Leukocyte Adhesion Deficiency
(CD11a, CD11b, CD11c, CD18)

FLOW LAD


Test Synonym:



CPT Code:
88184 – Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only, first marker
88185 x4 – Each additional marker (multiple)
88187 – Flow cytometry, interpretation; 2 to 8 markers


Turnaround Time:
<24 hours



Methodology:
Flow cytometry, multiparameter analysis



Specimen Requirements:

•  5.0ml (min. 2.0ml) heparin blood preferred, EDTA accepted

• 1.0ml (min. 0.5ml) heparin bone marrow preferred, EDTA accepted


Causes for Rejection:

Specimens stored at incorrect temperature; Non-viable specimens; Specimens in inappropriate anticoagulant; Too few cells; Hemolysis; Specimen clotted


Specimen Stability:
Whole blood or bone marrow stable for 48 hours at room temperature


Storage and Handling:
• Whole blood or bone marrow ship ambient
• Bone marrow aspirate ship in a styrofoam container with an ice pack (do not allow the ice pack to directly contact the sample)


Reference Range:
See Report

Indication:
Suspected leukocyte adhesion deficiency.


Leukocyte adhesion deficiency (LAD) is a rare disorder of leukocyte function. LAD has been classified into two major subtypes and rare variants.


LAD type 1 is the more common subtype and is characterized by decreased or absent expression of the CD11/CD18 complex resulting in an inability of leukocytes to emigrate from the bloodstream to sites of inflammation. Severely affected infants present with delayed umbilical cord detachment, recurrent or progressive non-purulent infections, delayed wound healing, and leukocytosis. Flow cytometry can be used to detect normal expression of the CD11/CD18 complex.


LAD type 2 is less common and is a disorder of fucosylation characterized by deficiency of sialyl Lewis X (sLex) and an inability of normal leukocyte rolling function on activated endothelium.


Other “variants” of LAD have been reported which include normal expression but dysfunctional CD11/CD18, E selectin/CD62E expressed but cleaved and present only as soluble form, and defective Rap-1 activator CalDAG-GEFI.

References:

  1. Lichtman et al (2006) Hematology, 7th editionMcGraw-Hill Companies, Inc. 2006, p 935-938
  2. Nervi SJ, et al. (Dec 5, 2007) Leukocyte Adhesion Deficiency. eMedicine.
  3. Cox et al (July 2007) Leukocyte adhesion deficiency type 1: an important consideration in the clinical differential diagnosis of prepubertal periodontitis. A case report and review of the literature. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology.
  4. Etzioni A. (July 2005) Leukocyte Adhesion Deficiency (LAD) Syndromes. Orphanet Encyclopedia.
  5. Hann et al (2006) Pediatric Hematology. Blackwell Publishing.
  6. John L. Carey et al. (2007) Flow Cytometry in Clinical Diagnosis 4th edition. ASCP Press.