What is aHUS?

aHUS is a disease of uncontrolled complement activation that affects as many adults as it does children1,2

Atypical hemolytic uremic syndrome (aHUS) is a rare, life-threatening, genetic disease. aHUS can damage vital organs such as the kidneys, heart and brain.2,3

Although aHUS does affect children, almost one-half of people affected are adults.1,2

In aHUS, the complement system (part of the immune system) is uncontrolled. It is always on and can attack the body it normally protects.4

Damage from the uncontrolled complement system is known as systemic thrombotic microangiopathy (TMA). If your complement system is uncontrolled, cells along blood vessel walls become damaged. Platelets become overactive and blood clots form in tiny blood vessels throughout the body. Clots can block blood flow, create inflammation, and travel to other organs, causing further damage.4,5,6

  • The uncontrolled complement part of the immune system causes abnormal clotting and inflammation
  • This results in damage to tiny blood vessels
  • The damage that occurs throughout the body is known as TMA
  • TMA can lead to problems in kidneys and other vital organs

1. Laurence J. Atypical hemolytic uremic syndrome (aHUS): making the diagnosis. Clin Adv Hematol Oncol. 2012;10(suppl 17):1-12. 2. Legendre CM, Licht C, Muus P, et al. N Engl J Med. 2013;368:2169-2181. 3. Sellier-Leclerc A-L, Frémeaux-Bacchi V, Dragon-Durey MA, et al; French Society of Pediatric Nephrology. Differential impact of complement mutations on clinical characteristics in atypical hemolytic uremic syndrome. J Am Soc Nephrol. 2007;18:2392-2400. 4. Noris M, Mescia F, Remuzzi G. STEC-HUS, atypical HUS and TTP are all diseases of complement activation. Nat Rev Nephrol. 2012;8:622-633. 5. Noris M, Caprioli J, Bresin E, et al. Relative role of genetic complement abnormalities in sporadic and familial aHUS and their impact on clinical phenotype. Clin J Am Soc Nephrol. 2010;5:1844-1859. 6. Caprioli J, Noris M, Brioschi S, et al; for the International Registry of Recurrent and Familial HUS/TTP. Genetics of HUS: the impact of MCP, CFH, and IF mutations on clinical presentation, response to treatment, and outcome. Blood. 2006;108:1267-1279.