Multicenter Comparison Trial of DNA Extraction Methods and PCR Assays for Detection of <i>Chlamydia pneumoniae</i> in Endarterectomy Specimens

TLDR

Detection rates of Chlamydia pneumoniae DNA in atherosclerotic lesions by PCR range from 0 % to 100 %. The study compared 16 PCR-based test methods across nine centers using 15 coded atheroma samples and 5 spiked controls. Positive controls were detected at 1, 0.1, and 0.01 inclusion bodies/ml by 100 %, 69 %, and 19 % of methods, respectively; three of 16 negative controls yielded false positives; atheroma positivity ranged 0–60 %, with a maximum concordance of 25 % for one carotid sample, and no consistent pattern or correlation with assay sensitivity was observed.

Abstract

ABSTRACT The reported rate of detection of Chlamydia pneumoniae DNA within atherosclerotic lesions by PCR varies between 0 and 100%. In this study, identical sets of coded experimental atheroma samples ( n = 15) and spiked controls ( n = 5) were analyzed by 16 test methods in nine centers by means of PCR. The positive controls were correctly identified to levels of 1, 0.1, and 0.01 inclusion bodies of C. pneumoniae /ml of tissue homogenate by 16 (100%), 11 (69%), and 3 (19%) of the test methods, respectively. Three out of 16 negative controls (19%) were rated positive. Positivity rates for atheroma samples varied between 0 and 60% for the different test methods, with the maximum concordant result for positivity being only 25% for one carotid artery sample. There was no consistent pattern of positive results among the various laboratories, and there was no correlation between the detection rates and the sensitivity of the assay used.