Rapid recovery of membrane cofactor protein (MCP; CD46) associated atypical haemolytic uraemic syndrome with plasma exchange.

Atypical haemolytic uraemic syndrome (aHUS), unlike typical HUS is due to complement dysregulation. At least one abnormality of the complement system can be identified in 70% of patients. aHUS is associated with a poor prognosis with 25% mortality and 50% progress to end-stage renal disease. Genetic abnormalities in the complement system, proteins including CFH, CFI, CFB, C3, CFHR1/3 and MCP (CD46) lead to uncontrolled complement activation in aHUS. We presented the second reported case of aHUS associated with a heterozygous c.191G > T mutation in exon 2 of MCP who responded rapidly to plasma exchange.