When I started investigating Lyme and blood tests, etc, I took note that they (Igenix? I don't remember) said to take the test after you have been off Abx for so many weeks.
However, also during my research, I learned that while too many tests are false negatives, often times they will become positive after the patient has been on abx for about 4-6 weeks.
Reason being, that too often, with a long term infection, the body is finally out of antibodies, or has become so depleted of them that it will not show on a test. So, once a patient has been on abx for awhile, the antibodies are strengthened and will then show up on a lab test.
Sooooooooo..... THIS is the reason that each band must be read and the significance of each band must be noted. My understanding is that even after some time on abx, our bodies are usually still infected. So altho a period on abx may mess w/ the test results, the results may still be very significant. And the abx would be more apt to cause a false negative than a false positive, and I intend this to mean that there are really no false positives on the WB, except when too many INsignifican't bands are positive.