Thursday, February 12, 2009

Seronegative Lyme

A Lyme patient was treated on clinical grounds. She was seronegative. An initial Western Blot from Labcorp showed only 41 IgM and IgG bands.

After 4 months of antibiotics a Western Blot was sent to IgeneX. These are the results:
IgM- 18 3+, 23 2+, 30 2+, 31 3+, 34 2+, 39 2+, 41 3+, 45 +, 58 2+, 66 +, 93 2+.
IgG- 41 2+.

According to the CDC web pages, regarding Lyme diagnosis she is seronegative.

If an initial positive IgM is not followed by a positive IgG response then the initial IgM response was a false negative.

Makes sense to me.


bitten said...

I had a similar experience but a much stronger IgG response (positive by IgeneX but negative by CDC) but IgM response was positive by both. Why does Labcorp get so poor results? Many cannot pay to have samples sent to IgeneX and those of us who do and get strong results have them discounted by IDSA because they do not come from Labcorp. Is there anything that can be done to have these other labs results (i.e. IgeneX or Clongen) seen as valid?

Joe Ham said...

Are the band designations reversed?

bitten said...
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Lyme report: Montgomery County, MD said...

The point is that the CDC has not recognized the specific immune responses seen with Lyme disease. Most patient tend to produce IgM responses preferentially over IgG responses. Previously, I have presented a theoretical framework which may be at play here. In the face of an overwhelming IgM response to Lyme the CDC would call these responses negative because of very restrictive criteria.