What is normal range of Anti TPO antiodies test?
My relative have undergone this test and got value 207. Her TSH is also 5.8
There are several reasons why we can't specify the range here on Health SE, especially for anti-TPO Ab.
Antibodies are proteins, produced by our immune system. Determining the concentration of a specific protein is somewhat more difficult than determining the concentration of a smaller molecule. Still, there are various methods for this - for antibodies those are mostly immunological assays.
If you test the same sample with various methods, you could get different results.
From Lab Tests Online:
The sensitivity and specificity of thyroid antibody testing is improving but is still not as good as health practitioners would like it to be. All of the thyroid antibody tests have changed over time. This is part of the reason that the tests have historically acquired many different names. There are also many distinct methodologies and each has different reference (normal) ranges. If someone is having serial testing done for monitoring purposes, it is best to have test done by the same laboratory each time, using the same methodology.
How can you trust these tests if they give different results? Each test method has to be validated and standardised. This means that various parameters (that have been determined as important) are checked for each method against a standard or a referent method. The important thing is that one interprets the value obtained by testing a certain sample by a certain method by comparing it to the referent range for that method.
From the same source:
Reference values are dependent on many factors, including patient age, sex, sample population, and test method, and numeric test results can have different meanings in different labs.
For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the specific reference range for your test(s).
This is pretty straight forward. E.g. if there are variations between sexes, the lab report should come with two referent ranges (one for each sex), and specify which is which. Sample population is also important, and some referent ranges are defined for the majority population living in a certain area.
If somebody told me that their body temperature is 97 degrees, I'd say that's impossible. This is because I'm used to Celsius scale, where water boils at 100 degrees Celsius. In fact, this calculator shows that 97.16 degrees Fahrenheit corresponds to 36.2 degrees Celsius, which is within normal body temperature range. Same goes for determining concentration - there are many "types" of concentrations (molar, mass, etc.) and each of these can be expressed in various units. Furthermore, the amount/level of the tested parameter doesn't have to be a concentration at all.
Conclusion 1: If you have your test results, they should have come with units and reference ranges (usually written in a column at the right of the report). If you don't have these, it might be a good idea to contact the test lab if possible and inquire for details.
If the results are not within the reference range, this can mean a number of things. It might imply that there is an underlying condition causing this. For thyroid, the values of TSH and anti-TPO Ab can point to several, very different conditions. You shouldn't try to discern these on your own - even if you have referent ranges. This is what doctors are for. You should not expect a physician to interpret these results via phone or e-mail, because laboratory tests are just one part of making a correct diagnosis. Other parts include: anamnesis, family anamnesis (medical history of your relatives), physical examination and possibly (but not necessarily) imaging methods, such as ultrasound.
What's more, even within a certain referent range, for some hormones it depends very much on your age e.g. in which part of the interval are the "ideal", i.e. optimal values.
Conclusion 2: Leave the interpretation and the diagnosis to your doctor.
Suggested reading: Reference Ranges and What They Mean