what's up with PCR testing

Can anybody tell me is getting private clinical PCR testing safe and accurate?
I 'm thinking about getting tested at labcorp just to ease my mind.

[paris420]

PCR testing is accurate if taken after 28 days from exposure. But remember it is a very sensitive test and can have chances of giving false positive result. Unless you are involved in a high risk exposure, doctors do not recommand taking this test because of its sensitivity and chances of giving false positive result. But once tested negative you don't have to worry anymore since it it checking for virus through DNA rather then blood which takes longer time to come in contact.

[Teak]

A PCR test is not for the purpose of screening or diagnosing someone that believes they have contracted HIV. A PCR test is used to monitor the viral load of persons already infected with HIV to see how their medication is or is not working.

[Tommy420]

2 reasons PCR testing is not recommended:

1) Possibility of a false positive result, which obviously, would freak you out, even though you do not have HIV.

2) It costs too much money.  Also it's a time-consuming test.  At 28 days, the possibility of testing positive on an antibody test is 90-95% if you are truly infected, so it just doesn't make sense to spend your money on the PCR test.

However, if you do test negative after 28 days, it is highly accurate, and if you want to spend the money to avoid feeling the anxiety, then go ahead and do it.

[Teak]

The main reason they're not recommended are, they are not approved for diagnosing anyone that thinks they had a possible exposure. They are approved to test infants that were born to infected mothers just because most infants will test positive the first 15-18 months due to antibodies from the mother and all other test would come back possible positive and the PCR is used to help rule HIV out.

[Tommy420]

Teak, you're right, that's what the CDC says about PCR testing.  But my comments are from Dr. HHH's words in one of the threads that I saw, and although I'm not his biggest supporter (b/c I think he's too liberal on his opinions sometimes), I do agree with his comment on the PCR testing.

[jake31]

too liberal on his opinions?  more like too conservative when it comes to risk assessment.
I have been reading these "Archives" and it seems to me that he suggests heteros test out to 6-8 weeks and homos like myself test out to 3 mos.

Aren't all testing methods the same regardless of risk?
Is not a risk a risk?

Do tell.

[regularjoey]

Look people, PCR is a FINE test for all purposes.
The bottom line is that ELISA is a BETTER test for multiple reasons (fewer false negatives, fewer false positives, cheaper, faster, etc. etc.).  Thus it is a recommended test, not PCR.  If you are 6 weeks or more post-exposure forget PCRs, take an ELISA and then move on, end of story.  

[Teak]

Not all test methods are the same, but the testing guidelines for str8 or gay are the same. 3 months is when you can get your conclusive negative test no matter if your str8 or gay.

[jake31]

well, I spoke to some person from GMHC today and they said that at 4 weeks 90-95% show up.
Tell me,..is this true?

[fret1]

yes, that is true for most people, though some people take longer to develop antibodies

[jake31]

well, if say 90% people show up at 4 weeks, then that leaves 10%
And of the 10%, that means you either got HIV or Not ?  5%
That means the test would indeed be 95% accurate if negative at 4 weeks...right?
The other 5% would have ot include an array of other factors,..such as entry way, the risk, etc..

[Teak]

Read this from GMHC on testing. http://gmhc.org/health/testing.html

[jake31]

I did...and I was not talking about PCR....but standard HIV antibody testing

[Teak]

Only the last part talked about PCR. I was talking about the window period.

[jake31]

yeah...I saw it. But the "vast majority" of people must be 90-95% of people...the "unvast majority" must be some seriously ill people.

[jake31]

and as far as I know...i do not have cancer or inject drugs

[jake31]

my concern was more on the performace of oral sex on a man who is gay and did not ejaculate in my mouth.
I just did not know if I had any oral cuts/abrasions that could have exposed me.

[Teak]

For those that are on chemo, anti-rejection drugs or chronic drug abuse only amount to 3%.

[Teak]

You didn't have a risk, so if you want to test the day after it would be conclusive.

[mike_no]

You have to understand that there are two types of PCR tests which looks for the HIV Proteins
1. PCR RNA
2. PCR DNA

Irrespective of the PCR type,the false positive rates have drastically dropped and every positive PCR is confirmed with another PCR for confirmatory reason, this eliminates the possibility of small amount of false positives(which was always 4%).

The HIV DNA PCR test measures something different than the HIV antibody. The DNA PCR test looks for HIV DNA in the white blood cells of a person, whereas the  ELISA (antibody tests) measure the immune response to the virus. If a person has a HIV DNA PCR test, the result may be positive even if insufficient antibodies are present for detection by the HIV antibody ELISA.An undectable PCR DNA taken at 28 days or more from the time of exposure only suggests no HIV infection.

