Wednesday, April 8, 2009

Explaining Lyme Tests

This is very difficult to understand. I apologize for that. I still don't understand it all. Try to get through it and read down to the bottom of the post. It is VERY important. :D

I have mentioned that testing for Lyme Disease is very controversial because of the inaccuracies of the test results.

The first and most common testing that Primary Care Physicians order to test for Lyme Disease is called the ELISA which stands for Enzyme-Linked Immunosorbant Serum Assay. *blah blah blah* They draw a blood sample and test the blood for antibodies that our bodies produce in response to being introduced to the Borrelia burgdorferi (Bb) (aka the Lyme Bacteria). In one study that I found, they tested 516 labs. In those 516 labs, 55 percent of the results were inaccurate. How would you feel if pregnancy tests were only 45 percent accurate? You get yourself psyched up for a blood pregnancy test.

How do they run the ELISA test? Well, they take different parts of the Lyme bacteria and break it down into segments and add the patient's blood. Any antibodies that are in the blood will bind to the different segments of the Lyme bacteria. The segments will change color and it will be diluted until there is no color. Then they will give you a dilution ratio. One Part Serum to (how many parts of water they had to use). 1:256 (would be 1 part serum to 256 parts water). Your results will show = Positive, Negative or Indeterminate (had to be diluted too much to be called a negative, but not enough to be called a positive).

For more information on the ELISA test and other tests:

There are many other types of tests for Lyme Disease, but generally LLMD's choose to use a Western Blot test (specifically from IgeneX a lab in California). However other doctors use Western Blots as well. The controversy in this test is that the IgeneX test uses more "bands" than a regular lab would use. I will try to explain a bit about the Western Blot.

When you receive a Western Blot from IgeneX, you receive two test results (actually four, but I will explain that too). IgG and IgM are the two things you will see when you look at your test from IgeneX. You will also note a bunch of different "numbers" with kDa next to them. Some of the numbers will show a double star (**). kDa stands for Kilo Daltons. Here is an example of what the labs see when they are determining your test results.



As you can see, some area (called bands) are dark and some are very light and others aren't there. Some of the bands are Lyme specific and others aren't. Out of a possible 25 bands, only 10 are reportable. Out of those 10 bands, FIVE must be positive on the IgG to be considered positive in the CDC (Centers for Disease Control). For the IgM to be considered positive, TWO out of THREE specific bands must be positive. It wouldn't matter if 8 of the 10 bands were positive, if two of those bands weren't specifically 23, 39, 41. then the CDC would say you had a negative Western Blog IgM.

For the IgeneX IGM results, you would have to have TWO of the double star numbers with a plus in order to be positive. For the CDC results to be positive, you'd have to have TWO of the BOLDED NUMBERS to be positive. (your results would be not bolded, i'm just bolding them here for you to see)

The test results you see from IgeneX may look like this:

IGENEX IGM RESULT: POSITIVE
CDC/NYS RESULT: POSITIVE

18kDa: ++
22kDa: -
**23-25 kDa: +
28kDa: -
30 kDa: +
** 31kDa: -
** 34kDa:-
** 39 kDa: IND
** 41 kDa: +
45kDa:-
58kDa:-
66kDa:-
73kDa:-
** 83-93 kDa: IND

For the Igenex test results to be positive, two or more ** numbers have to be positive.
For the CDC test results to be positive, FIVE of the bolded numbers have to be positive.

IGENEX IGG RESULTS: NEGATIVE
CDC/NYS RESULTS: NEGATIVE



18kDa: -
22kDa: -
**23-25 kDa: -
28kDa: -
30 kDa: -
** 31kDa: IND
** 34kDa:-
** 39 kDa: IND
** 41 kDa: ++
45kDa:-
58kDa:-
66kDa:-
73kDa:-
** 83-93 kDa: -

I have an important announcement to make tomorrow regarding the "sample" test results you see here.

1 comment:

Fliterary said...

Looking forward to reading your post tomorrow! I'll be on the road, but if I can get Internet service, I'll check in.