Serum H-ficolin levels: Clinical association with interstitial lung disease in patients with systemic sclerosis.

Ficolins, a group of oligomeric lectins consisting of three isoforms (H-, L- and M-ficolin), contribute to innate immunity via activating the complement pathway and/or acting directly as opsonins against pathogens and apoptotic cells. Because apoptotic cells likely drive the development of systemic sclerosis (SSc) partly through innate immunity, we assessed the clinical association of serum H-ficolin levels in SSc patients. Despite no difference in serum H-ficolin levels between SSc and control subjects, SSc patients with decreased serum H-ficolin levels tended to have a higher prevalence of interstitial lung disease (ILD). More importantly, serum H-ficolin levels inversely correlated with ground-glass opacity score on chest computed tomography in SSc-ILD patients. Therefore, H-ficolin-related innate immunity may be involved in SSc-ILD development.