The HIV RNA PCR test detects the HIV infected RNA directly. The time between HIV infection and RNA detection is 9-11 days.Hence, an undectable PCR RNA at 12 days or more from the time of exposure suggests no HIV infection.

Today, the advance PCR tests looks for as low as 10 copies of DNA/RNA in 1 ml of blood. If we analyze logically, after acquiring HIV the virus multiplies in great magnitudes every day and after 2 - 3 week post exposure, the viral count should be in thousand to millions, if an ultra sensitive PCR test with sensitivity of 10 -50 copies of DNA or RNA / ml of blood was undetected, you should be rest assured that you weren't infected at the first place.

It's always recomended to back up your undetectable PCR result with an antibody test at the 12 weeks. One can only expect a negative.

Good Luck

Mike :)

[regularjoey]

OK, I don't mean to be anal, but I think I've seen you say this many times before, so here it goes:

PCR tests do NOT look for proteins.  They detect genetic material - DNA or RNA.

[mike_no]

Joey ...why do you do this ?

I've said another thing time and again that you can STFU, if you don't know, just don't make up :D (I'm not attacking on you here, I'm kinda feeling funny, joey will always crisscross mike )

http://www.mcld.co.uk/hiv/?q=production%20of%20new%20viral%20RNA%20and%20proteins

Go figure out!

[mike_no]

Joey,

My apologies, I take my words back again, I skipped my mind on Elisa and PCRs.

YOU ARE CORRECT, IT'S THE GENETIC MATERIAL THAT PCR LOOKS FOR, ELISAS / P24 ANTIGEN LOOKS FOR PROTEINS.

Pardon my Ignorance

Mike

[regularjoey]

I rarely correct people here, because I believe that everyone is entitled to an opinion and because I know how much people hate to be corrected.  I do it only when someone is blatantly wrong, because I feel that I have that responsibility.  This was such a case and I knew that it wasn't simply a typo, because I've seen you say this before - and I only read maybe 5% of the threads here.  I won't make exceptions just because one is a regular poster, like yourself.  It does not give me any pleasure, I don't do this to crisscross anyone.  I wish somebody else would do this, but no one does, especially now that guiltworry and a few other competent people are no longer here.  

I accept your apology.  All I can say is that you shouldn't get so angry, it's OK to be wrong.  Arguing with regularjoey is a waste of time, since I'm always right.  Try not to be such a hothead and you won't have to apologize again.  Cheers.

[o_g]

PCR RNA can be negative in the later course of disease but PCR DNA is always positive. HIV virus resides in thymus where WBC's are reproduced. The DNA PCR looks for the infection in white blood cells rather than blood plasma itself. A RNA PCR looks for the virus in the blood plasma. RNA PCR is the most sensitive test soon after infection but from day 28  onwards DNA PCR becomes the most sensitive.

[mitm]

HIV-1 RNA Real Time PCR; Quantitative !!!
is it only for HIV1?? it means could not detecte viral load in HIV2?

[o_g]

That is 1 question left best to be answered by bood banks itself. I think both PCR DNA as well as PCR RNA are considered subsets of NAAT.
Moreover, these days many speciality labs use terminologies like Qualitative and Quantitative Analysis rather than simply naming it RNA or DNA types. There for sure is some discrepancy in variable understanding but one thing for sure is that a good antibody response to HIV infection can make HIV virus go undetected in blood whereas the WBC's produced in thymus where specifically the HIV virus resides do get infected and the infection can be traced by DNA PCR. Once a DNA PCR becomes positive, it remains positive for life but same can not be said about RNA PCR.

[mitm]

if there is any viral load the test should detecte it no matter it is HIVI or II!!!!?

[o_g]

I heard there is 1 by Ranbaxy labs called HIV DNA Detector or something like that but sounds wierd that it detects both.

[o_g]

Yes, in the above mentioned scenario, ideally speaking the person should test antibody positive.

[Rae1]

thought you were bad about hiv? http://forums.poz.com/index.php?topic=5613.0

see that thread?

[ExtremeStress]

lets not make that a goal to reach for.

[mitm]

yeah,what u said is exactly what i reached to it personally lol
it means atleast one of them must be detected in these tests.

[o_g]

I don't understand what is bothering you to such great lengths. You have tested out to 22 months. Well beyond CDC's earthly recommendations. I appreciate your trying to help other folks on these forums but when you really can not help yourself get over your fears, how can you go about offering others advice. C'mon man, you sound way too depressing after a 22 month negative test. For the folks, who are trying to find happiness after 12-13 weeks negative, you are giving a very bad example. You need help for sure but it has nothing to do with HIV. Take care...

