CD11b expression on Lymphocytes

Keith Bahjat kbahjat at
Thu Apr 20 16:19:12 EST 2000

Do a medline search for Leukocyte Adhesion Deficiency-1, or LAD-1. A
mutation in the CD18 locus on chromosome 21 causes LAD-1. CD18 is the shared
beta subunit of three different adhesion heterodimers, LFA-1 on B,T, and NK
cells; CR3 (or CD11b) on PMNs, momos, macs, eos, and NK cells; and p150,95,
another complement receptor. Delayed separation of the umbilical cord is
usually the first sign. patients have significantly elevated PMN counts
without infection.

You should have been looking for CD11b expression within the granulocytic
populations, not the lymphs. The CD11b positive lymphs were NK cells. the
difference in % may be due to normal variation in NK cell numbers amongst
the population. The CD18 expression on the lymphs is enough to rule out
LAD-1, I believe.

I love what physicians do with our health care dollars sometimes......


Keith Bahjat
Graduate Assistant
University of Florida
College of Medicine
Gainesville, Florida
Voice: (352) 392-4887
Fax: (352) 392-5393
e-mail: kbahjat at

> From: Maciej Simm <simmmmer at>
> Date: Wed, 19 Apr 2000 14:37:35 -0700 (PDT)
> To: Cytometry Mailing List <cytometry at>
> Subject: CD11b expression on Lymphocytes
> Greetings once again,
> We have recently received a blood specimen and were asked to stain
> for CD18/11b ( I love it how doctors don't explain the condition of
> the patient ahead of time, so we know what to look for )
> We found, that when compared to our NC's (N=300+ for this "tube" and
> growing) this patient had less +/+ lymphoctes (~30% vs. 12%). The
> expression of CD18 was not reduced - all of his leukocytes had >97%.
> A question came up: what is the significance of CD18+/CD11b-
> lymphocytes? what is the significance of a decrease in the +/+
> population?
> We do not routinely do CD11a or CD11c - are these mutually exclusive?
> I.e. it's either a, b or c but never any of them together?
> And finally, is the ligand for CD11b soluble and may have interfered
> with our staning?
> This staining was done in whole blood (which I just found is a
> no-no).
> I would appreciate if anyone could share any thoughts on this topic.
> Maciej
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