Rapid diagnosis of tuberculous meningitis using the Simple Dot ELISA method.
BACKGROUND
Tuberculous meningitis (TBM) is a serious central nervous system infection, which is seen in clinical practice fairly frequently in developing and underdeveloped countries. Our study was intended to develop a reliable and rapid diagnostic methodology for detecting mycobacterium tuberculous bacilli (MTB) in cerebrospinal fluid (CSF). Dot Enzyme Linked Immunosorbent assay (Dot ELISA) has been standardized to detect MTB antigens and antibodies against MTB in the CSF of TBM patients.


METHODS
CSF samples were collected from 156 registered patients suffering from various neurological disorders, including 56 cases of TBM. Polyclonal antibodies to Culture Filtrate Protein (CFP), H37Rv strain, an MTB antigen, obtained from Colorado State University (USA), were used to detect MTB antigen in the CSF of TBM patients using the Dot ELISA method.


RESULTS
The methodology yielded a positive reaction to MTB antigens in 48 CSF samples (86%) obtained from all 56 cases of suspected TBM. The sensitivity achieved through the developed methodology could give reactivity with an antigen level 10ng/dl and above. Dot ELISA for MTB antigen was positive in only 5 out of 100 (5%) of the other neurological disorders, mainly pyogenic meningitis.


CONCLUSIONS
This rapid methodology for the detection of MTB antigen in CSF is very simple, sensitive, specific, and cost effective. This technique can be easily and routinely employed in the pathology laboratory to support the clinical diagnosis.
Biochemistry Research Laboratory, Central India Institute of Medical Sciences, 88/2 Bajaj nagar, Nagpur-440010, India.
Rajpal S
RS
Kashyap
Rani P
RP
Kainthla
Saibal K
SK
Biswas
Neha
N
Agarwal
Nitin H
NH
Chandak
Hemant J
HJ
Purohit
Girdhar M
GM
Taori
Hatim F
HF
Daginawala
D000941:Antigens; D000942:Antigens, Bacterial; D002555:Cerebrospinal Fluid / Q000382:microbiology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D014390:Tuberculosis, Meningeal / Q000175:diagnosis*
D000941:Antigens; D000942:Antigens, Bacterial