Developing clinically relevant biomarkers in inflammatory arthritis: A multiplatform approach for serum candidate protein discovery.
To identify candidate biomarkers that have the potential to distinguish between patients with psoriatic arthritis (PsA) or rheumatoid arthritis (RA) and explore the value of combining different protein discovery platforms for the development of a multiplexed protein biomarker panel.



Serum samples from 32 patients (PsA; n = 16 and RA; n = 16) defined as active, early onset, and treatment naïve were analyzed using unbiased label-free LC-MS/MS, a microsphere bead-based immunoassay (Luminex xMAP) and an aptamer-based assay (SOMAscan).



LC-MS/MS was used to quantify 324 proteins, while the Luminex xMAP targeted 48 proteins and SOMAscan supported the measurement of 1129 proteins. The combined data from these techniques gave reproducible quantification of 1501 proteins in total. Of these, 42 (LC-MS/MS), 3 (Luminex xMAP), and 127 (SOMAscan) proteins were found to be differentially expressed between PsA and RA (p < 0.05).



Using three different and potentially complementary proteomic platforms we identified a total of 172 proteins that are differentially expressed in patients with PsA compared to RA. These proteins collectively represent candidates for inclusion in a protein signature that could be developed as a diagnostic test to discriminate patients with PsA from RA and therefore be of clinical utility.
School of Medicine and Medical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland.
Angela
A
McArdle
School of Medicine and Medical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland.
Aisha
A
Qasim Butt
Department of Rheumatology, St. Vincent's University Hospital, Elm Park, Dublin, Ireland.
Agnes
A
Szentpetery
Department of Pediatric Immunology, Laboratory of Translational Immunology LTI, Wilhelmia Children's Hospital, University Medical Centre Utrecht, Utrecht, The Netherlands.|Multiplex Core Facility, Laboratory of Translational Immunology LTI, University Medical Centre Utrecht, Utrecht, The Netherlands.
Wilco
W
de Jager
Department of Pediatric Immunology, Laboratory of Translational Immunology LTI, Wilhelmia Children's Hospital, University Medical Centre Utrecht, Utrecht, The Netherlands.
Sytze
S
de Roock
School of Medicine and Medical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland.|Department of Rheumatology, St. Vincent's University Hospital, Elm Park, Dublin, Ireland.
Oliver
O
FitzGerald
School of Medicine and Medical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland.
Stephen R
SR
Pennington
D000328:Adult; D015535:Arthritis, Psoriatic / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism*; D002853:Chromatography, Liquid; D003937:Diagnosis, Differential; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D053719:Tandem Mass Spectrometry
D015415:Biomarkers; D001798:Blood Proteins
LC-MS/MS; Luminex; Multiplexing; Psoriatic and Rhuematoid Arthritis; SOMAscan