Introduction: Atypical hemolytic uremic syndrome (aHUS) is a progressive and potentially life-threatening disease characterized by complement-mediated thrombotic microangiopathy. Patients with aHUS may experience fatigue, which can negatively impact their lives, but there is a knowledge gap regarding disease burden in these patients. Methods: In this longitudinal study, patients with aHUS from the Global aHUS Registry who completed patient-reported outcome assessments (Functional Assessment of Chronic Illness Therapy-Fatigue scale [FACIT-Fatigue], general health status, and work status) at ≥2 time points were assessed relative to treatment status: (i) never treated with eculizumab; (ii) on eculizumab at registry enrollment and continued therapy; and (iii) started eculizumab after registry enrollment. Results: Patients who started eculizumab after the baseline visit (n = 23) exhibited improvements in fatigue (nearly 75% achieved clinically meaningful improvement), improved general health status (55%), and 25% to 30% rate reduction in symptoms of fatigue, weakness, irritability, nausea/vomiting, and swelling at last follow-up. Among patients already on eculizumab at registry enrollment (n = 295) and those never treated (n = 233), these parameters changed minimally relative to the baseline. Emergency room visits and hospital admissions were similar between groups. The number of health care provider visits and work days missed were higher in patients who started eculizumab after registry enrollment. Conclusion: These real-world findings confirm the detrimental effects of aHUS on patients’ daily lives, including high levels of fatigue and impairments in general health status. The results suggest clinically meaningful improvement in fatigue, other patient-reported outcomes, and symptoms with eculizumab initiation after enrollment into the aHUS registry.
