What does CD percentage means?

[metekrop]

Sorry for my being damn azz.  But I have to ask this question. 

I always hear people are saying a CD percentage.  I never had a chance to ask my doc too.  But what does CD percentage means?  What ratio does it takes?  How it is interpreted in measuring once health or illness?  Is highest or the lowest persontage that is considered good?

Thanks

[Miss Philicia]

http://www.aidsmeds.com/articles/TCellTest_4727.shtml


What is the CD4 Percentage?

If you look at your lab report, you will also see something called your CD4+ percentage (%). This is an important number for you and your doctor to know. In healthy adults, the number of CD4 cells make up between 32% and 68% of the total number of lymphocytes?a large group of white blood cells that include CD4 cells, CD8 cells (see below), and B-cells. In fact, the lab uses the CD4 percentage to determine the number of CD4 cells in a sample of blood.

The CD4 percentage is sometimes a more reliable measurement than the CD4 count because it tends to vary less between measurements. For example, one person's CD4 count may vary between 200 and 300 over a several month period while their CD4 percentage remains constant at, say, 21%. Provided that the CD4 percentage stays at 21% or higher, the immune system still appears to be functioning properly, regardless of what the CD4 count is. At the same time, a CD4 percentage at or below 13%?regardless of what the actual CD4 count is?usually means that the immune system is damaged and that it is time to begin prophylactic treatment (drugs to prevent diseases) for opportunistic infections like PCP.

[metekrop]

http://www.aidsmeds.com/articles/TCellTest_4727.shtml


What is the CD4 Percentage?

If you look at your lab report, you will also see something called your CD4+ percentage (%). This is an important number for you and your doctor to know. In healthy adults, the number of CD4 cells make up between 32% and 68% of the total number of lymphocytes?a large group of white blood cells that include CD4 cells, CD8 cells (see below), and B-cells. In fact, the lab uses the CD4 percentage to determine the number of CD4 cells in a sample of blood.

The CD4 percentage is sometimes a more reliable measurement than the CD4 count because it tends to vary less between measurements. For example, one person's CD4 count may vary between 200 and 300 over a several month period while their CD4 percentage remains constant at, say, 21%. Provided that the CD4 percentage stays at 21% or higher, the immune system still appears to be functioning properly, regardless of what the CD4 count is. At the same time, a CD4 percentage at or below 13%?regardless of what the actual CD4 count is?usually means that the immune system is damaged and that it is time to begin prophylactic treatment (drugs to prevent diseases) for opportunistic infections like PCP.

Thank you Miss Phillica.

I never thought of the CD percentage in my blood work.  I only pay attention to the CD count and the VL.  I also never spoke with my doc about it.  Next time I will be having the detailed info of that percentage.  Last time the doctor ordered me Bactrim.  That was actually when My CD was 300, infact VL was not done that time.  I didn't know why he ordered Bactriem for me and simply thought that was for my VL.  May be now I am thinking that my CD percentage was law.  By the way this percentage have any correlation with the CD count?

Tx

[Etay1207]

My CD4% was 10.  I guess I'm fucked!

[GSOgymrat]

My CD4% was 10.  I guess I'm fucked!

There's a med for that.

[max123]

My CD4% was 10.  I guess I'm fucked!

etay,

yeah, you're definitely beyond the danger zone with a cd4% of 10...but you already know that. starting haart would be in your best interest...but you already know that too. so frankly, what's your point because i'm not quite getting it?

max

[tednlou2]

I always wonder when you read studies and treatment guidelines, they rarely talk about the %.  They usually just talk about absolute CD4 as to when to start treatment or health related issues.  When they give the CD4 of 500 or less as when to start treatment, they don't talk about %.  I suppose this means at CD4 of 500, you wouldn't expect your % to be like 13%??

[metekrop]

My CD4% was 10.  I guess I'm fucked!

Etay,

My CD% was 10 when my actual CD count was 300.  Anyways I will see you in the hospital soon. 

