Byline: Sehar Nigar, Ejaz Ahmed Khan and Tahir Aziz Ahmad
Leukocyte adhesion deficiency (LAD) is a rare primary immunodeficiency disorder with autosomal recessive inheritance which is characterized by presence of a defect of phagocytic function resulting from a lack of leukocyte cell surface expression of b2 integrin molecules (CD11 and CD18) that are essential for chemotaxis. The classic symptoms of the disease are failure of separation of the umbilical cord and recurrent bacterial infections, which continue throughout life.
We describe here two cases of infants who presented with characteristic history of recurrent infections, delayed separation of umbilical cord and marked leukocytosis.
Keywords: Leukocyte adhesion defect.
Three leukocyte adhesion deficiency (LAD) disorders have been well recognized, caused by genetic defects in Beta 2 integrin family consist of LFA-1 (CD11a/CD18), Mac-1 (CD11b/CD18), Complement receptor 4 (CD11c/CD18), and (CD11d/CD18).1
LAD-I is caused by mutations in the ITGB2 gene coding b2 subunit of beta 2 integrin family. This mutation results in formation of b2 subunit that cannot bind with other subunits to form b2 integrin. Leukocytes that lack these integrin fail to attach to blood vessel wall to contribute in immune response.1
LAD-II is a rare disorder characterized by deficiency in a guanosine diphosphate-fucose transporter in the Golgi apparatus, which is essential for fucosylating the ligands of the selectin adhesion receptors.4,5 Thus leukocytes fail to roll along the vasculature and integrin-mediated adhesion stabilization does not take place.2LAD-III, the most recently described type in which the integrins on bone marrow-derived leukocytes and platelets fail to function due to mutation in the FERMT3 gene coding for the kindlin-3 protein, thus introducing a premature stop codon resulting in a non-functioning protein.3,4
An 8 months old female child was brought to Shifa International Hospital in January 2016, with history of fever, and cough for 3 days. Fever was high grade, associated with vomiting and loose stools. Vomiting was non greenish, non-projectile, and loose stools were semi solid and greenish in colour, not associated with runny nose and runny eyes. She had multiple episodes of pyrexia from the age of 2 months, every 3-4 weeks that required multiple hospitalizations. She was the only child of consanguineous parents born at term by spontaneous vaginal delivery following an uncomplicated pregnancy. The umbilical cord separated on 41st postnatal day. There was no history suggestive of sepsis or umbilical infection in the neonatal period. She was developmentally normal and received her routine immunizations.
On examination, she had no dysmorphism, was...