Serodiagnosis of smear and culture-negative neurotuberculosis with enzyme linked immunosorbent assay for anti A-60 immunoglobulins.
Early diagnosis of neurotuberculosis (NTB), useful in prevention of mortality and morbidity, remains a challenge despite availability of several tests. An ELISA test to detect IgG and IgM antibodies against Mycobacterial antigen A-60 (Anda Biologicals, France) was done in 677 specimens; group 1 (NTB): 373 sera and 167 cerebrospinal fluid (CSF), group 2: 100 sera from healthy subjects, group 3: 17 CSF from patients undergoing neurosurgical operations for non-tubercular diseases. Anti-A 60 IgA estimation was done in 99 sera from group 1 and all 100 from group 2. Working dilutions were 1:200 for serum and 1:10 for CSF. Serum IgM and IgG anti-A 60 antibodies were more often detected in group 1 than in 2 (50% Vs 10%, p<.001). Anti-IgG and IgM antibody were detected more often in group 1 than in group 3 (33% Vs 6%, p<.001). In serum and CSF both IgM positivity was more than IgG in 2 subgroups of NTB and these are tubercular meningitis, spinal tuberculosis whereas in tuberculoma IgG positivity was more as compared to other 2 groups. Sera were more often positive than CSF (50% Vs 33%, p<.001). Of 32 patients, in whom magnetic resonance imaging (MRI) was done, 15/18 (83%) patients with suggestive findings in MRI had a positive ELISA (IgG or IgM). AntiA-60 antibody is a useful aid in the diagnosis of NTB, especially in smear and culture negative NTB where one does not have much diagnostic opportunities to choose from.
Ghoshal
Ujjala
U
Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
Kishore
Janak
J
Kumar
Birendra
B
Ayyagari
Archana
A
D000907:Antibodies, Bacterial / Q000097:blood / Q000134:cerebrospinal fluid; D000942:Antigens, Bacterial; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000276:immunology; D012698:Serologic Tests; D020306:Tuberculosis, Central Nervous System / Q000175:diagnosis* / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; C055539:mycobacterial A60 antigen