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Identification of plasma protein biomarkers associated with idiopathic pulmonary arterial hypertension
Author(s) -
AbdulSalam Vahitha B.,
Paul Gideon A.,
Ali J. Omar,
Gibbs Simon R.,
Rahman Dinah,
Taylor Graham W.,
Wilkins Martin R.,
Edwards Robert J.
Publication year - 2006
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200500510
Subject(s) - biomarker , proteomics , medicine , blood proteins , complement component 5 , complement system , gastroenterology , chemistry , immunology , antibody , biochemistry , gene
We have employed SELDI‐TOF MS to screen for differentially expressed proteins in plasma samples from 27 patients with idiopathic pulmonary arterial hypertension (IPAH) and 26 healthy controls. One ion ( m / z ∼8600) that was found to be elevated in IPAH was validated by SELDI‐TOF MS analysis of a second and separate set of plasma samples comprising 30 IPAH patients and 19 controls. The m / z 8600 was purified from plasma by sequential ion exchange and reverse‐phase chromatographies and SDS‐PAGE. It was identified, following trypsin digestion, by MS peptide analysis as the complement component, complement 4a (C4a) des Arg. Plasma levels of C4a des Arg measured by ELISA confirmed that the levels were significantly higher ( p < 0.0001) in IPAH patients (2.12 ± 0.27 μg/mL) compared with normal controls (0.53 ± 0.05 μg/mL). A cut‐off level of 0.6 μg/mL correctly classified 92% of IPAH patients and 80% of controls. Further studies will be needed to determine its performance as a diagnostic biomarker, whether used alone or in combination with other biomarkers. Nevertheless, this study demonstrates that putative biomarkers characteristic of IPAH can be identified using a conjoint SELDI‐TOF MS – proteomics approach.