[Inherited deficiency of the initiator molecules of the lectin-complement pathway]. / Arfgengur skortur í raesisameindum lektínferils komplímentvirkjunar.

The complement system is an important immune system. Its activation results in membranolytic elimination of microbes and opsonization. The classical, alternative and lectin pathways (LP) activate complement. Either mannan-binding lectin (MBL), ficolin-1, ficolin-2 or ficolin-3 initiate the LP through associated serine protease (MASP-2) after binding to microorganisms'surface carbohydrate patterns. Genetic polymorphisms behind MBL deficiency are rather common. Numerous studies indicate that MBL deficiency is a risk factor for invasive and recurrent infections, especially when other immune systems are immature, deficient or compromised. Research in ficolins is limited but last year ficolin-3 deficiency was described. This review focuses on these recently WHO defined immunodeficiencies.