HLA-DR2 subtypes & immune responses in pulmonary tuberculosis

Area of Science:

• Immunogenetics
• Tuberculosis Research
• Human Leukocyte Antigen (HLA) System

Background:

• The Human Leukocyte Antigen (HLA)-DR2 is linked to tuberculosis susceptibility and immune response alterations.
• Previous studies suggest a role for HLA-DR2 in pulmonary tuberculosis (TB).

Purpose of the Study:

• To investigate the influence of HLA-DR2 subtypes on antibody and lymphocyte responses to Mycobacterium tuberculosis antigens.
• To determine the association of DR2 subtypes with susceptibility to pulmonary TB.

Main Methods:

• Genotyping of HLA-DR2 subtypes (DRB1*1501, *1502, *1503, *1601, *1602) using PCR and SSOP.
• Measurement of antibody titres via ELISA and lymphocyte response using the lymphocyte transformation test (LTT).
• Comparison of allele frequencies and immune responses between active TB patients, inactive TB patients, and healthy controls.

Main Results:

• The DRB1*1501 allele frequency was significantly higher in pulmonary TB patients compared to controls.
• No significant differences in antibody titre or lymphocyte response to M. tuberculosis antigens were observed across DR2 subtypes in relation to disease status.
• Active TB patients (DRB1*1501 and *1502 positive or negative) showed higher antibody titres than controls and inactive TB patients.

Conclusions:

• DRB1*1501 may be associated with susceptibility to pulmonary tuberculosis, potentially with other DR2 alleles.
• The studied DR2 alleles did not appear to influence antibody or lymphocyte responses to M. tuberculosis culture filtrate antigens.
• The HLA-DR2 gene or its products as a whole might play a role in modulating the immune response in pulmonary tuberculosis.