CD45 100%?

[Vlaminck]

My flow cytometry had CD45 at 100%. I was just reading that normal CLL has low CD45. Anyone know significance? Anyone else have CD45 100%?

[Vlaminck]

Johnl, for some reason this site isn't show any responses -- IA can see the first part of your response on the email informing me of your response, which says, "From what i understand, CD45 immunoreactivity is specific for non-hodgkin lymphomas. CLL is a non -hodgkin lymphoma. My last flow cytometry which came back as MRD negative stated " The lower limit of sensitivity for detecting CLL cells established..." And ends there. Suspense! I am very interested in reading the rest of your response. Could you repost it?

[johnl in reply to Vlaminck]

Vlaminck, I took my response down because I wasn't sure about its correctness. I'm glad gardening girl responded as she has much more knowledge on these things.

john

[gardening-girl]

Vlaminck, it is my understanding that although CD 45 is expressed on almost all blood cells, it is typically expressed at lower levels on the surface of CLL B-cells. The 100% refers to the fact that all tested cells had detectable levels, a totally expected result. The intensity of the fluorescent 'stain' varies with cell type.

[Vlaminck in reply to gardening-girl]

Thank you, gardening-girl, for explaining that. I didn't understand what it meant obviously.

[johnl in reply to gardening-girl]

I'm still confused here because my flow cytometry for UMRD done at Northwestern and reviewed at M D Anderson stated "The lower limit of sensitivity for detecting CLL cells established in our laboratory is 0.01% of CD45+ luekocytes when one million events are collected. Adequate events are collected in this analysis." and I did a quick google search and found"CD45 is a transmembrane protein tyrosine phosphatase located on most haematopoietic cells. It has several isoforms, and haematopoietic cells express one or more of the isoforms—CD45RO, CD45RA and CD45RB. CD45 immunoreactivity is recognised to be highly specific for non–Hodgkin's lymphomas."

john

[gardening-girl in reply to johnl]

John, I can see why you are confused by this statement:

“CD45 immunoreactivity is recognised to be highly specific for non–Hodgkin's lymphomas."

However, in the context of the paper that you cite, that sentence means CD45 (leukocyte common antigen) expression is a way to distinguish heamatopoietic neoplasms from non-haematopoietic neoplasms. The authors cite the two papers below:

3.Kurtin P J, Pinkus G S. Leukocyte common antigen—a diagnostic discriminant between hematopoietic and nonhematopoietic neoplasms in paraffin sections using monoclonal antibodies: correlation with immunologic studies and ultrastructural localization. Hum Pathol 198516353–365. [PubMed] [Google Scholar]

4. Michels S, Swanson P E, Frizzera G.et al Immunostaining for leukocyte common antigen using an amplified avidin‐biotin‐peroxidase complex method and paraffin sections. A study of 735 hematopoietic and nonhematopoietic human neoplasms. Arch Pathol Lab Med19871111035–1039. [PubMed] [Google Scholar]

ncbi.nlm.nih.gov/pmc/articl...

Does that help?