ABSTRACT
Leukocyte adhesion deficiency type I (LAD-I) is a rare, inherited immunodeficiency with defect in the recruitment of leukocyte to the site of inflammation. Patients with severe LAD-I have absent or markedly reduced expression of CD18 and CD11. Here we report clinical profile of 7 cases of LAD-I diagnosed at our center over a period of 3 years. Recurrent skin and mucous membrane infections were the major presenting manifestations. All children had a history of delayed cord separation.
ABSTRACT
The beta2 integrins are expressed exclusively on leukocytes and participate in many immune and inflammatory processes. This subfamily comprises four heterodimeric glycoproteins with a common beta-subunit, designated beta2 (CD18). Spontaneous mutations of the CD18 gene result in leukocyte adhesion deficiency type I (LAD-I). Low level of CD18 expression has also been implicated in the pathogenesis of psoriasis. We here describe a child with recurrent skin infections without pus formation, persistent gingivitis and periodontitis. His blood counts showed persistent leukocytosis (neutrophilia). CD11b expression was defective on neutrophils, while that of CD18 was normal. So, our patient represents a mild variant of LAD-I with possible dysfunctional CD18. Moreover, he developed psoriasis with reduced CD18 expression on CD4+ T-cells. Psoriasiform dermatitis has been described before in association with LAD-I, however, clinically and histologically confirmed psoriasis in association with LAD-I has been described only in CD18 hypomorphic mice. Therefore, our patient represents the first clinically and histopathologically documented association between LAD-I and psoriasis in humans. It lends support to the role of beta2 integrins in the etiopathogenesis of psoriasis.