1
|
Agarwal AK, Bansal S, Nand V. A Hospital Based Study on Estimation of Adenosine Deaminase Activity (ADA) in Cerebrospinal Fluid (CSF) in Various Types of Meningitis. J Clin Diagn Res 2014; 8:73-6. [PMID: 24701487 PMCID: PMC3972604 DOI: 10.7860/jcdr/2014/7154.4012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 12/15/2013] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Tuberculosis kills 3.70 lakh patients in India every year,out of which 7-12 % are meningeal involvement. Delay in its diagnosis and initiation of treatment results in poor prognosis and squeal in up to 25% of cases. The aim of the present study is to look for a simple, rapid, cost effective, and fairly specific test in differentiating tubercular aetiology from other causes of meningitis. In the present study we measured the adenosine deaminase activity (ADA) in Cerebrospinal Fluid (CSF) of Tubercular Meningitis (TBM) and non-TBM patients. METHODS Fifty six patients attending hospital with symptoms and signs of meningitis were selected and divided into three groups: tubercular, pyogenic, and aseptic meningitis, depending upon the accepted criteria. CSF was drawn and ADA estimated. RESULTS Out of 32 tubercular patients, 28 had CSF-ADA at or above the cut-off value while four had below. Out of 24 non-tuberculous patients (pyogenic and aseptic meningitis), two aseptic meningitis (AM) patient had ADA levels at or above the cut-off value while 22 had below this value. RESULTS of our study indicate that ADA level estimation in CSF is not only of considerable value in the diagnosis of TBM, CSF, and ADA level 10 U/L as a cut-off value with sensitivity 87.5% and specificity 83.33% and positive predictive value of the test was 87.5%.and 83.3% negative predictive value. CONCLUSION It can be concluded that ADA estimation in CSF is not only simple, inexpensive and rapid but also fairly specific method for making a diagnosis of tuberculous aetiology in TBM, especially when there is a dilemma of differentiating the tuberculous aetiology from non-tuberculous ones. For this reason ADA estimation in TBM may find a place as a routine investigation.
Collapse
Affiliation(s)
- Ashok Kumar Agarwal
- Senior Resident, Department of Medicine, Rajendra Institute of Medical Science (RIMS), Ranchi, Jharkhand, India
| | - Sonia Bansal
- Microbiologist (Ex-Junior Resident), Department of Microbiology, Rajendra Institute of Medical Science (RIMS), Ranchi, Jharkhand, India
| | - Vidya Nand
- Assistant Professor, Department of Medicine, Rohilkhand Medical College, Bareilly, India
| |
Collapse
|
2
|
Sastry AS, Bhat K S, Kumudavathi. The Diagnostic Utility of Bact/ALERT and Nested PCR in the Diagnosis of Tuberculous Meningitis. J Clin Diagn Res 2013; 7:74-8. [PMID: 23450650 DOI: 10.7860/jcdr/2012/5098.2674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 11/07/2012] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The early laboratory diagnosis of Tuberculous Meningitis (TBM) is crucial, to start the antitubercular chemotherapy and to prevent its complications. However, the conventional methods are either less sensitive or time consuming. Hence, the diagnostic potentials of BacT/ALERT and Polymerase Chain Reaction (PCR) was evaluated in this study. MATERIAL AND METHOD The study group comprised of 62 cases and 33 controls. The cases were divided according to Ahuja's criteria into the confirmed (two cases), highly probable (19 cases), probable (26 cases) and the possible (15 cases) subgroups. Ziehl Neelsen's (ZN) and Auramine Phenol (AP) staining, Lowenstein Jensen (LJ) medium culture, BacT/ALERT and nested Polymerase Chain Reaction (PCR) which targeted IS6110 were carried out on all the patients. OBSERVATION AND RESULTS The sensitivity of the LJ culture was 3.22%. BacT/ALERT showed a sensitivity and a specificity of 25.80% and 100% and those of nested PCR were found to be 40.32% and 96.97% respectively. The mean detection time of growth of the LJ culture was 31.28 days, whereas that of BacT/ALERT was 20.68 days. The contamination rate in the LJ culture and BacT/ALERT were 7.2% and 5.8% respectively. CONCLUSION Nested PCR was found to be more sensitive, followed by BacT/ALERT as compared to the LJ culture and smear microscopy. As both false negative and false positive results have been reported for nested PCR, so it should not be used alone as a criterion for initiating or terminating the therapy, but it should be supported by clinical, radiological, cytological and other microbiological findings.
