Dear Dr. Holodniy:

I am confused by my most recent viral load results. In the past, they have usually said something like "HIV-1 RNA was detected in this sample at a level <50 copies/mL" but the results this time say "HIV-1 RNA was not detected in this sample."

I also notice that past Viral Load tests have used "Roche Cobas Amplicor UltraSensitive HIV-1 Monitor" while this most recent test used "Abbott RealTime HIV-1 assay."

I'm pasting below the complete results from the most recent VL test. If you could shed some light on what this means, I would greatly appreciate it. Thanks so much!

Component Your Value Standard Range Units Flag HIV PCR (COPIES/ML) 0.00 copies/mL

HIV-1.(SSRNA) (INTERP)

RESULTS AND INTERPRETATION Specimen: Frozen Plasma HIV-1 genomic target is NOT DETECTED

Test: Quantitative realtime PCR for HIV-1 viral RNA (Abbott RealTime HIV-1 assay on the automated Abbott m2000 system)

Comment: This result means HIV-1 RNA was not detected in this sample.

The stated lower limit of quantitation of this assay is 40 HIV-1 genomic copies per milliliter (copies/mL) of plasma. HIV-1 RNA may be detectable at lower levels and is reported as "DETECTED but <40 copies/mL". Samples with viral loads above the upper limit of quantitation (10,000,000 copies/mL) are reported as ">10,000,000 copies/mL". The RealTime HIV-1 assay was designed to achieve an inter-assay standard deviation (SD) of less than or equal to 0.25 log copies/mL in samples that contain HIV-1 RNA concentrations between 500 to 5,000,000 copies/mL.

Well they appear to be getting away with stating that the viral load is zero when the FDA approved lower limit of detection is 40 copies/mL. It is possible to extrapolate results below 40 copies and come up with a number. It is extremely difficult to have an assay that can reproducibly detect zero (in HIV infected patients). This also may not reflect zero copies in the blood, as there still could be detectable copies present if more blood was actually sampled (like 10 mLs or more).