Browsing by Author "MATHAI, A"

Now showing 1 - 15 of 15
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    A DOT-IMMUNOBINDING ASSAY FOR THE LABORATORY DIAGNOSIS OF TUBERCULOUS MENINGITIS AND ITS COMPARISON WITH ENZYME-LINKED-IMMUNOSORBENT-ASSAY
    (JOURNAL OF APPLIED BACTERIOLOGY, 1991)
    In an attempt to establish an alternative to standard bacteriological methods in the laboratory diagnosis of tuberculous meningitis (TBM), a simple dot-immunobinding assay (Dot-Iba) was standardized to detect Mycobacterium tuberculosis antigen 5 and antimycobacterial antibody in cerebrospinal fluid (CSF) specimens of patients with TBM. Sensitivity and specificity of Dot-Iba was compared with conventional enzyme-linked immunosorbent assay (ELISA) and standard bacteriological techniques. The Dot-Iba showed excellent correlation with indirect ELISA for the detection of antimycobacterial antibody in CSF and showed 60% sensitivity and 100% specificity in culture-negative patients with TBM. However Dot-Iba was less sensitive for the detection of antigen 5 in CSFs and showed false negative results (60%) in culture-positive patients with TBM.
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    CORRELATION BETWEEN CULTURE OF MYCOBACTERIUM-TUBERCULOSIS AND DETECTION OF MYCOBACTERIAL ANTIGENS IN CEREBROSPINAL-FLUID OF PATIENTS WITH TUBERCULOUS MENINGITIS
    (JOURNAL OF MEDICAL MICROBIOLOGY, 1990)
    A retrospective study was done to correlate culture of Mycobacterium tuberculosis and detection of mycobacterial antigen in cerebrospinal fluid (CSF) by an inhibition enzyme-linked immunosorbent assay (ELISA). M. tuberculosis was cultured from CSF of 14 out of 70 patients with a clinical diagnosis of tuberculous meningitis (TBM). Mycobacterial antigens were demonstrated in CSF specimens by inhibition ELISA in all 14 culture-positive patients with antigen concentrations of 14.5-295 ng/ml (mean 158.8 ng/ml). Thus there was positive correlation between the detection of mycobacterial antigen and isolation of M. tuberculosis. Based on this observation, 56 CSF specimens from culture-negative patients with clinically diagnosed TBM were examined for mycobacterial antigen and the data were compared with those from culture positive patients. ELISA gave positive results in 38 specimens, with antigen levels of 12.5-280 ng/ml (mean 152.6 ng/ml). In 70 CSF specimens from patients with non-tuberculous neurological disease (control group), ELISA results were negative. Thus, detection of mycobacterial antigen in CSF specimens by inhibition ELISA had a specificity of 100% and a sensitivity of 67.8% for the diagnosis of TBM and is of potential value in the laboratory diagnosis of TBM.
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    DETECTION OF MYCOBACTERIUM-TUBERCULOSIS ANTIGEN-5 IN CEREBROSPINAL-FLUID BY INHIBITION ELISA AND ITS DIAGNOSTIC POTENTIAL IN TUBERCULOUS MENINGITIS
    (JOURNAL OF INFECTIOUS DISEASES, 1991)
    Inhibition ELISA was used to quantitate Mycobacterium tuberculosis antigen 5 in cerebrospinal fluid (CSF) specimens of 40 patients with a clinical diagnosis of tuberculous meningitis. In all 10 culture-proven patients, the assay was positive; in 30 culture-negative patients, the assay yielded positive results for 21. CSF antigen 5 concentrations ranged from 9 to 82 ng/ml (mean +/- SD, 45.5 +/- 6.2). In 40 patients with nontuberculous neurologic diseases, mean concentration was 1.45 ng/ml. Thus, inhibition ELISA for the detection of M. tuberculosis antigen 5 in CSF has definite diagnostic potential during the active phase of the disease and should be a routine diagnostic test, particularly when bacteriologic cultures in CSF are negative for M. tuberculosis.
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    DIAGNOSTIC-SIGNIFICANCE OF CIRCULATING IMMUNE-COMPLEXES IN PATIENTS WITH PULMONARY TUBERCULOSIS
    (JOURNAL OF MEDICAL MICROBIOLOGY, 1992)
    A polyethylene glycol (PEG) precipitation method was used to examine sera of patients with active pulmonary tuberculosis (PT), leprosy and non-tuberculous pulmonary diseases and of healthy control subjects for immune complexes (ICs). Mycobacterium tuberculosis antigen 5 was detected in the ICs in 80% of patients with PT by the indirect (sandwich) enzyme-linked immunosorbent assay (ELISA). Detection of mycobacterial antigen in ICs has diagnostic potential as an adjunct in the laboratory diagnosis of PT, particularly when repeated bacteriological investigations for M. tuberculosis in clinical specimens are negative. Levels of ICs tend to decrease with the duration of anti-tuberculosis chemotherapy and their detection can also be used to assess the clinical response to therapy in patients with PT.