Collapse
|
3
|
Diagnosis and therapy of tuberculous meningitis in children. Tuberculosis (Edinb) 2012; 92:377-83. [DOI: 10.1016/j.tube.2012.05.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 05/22/2012] [Accepted: 05/29/2012] [Indexed: 11/22/2022]
|
4
|
Purification of modified mycobacterial A60 antigen by affinity chromatography and its use for rapid diagnostic tuberculosis infection. J Microbiol Methods 2011; 87:184-8. [PMID: 21896292 DOI: 10.1016/j.mimet.2011.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 08/12/2011] [Accepted: 08/12/2011] [Indexed: 10/17/2022]
|
5
|
Sardella IG, Singh M, Kumpfer S, Heringer RR, Saad MHF, Sohler MP. Evaluation of Lionex TB kits and mycobacterial antigens for IgG and IgA detection in cerebrospinal fluid from tuberculosis meningitis patients. Mem Inst Oswaldo Cruz 2010; 105:722-8. [DOI: 10.1590/s0074-02762010000500022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 04/01/2010] [Indexed: 11/22/2022] Open
|
6
|
Abebe F, Holm-Hansen C, Wiker HG, Bjune G. Progress in serodiagnosis of Mycobacterium tuberculosis infection. Scand J Immunol 2007; 66:176-91. [PMID: 17635795 DOI: 10.1111/j.1365-3083.2007.01978.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One-third of the world population is estimated to have Mycobacterium tuberculosis infection. Accurate and timely identification of infected individuals is critical for treatment and control. The current diagnostic methods lack the desired sensitivity and specificity, require sophisticated equipment and skilled workforce or take weeks to yield results. Diagnosis of extrapulmonary TB, TB-HIV co-infection, childhood TB and sputum smear-negative pulmonary TB pose serious challenges. Interest in developing serodiagnostic methods is increasing because detection of antibody is rapid, simple and relatively inexpensive, and does not require a living cell for detection. Three types of tests, namely screening tests to overcome diagnostic delay, specific tests for diagnosis of extrapulmonary TB and other bacteriologically negative cases, and tests for vaccine-induced immunity need critical consideration. Several factors must be considered to develop serodiagnostic methods for TB. Antigen recognition by infected individuals is highly heterogeneous due to stage of disease, differences in HLA types, strain of the bacilli, health of the patient and bacillary load. With advances in molecular biological techniques, a number of novel antigens have been identified. Some of these antigens have proven valuable in detecting specific antibodies in some of the most challenging TB patients. The best example is a fusion protein containing several M. tuberculosis proteins (e.g. CFP-10, MTB8, MTB48, MTB81 and the 38-kDa protein) which showed encouraging results in detecting antibodies in sera of patients, including TB-HIV co-infection. This review presents progress made in the serodiagnosis of TB during the last decade.
