Dysfunctional LAD-1 neutrophils and colitis

Abstract

Leukocyte adhesion deficiency 1 (LAD-1) is characterized by absent or dysfunctional beta2 integrin (CD18), leading to defective chemotaxis, adherence, phagocytosis, and bacterial killing. Colitis, except for rare intestinal necrotizing events, is not a well-recognized feature of this immunodeficiency. A case of nonspecific colitis clinically resembling Crohn's disease in a patient with the severe form of LAD-1 (0.5% < CD18) has been previously reported. We describe an adult patient with the moderate form of LAD-1 and chronic colitis characterized by extensive inflammation and ulceration of the right colon and terminal ileum, leading to adhesions and strictures. The chronic colitis described in this article associated with the dysfunctional neutrophils of LAD-1 represents a distinct pathology from the commonly encountered forms of inflammatory bowel disease (IBD). The existence of active IBD in the presence of dysfunctional CD18/CD11(a-b) intercellular adhesion molecules (ICAM-1) interaction is relevant to the proposed targeting of ICAM-1 for the treatment of Crohn's disease.