[o_g]

You sound depressed. Are you taking any meds for that because I will be really surprised if your doctor has still not prescribed you those. Try to stay away from all the negative thoughts for 3 weeks. It works!!!

[Rae1]

have you looked into other autoimmune disorders by chance? Or are you dead set on being the first person ever, in the history of HIV to seroconvert after this long?

[Teak]

People you can sit and debate the PCR tests all you like. None are approved for use for the diagnosing or screening of people that THINK that have had an exposure. They are not diagnosing tests. The PCR/RNA is approved to help with early diagnoses of HIV, but it is not a standalone test. PCR does not give a negative or a positive they give viral loads. PCR tests are approved to monitor the viral load of persons infected with HIV/AIDS. Go to the sites and read.

[longone]

Who cares about approval. The DNA/PCR test looks not at viral load but for the DNA of the virus in one's blood. If it is there your infected,if not you are not infected. The only down side of a DNA/PCR test is ,the cost and risk of false POZ. If you get a NEG. @ 20 days you are NEG. If you understand the risk of a false POZ and can afford it,go for it, its up to YOU.

[Teak]

You sir don't know what you are talking about. PCR test DO NOT give poz or neg results. Are you HIV Positive, I am and have a PCR test ran every three months to obtain my Viral Load status. If you don't know what you're talking about don't post.

RNA PCR tests are most frequently used for screening blood donations and donor organs for HIV, while DNA PCR tests are used for testing newborn babies born to HIV positive mothers. Both types of test can be used to measure the amount of virus that is present within a person's body (when they will usually be referred to as 'viral load' tests). http://www.avert.org/hivtesting.htm#q7a

[jake31]

apparently the PCR test was not all that valuable based on the fact that 4 people contracted HIV from that transplant recipient....just a  thought

[jake31]

I would think as well...that if the PCR was pos. by 20 days...you would know.
If it were negative...then you are negative. I do not know any one person that would later test @ 3 mos.

[Teak]

I take a PCR test every three months and my viral load is undectable, does that mean I'm HIV negative? hmmm, and I have AIDS.

[Teak]

How about undetectable.

[roo_boy]

Dr. Holodniy from thebody:

"Viral load will become detectable within several days after infection, and is detectable in essentially all HIV infected people forever unless effective treatment makes it undetectable. MH":  http://www.thebody.com/Forums/AIDS/Labs/Archive/History/Q5872.html

It should be followed up by an antibody test but if you have an undetectable viral load a week or so after infection then it is a good sign - we have Dr Handsfield supporting the test, and, another doctor from thebody commenting on viral load being detectable within several days. It is commonly used in high risk situations and should only really be done a few days to 2 weeks after the incident. Beyond 2 or 3 weeks, just wait for an antibody test at 6. Then maybe 12 but Harvard Health Services says 6 is cool.

[regularjoey]

Teak: you are confusing quanitative and qualitative PCR.  HIV-positive people like yourself get quantitative RNA PCR to measure a viral load.  In contrast, a qualitative PCR basically does give a positive or a negative result - it is calibrated to be sensitive enough to pick up the smallest quantity of the product, but cannot be used for quantitation.  That test is used for HIV screening purposes in special circumstances.  So these are two entirely different tests, don't compare apples and oranges here.  The point is that once you are passed 6 weeks, ELISA is a better test to take, period.  And yes, it is possible to be undetectable by PCR and positive by ELISA/WB.  Rare, but happens.

Jake: It's good to see you back, paying the "quacks" another $15 and giving us your valuable opinions!  FYI, a PCR is not used for organ transplants, which is partially the reason why those HIV transmissions took place a month ago.  Welcome back.  

[Rae1]

a PCR was not used, as Joey said, on the person whose organs were used. Antibody tests were used and he/she was in the window period.

[jake31]

A PCR as stated by one post by a Dr. on here has said, "Once the PCR is positive, the PCR is always positive".
So , unless you are getting a false positive after 4weeks, you would not need to retest.
BUt still I would think someone would want an antibody test regardless.

Joe,...you think the Dr.'s on here are quacks?

[Teak]

How in the world would you know if you got a false positive at 4 weeks if you weren't retested?

[regularjoey]

No, "quack" was the term that you used for Dr.H. before you got banned, in case you forgot.  You still paid him twice for the advice - ouch!

Anyway, I read your sad story: sounds like the CSW did give you something when he gave you a BJ, leukocytes in the urine is a pretty good sign of genital infection.  I wouldn't worry about HIV or STD at this point though.  Keep working with your urologist.

[jake31]

who are you talking about?