Collapse
Affiliation(s)
- F Abebe
- Institute for General Practice and Community Medicine, Section for International Health, University of Oslo, Oslo, Norway.
| | | | | | | |
Collapse
|
7
|
Mudaliar AV, Kashyap RS, Purohit HJ, Taori GM, Daginawala HF. Detection of 65 kD heat shock protein in cerebrospinal fluid of tuberculous meningitis patients. BMC Neurol 2006; 6:34. [PMID: 16978411 PMCID: PMC1578580 DOI: 10.1186/1471-2377-6-34] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Accepted: 09/15/2006] [Indexed: 11/10/2022] Open
Abstract
Background Diagnosis of tuberculous meningitis (TBM) is difficult. Rapid confirmatory diagnosis is essential to initiate required therapy. There are very few published reports about the diagnostic significance of 65 kD heat shock protein (hsp) in TBM patients, which is present in a wide range of Mycobacterium tuberculosis species and elicits a cellular and humoral immune response. In the present study we have conducted a prospective evaluation for the demonstration of 65 kD hsp antigen in cerebrospinal fluid (CSF) of TBM patients, by indirect ELISA method using monoclonal antibodies (mAb) against the 65 kD hsp antigen, for the diagnosis of TBM. Methods A total of 160 CSF samples of different groups of patients (confirmed TBM {n = 18}, clinically suspected TBM {n = 62}, non TBM infectious meningitis {n = 35} and non-infectious neurological diseases {n = 45}) were analyzed by indirect ELISA method using mAb to 65 kD hsp antigen. The Kruskal Wallis test (Non-Parametric ANOVA) with the Dunnett post test was used for statistical analysis. Results The indirect ELISA method yielded 84% sensitivity and 90% specificity for the diagnosis of TBM using mAb to 65 kD hsp antigen. The mean absorbance value of 65 kD hsp antigen in TBM patients was [0.70 ± 0.23 (0.23–1.29)], significantly higher than the non-TBM infectious meningitis group [0.32 ± 0.14 (0.12–0.78), P < 0.001] and also higher than the non-infectious neurological disorders group [0.32 ± 0.13 (0.20–0.78), P < 0.001]. A significant difference in the mean absorbance of 65 kD hsp antigen was noted in the CSF of culture-positive TBM patients [0.94 ± 0.18 (0.54–1.29)] when compared with clinically suspected TBM patients [0.64 ± 0.20 (0.23–0.98), P < 0.05]. Conclusion The presence of 65 kD hsp antigen in the CSF of confirmed and suspected cases of TBM would indicate that the selected protein is specific to M. tuberculosis and could be considered as a diagnostic marker for TBM.
Collapse
Affiliation(s)
- Anju V Mudaliar
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, Nagpur – 440 010, India
| | - Rajpal S Kashyap
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, Nagpur – 440 010, India
| | - Hemant J Purohit
- Environmental Genomics Unit, National Environmental Engineering Research Institute, Nehru Marg, Nagpur-440020, India
| | - Girdhar M Taori
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, Nagpur – 440 010, India
| | - Hatim F Daginawala
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, Nagpur – 440 010, India
- Central India Institute of Medical Sciences, 88/2 Bajaj Nagar, Nagpur-440010, India
| |
Collapse
|
8
|
Kashyap RS, Kainthla RP, Mudaliar AV, Purohit HJ, Taori GM, Daginawala HF. Cerebrospinal fluid adenosine deaminase activity: a complimentary tool in the early diagnosis of tuberculous meningitis. Cerebrospinal Fluid Res 2006; 3:5. [PMID: 16571142 PMCID: PMC1448186 DOI: 10.1186/1743-8454-3-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2005] [Accepted: 03/30/2006] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Tuberculous meningitis (TBM) is the commonest form of neurotuberculosis caused by Mycobacterium tuberculosis bacilli (MTB). The diagnosis of TBM is often difficult. A reliable, cost-effective and rapid diagnostic test, which can be performed in any standard pathology laboratory, could be of help in the diagnosis of TBM. In the present study we measured the adenosine deaminase (ADA) activity in cerebrospinal fluid (CSF) of TBM and non-TBM patients. METHOD ADA activity in CSF was determined according to a method based on the Berthlot reaction, which is the formation of a colored indophenol complex from ammonia liberated from adenosine, and quantified spectrophotometrically. RESULTS The CSF ADA activity from TBM patients was compared with CSF ADA from non-TBM infectious meningitis patients, and from patients with non-infectious neurological disorders. The mean CSF ADA activity was found to be significantly higher in CSF of TBM patients, 14.31 +/- 3.87 (2.99-26.94), mean +/- SD with range, than in the CSF from non-TBM infectious meningitis, 9.25 +/- 2.14 (4.99-13.96) and from the non-infectious neurological disorders group, 2.71 +/- 1.96 (0.00-7.68), P < 0.0001 for both comparisons. A cut-off value of 11.39 U/L/min for the TBM patients was calculated from the mean + SD of the non-TBM patients. The ADA test gave a sensitivity of 82% and a specificity of 83% for infectious TBM when this cut-off value was used. CONCLUSION This study demonstrated that ADA activity in the CSF of TBM patients, using a cut-off value 11.39 U/L/min, can be useful for the early differential diagnosis of TBM. This test can be performed in any pathology laboratory where more sophisticated methods are not available.
