Diagnostic value of an amplification method (Gen-Probe) compared with that of culture for diagnosis of tuberculosis.
AUTOR(ES)
Vlaspolder, F
RESUMO
Five hundred fifty respiratory and nonrespiratory specimens from 340 patients were analyzed by comparing the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) with conventional culture, which was the method of reference, for the detection of the Mycobacterium tuberculosis complex. After resolution of discrepant results by retesting the samples and reviewing the patients' clinical histories, a total of 60 respiratory specimens were MTD and culture positive, 347 were MTD and culture negative, 4 were MTD positive and culture negative, and 1 was MTD negative and culture positive. This results in a sensitivity of 98.4%, a specificity of 98.9%, and positive and negative predictive values of 93.8 and 99.7%, respectively. Repeatedly, clinicians asked to test specimens of nonpulmonary origin by MTD. Although, MTD is not approved for use with nonrespiratory specimens, the following results were shown. Sixty-one pleural exudate specimens showed disappointing results (sensitivity, 20%). However, MTD performed well with another 77 nonrespiratory specimens; 17 samples were positive and 57 samples were negative by both MTD and culture. No false-negative results were found by MTD. Three MTD-positive, culture-negative specimens had high sample relative light unit/cutoff relative light unit ratios, strongly suggesting true tuberculosis. Positive microscopy and positive culture with MTD-negative results occurred 12 times. Those cultures showed atypical mycobacteria 11 times and Actinomyces species once. The stability of the reagents in the MTD kit was also assessed by testing reagents, including the enzyme mixture, kept at -70 degrees C for at least 6 months. No loss of activity was seen.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=228558Documentos Relacionados
- Value of a DNA probe assay (Gen-Probe) compared with that of culture for diagnosis of gonococcal infection.
- Comparison of DNA probe (Gen-Probe) with culture for the detection of Neisseria gonorrhoeae in an urban STD programme.
- Diagnosis of extrapulmonary tuberculosis by Gen-Probe amplified Mycobacterium tuberculosis direct test.
- Identification of mycobacteria from culture by using the Gen-Probe Rapid Diagnostic System for Mycobacterium avium complex and Mycobacterium tuberculosis complex.
- Clinical Evaluation of the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test for Rapid Diagnosis of Tuberculosis Lymphadenitis