Evaluation of Serum Follistatin-Like Protein 1 Levels in Behcet's Disease and Its Association With Disease Activity

Behçet's disease (BD) is a multi-system auto inflammatory disorder with vasculitic features Clinical manifestation of BD includes recurrent oral and genital ulcerations, uveitis, skin lesions, vascular, neurological, and gastrointestinal manifestations.The exact etiological of BD is still obscure, although environmental and genetics factors have been found to be involved in disease pathogenesis.

Most of BD manifestations have features of systemic perivasculitis. Cell-mediated immunity has a significant role in BD pathogenesis . Activation of Type 1 helper T (Th1) cell will increase levels of circulating T-lymphocytes, with subsequent increase in the levels of proinflammatory cytokines accounting for most of BD symptoms. These proinflammatory cytokines may be used as an indicator of disease severity. Also Increased macrophage activation, neutrophil chemotaxis, and phagocytosis have been described in BD lesion.

Indeed, the need for studying biomarkers that may drive inflammatory pathways involved in BD pathogenesis is crucial.

Follistatin-like proteins (FLP) belong to the family of acidic cysteine-rich secreted glycoproteins (SPARC) that are highly homologous to the activin-binding protein, follistatin (FST)(7). this group of proteins include five types: FSTL1, FSTL2, FSTL3, FSTL4 and FSTL5.

Follistatin-like protein 1 (FSTL-1) is a soluble gly¬coprotein expressed by mesenchymal cells. It has been involved in various signaling pathways and biological processes. FSTL1 has dual effect in inflammatory processes and has been evaluated in some laboratory models and can serve as pro-inflammatory and anti-inflammatory markers.