Is LapCorp reliable for Bartonella (my daughter)

An antibody titer refers to the highest dilution of a serum sample that causes a positive test reaction.

so actually those tests that have a higher titre dilution ratio eg 1:320 are setting the limits of the test LOWER than those that set the threshold to be lower - eg 1:64

however - serologic testing for bartonella is fraught with difficulties and should not be relied upon
numerous studies show that serology is completely negative in a large proportion of cases confirmed by other means.
briefly - the reasons are
- immune suppression - bartonella suppresses the host immune system interfering with the hosts ability to produce the expected antibodies
- species specificity - there are around 40 species of bartonella known - most are known to cause illness in humans - but most labs only test for 2 of these - so if you have other species - the chances of getting a negative result are high
-species antigenic variation - some recent work showed that due to genetic variation in the strains inside species - you need to test for around 45 different antigens to be confident of catching even common species with serology

in short - serology has been demonstrated to have less than 50% sensitivity ( coin toss of getting a positive result even if you are infected ) - often much less - depending on the species / strain involved

the best test available for bartonella at this point in time is the triple draw DD ePCR from galaxy - but is expensive $1600usd
the next best is probably T-Labs fluorescent laser confocal microscopy of blood - but also expensive
the next best - probably igenx multispecies bartonella western blot - but less sensitive than the abobe
the rest are not worth the trouble for the reasons listed above

BTW - if your child has had the bart red/purple streaks ( striae ) i would save your money as that's as definitive as any blood test on the market

Garzie said...
An antibody titer refers to the highest dilution of a serum sample that causes a positive test reaction.

so actually those tests that have a higher titre dilution ratio eg 1:320 are setting the limits of the test LOWER than those that set the threshold to be lower - eg 1:64

You sure about this g-man?

A 1:320 means they dilute it 320x and the antibody still needs to be detected to test positive. That’s a much higher hurdle than 1:64, where it’s diluted only 64x, so the antibody is easier to detect

There's a lot of misunderstanding about this, unfortunately, even among doctors.

Those tests look for antibodies, and with many infections, people will produce antibodies for life once infected. Antibody tests may vary based on what condition the immune system itself is in, but they cannot determine whether an infection is active and causing symptoms. You can make Lyme antibodies, and therefore test positive, for the rest of your life, even once the infection has been treated and is no longer causing issues. Testing is not a way to measure treatment progress.

These infections are diagnosed clinically, based on signs and symptoms. Does your child still have symptoms? Sounds like a good idea to find a new LLMD. Sorry to hear the one you liked retired!