[Deficiency of mannan-binding protein--a recently discovered complement defect syndrome].

Mannan-binding protein (MBP) is a newly discovered serum protein which activates the complement system by the classical pathway by binding to mannose-rich surfaces on microorganisms. MBP deficiency predisposes to infection in infancy. MBP is a C-type lectin with collagen structure, a so-called collection. The paper discusses the structure and physiological functions of MBP. MBP may be an important parameter in the investigation of immunodeficiencies in children.