Human leukocyte antigens and susceptibility to tuberculosis: a meta-analysis of case-control studies.

OBJECTIVE: To evaluate the association between human leukocyte antigens (HLA) of the major histocompatibility complex (MHC) and thoracic tuberculosis (TB) in immunocompetent adults.
DESIGN: We searched Medline, Pascal, Pascal Biomed and Francis databases (all years) with the terms 'tuberculosis' and 'HLA'. Case-control studies were included that reported frequencies for the full range of antigens analysed by serological methods in healthy controls and adult patients not treated with glucocorticoids or immunosuppressive drugs, human immunodeficiency virus status negative or not reported, no debilitating chronic disease, and with a diagnosis of thoracic TB based on microbiological or histological criteria. Two authors independently abstracted the data and resolved disagreements by consensus.
RESULTS: We summarised 60 HLA antigens reported in at least four of 22 studies totalling 1988 patients and 2897 controls. A lower risk of thoracic TB was found in carriers of B13 (OR 0.64, 95% CI 0.50-0.81, P < 0.0001), DR3 (OR 0.72, 95% CI 0.59-0.89, P = 0.002), and DR7 antigens (OR 0.65, 95% CI 0.53-0.80, P < 0.0001). Carriers of DR8 were at higher risk for thoracic TB (OR 1.72, 95% CI 1.21-2.46, P = 0.003). For these antigens, we found no significant heterogeneity between samples or evidence of publication bias. The risk of thoracic TB tended to be higher in carriers of DR2 (OR 1.67, 95% CI 1.16-2.41, P = 0.006), but the results were not consistent between studies (P value for heterogeneity < 0.0001).
CONCLUSION: Susceptibility to TB is modulated by class I and II HLA antigens. However, these results based on the serological determination of antigens require confirmation by DNA-based methods to precisely identify those alleles involved.