Demonstration of Components of Antigen 85 Complex in Cerebrospinal Fluid of Tuberculous Meningitis Patients

Abstract

Tuberculosis is the leading cause of death among communicable diseases, killing nearly 2 million people each year (2, 13). Among tubercular infections, tuberculous meningitis (TBM) leads to multiple central nervous system (CNS) complications and remains a major health problem in underdeveloped and developing countries (1, 9, 16). Even in developed countries where a decade ago it was rare, it has reappeared following human immunodeficiency virus infection (6, 14, 29). Early and rapid confirmatory diagnosis is still difficult due to the clinical picture of TBM and similarities of TBM cerebrospinal fluid (CSF) to that of partially treated pyogenic meningitis, which results in frequent diagnostic confusion (4,21,28,33). Early and reliable diagnosis of TBM still poses a great challenge. In most of the cases, diagnosis relies on clinical observations, imaging of the infected area, and detection of Mycobacterium tuberculosis in CSF by acid-fast bacillus (AFB) staining and culturing. A number of immunological and molecular methods have been reported, but these cannot be employed in standard pathology laboratories and are often not useful for early confirmative diagnosis of TBM (3,7,11,15,22,23,25,26,31,35).To overcome the deficiencies in TBM diagnosis, we set forth to identify specific protein markers unique to CSF samples collected from suspected patients with TBM. By analyzing the total sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) protein profile of such CSF, we observed a 30-kDa protein band specific to these patients (18). Further, all 30-kDa protein-positive CSF samples tested with polyvalent antibodies against culture filtrate proteins (CFP) of M. tuberculosis strain H 37 Rv by the single radial immunodiffusion (SRID) method indicated that the CSF of TBM patients possesses M. tuberculosis antigens (17).These early investigations led us to hypothesize that molecular identification of the TBM-specific 30-kDa CSF protein would allow for development of specific reagents and protocols for the rapid and accurate diagnosis of TBM. In this report, the application of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and liquid chromatography tandem mass spectrometry (LC-MS/MS) identified two mycobacterial proteins of the antigen 85 (Ag85) complex (Rv3804c and Rv1886c) and one host-derived protein (immunoglobulin [Ig] kappa light * Corresponding author. Mailing address:

Impact of MHC class I alleles on the M. tuberculosis antigen-specific CD8+ T-cell response in patients with pulmonary tuberculosis

“…7,8 Ag85 complex proteins rank among the top MTB vaccine candidates, 9 they are elevated and readily detectable in serum from patients with active tuberculosis, 10 as well as in cerebrospinal fluid from patients with MTB meningitis. 11 Antigen-specific CD8 þ T cells were suggested to control MTB infection and MHC class I-restricted CD8 þ T-cells recognizing MTBassociated antigens have been reported. [12][13][14] The precise MHC class I-peptide-binding profile and the broader pattern of Ag85 specific cellular immune responses in patients with active tuberculosis has not yet been defined.…”

Rapid Diagnosis and Simultaneous Identification of Tuberculous and Bacterial Meningitis by a Newly Developed Duplex Polymerase Chain Reaction

“…This group included non-TBM and non-BM infectious patients of viral and fungal meningitis with the observations as reported earlier [15,16] along with good clinical response to antiviral and antifungal drugs respectively.…”

“…Recruitment of patients in this group was done as per the laboratory findings reported earlier by us [15,16].…”

“…Clinically Suspected BM Patients (n = 11) BM diagnosis was based on clinical features including fever and/or signs of meningeal irritation or high fever and/ or signs of meningeal irritation with or without CNS manifestations and good clinical response to broad spectrum antibiotics [15,16].…”

Comparación de adenosina deaminasa y detección de anticuerpos anti-antígeno A60 para el diagnóstico de meningitis tuberculosa

“…Por otra parte, los nuevos tests diagnósticos basados en amplificación de ácidos nucleicos (RPC) para M. tuberculosis en LCR, además de ser de mayor costo y complejidad técnica, también están limitados por una baja y variable sensibilidad (50-60%), por lo que tampoco permiten excluir una meningitis con seguridad 6 . De acuerdo a varias publicaciones, la respuesta inflamatoria de M. tuberculosis en el sistema nervioso central se caracteriza por síntesis intratecal de inmunoglobulinas (Ig) oligoclonales detectables en LCR durante la infección meníngea 7,8 . Numerosos componentes antigénicos de las micobacterias tal como ESAT-6, 14 kDA, MPT63, 19kDA, MPT64, 38 kDA y A60 han sido caracterizados para detección mediante técnicas de inmunoensayo y serología en el diagnóstico de tuberculosis pulmonar y extra-pulmonar [9][10][11] .…”