False Positive Lyme Disease IgM Immunoblots in Children

J Pediatr. 2016 Jul:174:267-269.e1. doi: 10.1016/j.jpeds.2016.04.004. Epub 2016 May 4.


In our cross-sectional sample of 7289 serologic tests for Lyme disease, we identified 167 instances of a positive IgM immunoblot but a negative IgG immunoblot test result. Considering that only 71% (95% CI 64%-78%) of patients had Lyme disease, a positive IgM immunoblot alone should be interpreted with caution to avoid over-diagnosis of Lyme disease.

Keywords: Lyme disease; diagnostic tests; immunoblots; pediatrics.

MeSH terms

  • Adolescent
  • Child
  • Cross-Sectional Studies
  • False Positive Reactions
  • Female
  • Humans
  • Immunoblotting*
  • Immunoglobulin M / blood*
  • Lyme Disease / blood
  • Lyme Disease / diagnosis*
  • Male
  • Retrospective Studies
  • Sensitivity and Specificity


  • Immunoglobulin M