L SKEAT1, S DHEDA1
1Cairns Base Hospital, Cairns, Australia
Background: Atypical haemolytic uraemic syndrome (aHUS) represents a subset of thrombotic microangiopathies strongly associated with genetic abnormalities in the alternative complement pathway. Recurrence of aHUS in renal allografts is common, as is de novo disease. Surveillance involves monitoring of peripheral haemolysis markers including thrombocytopenia, LDH, haptoglobin, haemoglobin and fragments on blood film. However, multiple case reports of subclinical aHUS are emerging, calling into question the accuracy of peripheral haemolysis markers. We present a case of recurrent aHUS with normal haemolysis markers, suggesting that aHUS can recur in the allograft in the absence of haematological abnormalities.
Case Reports: A 55-year -old Caucasian women with both native and previous renal graft loss from aHUS, with a confirmed C3 mutation presented with worsening graft function of her second renal transplant. Initial biopsy showed antibody mediated rejected treated with plasma exchange, intravenous immunoglobulin and steroids. Graft function did not improve and two further biopsies were inconclusive. Haemoglobin, platelets, LDH, haptoglobin and blood film remained normal during this time. Given a high index of suspicion and with her genetic propensity, a 3rd biopsy was performed with showed covert renal restricted TMA, confirming recurrent aHUS in her graft. Renal function stabilized with eculizumab and the patient has remained on this therapy while completing a 6-month trip around Australia.
Conclusion: This case highlights that aHUS can recur in renal allografts in the absence of haematological abnormalities. Clinicians should maintain a high level of suspicion for recurrent aHUS and have a low thresh-hold to perform a renal biopsy, particularly in those with a confirmed genetic mutation.
Dr Lee Skeat is a current trainee renal registrar who has spent time working in Far North Queenslan