We show that significant interlaboratory and intralaboratory variations exist in Lyme disease proficiency testing.
Six case-defined Lyme serum samples and three serum samples from individuals with no history of Lyme disease were randomized in four shipments and distributed to 45 participating laboratories.
Interlaboratory and intralaboratory performances were highly variable. Approximately 4% to 21% of laboratories failed to identify correctly positive serum samples with titers of 512 or more using polyvalent serum or immunoglobulin G conjugates. With lower levels of anti-Borrelia burgdorferi antibody in the serum sample, approximately 55% of participating laboratories did not identify a case-defined serum. There was also a striking inability of many laboratories to reproduce their results on split samples from the same individual. In addition, 2% to 7% of laboratories identified serum samples from individuals with no known exposure to B burgdorferi as positive using polyvalent serum. The false positivity rate increased to 27% with the use of immunoglobulin G conjugate.
Our results indicate that there is an urgent need for standardization of current testing methodologies. Until a national commitment is made, serological testing for Lyme disease will be of questionable value for the diagnosis of the disease.