Confusion with results

Introduction/Orientation
1

Hello everyone,
What does it mean that sometimes in the results of the Hvb DNA tests it says that the number of copies is lower than the arrest limit and other times it says detectable but not quantifiable.

2

Dear Luis,

I’m not sure what “arrest limit” means, but there are 2 limits to the PCR assay:

  1. Limit of quantification, which means HBV is detected, but you cannot accurately say how much there is. Usually a PCR test has a quantification limit of around 10 or 20 viruses/mL of blood.
  2. Detection limit, which means when nothing comes up in the test.

Hope this helps,
Thomas

1 Like
3

Thanks for answering me,
Sometimes it puts the following:

Copies name less than detection limit and other times Viral load detectable but not quantifiable to be less than linearity of the technique.
The meaning is the same, right?

Dynamic range of determination: 10 - 1 x 10^9 IU/mL
A value < 10 IU/mL indicates that the patient’s viral load is below the cutoff
of linearity of the assay, and will be reported as ILQ (detectable not quantifiable)
A value > 1 x 10^9 IU/mL indicates that the viral load exceeds the range of
linearity of this analysis
Conversion factor:
1 IU/mL= 3.41 copies/mL

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4

Yes, I believe you are correct. I think this essentially means:

If HBV detected and the level is 10-1000000000 IU/mL = Quantified
If HBV detected and the level is less than 10 IU/mL = Detectable, not quantifiable
If HBV not detected = undetected.

TT

2 Likes
5

ok, what I do not understand and try to explain is because sometimes I give me the results in copies and other times not (not quantifiable detectable)
if it is practically the same, right?

greetings

6

If you got results in copies you should have explanation below how many copies is 1 IU. 1 copy is not 1 IU. But if it’s lower than limit of detection it’s very good result especially if you are not on any therapy.

1 Like
7

If it is below 10, it cannot be accurately counted, so that’s why it is returned as “not quantifiable, detectable”. If it above 10, then it can accurately be counted so you get the results in copies.

Thomas