Study On The Normal Value Of Serum MBL And Gene Polymorphism Among Children In Middle And Western Part Of China

Background : Human mannose-binding lectin (MBL) is a liver-produced, C-type serum lectin that seems to play an important role in innate immunity. MBL is a multichain molecule of up to six subunits; each subunit consists of three identical 32-kD polypeptide chains that contain a N-terminal segment, a collagenous region, a "neck" region, and a carbohydrate-binding domain. Upon binding to certain carbohydrate moieties on various pathogens, MBL may mediate phagocytosis and use MBL serine proteases to activate the MBL pathway of complement. MBL gene polymorphism influences sero-MBL levels. Three allelic variants in exon1 codons 52 (D mutation), 54 (B mutation), and 57 (C mutation) cause disruption of the collagenous triple helix, which is critical for oligomerization, while promoter polymorphism regulates gene transcription and effect synthesis of MBL. Abnormal level of MBL caused by MBL gene deficiency is associated with infectious disease and autoimmune disease. As serum MBL concentration varys in individuals, different normal reference standard of serum MBL concentration has been reported in...