PCR for M. tuberculosis in tissue samples.
BACKGROUND
The presence of granuloma, visualized in histopathology for diagnosing tuberculosis in tissue samples, is not a specific finding. Moreover, histopathological examination of tissue sections needs one to two weeks for final reporting. A rapid and sensitive method is therefore needed for detection of Mycobacterium tuberculosis in these paucibacillary tissue samples.


METHODS
A PCR-assay specific for IS6110 was evaluated for 104 different tissue samples in comparison to histopathology that was considered gold standard.


RESULTS
PCR showed 74.1% sensitivity and 96.1% specificity. False positive and false negative results were observed in three (2.88%) and seven (6.73%) samples, respectively. Positive agreement between histopathology and PCR was observed as 0.737, indicating substantial good agreement between two tests.


CONCLUSIONS
PCR can be used for early diagnosis of tuberculosis in tissue samples that can help to initiate timely anti-tubercular treatment and prevent progression to irreversible changes.
Chawla
Kiran
K
Department of Microbiology and Pathology, Kasturba Medical College, Manipal, Karnataka, India. arunkiranchawla@yahoo.com
Gupta
Soham
S
Mukhopadhyay
Chiranjay
C
Rao
P Sugandhi
PS
Bhat
Sudha S
SS
D004251:DNA Transposable Elements / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D042241:Early Diagnosis; D005189:False Positive Reactions; D006099:Granuloma / Q000175:diagnosis* / Q000382:microbiology*; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis*
D004251:DNA Transposable Elements; D004269:DNA, Bacterial