Immunoglobulin G response to mammalian cell entry 1A (Mce1A) protein as biomarker of active tuberculosis

Area of Science:

• Immunology
• Microbiology
• Infectious Diseases

Background:

• Mycobacterium tuberculosis cell wall components are key virulence factors.
• Mammalian cell entry protein 1A (Mce1A) facilitates pathogen entry into host cells.
• Immune responses to Mce1A are crucial in tuberculosis pathogenesis.

Purpose of the Study:

• To evaluate serum immunoglobulin (IgA, IgM, total IgG) levels against Mce1A as potential biomarkers for tuberculosis (TB) diagnosis.
• To assess the utility of Mce1A antibodies in monitoring TB treatment response.
• To compare the diagnostic performance of Mce1A antibody detection with routine sputum smear microscopy.

Main Methods:

• Serum samples from 39 pulmonary TB patients and 65 controls were analyzed using ELISA.
• Levels of IgA, IgM, and total IgG antibodies against Mce1A were quantified.
• Diagnostic sensitivity and specificity of antibody detection were calculated and compared to sputum smear results.

Main Results:

• Significantly higher median levels of IgA, IgM, and total IgG were observed in TB patients compared to all control groups.
• Positive test results for IgA, IgM, and IgG were 62%, 54%, and 82%, respectively.
• IgG antibody detection showed a sensitivity of 79.5% and specificity of 84.4%, outperforming sputum smear microscopy (67% sensitivity).
• A significant decrease in antibody levels post-treatment was noted.

Conclusions:

• Circulating total IgG antibodies against Mce1A show promise as a complementary diagnostic biomarker for pulmonary TB.
• Mce1A-specific antibody detection could potentially aid in monitoring treatment response in TB patients.
• Further validation is warranted to establish Mce1A antibody assays in clinical TB diagnostics.