Critical Evaluation of Urine-Based PCR Assay for Diagnosis of Lyme Borreliosis
... Despite optimized conditions, analysis of urine samples of 12 patients with erythema migrans, the clinical stage considered to be associated with the highest bacterial load, revealed a positive result in only one sample. All 12 samples were negative by an alternative PCR targeting flagellin. The results of our study support doubts that urine is a suitable material for diagnosis of Lyme borreliosis.
...Since 1991, when the detection of
BorreliaDNA in urine was shown for the first time by Goodman et al. (
14), many studies have been carried out (for reviews, see references
11,
19, and
29). A comparison between the different reports is nearly impossible because of significant differences in patient selection, study design, and DNA extraction and PCR methods. Nevertheless, a meta-analysis of urine PCR assays for diagnosis of LB showed an overall sensitivity of 68% (range, 13 to 100%) and a specificity of 99% (range, 95 to 100%) (
11).
Even when comparing only reports on urine of patients with erythema migrans (EM) who clearly have an active infection, detection of
BorreliaDNA in urine ranged between 13% and >90% (
1,
5,
20,
25,
28,
30). A caution was issued by Brettschneider et al., who were not able to confirm the presence of
BorreliaDNA in the 27% PCR-positive urine specimens by hybridization or sequencing (
7). Thus, despite all efforts, the value of PCR as a diagnostic tool for LB and of urine as a sample material remains unclear and is controversial (
7,
12,
30).
Смотрите детали
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1182183/
Интересный факт:
Only few studies quantified
Borrelia burgdorferi sensu lato DNA in clinical specimens: the number of spirochetes in a 2-mm
skin biopsy of 50 patients with EM ranged from 10 to 10,000, with a median of 1,450 spirochetes (
22); in five
synovial fluid samples, the number varied from 20 to 41,000 per ml (
31). For urine, no proper quantification is available, but Goodman et al. calculated an equivalent of 50 to 5,000 organisms per ml of urine by extrapolation of signal intensities (
14). Hence, the number of spirochetes in clinical specimens seems to be rather low, and procedures that concentrate the number of organisms in a given sample and that display high sensitivity are imperative.