Leukocyte adhesion deficiency (LAD)

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at LSU (Shreveport) Department of Allergy and Immunology

Phagocyte immunodeficiencies (click to enlarge the image):



Leukocyte adhesion deficiency (abbreviated LAD) is an immunodeficiency resulting in recurrent infections.

There are several types:

LAD I - beta 2-integrin family is deficient or defective.
LAD II - fucosylated carbohydrate ligands for selectins are absent, fewer infections but more developmental delay as compared to LAD I.
LAD III - activation of all beta–integrins (1, 2, and 3) is defective.

Leukocyte adhesion deficiency II (LAD2 ) is characterized by which of the following?

(A) X-linked inheritance

(B) neutropenia

(C) hypogammaglobulinemia

(D) severe mental retardation

(E) autosomal recessive inheritance

(F) CD18 defect

(G) Sialyl LewisX-related defect

Answers: D, E, G. LAD1 is related to CD18 defect (not LAD2).

Related reading

Leukocyte adhesion deficiency type I (LAD I)
Leukocyte adhesion deficiency type II (LAD II)
Leukocyte adhesion deficiency type III (LAD III)

References

ABAI Board Review, 2008.
Adhesion Molecules
Leukocyte adhesion deficiency. Wikipedia.
CD18. Wikipedia.
Sialyl Lewis X. Wikipedia.

Published: 05/18/2009
Updated: 08/19/2010