Bloodwork question

[PattyG]

I know this is a question for the hematologist, but so far I've felt that doctors don't know much about MC so am asking a question here, just to see if anyone knows. Has anyone had a cancer market show positive (100%) for CD45? I think it has to do with lymphocytes and possible Hodgkins lymphoma (Dr. Google) but wondered if the test ever shows positive results due to lymphocytic colitis? My doc gave me choice of either getting a bone marrow biopsy, waiting and retesting blood again in 3 months or doing nothing, but she said she wouldn't do the 3rd. Am nervous so lean toward biopsy, but am taking family on vacation in 2 weeks and hate to worry if bad news. So
I opted to retest in 3 months. Does anyone know if LC sometimes causes a positive marker on blood test? Thank you.

[tex]

I've never heard of that, but that certainly doesn't mean that it's not possible. Like you, I googled it and couldn't find any information, but I have a Chat GPT40 account and it gave me the following answer:

Yes, lymphocytic colitis can be associated with a positive CD45 marker. CD45 is a common leukocyte antigen found on the surface of most hematopoietic cells, including lymphocytes. In lymphocytic colitis, there is an increase in intraepithelial lymphocytes in the colon, which would express CD45. Therefore, a biopsy from a patient with lymphocytic colitis could show a positive CD45 marker due to the presence of these lymphocytes.

Note that I've caught ChatGPT making medical mistakes, on occasion, so an AI response can't be trusted as gospel truth — it has to be verified by checking the actual facts. That said, that response appears to be correct. Most likely the reason I've never heard of it before, is because normally, when diagnosing microscopic colitis, pathologists don't bother noting positive markers such as that. Please don't accept this as medical advice. Check it out with your doctors, just to be safe. But you can probably safely relax, while you're taking that family vacation.

Tex

[PattyG]

Thanks for the encouraging words, Tex! We’re leaving the unGodly heat of Texas, for the unGodly heat of Florida, ha.

[PattyG]

Meant to reply to you, Tex, after my hematologist appointment last year. I went to MD Anderson for a 2nd opinion on the lymphocytic leukemia, since I didn't trust the hematologist I went to in the Woodlands. It turns out the doc here made an overcall, it wasn't cancer after all. I asked the doc at MDA if he thought my lymphocytic colitis could have caused the positive cancer marker and he thought that was very interesting. (I loved that he was eager to check it out, since its a research hospital, as you know) He said he'd research it but later told me he couldn't find anything on it "but that it doesn't mean it's not possible". I should have shown him your Chat GP reply. He has since retired but if I ever go back to MDA, will mention it again. Am glad I didn't submit myself to an unnecessary bone marrow biopsy by the original hematologist/oncologist. When I had asked my records to be sent to MDA for 2nd opinion, she said "If you go there, don't ever step foot in my office again". Wow!! No problem, ha!

[tex]

Thanks for the update. That's an interesting story. It sounds as though you were originally seeing a rather testy hematologist/oncologist. I could be wrong, but I can't help but wonder if she made that remark because she had a hunch that the specialists at MD Anderson would find her "diagnosis" incorrect.

Tex

[PattyG]

I agree! Thanks,Tex.