Dear Dr. H - Can you help me with this please. My doctor recently had me take a HIV-2 Qualitative DNA PCR from SKB. I don't know why he ordered the PCR test because the potential exposure I was worried about was back in January 1999, and it wasn't with a West African either. Anyway, I got the following result today - Indeterminate. The following was written below the result: Internal quality control testing indicates that this specimen inhibited the polymerase chain reaction (PCR) used to amplify the target genetic sequence. Because of this inhibition we are unable to determine the presence or absence of the HIV-2 proviral DNA. Inhibition of the PCR reaction of transiently observed with certain specimens taken from the same patient. The exact cause of this inhibition remains unknown. An additional specimen should be submitted for HIV-2 DNA PCR testing. Reference range - Not detected. My doctor was not exactly certain what the above means. Can you explain to me in plain English what SKB's comments mean. Does it mean that the blood sample was somehow "damaged" in transit or does it mean they weren't able to run the test consistently or what. I really don't think a HIV-2 PCR was neccessary in the first place nor do I want to take another one. Based on the comments you have made to people in the past about HIV-2 I'm really not too certain it's something I should have been worried about in the first place. I have taken a few HIV-1 Elisa's and 1 HIV-1 DNA PCR since that potential exposure - all negative. Sorry this post is so long. Thank you in advance for your help.

Good labs have internal controls to monitor the integrity of the samples and the integrity of the assays. Sometimes the PCR assays don't work, either because something was in the sample that caused the reaction to fail (ie wrong anticoagulant, hemolysed blood) or their controls for the PCR reaction failed or didn't give the correct readings. MH