/monthly, losartan 100 mg/daily and immunosuppressive therapy (prednisone, tacrolimus and mycophenolate-mofetil).

Conclusion This case adds to the evidence of the efficacy of eculizumab prior to kidney transplantation in preventing the progression of aHUS post-transplant and without the need for plasmapheresis.

No conflict of interest