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At a glance

It is a group of rare inherited disorders affecting the immune system and leukocytes resulting in localized recurrent bacterial infections rapidly progressing to an extensive life-threatening level. It is characterized by defects in leukocytes. There are three distinct types of Leukocyte Adhesion Syndrome. Additional symptoms may occur depending upon the specific subtype present.


Lymphocyte Function-Associated Antigen-1 Immunodeficiency; LFA-1 Deficiency.


LAD I was first described in the medical literature in 1979. LAD II was first reported in 1992. LAD III was first reported in 1997.


Immunologic disorder affects phagocytic properties of leukocytes as a consequence of lack of expression of β2 integrin CD18 (LAD I) or of its selective ligand (LAD II).


There are three types of Leukocyte Adhesion Syndrome:

  • Leukocyte Adhesion Deficiency Type I: Individuals affected with this type show variable symptoms from one to person to another. The infections usually develop shortly after birth and are life-threatening in most and the milder form of LAD I have fewer and less severe infections. It is usually characterized by recurrent, often severe, bacterial or fungal infections (skin and mucosa), and delayed detachment of the umbilical cord. The absence of pus at the site of infection is an important feature that usually confirms the leukocyte adhesion deficiency. It is associated with an omphalitis and delayed detachment of the umbilical cord.

  • Leukocyte Adhesion Deficiency Type II: Infants affected with this type develop recurrent, milder bacterial infections than those with LAD I. Pneumonia, chronic otitis media, periodontitis, and cellulitis occur commonly in LAD II. The infections are usually not life-threatening. It is also characterized by the absence of pus formation. The frequency of infections in LAD II decreases after 3 years of age. As affected individuals grow older, severe periodontitis is the main infectious complication.

  • Leukocyte Adhesion Deficiency Type III: Patients affected with this type present recurrent bacterial and fungal infections with a similar course as seen in individuals with LAD I. It is characterized by bleeding tendency that resembles those observed with ☞Glanzmann thrombasthenia. It can be life-threatening in both cases. This represents an important anesthesia consideration for surgery. Other features include ecchymosis, epistaxis, gingival hemorrhages, and/or bleeding large red or purple colored spots on the skin. The onset of the disease is reported at birth.


The exact incidence remains unknown. LAD I is by far the more common one with several hundreds of patients reported in the medical literature all over the world. LAD II is very rare reported in less than 10 patients and LAD III is also rare with 25 patients mainly from the Middle East region. There is no racial predominance for LAD I and LAD II. LAD ...

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