Leukocyte Adhesion Deficiency, also known as LAD, is an immune system disorder involving both B and T cells. Deficiencies in certain molecules that immune cells use to stick to each other when they need to communicate or move from one place to another are inhibited in LAD sufferers.
The inability of Leukocytes to move to the site of an infection to begin the process of destroying invading bacteria and viruses leaves those with this adhesion deficiency prone to repeat infections that could be life-threatening to the sufferer without medical intervention. When the immune cells fail to attach themselves to infected cells, they allow bacteria and viruses to multiply out of control.
There are three types of LAD. Type I is caused by mutations in the CD18 gene, and this results in a deficiency in beta-2 Integrin. In type II, there is an absence of Sialyl Lewis X of E-selectin. Type III is characterised by a defect in beta integrins 1, 2, and 3. This is caused by a mutation in the kindlin-3 gene.
Leukocyte Adhesion Deficiency causes numerous symptoms in sufferers, such as pneumonia, periodontitis, gingivitis, and sinusitis. Infections caused by the bacteria Staphylococcus aureus and Pseudomonas aeruginosa are also common.
Type II sufferers have fewer and less severe infections compared to LAD type I sufferers. Type III sufferers are more at risk from blood disorders such as abnormal bleeding and bone marrow failure.
The cause of Leukocyte Adhesion Deficiency is a mutation in certain genes that cause cells involved in immunity to behave in an incorrect manner leading to immunodeficiency disorders. Those with this disorder risk having their life expectancy reduced due to frequent infections.
LAD is inherited in what is known as an autosomal recessive pattern. This means that both copies of the gene in each cell express the specific gene mutations that can cause LAD. Although the parents of a LAD sufferer will both carry one copy of the mutated gene, two copies are needed to develop the illness, and one copy from each parent leads to any offspring becoming LAD sufferers.
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Severe Combined Immunodeficiency (SCID)
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STAT3 Gain-Of-Function Disease (STAT3 GOF)
Warts, Hypogammaglobulinemia, Infections, And Myelokathexis (WHIM) Syndrome
Wiskott-Aldrich Syndrome (WAS)
X-Linked Agammaglobulinemia (XLA)
X-Linked Lymphoproliferative Disease (XLP)
Immunodeficiency Disease Medications
Diagnosis of Leukocyte Adhesion Deficiency is made by physical examination and an assessment of the symptoms and infections present. Lab tests such as blood tests can check for any abnormalities in the immune cells. Gene testing is also carried out to confirm the presence of the mutation in the genes of the sufferer.
Treatment is usually used to prolong life and ease symptoms. Antibiotics, antifungals, and antivirals are used to help the compromised immune system battle these various types of infections.
Stem cell therapy can also be used in an attempt to produce an immune system that acts correctly and, in turn, fight infections more efficiently. However, this option is considered risky because a number of complications can arise from this treatment.
The only way to prevent an individual from developing this condition is by gene testing and discussing options with potential parents that are carriers of the gene mutation. They may have to consider adoption or other ways of becoming parents to avoid passing both defective genes to any potential children.