SYNOVIAL MAST CELLS CORRELATE WITH INFLAMMATION AND CELLULAR INFILTRATION AND ARE ASSOCIATED WITH ECTOPIC LYMPHOID STRUCTURES IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS

Abstract

The analysis of synovial membrane has gained much attention in recent years as a biomarker for patient stratification in RA. Different degrees of cellular infiltration have been described, leading to the definition of specific histological patterns (pathotypes). Mast cells (MCs) are among the immune cells infiltrating the inflamed synovium, and many experimental observations suggest that they participate to the inflammatory response in RA. However, their contribution to the pathogenesis of RA is still controversial and, in particular, their presence in the synovial membrane has never been analysed systematically, nor their relation to synovial inflammation and pathotypes. The aim of this study was to evaluate the presence of MCs in the synovial membrane of early RA patients and assess the correlation with synovial inflammation and cellular infiltration.