A 3-week-old male infant has recurrent infections with Staphylococcus aureus and Pseudomonas, delayed separation of the umbilical cord, and absent pus at infected sites despite marked tissue inflammation. Flow cytometry shows absent expression of CD18 on neutrophils. What is the diagnosis?

• A Leukocyte adhesion deficiency type 1 ✓
• B Chronic granulomatous disease
• C Chediak-Higashi syndrome
• D Myeloperoxidase deficiency

Explanation

Leukocyte adhesion deficiency type 1 arises from mutations in ITGB2 encoding the beta-2 integrin subunit CD18, preventing formation of LFA-1 and Mac-1. Neutrophils cannot adhere to endothelium or migrate into tissues, so infections lack pus and umbilical cord separation is delayed, while blood neutrophil counts are paradoxically high. In CGD neutrophils reach tissues normally but cannot generate a respiratory burst.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.