I think the following article is fine as far as this CD thing is concerned.  Please go through it.

http://aids.about.com/od/aidsfactsheets/a/cd4percent.htm

[Hellraiser]

My % is 8.  I need to find out what it was when I was diagnosed, I really don't think it has moved that much.

[Miss Philicia]

My % is 8.  I need to find out what it was when I was diagnosed, I really don't think it has moved that much.

I got my new lab results this afternoon and mine are now 50%, the highest EVAH   My lowest when diagnosed were 14%, and just five years ago they were only 31%.

[Rev. Moon]

and just five years ago they were only 31%.

"Only" 31%?  C'mon, you'll make the poor child in his teens feel badly.

My CD4% was 10.  I guess I'm fucked!

::sigh:: gotta love it.

[tednlou2]

I got my new lab results this afternoon and mine are now 50%, the highest EVAH   My lowest when diagnosed were 14%, and just five years ago they were only 31%.

At 50%, can you feel a huge difference in how you feel?  I've heard so many, especially those who believe starting meds sooner, say they felt 100 times better once that % got above 30%.  From your story and others, I know that can sometimes take a long time to achieve those numbers. 

[Miss Philicia]

At 50%, can you feel a huge difference in how you feel?  I've heard so many, especially those who believe starting meds sooner, say they felt 100 times better once that % got above 30%.  From your story and others, I know that can sometimes take a long time to achieve those numbers. 

When I had a % in the 20's like you do I was still going to the gym five times a week and going out to clubs at least twice a week, and working 50 hour work weeks.  I'm not sure how much better one can feel.  However, if I get something like bronchitis instead of feeling miserable for a week I only feel bad for three days.

I'd go further and say if you're having fatigue issues then controlling your viral load will tend to solve that more than getting your % to where mine is.  Depression and anxiety issues also can cause someone to feel tired and worn out.

[Granny60]

My % 12 went to 16 then down to 11  and now up to 21.  Any reason for it to be bouncing like a ball?  Cd4 crawled from 228  to 340 in that time after a year of dropping cd4 but still UN  VL. I think the labs wackky. ::)Tried fasting labs,  morning labs, all that kind of  crap to get a high lab number.

[tednlou2]

  Depression and anxiety issues also can cause someone to feel tired and worn out.

Very true.  I know anxiety is probably responsible for 90% of any fatigue and feeling lousy that I have.  To help manage this, I often tell myself if I hadn't learned my status, I would probably feel great and out running marathons.  Well, probably not marathons--maybe a good power-walk with the old lady next door.  I should ask her if she wants to put on our polyester jump suits and put this into practice.
 

[GSOgymrat]

50% is amazing. I have been stuck at 25-27% for years.

[hotpuppy]

I got my new lab results this afternoon and mine are now 50%, the highest EVAH   My lowest when diagnosed were 14%, and just five years ago they were only 31%.

Damn, I'm only half as good as you..... at 25%  ....   

Guess that means I'll have to do it twice.......   

Reminds me of that old joke....
Man:" Hey Queen, you want 16" of cock?"
Queen: "Sure baby, but you don't look like your packin..."
Man:" We'll just have to do it 4 times."

And on that note..... congrats on your numbers... those rock!

[hotpuppy]

50% is amazing. I have been stuck at 25-27% for years.

It must be her special milkshake diet......

[Miss Philicia]

50% is amazing. I have been stuck at 25-27% for years.

You need to do more poppers.

[elf]

I got my new lab results this afternoon and mine are now 50%, the highest EVAH   My lowest when diagnosed were 14%, and just five years ago they were only 31%.

I am so happy for you.
I don't know my latest numbers.
I was too scared to go to get them.
No news is good news, I guess.

[GSOgymrat]

I am so happy for you.
I don't know my latest numbers.
I was too scared to go to get them.
No news is good news, I guess.

Ignorance is not bliss. Please take care of yourself.

[jay195]

On my labs there has never been  CD% , only the VL  and the CD 4 count, cholesterol etc......

I asked my doctor about it and he shrugged it off saying that the VL and CD4s were what mattered most.
 