[longone]

Teak, I can't believe you consider yourself an expert. This is testing 101. You will loose all credibility with junk like this, read and learn. Try google, it's really easy to use. I have had two DNA PCR test in the past not an RNA wh ich you refer to Ghezzzzzz.

"You sir don't know what you are talking about. PCR test DO NOT give poz or neg results. Are you HIV Positive, I am and have a PCR test ran every three months to obtain my Viral Load status. If you don't know what you're talking about don't post."
------------------------------------------------------------------------------------------------------------------------------------------------

The HIV DNA PCR test measures something different than the HIV antibody ELISA and HIV antibody Western blot assays. The HIV DNA PCR test looks for HIV-1 DNA in the white blood cells of a person, whereas the HIV antibody ELISA and HIV antibody Western blot assays measure the immune response to the virus. If a person has a HIV DNA PCR test, the result may be positive even if insufficient antibodies are present for detection by the HIV antibody ELISA.

[Teak]

Longone you still don't know what you are talking about. PCR tests are not approved for screening or diagnosing HIV. They are monitoring tests. The only time they are used is; PCR/DNA on infants born to infected mothers up to 15-18 months of age and PCR RNA is a supplemental test to help with early detection of HIV in those recently infected. PCR RNA is not a stand alone test and not a diagnostic test. None are used for the diagnosing of HIV infection. The are expensive and unreliable to use for diagnostic purposes.

[longone]

Teak are you drinking?  I Said "Who cares about approval" in my post. They were the first words. I am not talking about an RNA test, I am talking about a DNA test. They are two different types of PCR tests. You have to know this!!!!  One looks at viral load [RNA] and one looks for the DNA of the virus in white blood cells. I have never said these test were used for screening, just read my post. Have a good day and drink up.

[Teak]

You want to give out false information go elsewhere. No one cares what you think or your opinions. For you information, I don't drink. Go play on another forum.

[mitm]

please please lol Longone , we do believe Teak is an expert in this forum ...
the test that teak has to do every months is RNA and is not giving positive or negative,what s the point then?  

[regularjoey]

What is this argument about???
It has been said a million times here, a QUALITATIVE HIV PCR can be used for screening, in SPECIAL CIRCUMSTANCES.  That means, if there is high risk of HIV transmission to others in the antibody window period.  This includes blood donors, porn actors etc.  Everybody else should not bother - wait 6-8 weeks and get an ELISA.
Also, a PCR can be used as a diagnostic test in special circumstances, when a person is suspected of having an especially severe ARS sickness.  A PCR is always positive during ARS by definition, while an ELISA may be not.
Let's just stop this argument here already, please, before medhelp starts banning people.

[Teak]

PCR is never a diagnostic test unless you are a new born, born to infected mothers and a conclusive test is never based off a PCR test.

[regularjoey]

That is correct, newborns are also screened with an HIV PCR.  That is because a positive serology in a newborn may not indicate true HIV infection, as antibodies could be simply acquired through breastfeeding.

So HIV PCR is very useful in a variety of settings to screen and/or diagnose HIV.  But this does not apply to ANY forum users here.  Get a serology test at a proper time and then move on with your lives.  

[longone]

Who cares is right. I simply find it amazing that people don't know there are TWO types of PCR tests. RNA and DNA ,both look at different things.
BTW, one of the most respected Dr. in my area will order a DNA/PCR test for a person that is freeking out. He says the only reason its not used routinly is cost. That's all I'm going to say.

[mike_no]

Joey, I appreciate that you have corrected me here but not to forget we all know that you are only right 'SOME TIMES'. and you're talking about me apologizing to some one next time, I just don't see a problem there, if I'm wrong about some thing I will certainly apologize and get myself corrected unlike YOU, always gung ho about  your own self and own statements, it just doesn't matter for you even if you're wrong. I can still recall your advises like *testing out to 6 months*, *one can't get other STIs by getting a BJ* and the likes...

Try not to always brag about yourself to the glory, it can almost always get you in a weird position.

Cheers!

Joey,

[mike_no]

You were better known as Dr. Stupid (honest suggestion) :D

[regularjoey]

Of course I'm wrong sometimes.  I was 100% sure US was going to bomb Iran for example - looks like I was completely wrong.  But I am almost never wrong when it comes to HIV.

About the 6 month thing - I always answer the questions honestly.  When somebody asked for CDC recommendations for a rape, I said 6 months.  That's what it is, it's there in plain english.  Do I agree with the CDC recommendations?  NO.  But they are what they are, I answered the question.  It's not my fault that answer made everyone uncomfortable.  You don't like it - contact CDC tell them what you think.  

