OBJECTIVES

: Atypical hemolytic uremic syndrome (aHUS) is a rare but serious condition that results from the overactivation of the alternative complement pathway leading to microvascular blood clots. A systematic literature review was conducted to examine international aHUS incidence and prevalence to provide a comprehensive overview of the current epidemiological landscape.

METHODS

: A comprehensive literature search was conducted in EMBASE and MEDLINE. Additionally, we reviewed practice guidelines, national/international organizations, and regulatory agencies. Eligibility criteria were based on type of study and population definition. The population of interest were individuals diagnosed with atypical hemolytic uremic syndrome. Eligible studies included population-based observational studies assessing the incidence and/or prevalence of aHUS. Due to the potential of including other hemolytic uremic syndrome (HUS) disorders in the epidemiologic estimates, aHUS incidence and prevalence must have been strictly defined separately from all other HUS’.

RESULTS

: A total of 2,960 publications were identified. A total of eight full-text articles met all inclusion criteria and were retained for data extraction. All studies were conducted in Europe, Australia, or New Zealand. In Europe reported incidence ranged between 0.23 to 1.9 per million annually in the population. In Australia the only identified study was conducted in pediatrics with a calculated incidence of 0.44 per million annually. Meanwhile, in adult studies, incidence ranged between 0.42 to 1.9 per million annually. In individuals under 20 years of age, prevalence ranged between 2.21 to 9.4 per million people. Prevalence in adults was higher in Europe compared to Australia/New Zealand (5.75 to 2.4 per million people respectively).

CONCLUSIONS

: To our knowledge, this is the first systematic review conducted to provide an overview of global aHUS epidemiology. In general, incidence estimates were similar across all the studies, however prevalence data was found to be more variable.