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    ELISA OF IGG ANTIBODY TO MYCOBACTERIUM-TUBERCULOSIS ANTIGEN-5, PPD IN CSF IN TUBERCULOUS MENINGITIS PATIENTS
    (INDIAN JOURNAL OF MEDICAL RESEARCH SECTION A-INFECTIOUS DISEASES, 1990)
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    ENZYME-LINKED-IMMUNOSORBENT-ASSAY TO DETECT MYCOBACTERIUM-TUBERCULOSIS ANTIGEN-5 AND ANTIMYCOBACTERIAL ANTIBODY IN CEREBROSPINAL-FLUID OF PATIENTS WITH TUBERCULOUS MENINGITIS
    (JOURNAL OF CLINICAL LABORATORY ANALYSIS, 1991)
    Inhibition ELISA and indirect ELISA was standardised to detect Mycobacterium tuberculosis antigen 5 and antimycobacterial antibody in cerebrospinal fluid (CSF) specimens of 75 patients with tuberculous meningitis, (TBM) and 75 patients with non-tuberculous neurological diseases (control group). In both ELISAs, no false-negative results were observed in 15 culture proven patients with TBM. Detection of M. tuberculosis antigen 5 is more sensitive than detection of antimycobacterial antibody. However, both ELISAs showed 100% specificity for tuberculous aetiology in culture-negative patients with TBM. ELISA should be considered as one of the approaches in the laboratory diagnosis of TBM, particularly when standard bacteriological methods are unable to demonstrate M. tuberculosis in CSF specimens of patients with TBM.
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    IGG ANTIBODY TO MYCOBACTERIUM-TUBERCULOSIS ANTIGEN-5 IN CEREBROSPINAL-FLUID AND ITS DIAGNOSTIC APPLICATION IN TUBERCULOUS MENINGITIS
    (INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY, 1990) MATHAI, A; RADHAKRISHNAN, VV; SEHGAL, S
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    IMMUNOELECTROPHORESIS OF MYCOBACTERIAL ANTIGENS
    (INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY, 1990)
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    ISOLATION OF 2 ANTIGENS FROM THE CULTURE FILTRATES OF MYCOBACTERIUM-TUBERCULOSIS AND THEIR APPLICATIONS IN THE LABORATORY DIAGNOSIS OF THE TUBERCULOUS MENINGITIS
    (MEDICAL MICROBIOLOGY AND IMMUNOLOGY, 1991)
    Two antigens were isolated from the culture filtrates of H37Ra Mycobacterium tuberculosis by immunoabsorbent affinity chromatography, M. tuberculosis antigen 5 and immunoabsorbent affinity column-purified antigen (IAP). The potential application of these two mycobacterial antigens in the laboratory diagnosis of tuberculous meningitis was evaluated by indirect enzyme-linked immunoabsorbent assay in cerebrospinal fluid specimens. IAP antigen was more sensitive than antigen 5, although antigen 5 was more specific than IAP antigen in detecting tuberculous aetiology. Technical aspects of immunoabsorbent affinity chromatography have been highlighted in this study.
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    POTENTIAL APPLICATION OF DOT-IMMUNOBINDING ASSAY AS A RAPID DIAGNOSTIC-TEST IN TUBERCULOUS MENINGITIS
    (INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY, 1991)
    A simple dot-immunobinding assay (Dot-Iba) in nitrocellulose paper was developed for the detection of specific IgG antibody to Mycobacterium tuberculosis antigen 5 and mycobacterial antigen in cerebrospinal fluid of patients with tuberculous meningitis (TBM). The assay gave 77.1% sensitivity for the detection of IgG antibody to M. tuberculosis antigen 5 and 48.6% sensitivity for the detection of mycobacterial antigen in patients with TBM.
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    RAPID DIAGNOSIS OF TUBERCULOUS MENINGITIS WITH A DOT ENZYME-IMMUNOASSAY TO DETECT ANTIBODY IN CEREBROSPINAL-FLUID
    (EUROPEAN JOURNAL OF CLINICAL MICROBIOLOGY & INFECTIOUS DISEASES, 1991)
    A simple dot enzyme immunoassay (Dot-EIA) was carried out to detect antibody to Mycobacterium tuberculosis antigen 5 in cerebrospinal fluid (CSF) specimens from 40 patients with a clinical diagnosis of tuberculous meningitis (TBM). The assay gave a positive reaction in all ten patients with culture proven TBM. In 30 culture negative patients with TBM, the assay was positive at a titre of 1:16 in 18 patients. In 40 patients with non-tuberculous neurological diseases (control group) the assay was negative at a titre of 1:16. The Dot-EIA had an overall sensitivity of 70% and a specificity of 100% in the diagnosis of TBM. This assay could be used as a rapid screening test to establish the diagnosis of TBM, particularly in patients in whom bacteriological investigations for Mycobacterium tuberculosis in CSF specimens are negative.
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    RAPID SERODIAGNOSTIC TEST FOR PULMONARY TUBERCULOSIS
    (INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY, 1991) RADHAKRISHNAN, VV; MATHAI, A; SUNDERAM, B
    Immune complexes (ICs) were isolated from sera of patients with pulmonary tuberculosis (PT), non-tuberculous pulmonary diseases and healthy control subjects by polyethylene glycol (PEG) precipitation method. Specific mycobacterial antibody in ICs was tested against an affinity purified mycobacterial antigen by counter-current immunoelectrophoresis (CIE). The results show that specific mycobacterial antibodies are present only in ICs of patients with PT (70%). Therefore CIE could be used as a simple and rapid serodiagnostic test in patients with PT, particularly when bacteriological methods in sputum specimens are negative for Mycobacterium tuberculosis. CIE has several operational advantages over ELISA and best suited to laboratories with limited resources.