Dr. Young, I am hopeful you might be able to shed some light on the correlation between CD4 count and CD4%. The reason I ask is that my most recent results indicate a very high CD4 count of just over 1,100 but a CD4% of 25%. This is a decrease in percentage from 27 to 25 yet my CD4 count actually increased from basically 1,000 to 1,100. Perhaps this is realistically viewed by the medical community as a negligible difference, but I somehow would think that someone with 1,000+ CD4 count should also have a percentage in the normal range, yet mine is not. Do I have need for worry at this point? The bigger question though really is if you could shed some light on how the count and percentage correlate. I just am not getting it.
Thanks for your post.
You're correct in that the changes in your CD4 counts and percentages between the two tests are within the day-to-day variability that we observe in otherwise healthy individuals.
You're also correct that your CD4 absolute count is higher than might be predicted by your CD4%. Typically, the average (this is key) absolute count observed when the 25% is about 350 cells (or about 100 cells per 7.5%).
What these numbers indicate to me is that your absolute count tends to run higher than the percentage might otherwise predict.
The key thing is not to base prognostics on the basis of one or two tests. Any change of 100 cells or 2% might be the beggining of a trend or might not; I (or your doctor) can't tell on the basis of two tests; in cases like yours I'd keep a close eye on the trends. Your accusation of our medical view of this as "negligible" isn't because we don't care, but rather that the normal variability of the tests is greater than the observed differences.
Hope this helps. BY