Adenosine deaminase estimation and multiplex polymerase chain reaction in diagnosis of extra-pulmonary tuberculosis.
METHODS
Extra-pulmonary tuberculosis (EPTB), including mycobacteriosis, contributes 15-20% of all tuberculosis (TB) cases. The diagnosis of EPTB remains elusive because of the inadequate sensitivity of routine and conventional bacteriological methods for the detection of Mycobacterium tuberculosis and related organisms in clinical specimens such as cerebrospinal fluid (CSF), pleural fluid and peritoneal fluid.


OBJECTIVE
To develop a better diagnostic marker for EPTB.


METHODS
In our study, 179 cases of EPTB were analysed for acid-fast bacilli (AFB) smear, adenosine deaminase activity (ADA) and multiplex polymerase chain reaction (PCR). Although estimation of ADA is helpful, its sensitivity and specificity varies widely. On the other hand, a multiplex PCR using amplicons such as IS6110, dnaJ gene and hsp65 genes has high sensitivity (60-88%) and specificity (81-100%).


RESULTS
On comparing AFB and ADA results with PCR, the PCR is clearly more effective than AFB (P < 0.001) and ADA estimation (P < 0.02) in CSF. The same result was observed with peritoneal fluid (P < 0.001 vs. P < 0.05) and pleural fluid (P < 0.001 and P < 0.05).


CONCLUSIONS
The study shows that multiplex PCR remains the best tool and is a much better marker for diagnosing EPTB.
Bandyopadhyay
D
D
Biochemistry Research Wing, Department of Biochemistry, Institute of Post Graduate Medical Education & Research, Seth Sukhlal Karnani Memorial Hospital, Kolkata, India.
Gupta
S
S
Banerjee
S
S
Gupta
S
S
Ray
D
D
Bhattacharya
S
S
Bhattacharya
B
B
D000243:Adenosine Deaminase / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D001826:Body Fluids; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis* / Q000201:enzymology
D015415:Biomarkers; D000243:Adenosine Deaminase