Leukocyte Adhesion Deficiency

Etiology
  • Leukocyte Adhesion Deficiencies (LADs) are caused by defects in the ability of neutrophils to extravasate from the vasculature in order to enter sites of inflammation (Described in Acute Inflammation). Two subtypes of LAD exist (LAD-1 and LAD-2) which are due to mutations in different molecules. These molecules are critical for neutrophilic rolling and subsequent adhesion to the vascular wall as discussed in Acute Inflammation.
Clinical Consequences
  • Infection susceptibility manifesting as recurrent infections with pyogenic bacteria, especially Staphylococcus aureus, that are very slow to heal and may become life-threatening. Patients may have a history of delayed separation of the ubilicus. Because neutrophils cannot extravasate from the blood, a neutrophilic leukocytosis is observed.
Genetics
  • Both LAD-1 and LAD-2 are autosomal recessive.