A 5-year-old boy has recurrent bacterial infections. Neutrophil count and morphology are normal, integrin expression including CD11/CD18 is intact, but neutrophils fail to roll on inflamed endothelium. Molecular testing shows absent expression of fucosylated glycans on the neutrophil surface. The diagnosis is:

• A Leukocyte adhesion deficiency type I
• B Leukocyte adhesion deficiency type II ✓
• C Chediak-Higashi syndrome
• D Myeloperoxidase deficiency

Explanation

LAD-II results from a defect in fucose metabolism (defective GDP-fucose transport), leading to absence of sialyl-Lewis X, the carbohydrate ligand for selectins. Leukocytes therefore cannot roll on endothelium, producing recurrent infections without pus, similar clinically to LAD-I. The key discriminator given here is preserved CD11/CD18 integrin expression, which excludes LAD-I, whose defect lies in the beta-2 integrin chain rather than in fucosylated glycans.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.