                                   Jay.

[phildinftlaudy]

On my labs there has never been  CD% , only the VL  and the CD 4 count, cholesterol etc......

I asked my doctor about it and he shrugged it off saying that the VL and CD4s were what mattered most.

                                   Jay.

Hi Jay:

I have always seen it on labs (the cd4 %) -- on mine it is in an area called the "Lymphocyte Subset Panel 4" this area includes: % CD4, Absolute CD4, % cd8, Absolute CD8, Helper/Supressor Ratio..."

Most docs talk about the cd4 and VL; however, cd4% is much more stable of a reading - the last doc that I sat in a presentation with said that cd4% is something that doc see as more reliable in conjunction with VL, as cd4 count can change substantially depending on time of day of the draw and many other factors.  The doc stated it this way also - a person can have 600 cd4s for example but only have a % of 14 and this wouldn't be as good as having a cd4 of 450 and a % of 30.  Basically, the % from how he put it is reflective of the quality/strength of functioning of the cd4s.

Is your doc an HIV specialist?  I'm not knocking him - because as you will note from the posts on this thread a lot of people have said that their  docs don't go into the % with them.

My last labs showed a slight drop in my cd4 count but my highest cd4% and I can tell that I geel better then ever. 

[Miss Philicia]

a person can have 600 cd4s for example but only have a % of 14 and this wouldn't be as good as having a cd4 of 450 and a % of 30.  Basically, the % from how he put it is reflective of the quality/strength of functioning of the cd4s.

Very true, and why a doctor should be discussing/explaining this to a patient.

[eric48]

Margin of errors

Most labs (if not all) never count CD4. The count lymphocytes and have an assay that determines the % of CD4.

They , then multiply the number of lymphocyte by the percentage to report the total (calculated) CD4 count.
If your lab sheet does not report CD4% you can still calculate from the reported values of CD4 count and total lymphocytes.

Not only total count of lymphocyte may vary due to various conditions (time, tiredness, vaccination, ...) (hence the calculated CD4 count will vary), but I recently found out that the measurement of total lymphocytes have a margin of error too...
I had my blood drawn the same day, one the same needle, that were ordered by 2 different doctors (one is my HIV specialist, the other is my diabetes specialist). Same blood, same lab, same guy (no sex change during blood work), poored into 2 different vials
one came with a lymphocyte count of 2 491 the other with 2425 : difference is    66, therefore about 3 %. One, therefore can estimate that labs have an error margin of 5% (on the total lymphocyte count)

In my case, on my lab sheets I have one that shown CD4 count 776 and the other 797... (same blood..)

The CD4% also have a margin of error of 2% . When being reported a % of 20, it can in fact be 18,19, 20, 21 or 22. When your number of total lymphocytes is high and percentage is low, the error on CD4 count can therefore be pretty high ! (50 to 100)

relevance of percentage
CD4 counts and/or % are of interest because they can be used as a predictor to AIDS events.
There has been a good number of concordant papers that show that AIDS events are more likely and more severe as the CD4 is low.
Everyone here knows the rule of thumb:
> 500 : safe 350-500: more or less safe 200-350 : less safe, <200 danger, etc...

Problem is that if you immune system is damaged and fighting (with poor arms) againt the infection, CD4 will raise, but immune system will have a hard time to win.
It is therefore documented (I lost the link, google for it) that IF CD4 is over 500,  then % is the predictor of choice (and not the CD4 count itself)
that article also had a predictor for people over 500 depending the %. on the top of my mind it was like:
(this, for people who are NOT under HAART)
< 15 % : less that 2 years
15 to 20 less than 4 years
> 20 : much more time.

