CD Markers
CD11a

Author: Nat Pernick, M.D. (see Authors page)

Revised: 21 December 2015, last major update September 2013

Copyright: (c) 2003-2015, PathologyOutlines.com, Inc.

PubMed Search: CD11a

Related topics: CD11, CD11b, CD11c, CD11d

Definition / General
  • Alpha integrin chain at 16p11-13.1 that binds to CD18 and has various leukocyte functions (OMIM #153370)
  • Also called integrin alpha L, ITGAL and LFA1 alpha chain (in complex with CD18)
Pathophysiology
  • Alpha integrin chain which binds to CD18 and mediates leukocyte adhesion to endothelium, leukocyte trafficking through activated endothelium, lymphocyte blastogenesis, lymphocyte-endothelial cell adhesion, lymphocyte recirculation through lymph nodes, cytotoxic T cell mediated killing and antibody dependent killing by neutrophils and monocytes
  • Also mediates binding to unopsonized bacteria (e.g. E. coli) and fungi (e.g. Histoplasma capsulatum)
  • With CD18, binds to ICAM1 (CD54), ICAM2 (CD102), ICAM3 (CD50) and ICAM4 (CD242)
  • CD11a identifies effector and memory CD8+ T cells, independent of antigen specificity (Oncoimmunology 2013;2:e23972)
  • Decreased levels in CD4+ T cells in infants with biliary atresia, due to hypermethylation of CD11a promoter region (Biochem Biophys Res Commun 2012;417:986)
  • Increased levels in CD4+ T cells with immune thrombocytopenia (ITP, J Clin Immunol 2011;31:632)
Clinical Features
Uses by Pathologists
  • CD11a deficiency during flow cytometry useful to diagnose acute promyelocytic leukemia (Am J Clin Pathol 2012;138:744)
  • CD11a deficiency during flow cytometry useful to diagnose AML-M7, Down syndrome related AML and transient myeloproliferative disease in children with and without Down syndrome (Cytometry B Clin Cytom 2013;84:370)
Micro Images

Images hosted on other servers:

Spleen-normal

Intestinal mucosa (fig F)

Eruptive papules with efalizumab therapy

Positive Staining - Normal
  • All leukocytes
Positive Staining - Disease
Negative Staining
  • Platelets, various intermediate and high grade lymphomas