9/07/2010

Lyme Disease - Testing & Diagnosis - Lesson Learned

I wanted to start by thanking everyone who has sent me emails with questions and positive feedback about my blog! Can't believe its now being read in 5 countries!! Thanks for everyone's help in getting the word out! If we don't do it, no one will.......

A few people have emailed me asking why Lyme Disease is so difficult to diagnose. I wish there was an easy answer to this question but, as with all Lyme topics, lots of factors come into play.

Lyme is a tricky entity. It can mimic and/or cause hundreds of other diseases and symptoms vary greatly from person to person. It's also a "clinically diagnosed” disease - meaning blood-work should be looked at as a guideline but the diagnosis itself should be based on the symptoms the patient demonstrates with, even when a negative result is found!

Many doctors think in black and white terms - if the test is negative, you don't have it, right? Well, unfortunately in millions of cases the answer is "WRONG!".

We have to start thinking about who defines the black and white criteria......media, the Centers for Disease Control, pharmaceutical and laboratory companies. At this point, each laboratory has its own criteria for a positive and negative result. So you could have two completely different results from the same blood sample.

Let's break down some of obstacles in diagnosing Lyme Disease:

-The way in which Lyme tests are promoted (financially backed)

- Reliability not only depends on the test given but also on the criteria used by the laboratory processing the blood-work.

- The tests are primed to recognize laboratory strains of Bb (Borrelia burgdorferi - i.e. Lyme) rather than naturally occurring strands


- The Lyme spirochete can hide in the body and confuse the immune system into thinking its not there. So, no antibodies are produced, resulting in false negatives.

On top of that - Have we recognized all the strains and species of Borrelia that cause Lyme disease symptoms and are we incorporating them into our tests? The answer is no.

Lyme testing is still in its beginning phase and includes a huge margain of error. Let's look at the two main tests given:
1) Enzyme-linked immunosorbent assay (ELISA)

This is the first, and often only, test people are given by their doctor. At best its reported to be 50% reliable (why not just toss a coin?). In my opinion, it should be considered more of a screening tool and not diagnostic tool.

The ELISA panel tests for antibodies that your body makes to defend itself against the spirochetes that make up Lyme Disease. I'll discuss what spirochetes are in another blog, for now just think of them as microscopic corkscrew-shaped bacteria. Research has shown that after approximately 3 months, depending on the strength of your immune system prior to infection, the body naturally stops creating antibodies. What does this mean? It means that if you have been infected for more than 3 months - you will most likely test negative!
2) Western Blot

In as simple of terms as possible, the Western Blot makes a map of the different antibodies the immune system produces to certain bacteria. The map separates the antibodies by the weight of their respective antigens and are reported in units called kilo daltons or kDa.

For example, a Western Blot may report bands at 22, 23, 25, 31, 34, 39, and 41 kDa. Each of these bands represents an antibody response to a specific protein found on the spirochete. Some doctors and laboratories feel that unless you have multiple bands, you don't have Lyme or another tick-borne infection. This way of thinking makes no sense to me – particularly when research has shown that even one positive band responds to treatment. In one study, 88% of patients improved with treatment when only one band was present. How much more evidence is needed?


Now to complicate things even further, there are two version of each test.

- ELISA IgM

- ELISA IgG

- Western Blot IgM

- Western Blot IgG
 
I know this is a lot to take in at once so I feel its best to do it in installments. Until I got sick, I had no idea that any tests other than the ELISA existed or that the tests were far from accurate. I also trusted that doctors would be more educated than I was about Lyme Disease. Lesson Learned!
 
 
Next blog will explain the antibodies IgM and IgG.....