Brain-derived neurotrophic factor as biomarker

The publication on “Prognostic significance of brain-derived neurotrophic factor (BDNF) levels in patients with heart failure and reduced left ventricular ejection fraction” is very interesting (1). Barman et al. (1) concluded that decreased serum BDNF levels were associated with death and rehospitalization in patients with HF, suggesting their usefulness as prognostic biomarkers. As commented in the editorial, concurrent medical disorders can alter the clinical significance of BDNF (2). Nevertheless, there are other concerning factors regarding the usefulness of BDNF as a biomarker. For example, in laboratory medicine, poor reproducibility of the BDNF assay is common, which limits its usefulness as a biomarker (3). In addition, the conditions of blood sample collection and processing can significantly affect the BDNF levels (4). As reported by Tsuchimine et al. (5), anticoagulant compounds as well as the storage time and temperature during blood sampling can affect the measurements of plasma BDNF levels