Collapse
Affiliation(s)
- Rajpal S Kashyap
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, 88/2 Bajaj Nagar, Nagpur-440010, India
| | - Rani P Kainthla
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, 88/2 Bajaj Nagar, Nagpur-440010, India
| | - Anju V Mudaliar
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, 88/2 Bajaj Nagar, Nagpur-440010, India
| | - Hemant J Purohit
- Environmental Genomics Unit, NEERI, Nehru Marg, Nagpur-440020, India
| | - Girdhar M Taori
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, 88/2 Bajaj Nagar, Nagpur-440010, India
| | - Hatim F Daginawala
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, 88/2 Bajaj Nagar, Nagpur-440010, India
| |
Collapse
|
9
|
Kashyap RS, Dobos KM, Belisle JT, Purohit HJ, Chandak NH, Taori GM, Daginawala HF. Demonstration of components of antigen 85 complex in cerebrospinal fluid of tuberculous meningitis patients. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2005; 12:752-8. [PMID: 15939750 PMCID: PMC1151969 DOI: 10.1128/cdli.12.6.752-758.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Revised: 02/19/2005] [Accepted: 04/06/2005] [Indexed: 11/20/2022]
Abstract
Tuberculous meningitis (TBM) is the most common form of chronic infection of the central nervous system. Despite the magnitude of the problem, the general diagnostic outlook is discouraging. Specifically, there is no generally accepted early confirmative diagnosis protocol available for TBM. Various Mycobacterium tuberculosis antigens are now recognized as potential markers for diagnosis of TBM. However, their presence remains questionable, and many of these antigens are reported in the blood but not in the cerebrospinal fluid (CSF). This study identifies a specific protein marker in CSF which will be useful in early diagnosis of TBM. We have demonstrated the presence of a 30-kDa protein band in CSF of 100% (n = 5) of confirmed and 90% (n = 138) of suspected TBM patients out of 153 TBM patients. The 30-kDa band was excised from the gel, destained extensively, and digested with trypsin. The resulting peptides were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Partially purified proteins from CSF samples of TBM were analyzed by two-dimensional polyacrylamide gel electrophoresis and Western blotting. Immunoblotting and enzyme-linked immunosorbent assay (ELISA) were performed to confirm the presence of proteins in the 30-kDa protein band. The antigen 85 (Ag 85) complex was detected in CSF of TBM patients by indirect ELISA using antibodies against Ag 85 complex. The results of this study showed the 30-kDa protein band contained MTB proteins Rv3804c (Ag85A) and Rv1886c (Ag 85B), both members of the Ag85 complex. This was also confirmed by using immunotechniques such as indirect ELISA and the dot immunobinding assay. Detection of Ag85 complex was observed in CSF of 89% (71 out of 80) of suspected TBM patients that were 30-kDa protein positive. The observed 30-kDa protein in the CSF is comprised of the MTB Ag85 complex. This protein was earlier reported to be present in the blood of patients with extra-central nervous system tuberculosis. Therefore, this finding suggests that this protein can be used as a molecular marker for any type of tuberculous infection. It also provides a more sensitive immunoassay option for the early and confirmatory diagnosis of TBM.
