Leukocyte adhesion deficiency-1
|Leukocyte adhesion deficiency-1|
|Autosomal recessive is how this condition is inherited|
Leukocyte adhesion deficiency-1 (LAD1) is a rare and often fatal genetic disorder in humans.
Signs and symptoms
The main sign of the disease is life-threatening, recurrent bacterial or fungal soft tissue infections. These infections are often apparent at birth and may spread throughout the body. Omphalitis (infection of the umbilical cord stump) is common shortly after birth. Other signs include delayed separation of the umbilical cord, periodontal disease, elevated neutrophils, and impaired wound healing, but not increased vulnerability to viral infections or cancer. Such patients have fever as the manifestation of infection, inflammatory responses are indolent.
LAD1 is caused by mutations in the ITGB2 gene which are inherited autorecessively. This gene encodes CD18, a protein present in several cell surface receptor complexes found on white blood cells, including lymphocyte function-associated antigen 1 (LFA-1), complement receptor 3 (CR-3), and complement receptor 4 (CR-4). The deficiency of LFA-1 causes neutrophils to be unable to adhere to and migrate out of blood vessels, so their counts can be high. It also impairs immune cell interaction, immune recognition, and cell-killing lymphocyte functions. The lack of CR3 interferes with chemotaxis, phagocytosis, and respiratory burst
Because the CD18 gene has been cloned and sequenced, this disorder is a potential candidate for gene therapy.
- Etzioni A, Harlan JM. Cell adhesion and leukocyte adhesion defects. In: Ochs HD, Smith CIE, Puck JM, eds. Primary immunodeficiency diseases: a molecular and genetic approach. Oxford: Oxford University Press, 2007:550–564.
- Candotti F, Fischer A. Gene therapy. In: Ochs HD, Smith CIE, Puck JM, eds. Primary immunodeficiency diseases: a molecular and genetic approach. Oxford: Oxford University Press, 2007:688–705.
- Etzioni, A. (2010). "Defects in the leukocyte adhesion cascade". Clinic Rev Allerg Immunol. 38 (1): 54–60. doi:10.1007/s12016-009-8132-3. PMID 19437145. S2CID 3068072.