HSV2 Inhibition Test Result

[nomissyas]

Hi Terri,

I had unprotected sex in January and was tested positive for HSV2 in April here's my result:

4/1/2011  
Herpes I Ab. (IgG): 0.11
Herpes II Ab. (IgG): 1.91

4/7/2011
HSV-2 IgG Inhibition, ELISA: screening index is 1.37, % inhibition is 88

The clinic told me that this inhibition test was a confirmatory test that I'm truly hsv2 positive. None of them could explain the numerical results to me well. So here are my questions:
What is the screening index of 1.37? Is that also the antibodies level?
What does the 88% mean? Does that mean the % amount of my viral load?
I've read some posts of others that they had low positives for the first few test so decided to do a WB and eventually came back negative. Also, someone had an inhibition test of 91% and after a year got a negative result from WB. How accurate is the inhibition test? Should I accept the fact that I'm hsv 2 positive? At this point, would you suggest that I get a WB test?


Thanks

[Terri Warren, RN, Adult Nurse Practitioner]

The index value (the 1.37) just is a measure of the optical density of the antibody response - too complicated to really talk about in depth here, but a 1.37 is a very low index value, and definitely needs confirmation by western blot.  For sure!  Do not accept your HSV 2 status yet.  The western blot is done at the University of Washington only, we do it through Quest Labs that transports it there for us.  The Quest code is 34534.  If you can't get it done, we can order it through our clinic for you.  I've no confidence in the inhibition assay anymore, frankly.

Terri

[Terri Warren, RN, Adult Nurse Practitioner]

No, that's definitely the other way to do it for people who have a cooperative MD.  That's just fine!  
Both those values are low positives, and are worth confirming.  At 1.37, statistics say that only 15% will confirm.  At 1.91, about 40% will confirm. I think you are just going to have to get the test and see what happens.  If it is positive, you are no worse off than you are now, right?  I think well worth the money.

Terri

[nomissyas]

Hi Terri,

Thank you for the reply. I've called the U of Washington and the sent me a WB info packet with a Clinical Lab Request form. I plan to bring these in to my physician and have the blood collected and send everything to U of Washington lab. Is this the correct process? Or do I have to ask my physician to order it through Quest Lab?

Also, is the 1.37 same as the 1.91 antibody level on my first test? My doctor said 88% means I'm positive regardless.

Thanks