Collapse
Affiliation(s)
- Rajpal S Kashyap
- Biochemistry Research Laboratory, Central India Institute of Medical Sciences, 88/2 Bajaj Nagar, Nagpur-440010, India
| | | | | | | | | | | | | |
Collapse
|
10
|
Kulkarni SP, Jaleel MA, Kadival GV. Evaluation of an in-house-developed PCR for the diagnosis of tuberculous meningitis in Indian children. J Med Microbiol 2005; 54:369-373. [PMID: 15770022 DOI: 10.1099/jmm.0.45801-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Early and rapid detection of the causative organism is necessary in tuberculosis, particularly tuberculous meningitis, as the disease affects mainly children and if untreated or improperly treated can cause severe central nervous system disorders and can often be fatal. An in-house-developed PCR technique was developed for the detection ofMycobacterium tuberculosisDNA, in which the target for amplification was a 340 bp nucleotide sequence located within the 38 kDa protein gene. The test can detect as small an amount of DNA as 10 fg, which is equivalent to two to three organisms, and is highly specific. Amplified product was detected by ethidium bromide staining after electrophoresis and Southern hybridization. Evaluation of test sensitivity and specificity was carried out using acid-fast bacilli-positive sputum samples from patients with pulmonary tuberculosis and an equal number of non-tuberculosis patient samples as negative controls. In a double-masked study 30 cerebrospinal fluid samples from tuberculous meningitis patients and 30 samples from non-tuberculous meningitis patients were investigated. Out of the 30 samples 22 were positive by ethidium bromide-stained gel electrophoresis and 27 gave positive results by Southern hybridization. All of the 30 control samples showed negative results. The sensitivity of this PCR was 90 % and specificity, 100 %.
Collapse
Affiliation(s)
- S P Kulkarni
- Laboratory Nuclear Medicine Section, Isotope Group, BARC, C/o Tata Memorial Centre, Annexe, Mumbai - 400012, India 2Department of Pediatrics, KEM Hospital, Mumbai - 400012, India
| | - M A Jaleel
- Laboratory Nuclear Medicine Section, Isotope Group, BARC, C/o Tata Memorial Centre, Annexe, Mumbai - 400012, India 2Department of Pediatrics, KEM Hospital, Mumbai - 400012, India
| | - G V Kadival
- Laboratory Nuclear Medicine Section, Isotope Group, BARC, C/o Tata Memorial Centre, Annexe, Mumbai - 400012, India 2Department of Pediatrics, KEM Hospital, Mumbai - 400012, India
| |
Collapse
|
11
|
Serologic Testing for Tuberculosis. Tuberculosis (Edinb) 2004. [DOI: 10.1007/978-3-642-18937-1_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
12
|
Tyagi AK, Dhar N. Recent advances in tuberculosis research in India. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2003; 84:211-73. [PMID: 12934938 DOI: 10.1007/3-540-36488-9_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Tuberculosis (TB) continues to be the leading killer of mankind among all infectious diseases, especially in the developing countries. Since the discovery of tubercle bacillus more than 100 years ago, TB has been the subject of research in an attempt to develop tools and strategies to combat this disease. Research in Indian laboratories has contributed significantly towards developing the DOTS strategy employed worldwide in tuberculosis control programmes and elucidating the biological properties of its etiologic agent, M. tuberculosis. In recent times, the development of tools for manipulation of mycobacteria has given a boost to researchers working in this field. New strategies are being employed towards understanding the mechanisms of protection and pathogenesis of this disease. Molecular methods are being applied to develop new tools and reagents for prevention, diagnosis and treatment of tuberculosis. With the sequencing of the genome of M. tuberculosis, molecules are being identified for the development of new drugs and vaccines. In this chapter, the advances made in these areas by Indian researchers mainly during the last five years are reviewed.
