Association of the Presence of the IS6110 Gene and the Polymorphisms of the Receptor of the Bactericide P2X7 (A1513C and -762 C/T) in Mexican Patients with Takayasus Arteritis and Tuberculosis. Is the Vasculitis A Manifestation of Extrapulmonary Tuberculosis?

Background and objective: Takayasu's arteritis is a disease that has been associated with tuberculosis, based upon the presence of Langerhans giant cells and granulomas. ATP treatment of mycobacteria infected macrophages induces apoptosis mediated via the P2X7 pathway. Here we evaluated if the polymorphisms of the P2X7 receptors are associated to the presence of tuberculosis in Mexican patients with Takayasu´s arteritis. Methods: 63 aortic samples, 33 from Takayasu´s and 30 from tuberculosis subjects were studied. Histological analysis was made and the sequence of the gene IS6110 which identifies the presence of Mycobacterium tuberculosis was amplified. Polymorphisms of the A1513C and -762 C/T receptors for the P2X7 gene were analyzed. Results: The analysis showed a high percentage of extra pulmonary lesions (36.3%) in the Takayasu´s group. No significant differences between the studied genotypes were found in any of the models analyzed or in any of the two P2X7 polymorphisms analyzed. Moreover, an increase in the 1513C allele in presence of IS6110 gene in the Takayasu´s group was observed when comparing with the group of tuberculosis. Conclusion: We found a high percentage of extra pulmonary tuberculosis in subjects with Takayasu´s arteritis; this increase was associated with a high frequency in the allele 1513C in the presence of IS6110 gene. Thus, these alleles may confer a significant susceptibility at the aortic level in the Mexican population having these diseases.