In a previous post, I explained four reasons the Lyme Ab Screen fails. In today’s post, I’m going to tackle two controversies about the western blot. This Lyme blood test is a protein immunoblot that comes in two parts. The IgM test looks for early antibodies, while the IgG test looks for late ones. But what are bands and why are they controversial?
According to the National Institutes of Health, “Western blot is often used in research to separate and identify proteins. In this technique a mixture of proteins is separated based on molecular weight, and thus by type, through gel electrophoresis. These results are then transferred to a membrane producing a band for each protein.”
The CDC’s image above depicts “…a Western blot strip in a test tray. Antigens if present will bind to this sheet and later be detected.”
Oxford Languages defines an antigen as “a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.”
According to CDC standards, you need two out of three bands on the IgM or five out of ten bands on the IgG to test positive. But how did the CDC decide which bands to include?
Which Bands Are Included on the Blood Test?
From the beginning, the CDC’s Lyme western blot has sparked controversy. This is partly due to the bands that were excluded.
According to Fallon and Sotsky in Conquering Lyme Disease, “…the CDC’s list of significant bands excludes certain bands, such as the 31 kDA and 34 kDa, even though Lyme vaccines were developed or considered that target these specific proteins.”
In other words, two proteins that Lyme vaccines have targeted are not included on the test. Why?
In the 1990s, a vaccine was being developed that helped patients produce antibodies against the 31 band. Perhaps the CDC excluded 31, so vaccinated patients wouldn’t get a false positive. But there’s another—perhaps simpler—reason.
Fallon writes, “The CDC adopted the Dressler and colleagues criteria (1993) in which the ten most frequently observed IgG bands among patients with new-onset Lyme disease were chosen.”
In other words, the ten bands chosen were the most common in a study of early Lyme disease. But what about late-stage Lyme?
Fallon and his team did their own study of patients with chronic symptoms. They found that the two excluded bands were the eleventh and twelfth most common.
Still, should you really need five bands to test positive when two bands are excluded?
How Many Lyme Bands Do You Need?
Fallon writes, “A lab test that reveals four out of five IgG bands, while not positive by CDC standards, would be considered very highly suggestive of prior exposure to B. burgdorferi.”
In fact, some scientists think that—for some bands—just one could be enough.
Global Lyme Alliance says, “Some Lyme specialists and scientists believe that there are five very specific bands . . . that are highly indicative of Lyme disease, band numbers 23, 31, 34, 39 and 93. If any of these bands are positive and the patient is experiencing symptoms . . . they may feel treatment is warranted.”
In this post, I introduced two of the controversies surrounding the Lyme blood test. In my next post, I reveal the high false-negative rate of the two-tiered test. Click here to read it!