Ask the Lab Scientist Q3 2020

Questions submitted by readers and answered by the CLL Society Medical Advisory Board

By Susan Leclair, PhD, CLS (NCA)

I have been diagnosed from dissection of a lymph node with SLL.  I have been told that for a CLL diagnosis, the lymphocyte count has to be at or above 5,000.  On my recent blood tests, the absolute lymphocyte count is shown as 6.90.  Does this translate to 6900?  I am a little confused by the numbers I have been given and how those translate to the blood test results.

Here is the answer from lab scientist, Dr. Susan Leclair:

What is confusing is that there are two number systems. 

The first – the traditional one used by the U.S.A. for decades read “6 thousand, nine hundred” and “five thousand.”

The second – the international one was developed about forty years ago and all nations agreed to use the same system so that there would be ease of international use as people used to travel quite a bit.  For that system, the numbers would read “6.9 times 10 raised to the 9th power per liter and 5.0 times 10 raised to the 10th power (x10⁹/L) or 6.9 and 5.0.”

Long answer I know but yes, your 6.9 is greater than 5.0 and meets one of the criteria for CLL.

I would add that the 5,000 cells must be monoclonal to be diagnostic of CLL and that requires a flow cytometry test.

 

My Lymphocytes % was 14.8% in my last blood test…is that concerning?

Answer from Dr. Koffman:  The absolute count is what needs to be followed.  Don’t focus on the percentage.  Dr. LeClair has written on this extensively and it’s all searchable on the website.

 

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Susan Leclair, PhD, CLS (NCA) is Chancellor Professor Emerita at the University of Massachusetts Dartmouth; Senior Scientist, at Forensic DNA Associates; and Moderator and Speaker, PatientPower.info – an electronic resource for patients and health care providers.