Mannan-binding lectin deficiency — Good news, bad news, doesn't matter?

• Published in: Clinical immunology (Orlando, Fla.) Vol. 143; no. 1; pp. 22 - 38
• Main Authors: Heitzeneder, Sabine, Seidel, Markus, Förster-Waldl, Elisabeth, Heitger, Andreas
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.04.2012; Elsevier
• Subjects: Allergy and Immunology; Biological and medical sciences; Disease association; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Genetic Predisposition to Disease; Genotype; Humans; Immunodeficiencies; Immunodeficiencies. Immunoglobulinopathies; Immunodeficiency; Immunopathology; Innate immunity; Lectin pathway of complement; Mannan-binding lectin; Mannose-Binding Lectin - blood; Mannose-Binding Lectin - deficiency; Mannose-Binding Lectin - genetics; Medical sciences; Models, Genetic; Pattern recognition molecules; Polymorphism, Single Nucleotide; Mannan-binding lectin; Lectin pathway of complement; single nucleotide polymorphism; Immunodeficiency; Innate immunity; small Mannan-binding lectin associated protein; sPRM; MASP; small pattern recognition molecule; SNP; MBL; Mannan-binding lectin associated serine protease; Disease association; sMAP; Pattern recognition molecules; Immunopathology; Mannose binding lectin; Deficiency; Natural immunity; Complement; Immune deficiency; Association; Immunology; Recognition
• ISSN: 1521-6616; 1521-7035
• DOI: 10.1016/j.clim.2011.11.002

Abstract Mannan-binding lectin (MBL) deficiency has been classified as a commonly occurring immune disorder, affecting approximately 30% of the human population. MBL, being part of the innate immune system, supports the recognition of infectious pathogens by binding to carbohydrate moieties expressed on microorganisms and activates the lectin pathway of the complement system. MBL2 gene polymorphisms are associated with quantitative and qualitative MBL abnormalities in the serum. The clinical impact of MBL deficiency and its association to a wide variety of diseases has been extensively studied. The picture is puzzling as the studies suggest a detrimental or beneficial or no impact of low or high MBL serum levels on disease susceptibility. In this review we attempt to extract what is relevant from the literature and address controversial issues. We finally suggest that a comprehensive understanding of the role of MBL in human diseases requires considering its context-dependency.