Differentially Expressed Plasma Peptides in Heart Failure

Background: While the socioeconomic and human costs of chronic heart failure (HF) increase throughout the developed world, the number of useful diagnostic biomarkers is small. Cardiovascular lesions are likely to leave peptide traces in the bloodstream that are informative of pathology. Furthermore, analysis of multiple peptide biomarkers may increase diagnostic/prognostic test sensitivity and specificity. This study uses peptide profiling to identify potentially clinical-relevant peptide biomarkers for HF. Methods: Normal and HF patient blood plasma collected and depleted of highly abundant proteins before MALDI/ToF peptide profiling. ClinProTools software was used to process and analyse the mass spectra and identify differentially expressed peptides. Results: The ion peak areas of 17 peptide ions were differentially expressed in HF patients compared with normal subjects (figure). Of these peptides, 9 were identified by searching a human protein databases using the Mascot or Peaks programs. Of these, five originate from cell membranes and secreted proteins and several have known cardiovascular functional activity. In particular, gamma-glutamyl-transpeptidase 2 is a known HF biomarker. Conclusion: This study demonstrates the utility of our peptidomic approach for identifying blood-borne peptides differentially expressed in HF patients. We intend to further validate these peptides for use in multimarker diagnostic/prognostic assays.