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What Does This Following Lab Report Indicate?
Posted on
Sun, 15 Jan 2017
Medically reviewed by
Ask A Doctor - 24x7 Medical Review Team
Sun, 15 Jan 2017
Answered on
Sat, 4 Feb 2017
Last reviewed on
Question : hi can you please 1) interpret the attached report. it was done at 3.5 weeks of possible exposure. 2) what type of test it is 3) is it reliable? as I heard such is highly accurate at 4 weeks.
Brief Answer:
Your test is reliable and conclusive
Detailed Answer:
Hello. Thank you again for writing to us
In addition to what I wrote you earlier regarding the interpretation of this test i.e negative and reliable I would like to add that even at 3.5 weeks and beyond this test is highly sensitive and specific because at about 21 to 23 days from HIV infection HIV antibodies become detectable by this Dual test even though beyond this the appearance of HIV antibodies may interfere with P 24 antigen assay.
The purpose of the Dual test is to shorten the window period of detection to about 2 weeks as it incorporates a P 24 antigen assay as compared to a 3rd generation test (which only detects HIV antibodies). In most individuals P 24 antigen are only detectable between 2 weeks and 3 weeks after infection i.e transiently. Once antibodies appear (at about 3 weeks) these form complexes with P 24 antigen and interfere with P 24 antigen assay. However, in very rare cases antibodies may develop as late as 3 months after infection rather than 3 weeks. In those rare individuals P 24 antigen may be detectable for longer periods after infection. Hence, while dual testing at 3-4 weeks would almost certainly detect either P 24 antigen or HIV antibody even covering those rare cases, whereas a 3rd generation test (a pure antibody based test) would not be able to detect HIV infection at 3-4 weeks in those rare cases.
To summarize, the Dual test result is accurate at anytime at anout and beyond 2 weeks after a risky sexual encounter.
Regards
Your test is reliable and conclusive
Detailed Answer:
Hello. Thank you again for writing to us
In addition to what I wrote you earlier regarding the interpretation of this test i.e negative and reliable I would like to add that even at 3.5 weeks and beyond this test is highly sensitive and specific because at about 21 to 23 days from HIV infection HIV antibodies become detectable by this Dual test even though beyond this the appearance of HIV antibodies may interfere with P 24 antigen assay.
The purpose of the Dual test is to shorten the window period of detection to about 2 weeks as it incorporates a P 24 antigen assay as compared to a 3rd generation test (which only detects HIV antibodies). In most individuals P 24 antigen are only detectable between 2 weeks and 3 weeks after infection i.e transiently. Once antibodies appear (at about 3 weeks) these form complexes with P 24 antigen and interfere with P 24 antigen assay. However, in very rare cases antibodies may develop as late as 3 months after infection rather than 3 weeks. In those rare individuals P 24 antigen may be detectable for longer periods after infection. Hence, while dual testing at 3-4 weeks would almost certainly detect either P 24 antigen or HIV antibody even covering those rare cases, whereas a 3rd generation test (a pure antibody based test) would not be able to detect HIV infection at 3-4 weeks in those rare cases.
To summarize, the Dual test result is accurate at anytime at anout and beyond 2 weeks after a risky sexual encounter.
Regards
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
thank you for answering. but then can you please tell me why many sources mention a 28 day period to consider this test as conclusive?
Brief Answer:
Dual test has a short window period
Detailed Answer:
Hi
This is in reference to the fact that at 4 weeks most of the patients would have seroconverted i.e would have developed HIV antibodies. Whereas, now a days most labs employ highly sensitive dual tests which is conclusive beyond 2 weeks as it screens for an early serum marker of HIV i.e P24 antigen.
Regards
Dual test has a short window period
Detailed Answer:
Hi
This is in reference to the fact that at 4 weeks most of the patients would have seroconverted i.e would have developed HIV antibodies. Whereas, now a days most labs employ highly sensitive dual tests which is conclusive beyond 2 weeks as it screens for an early serum marker of HIV i.e P24 antigen.
Regards
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Thank you for your response. she did another test at 29 days as per report hereby attached.
Brief Answer:
Reconfirms previous report
Detailed Answer:
Hi.
This report too reconfirms that she is HIV negative
Regards
Reconfirms previous report
Detailed Answer:
Hi.
This report too reconfirms that she is HIV negative
Regards
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
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