Diagnosis of tuberculosis infection based on synthetic peptides from Mycobacterium tuberculosis antigen 85 complex.
OBJECTIVE
The laboratory diagnosis of pulmonary tuberculosis (TB) and tuberculous meningitis (TBM) is particularly challenging. The aim of the present work is to develop an immunoassay for the diagnosis of TB infection, using synthetic peptides of antigen (Ag) 85 complex of M. tuberculosis (Mtb) H37Rv.


METHODS
Four peptides (7-10 amino acids long) corresponding to group-specific epitopes of Ag 85 complex of Mtb were synthesized. All peptides were evaluated by enzyme-linked immunosorbent assay (ELISA) for immunoreactivity with sera and CSF samples of TB and TBM patients respectively. The diagnostic value of the four peptides was evaluated in both the samples.


RESULTS
It was observed that Ag 85 peptide 1, 3 and 4 had the highest positive rates in the pulmonary patients; however, Ag 85 peptide 1 and 2 had shown good positivity in the TBM subjects.


CONCLUSIONS
The synthetic peptide based ELISA using Ag 85 complex peptides is a sensitive, specific, rapid and cost effective immunoassay for early diagnosis of pulmonary and extrapulmonary TB. In addition, these synthetic peptides are comparatively easy to produce in a reproducible manner compared with the whole antigen.
Biochemistry Research Laboratory, Central India Institute of Medical Sciences, Nagpur 440010, India. raj_ciims@rediffmail.com
Rajpal S
RS
Kashyap
Seema D
SD
Shekhawat
Amit R
AR
Nayak
Hemant J
HJ
Purohit
Girdhar M
GM
Taori
Hatim F
HF
Daginawala
D000217:Acyltransferases / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology*; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology*; D013056:Spectrophotometry, Ultraviolet; D013129:Spinal Puncture; D014390:Tuberculosis, Meningeal / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000276:immunology; D014397:Tuberculosis, Pulmonary / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000276:immunology
D000942:Antigens, Bacterial; D010455:Peptides; D000217:Acyltransferases; C112580:antigen 85A, Mycobacterium tuberculosis