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Journal of Clinical Microbiology, March 2009, p. 569-576, Vol. 47, No. 3
0095-1137/09/$08.00+0 doi:10.1128/JCM.02051-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Diagnostic Accuracy of In-House PCR for Pulmonary Tuberculosis in Smear-Positive Patients: Meta-Analysis and Metaregression
,
S. Greco,1*
M. Rulli,1
E. Girardi,2
C. Piersimoni,3 and
C. Saltini4
Dipartimento di Malattie Polmonari, Azienda Ospedaliera San Camillo-Forlanini, Rome,1 Dipartimento di Epidemiologia, INMI L. Spallanzani-IRCCS, Rome,2 Servizio di Microbiologia Clinica, Azienda Ospedaliero-Universitaria Ospedali Riuniti, Ancona,3 Dipartimento di Medicina Interna, Università di Roma Tor Vergata, Rome, Italy4
Received 22 October 2008/ Returned for modification 4 December 2008/ Accepted 6 January 2009
In-house PCR (hPCR) could speed differential diagnosis between tuberculosis (TB) and nontuberculous mycobacterial disease in patients with positive smears and pulmonary infiltrates, but its reported accuracy fluctuates across studies. We conducted a systematic review and meta-analysis of hPCR sensitivity and specificity for smear-positive TB diagnosis, using culture as the reference standard. After searching English language studies in MEDLINE and EMBASE, we estimated cumulative accuracy by means of summary receiver operating characteristic analysis. The possible influence of hPCR procedures and study methodological features on accuracy was explored by univariate metaregression, followed by multivariate adjustment of items selected as significant. Thirty-five articles (1991 to 2006) met the inclusion criteria. The pooled estimates of the diagnostic odds ratio, sensitivity, and specificity (random-effect model) were, respectively, 60 (confidence interval [CI], 29 to 123), 0.96 (CI, 0.95 to 0.97), and 0.81 (CI, 0.78 to 0.84), but significant variations (mainly in specificity) limit their clinical applicability. The quality of the reference test, the detection method, and real-time PCR use explained some of the observed heterogeneity. Probably due to the limited study power of our meta-analysis and to the wide differences in both laboratory techniques and methodological quality, only real-time PCR also displayed a positive impact on accuracy in the multivariate model. Currently, hPCR can be confidently used to exclude TB in smear-positive patients, but its low specificity could lead to erroneous initiation of therapy, isolation, and contact investigation. As the inclusion of samples from treated patients could have artificially reduced specificity, future studies should report mycobacterial-culture results for each TB and non-TB sample analyzed.
* Corresponding author. Mailing address: Dip.to di Malattie Polmonari, Azienda Ospedaliera San Camillo-Forlanini, P.za Carlo Forlanini 1, 00151 Rome, Italy. Phone: 39 06 58703583. Fax: 39 06 58704713. E-mail: stgreco{at}scamilloforlanini.rm.it
Published ahead of print on 14 January 2009.
Supplemental material for this article may be found at http://jcm.asm.org/.
Journal of Clinical Microbiology, March 2009, p. 569-576, Vol. 47, No. 3
0095-1137/09/$08.00+0 doi:10.1128/JCM.02051-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
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