Leukocyte adhesion deficiency

Leukocyte adhesion deficiency (LAD) is a rare autosomal recessive disorder characterized by an inability of leukocytes (white blood cells) to migrate towards sites of infection or inflammation. This results in recurrent bacterial and fungal infections, delayed wound healing, and impaired pus formation.

Symptoms and Signs

Patients with LAD typically present with recurrent, severe bacterial and fungal infections that lack the usual pus formation seen in normal immune responses. These infections often affect the skin, mucous membranes, and respiratory tract. Other symptoms may include delayed separation of the umbilical cord after birth, poor wound healing, and periodontal disease.

Causes

LAD is caused by mutations in the ITGB2 gene, which encodes for the CD18 protein. This protein is a component of integrins, which are molecules that aid in the adhesion and migration of leukocytes. Without functional CD18, leukocytes are unable to adhere to the walls of blood vessels and migrate to sites of infection or inflammation.

Diagnosis

Diagnosis of LAD is based on clinical symptoms and laboratory tests. Laboratory findings may include elevated levels of leukocytes in the blood, due to their inability to migrate out of the bloodstream. Genetic testing can confirm the diagnosis by identifying mutations in the ITGB2 gene.

Treatment

There is currently no cure for LAD. Treatment is focused on managing symptoms and preventing infections. This may include the use of antibiotics, antifungal medications, and granulocyte transfusions. In severe cases, a hematopoietic stem cell transplantation may be considered.