PCR DIAGNOSES TUBERCULOSISFrench researchers found that polymerase chain reaction (PCR)can provide accurate, early diagnosis of tuberculosis infection,according to Saturday's issue of The Lancet.
PCR is more sensitive than available laboratory cultures indetecting the infection, wrote the researchers, who are fromthe Institut Pasteur in Paris and various French hospitals. Ofspecimens from patients with a definite diagnosis oftuberculosis, PCR detected 80 percent positive, but cultureshowed only 67 percent positive. Of 489 samples tested byPCR, 97 percent agreed with culture or clinical findings.
Problems with using PCR for tuberculosis diagnosis includethe presence of inhibitors in body fluids causing false-negative results, but appropriate pretreatment of samples canavoid this. Of the 489 samples, six were false negatives andthree were false positives using PCR.
The method should be "especially useful in the diagnosis oftuberculosis meningitis, tuberculosis pleurisy and TB in HIVpa-tients," the researchers concluded.
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