Tested using 4th gen ab/ag testing in labcorp post 9 week of exposure.

However came across website which says about potential interference with biotin .

1. Does biotin interfere with antibody detection or antigen detection during the case of excess biotin ?

2. Does 9 week post exposure test still 

Interfered with biotin? 

3. I heard antigen only detectable in the blood  /serum  for first 1-2 months from initial exposure  , so any test done during 9th week only detect antibodies? If so , does excess biotin affects test result even in the case excess biotin consumption?

We get fairly frequent questions about biotin and HIV testing, most of them similar to yours -- worry about reliability of negative HIV test results. You really needn't worry at all. The business about biotin interference with testing is mostly an urban myth. It isn't truly a myth, because very high doses -- far higher than normally used in conditioning programs -- indeed can interfere with HIV antibody or antigen-antibody testing. But not at all at the usual doses. And to the extent someone fears interference, all one need do is skip taking biotin for 2-3 days before an HIV test is done. 

Those comments pretty well cover your specific questions, but to assure no misunderstanding:

1. No significant chance of interference.

2. Your negative result 9 weeks after the exposure you are concerned about is conclusive; you did not catch HIV.

3. The basic fact is correct in that antigen appears first, before antibody. But the time is much quicker than you state:  antigen is generally detectable by 10-14 days after exposure, and antibody starts to be detected by 15-20. Rarely these times can be longer, but by 4 weeks after infection almost everybody (98-99%) test positive with the AgAb tests, and it's 100% by 6 weeks.

So you can be very sure you do not have HIV. But if you want additional reassurance about it, and if you take more than the usual doses of biotin, just skip the stuff for a few days and have another blood test. You can be sure it will also be negative.

For more information, you can use the forum's search function to find several other discussions about biotin.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

Follow up questions ,

1. No significant chance of interference. Both antibody and antigen impacted ? Is it more in a cute stage than the later stage ?If someone consume dose like 10mg a day , would that impact ? Also how soon the biotin get into blood stream after consumption?

3. The basic fact is correct in that antigen appears first, before antibody. Asked this because if antigen only stays to detectable level until antibodies develop high enough, which means after 6 weeks 4 th gen only find antibody  to the most part ? Does it has any relation with biotin ?

5. Is there any list of immunoassay which are impacted by biotin for hiv 4 th gen?

Having very high anxiety about the testing . Hence why trying to understand test result post 9 weeks of exposure . 

Would that be impacted still impacted by biotin ? The lab which I took test is labcorp . Have you seen  from your experience any such cases of turning negative to positive after 9 week due to biotin ?

It doesn't matter what lab does the test. There are only a few different AgAb tests and they're all done with exactly the same equipment etc in all laboratories. And LabCorp is very reliable in all respects.

That completes the two follow-up exchanges included with each question and so ends this thread. I hope the information sinks in to a point that you find my replies to have been helpful. Best wishes.