A one-month-old sick-looking new-born child was admitted with a history of delayed cord separation and multiple ulcers in the body. The child was sick looking with ulceration in the periumbilical region, left axilla, and perianal regions. There was no pus in the ulcers. The child was investigated for acquired immune deficiency and was normal. The leucocyte count was one lakh. Flow cytometry showed C1118 deficiency of integrins.
Leukocyte adhesion deficiency (LAD), is a rare autosomal recessive disorder characterized by immunodeficiency resulting in recurrent infections. Leukocyte adhesion deficiency (LAD) a disorder involving both B and T cells and is characterized by an inability of leukocytes to migrate to the site of infection to kill offending microbes. The adhesion defects result in poor leucocytes and chemotaxis, particularly neutrophils, inability to form pus, and neutrophilia.
It is divided into three subtypes – LAD I, II, and III. Patients with LAD1 have an inherited molecular defect that causes a deficiency of the β-2 integrin subunit, also called CD18, which is encoded by the ITGB2 gene found on chromosome 21. LAD-II diagnosis includes the study of different glycosylated forms of the transferrin protein. In LAD-III, as platelet function is also affected, this could be used to differentiate it from the other types. Each subtype is diagnosed by genetic testing.
Diagnosis
This disorder is characterized by delayed separation of the umbilical cord, severe recurrent bacterial infections, impaired formation of pus, high leukocyte counts, and abnormalities in granulocyte-adherence dependent function. The subtypes can be diagnosed by genetic testing. Most of the children die with fulminant infections although patients can receive intensive antibiotic therapy and even granulocyte transfusions from healthy donors.
Treatment
The only current curative therapy is the haematopoietic stem cell transplant.