Nucleic Acid Amplification Test Quantitation as Predictor of Toxin Presence in Clostridium difficile Infection
| Autor: | Cees M. Verduin, Nikolas Duszenko, E.J. Kuijper, Monique J. T. Crobach, E.M. Terveer |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Microbiology (medical) medicine.medical_specialty Bacterial Toxins 030106 microbiology diagnostic Clostridium difficile toxin A Clostridium difficile toxin B medicine.disease_cause Gastroenterology Immunoenzyme Techniques Enterotoxins Feces 03 medical and health sciences 0302 clinical medicine Bacterial Proteins Predictive Value of Tests Internal medicine medicine Humans 030212 general & internal medicine Netherlands Retrospective Studies NAAT quantitation Receiver operating characteristic medicine.diagnostic_test Clostridioides difficile Diagnostic Tests Routine business.industry Toxin Bacteriology Clostridium difficile Hospitals Preliminary diagnosis ROC Curve Immunoassay Clostridium Infections Nucleic acid business Nucleic Acid Amplification Techniques Algorithms |
| Zdroj: | Journal of Clinical Microbiology, 56(3) |
| ISSN: | 1098-660X 0095-1137 |
| DOI: | 10.1128/jcm.01316-17 |
| Popis: | Multistep algorithmic testing in which a sensitive nucleic acid amplification test (NAAT) is followed by a specific toxin A and toxin B enzyme immunoassay (EIA) is among the most accurate methods for Clostridium difficile infection (CDI) diagnosis. The obvious shortcoming of this approach is that multiple tests must be performed to establish a CDI diagnosis, which may delay treatment. Therefore, we sought to determine whether a preliminary diagnosis could be made on the basis of the quantitative results of the first test in algorithmic testing, which provide a measure of organism burden. To do so, we retrospectively analyzed two large collections of samples ( n = 2,669 and n = 1,718) that were submitted to the laboratories of two Dutch hospitals for CDI testing. Both hospitals apply a two-step testing algorithm in which a NAAT is followed by a toxin A/B EIA. Of all samples, 208 and 113 samples, respectively, tested positive by NAAT. Among these NAAT-positive samples, significantly lower mean quantification cycle ( C q ) values were found for patients whose stool eventually tested positive for toxin, compared with patients who tested negative for toxin (mean C q values of 24.4 versus 30.4 and 26.8 versus 32.2; P < 0.001 for both cohorts). Receiver operating characteristic curve analysis was performed to investigate the ability of C q values to predict toxin status and yielded areas under the curve of 0.826 and 0.854. Using the optimal C q cutoff values, prediction of the eventual toxin A/B EIA results was accurate for 78.9% and 80.5% of samples, respectively. In conclusion, C q values can serve as predictors of toxin status but, due to the suboptimal correlation between the two tests, additional toxin testing is still needed. |
| Databáze: | OpenAIRE |
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