Figure 1

Outline of the strategy implemented in the study. Synovial fluid samples from RA and SpA patients were subjected to multilectin affinity enrichment. Three lectins - Concanavlin A (C), Wheat Germ Agglutinin (W) and Jacalin (J) were pooled together and used for glycoprotein enrichment from synovial fluid samples of RA and SpA. The enriched proteins were trypsin digested followed by iTRAQ labeling (RA with 116 and SpA with 117). The labeled tryptic peptides were pooled and fractionated by SCX chromatography. The samples were then analyzed on an LTQ-Orbitrap Velos mass spectrometer coupled to a nano-HPLC unit. Data obtained were searched using SEQUEST and Mascot. Finally, an ELISA assay was carried out to validate the upregulation of sVCAM-1 in RA as compared to SpA.