Statistically, based on cohorts studies, if your % is lower than 15 then you are in (immediate and certain) danger. This is why 14% was considered as an AIDS defining point.
I had always wondered why 14 ? why not 13 or 15 ? that because there is plateau between 15 and 20 but past that plateau the decline in health is (statistically) fast. Hence the value of 14%

Dr Gallant had one comment like this. Even if CD4 count is high, a % of 14% is CLINICALLY equivalent to CD4 = 200

As for myself, my CD4 where in the 500-450 range BUT % was 16-20%. I have considered that the time-to-need-the-meds (either my % declines to 14 or CD4 declines to 350) was about 2 years
There was no benefit in waiting. (at my age 2 years might be 10% of rest of life..., for a younger person, could be perceived differently)

That some docs may shrug at percentage is understandable: the relevance of % depends on
- patient is on MEDS or NOT (if on meds, it is not so much relevant, because while on meds what they look at is VL)
- patient's CD4. (if CD4 at 100, there is no further need to look at %, you kind of know where patient is at...)

phildinftlaudy reports:
3/10:  CD4=730; %=30; VL=<48
6/10:  CD4=672; %=41; VL=<48

the drop in CD4 is in the margin of error BUT the increase in % is significant and is NOW in reference range for HIV neg people. So that is VERY GOOD !!

All the above is my humble newbie opinion. exceptions to statistics are many, but still...

Thanks to Miss Philicia for pointing to the link:
http://www.aidsmeds.com/articles/TCellTest_4727.shtml

I was a bit concerned because after 2 months under meds all numbers had nicely increased but my VL still at 700. I therefore felt very comforted by this statement:

most experts agree that once anti-HIV therapy is started, an increase in the T-cell ratio (i.e. a rising CD4 count and a falling CD8 count) is a telltale sign that drug treatment is working.

This is my case (base line ratio at 0.25, now 0.7) and I felt very happy after I read that post/link

Thanks !

Eric

[jay195]

Hi P, thanks for your reply.

Yes, my doctor is an HIV specialist.

I will talk to him again on my next visit.

I am on Truvada, Reyataz and Norvir and was diagnosed in April 2008.

VL is undectable and CDs are around 680.

Thanks                                        Jayxx

[dvinemstre]

I found some of the answers helpful and some of them scary. I want to make anote about how things are defined, etc, and let's be clear it's almost always about $$$$$$. From a diagnositic point of view and a legal point of view, if a person is diagnosed with AIDS, it is not just about the %5 or CD4 level or anything, but rather a set of several criterion, including secondary medical conditions. In the past, there was no real way to get government funded insurance coverage solely on the basis of an HIV+ diagnosis, but once a person tipped over into AIDS diagnosis the public funding for things really changed. Now, hopefully, this will shift as the new health care act will provide more publically funded insurance options to person who are LIVING with HIV, and not wait until they are DYING with AIDs, so to speak. HIV+ is considered high risk pool, like a bunch of other conditions, including things like Migraines, depression, blah blah blah. So, the seemingly arbitrary decisions to pick %14 for example as a qualifier for AIDS diagnosis is money driven and treatment driven.

Z

[dvinemstre]

oh yeah, btw, I always just get a hard copy of my labs and then I don't have to even bother with wondering in case I forget to ask Dr about it. ALso, the labs tool on poz.com is great.

[OneTampa]

50% Wow! Ms. P. that is fantastic for you.  I've stayed around 28% - 33% for years.

[tommy246]

I got my new lab results this afternoon and mine are now 50%, the highest EVAH   My lowest when diagnosed were 14%, and just five years ago they were only 31%.

thats amazing miss philicia 50% with your long history is this down to your new meds regimen and secondly is this unusual to climb so high from 14 %. i was 14 % when i started meds even though my cd4 was around 500 or 600 . I think thats why i ended up in hospital with pnuemonia as my doc paid to much attention to my high cd4 and not my low %.

[Miss Philicia]

thats amazing miss philicia 50% with your long history is this down to your new meds regimen and secondly is this unusual to climb so high from 14 %. i was 14 % when i started meds even though my cd4 was around 500 or 600 . I think thats why i ended up in hospital with pnuemonia as my doc paid to much attention to my high cd4 and not my low %.

I can't really say -- my doctor seems to thin it unusual but I"m jut guessing from the look on his face.