[scaredinmo]

What's up everyone? I have been monitoring this thread and want to chime in. I agree with Teak, but I also agree somewhat with chris. If you're freaking out, a PCR might be helpful for your mental health, but then again it may not. There are a lot of false positives and indeterminates in PCR testing. Common sense would tell you that this is a good reason not to license it for diagnosis purposes. I paid alot for the test twice and came out negative on both, however, I feel much better about my 6 week ELISA than the PCR. Why? The test isn't approved to diagnose for whatever the reason, I can't seem to find any scientific data on the subject other than some isolated studies and their use in newborns and monitoring viral load. So, two things come into play in this decision. First, the PCR "can" detect the virus which is why it is used in monitoring viral load. Can't be a standalone diagnosis, but useful, persay. The use of it is to better help you to wait out the timeframe for a conclusive ELISA, that's my opinion and advise if someone is considering it. However, be aware that the false positive and indeterminate rates are much higher than some other tests. Second, ELISA reliability. The following sites shadow the vast knowledge of our much appreciated Dr. HHH when it comes to the ELISA, which very well may make the whole PCR testing argument benign:

http://www.dshs.state.tx.us/hivstd/info/edmat/seroconversion.pdf
http://en.allexperts.com/q/Immunology-including-AIDS-973/ELiSA-6-Weeks.htm?zIr=4

[coz100]

then should i take dna pcr also after my 6.5 months negative western blot and antibody test.??....
coz

[regularjoey]

PCR is not approved for diagnosis of HIV, but that does not mean that it can't be used for it - it is sometimes.  In fact, we had a person on this forum diagnosed (correctly) with just the PCR (antibody tests were negative).  But this only concerns people who are either very early or very late in HIV disease progression, all others will test positive with ELISA.  Nobody here needs to be taking PCRs.

[scaredinmo]

Not saying you should do anything, just giving you data and my opinion. Personally, I'd wait till 6 weeks, get the antibody test, then at 8, then at 12.... all three are cheaper than one PCR and provide you more certainty. Like I said, I had two PCRs and I'm following up with the ELISA. Soooo, I think the PCRs didn't help my sanity much, and definitely not my pocketbook.

[coz100]

I already had 2 western blots,three duo test in these 6 months.western blot cost is same as dna pcr.
if you had dna pcr done after 28 days the there is less chance.....
Only thing why I am worried because of these wiered persisting symptoms.
white coated tongue,big yellow skin rash with pimples and these are for more than 4-5 months so no idea what to think.
anyway I will need money when live long but here I have a big doubt :=((
Regards
coz

[Rae1]

a dna pcr after 28 days is pretty much evidence you arent infected

[scaredinmo]

Calm down. I read your post wrong. You have absolutely nothing to be concerned about when it comes to HIV. There is something else going on that you need to divert your attention to. If you spent more time worrying about what was really wrong than what is not, you'd get somewhere. It is not HIV. Stop worrying yourself, the stress itself is probably impairing your immune system. Eat some oranges.

[kris188]

look guys dispite what u guy saying abt pcr dna the fact of the matter is the pcr dna is something that is being use more and more  in the united states.the only reason why its not fda approve is just because the cost.can you imagine if the health dept was giving these test and how many people everyday will take these test it will be hundrends of dollars.so these are good test.if you go to other websites people will have diff advised and views abt these test.

[kris188]

look guys dispite what u guy saying abt pcr dna the fact of the matter is the pcr dna is something that is being use more and more  in the united states.the only reason why its not fda approve is just because the cost.can you imagine if the health dept was giving these test and how many people everyday will take these test it will be hundrends of dollars.so these are good test.if you go to other websites people will have diff advised and views abt these test.

[kris188]

look guys dispite what u guy saying abt pcr dna the fact of the matter is the pcr dna is something that is being use more and more  in the united states.the only reason why its not fda approve is just because the cost.can you imagine if the health dept was giving these test and how many people everyday will take these test it will be hundrends of dollars.so these are good test.if you go to other websites people will have diff advised and views abt these test.

[kris188]

look guys dispite what u guy saying abt pcr dna the fact of the matter is the pcr dna is something that is being use more and more  in the united states.the only reason why its not fda approve is just because the cost.can you imagine if the health dept was giving these test and how many people everyday will take these test it will be hundrends of dollars.so these are good test.if you go to other websites people will have diff advised and views abt these test.

[Teak]

FDA has nothing to do with the pricing of any tests. Move on. We've been over this already. Everyone is way beyond why PCR tests are NOT an approved diagnostic test.

[Angela183]

Is there a chance that if someone took the elisa test the same week as they had their flu shot and had a cold that a positive test could really be negative?