Congenital H-ficolin deficiency in premature infants with severe necrotising enterocolitis

In a recent issue of Gut , Muller et al reported on excessive colitis in a murine model of mannan-binding lectin (MBL) deficiency.1 They showed that absence of MBL can lead to uncontrolled intestinal inflammation detrimental to the host. MBL is a pattern-recognition molecule activating the complement system by the lectin pathway. H-ficolin is structurally closely related to MBL and can activate the lectin pathway of complement independently of MBL. While low levels of MBL occur in 10% of Caucasians, H-ficolin deficiency is extremely rare: studies involving over 100 000 adults found no case of H-ficolin deficiency, suggesting it exerts crucial functions for the human immune system.2 The first report on the so far only patient diagnosed with H-ficolin deficiency was published only recently,3 describing a patient with repeated infections who presented …