Collapse
Affiliation(s)
- Anil K Tyagi
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi-110021, India.
| | | |
Collapse
|
13
|
Chan ED, Heifets L, Iseman MD. Immunologic diagnosis of tuberculosis: a review. TUBERCLE AND LUNG DISEASE : THE OFFICIAL JOURNAL OF THE INTERNATIONAL UNION AGAINST TUBERCULOSIS AND LUNG DISEASE 2001; 80:131-40. [PMID: 10970761 DOI: 10.1054/tuld.2000.0243] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The diagnosis of tuberculosis (TB) principally rests on the sputum examination and culture. However, the sensitivity of sputum smear for acid-fast bacteria is only approximately 50% and sputum culture has a relatively long turnaround time. As a result, a number of studies have been conducted in an attempt to find a rapid and accurate diagnostic test for TB. They include serological assays against various mycobacterial antigens. Here we review the merits and deficiencies of the serological tests for TB. In general, serological assays have a high negative predictive value, making them potentially useful as a screening test to rule out active TB although in HIV-positive individuals, low sensitivity and low negative predictive value compromises the accuracy of the seroassays in this group of individuals. In populations where the prevalence of latent TB infection is high, the relatively low positive predictive value of the tests reduces their specificity for active TB. Furthermore, the higher costs and greater training required in performing these tests makes it important that future studies also assess whether their use affects patient outcomes in management of TB.
Collapse
Affiliation(s)
- E D Chan
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Sciences Center and National Jewish Medical and Research Center, Denver, CO, USA.
| | | | | |
Collapse
|
14
|
Chiang IH, Suo J, Bai KJ, Lin TP, Luh KT, Yu CJ, Yang PC. Serodiagnosis of tuberculosis. A study comparing three specific mycobacterial antigens. Am J Respir Crit Care Med 1997; 156:906-11. [PMID: 9310012 DOI: 10.1164/ajrccm.156.3.9607122] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
To compare the efficacy of different mycobacterial specific antigens and to assess the applicability of the combination of several different antigens in the diagnosis of tuberculosis, three ELISA tests derived by Antigen 60, 38kda, and Kp90 were evaluated in 594 Chinese patients (312 patients with active pulmonary tuberculosis and 282 control subjects). Quantified levels of sensitivity and specificity were compared with those in the nontuberculous control groups. Antigen 60 IgG (sensitivity and specificity, 80.77 and 88.4%) was more antigenic and more effective in its determination than was 38kda IgG (sensitivity and specificity, 64.21 and 80.74%) and Kp90 IgA (sensitivity and specificity, 62.58 and 66.3%). The clinical significance of the difference, however, was not striking: negative predictive value of Antigen 60, 38kda, and Kp90 was 93, 86 and 83%, respectively; positive predictive value of Antigen 60, 38kda, and Kp90 was 71, 54, and 39%, respectively. Combination of different antigens could improve the sensitivity and specificity by no more than 10%, with the sacrifice of the opposite parameter by no less than 20%. The same improvement in sensitivity could be easily achieved by adjusting the cutoff values in the ELISA test by a single antigen. We conclude that the sensitivity and specificity of presently available antigens for serodiagnosis of tuberculosis still remains limited at around 80%, which makes it a poor diagnostic tool for disease confirmation. In low incidence areas, its clinical value may be useful in disease exclusion. A combination of several different antigens provides no more improved diagnostic yield than what can be provided by cutoff value adjustment in a single antigen serologic test.
Collapse
Affiliation(s)
- I H Chiang
- Taiwan Provincial Chronic Disease Control Bureau, Department of Laboratory Medicine, College of Medicine, National Taiwan University, Taipei, Republic of China
| | | | | | | | | | | | | |
Collapse
|