HLA-A and B antigens and pulmonary tuberculosis in Greeks

Genetic susceptibility in tuberculosis

The importance of host genetic factors in determining susceptibility to tuberculosis (TB) has been studied extensively using various methods, such as case-control, candidate gene and genome-wide linkage studies. Several important candidate genes like human leucocyte antigen/alleles and non-human leucocyte antigen genes, such as cytokines and their receptors, chemokines and their receptors, pattern recognition receptors (including toll-like receptors, mannose binding lectin and the dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin), solute carrier family 11A member 1 (formerly known as natural resistance-associated macrophage protein 1) and purinergic P2X7 receptor gene polymorphisms, have been associated with differential susceptibility to TB in various ethnic populations. This heterogeneity has been explained by host-pathogen and gene-environment interactions and evolutionary selection pressures. Although the achievements of genetics studies might not yet have advanced the prevention and treatment of TB, researchers have begun to widen their scope of investigation to encompass these practical considerations.

Association of various inflammatory diseases with human leukocyte antigens B27, B7, Bw4 and Bw6 in patients with SSA

Seronegative spondyloarthropathies (SSA) are a group of inflammatory disorders, which clinically involve the axial skeleton and the sacroiliiac and shoulder joints. The aim of the present study was to study the association of HLA B27, B7, Bw4 and Bw6 with some inflammatory diseases, in SSA patients in our area. A total of 220 SSA patients were studied and HLA typing for these antigens were done by the complement-mediated microcytotoxicity method. The total positivity of B27 was found to be 68.64% in SSA patients. Tubercular infection (chi(2) = 8.06) and acute anterior uveitis (chi(2) = 6.19) were found to be statistically significant (P < 0.05) in B27-positive SSA patients. Tuberculosis was also found to be significantly (chi(2) = 6.40) associated with Bw4. In SSA urinary tract infection, gastrointestinal infection and streptococcal infection were not significantly associated with B27, B7, Bw4 or Bw6 antigens. Our study concludes that microbial infections do have some pathogenic role in causing SSA.

Comparative analysis of HLA class I antigens in pulmonary sarcoidosis and tuberculosis in the same ethnic group

OBJECTIVE

To compare occurrences of respective HLA class I antigens in patients with sarcoidosis (SA), patients with tuberculosis (TB), and healthy controls in the same ethnic group in Poland.

PATIENTS AND METHODS

HLA-A, -B, and -C antigens were determined from 1994 to 1997 by using the National Institutes of Health method in 100 patients with SA, 100 patients with TB, and 100 healthy controls. Frequencies of specific antigens were compared among the 3 groups.

RESULTS

Our study showed that among SA patients, the HLA-B51(5) and HLA-B8 antigens tended to be more common and the HLA-B13, -B35, and -Cw4 antigens tended to be less common than in the controls. However, after Bonferroni correction, only the HLA-B35 antigen was found to be significantly different in SA patients and controls. In TB patients, the expression of HLA-B62(15) and HLA-Cw5 antigens tended to be more common compared with controls and HLA-A2 less common compared with controls, but only the differences in B62(15) and Cw5 were significant after Bonferroni correction. HLA-B51(5) and HLA-B8 antigens were statistically more frequent and B13, B62(15), and Cw4 less frequent in SA than in TB patients and remained significant after Bonferroni correction. The occurrence of other antigens studied in both populations was comparable.

CONCLUSION

We identified associations of HLA class I antigens in patients with SA or TB, with an expression pattern specific and different for each group.

Association of pulmonary tuberculosis and HLA in south India

In 204 patients with smear-positive pulmonary tuberculosis HLA-A10, B8 and DR2 were more frequently found than in 404 control subjects (p = 0.01); the greatest attributable risk (0.29) was associated with HLA-DR2. The radiographic extent of disease was also associated with HLA-DR2 (p = 0.0001). In 152 patients with smear-negative pulmonary tuberculosis, the frequencies of HLA-A10 and B8, but not DR2, were greater in the control subjects (p = 0.001 and 0.01 respectively). HLA-DR2 may be involved in the pathogenesis of advanced pulmonary tuberculosis. Study of endogamous, genetically disparate populations (caste) revealed other HLA associations (A3, B12 and DR4) unique to them, suggesting that genes linked with the HLA complex might also be significant in the pathogenesis of tuberculosis.