Anemia is a new complication in Fabry disease: data from the Fabry Outcome Survey.

BACKGROUND: The prevalence and causes of anemia among patients with Fabry disease are unknown.

METHODS: In a cross-sectional study we examined hemoglobin concentrations of patients with Fabry disease using a large international database, the Fabry Outcome Survey (FOS), and analyzed the association of renal function, heart failure, gastrointestinal symptoms, and inflammation, with anemia (hemoglobin <12 g/dL in females and <13 g/dL in males).

RESULTS: Anemia was present in 34% of 345 patients with Fabry disease. Median hemoglobin in 158 females was 12.9 g/dL and the median hemoglobin of 187 male patients was 13.2 g/dL. The prevalence of anemia among females was 20%, and among males 47%. Among patients with normal renal function [estimated glomerular filtration rate (GFR) >90 mL/min/1.73 m(2)] and anemia, heart failure [New York Heart Association (NYHA) class II to IV] and/or elevated C-reactive protein (CRP) levels were documented in 82% of patients. Up to 67% of patients with decreased estimated GFR presented with anemia. There was also a trend for lower hemoglobin levels among patients with signs of inflammation (defined by an elevated CRP level). We observed no association of the presence of gastrointestinal symptoms with anemia. Analyses in 53 patients receiving enzyme replacement therapy for up to 2 years, suggest no effect on anemia.

CONCLUSION: The results of this study point to a high prevalence of anemia among patients with Fabry disease that is in most instances related to impaired renal function, heart failure, and inflammation. This finding may be of clinical relevance, because anemia is a major risk factor for patients with kidney disease, heart failure, or stroke, which are important manifestations of Fabry disease.