Rauter C et al. (2005) Critical evaluation of urine-based PCR assay for diagnosis of Lyme borreliosis. Clin Diagn Lab Immunol 12: 910–917

Researchers from Germany have shown that, despite developing an optimized protocol, polymerase chain reaction (PCR) analysis of urine is not an acceptable method for diagnosing Lyme borreliosis (LB).

Serologic testing is currently used to confirm a diagnosis of LB, but it has several limitations including serologic cross-reactivity, delayed production of antibodies and an inability to distinguish between ongoing and previous infections. PCR detection of DNA from Borrelia burgdorferi sensu lato—the causative organism of LB—would overcome these limitations, and urine is an attractive sample material because it is easily obtained. PCR analysis of urine samples for diagnosing LB is a controversial issue, however, due to previous conflicting results. Rauter et al. aimed to create an optimized PCR protocol and determine its efficacy in detecting Borrelia DNA and Borrelia organisms in urine.

Urine samples from healthy patients were spiked with whole Borrelia and Borrelia DNA. Investigations demonstrated that spiked urine could be stored for up to 6 months at −20 °C without negative effect on spike recovery, that centrifugation had a positive effect on all samples for detecting both DNA and whole Borrelia, and that the inhibition of spike recovery could be attributed to nuclease activity in urine. Taking into account these findings, an optimized, well-controlled and highly sensitive PCR protocol was developed and was used to test urine samples from 12 patients with erythema migrans—an acute infection with Borrelia. Only one patient had a positive PCR result, and the authors conclude that urine is not a suitable material for diagnosing LB.