LabCorp to deny physicians access to western blot tests for Lyme disease

Labcorp will not offer a western blot test for individuals unless they are positive or equivocal for the Enzyme Immunoassay (EIA) or Immunoflorescense (IFA) screening tests for Lyme disease as of August 11, 2014.[1]

img-ldpr2Physicians have been disappointed by the poor sensitivity of the EIA or IFA screening tests for Lyme disease. The sensitivity of the whole-cell enzyme-linked immunosorbent assay (ELISA) to the B31 strain typically falls between 33-49% for patients presenting with an EM.[2-4] The sensitivity of the Food and Drug Administration (FDA) approved complement peptide C6 (C6-peptide) was 37% in 89 clinically well-defined individuals with LD [5] and 66.5% 403 sera from patients with an EM rash.[6]

Physicians have commonly ordered the western blot test for Lyme disease even in the absence of positive or equivocal testing. An IgM Western blot test can persist for at least 2 years in individuals with established Lyme disease infection. A IgM WB can persist for months to years in LD even if an individual is treated with antibiotics.[7-9]  An IgG can be positive in individuals with a negative screening test.

LabCorp’s decision to deny physician assess to western blot test for Lyme disease only makes testing sensitive than it already is.

It important that LabCorp reverse their position and allow physicians to continue to order western blot tests for Lyme disease even if the EIA and/or IFA are negative. Until then, clinicians may have to direct their patients to other labs.

  1. LabCorp newsletter for clients. Lyme disease testing now employs a two-tier antibody standard, Available from https://  Last accessed 8/16/14.
  2. Aguero-Rosenfeld ME, Nowakowski J, Bittker S, Cooper D, Nadelman RB, Wormser GP. Evolution of the serologic response to Borrelia burgdorferi in treated patients with culture-confirmed erythema migrans. J Clin Microbiol, 34(1), 1-9 (1996).
  3. Trevejo RT, Krause PJ, Sikand VK et al. Evaluation of two-test serodiagnostic method for early Lyme disease in clinical practice. J Infect Dis, 179(4), 931-938 (1999).
  4. Aguero-Rosenfeld ME, Nowakowski J, McKenna DF, Carbonaro CA, Wormser GP. Serodiagnosis in early Lyme disease. J Clin Microbiol, 31(12), 3090-3095 (1993).
  5. Ang CW, Notermans DW, Hommes M, Simoons-Smit AM, Herremans T. Large differences between test strategies for the detection of anti-Borrelia antibodies are revealed by comparing eight ELISAs and five immunoblots. Eur J Clin Microbiol Infect Dis,  (2011).
  6. Wormser GP, Schriefer M, Aguero-Rosenfeld ME et al. Single-tier testing with the C6 peptide ELISA kit compared with two-tier testing for Lyme disease. Diagn Microbiol Infect Dis,  (2012).
  7. Steere AC, Hardin JA, Ruddy S, Mummaw JG, Malawista SE. Lyme arthritis: correlation of serum and cryoglobulin IgM with activity, and serum IgG with remission. Arthritis Rheum, 22(5), 471-483 (1979).
  8. Massarotti EM, Luger SW, Rahn DW et al. Treatment of early Lyme disease. Am J Med, 92(4), 396-403 (1992).
  9. Craft JE, Grodzicki RL, Shrestha M, Fischer DK, Garcia-Blanco M, Steere AC. The antibody response in Lyme disease. Yale J Biol Med, 57(4), 561-565 (1984).

25 Replies to "LabCorp to deny physicians access to western blot tests for Lyme disease"

  • Lee
    08/20/2014 (4:19 pm)

    We know that indirect tests that only test our immune response (ELISA & Western Blot etc) are less than definitive for diagnosis and that the ELISA is less definitive than the WB and don’t forget…it is also less costly (a factor?) And the whole ELISA/WB system of testing was initially devised for surveillance numbers…not clinical diagnosis. Even back in 1994 at the Dearborn convention when this protocol was established (note with some dissent) they knew the ELISA sucked and limited official case numbers. I would suggest that this was not decreed by LabCorp. (It wouldn’t make sense for them to limit their income by reducing testing)

  • Lori Mattix
    08/20/2014 (9:54 am)

    I was misdiagnosed originally because of this Elissa test done at St Johns? Specifically looking for Lyme’s disease? They came back negative? My Dr. Told me I did not have? Even though I had Bullseye, fever and malaise ? I was bit and after a year went to get tested and was told Negative? 4 yrs later 5 bands of Borrelius in western blot? We have to boycot and march? We are back to the 70s? When to only test for Aids was the Western Blot? They are purposely making it difficult to diagnose? Why?

  • Val
    08/20/2014 (7:16 am)

    Who are you working for Lab Corp.? This is as dirty as it gets. I will NEVER use your labs or services again. You are helping the epidemic spread by denying tests that people need. Shame on you!

  • Linda Olley
    08/20/2014 (2:20 am)

    It is well known the unreliability of the Elisa and the Western Blot, missing over 50 % of patients with Lyme. With this new unconchionable change in practice, patient’s will endure increased harm due to lack of an early diagnosis and failure to treat promptly and appropriately. Who is controlling and practicing medicine in America??!!!!!
    I can only speculate this was not LabCorps decision but an edict from the CDC and/or IDSA.
    There will never be an accurate account of Lyme cases with detrimental decisions like this. Is there a reason some organizations wish the numbers to be inaccurate? Concealed? A question I would like answered.

  • Connie
    08/20/2014 (12:27 am)

    I don’t understand why a lab would no longer make a superior diagnosing test unavailable. Why are they policing the test? Why can’t the doctors make the decision about appropriate testing? What is the downside to offering? Who benefits from it being off the market? What is in it for Labcorp?

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