It’s important to know the normal, especially when it ties into pathology.
Leukocyte Adhesion Deficiency (LAD) Disorders
LAD type 1
・Absence of CD18 subunit of β2-integrin
・Impaired leukocyte adherence & transmigration
LAD type 2
・Impaired fucosylation of sialyl Lewis X on leukocytes → defeciency of endothelial cell selectin binding
LAD type 3
・Impaired cytokine signaling prevents integrin activation
Clinical features:
・Recurrent skin infections → celulitis, abscess, omphalitis (superficial cellulitis around umbilical stump)
・Recurrent mucosal infections → severe periodontitis
・Inflammation with notable lack of purulence (no PMNs)
・♥︎ Delayed separation of umbilical cord (>21 days)
・Poor wound healing
・Peripheral blood neutrophilic leukocytosis (loss of marginating pool) with neutrophilia