Surfactant protein genetic marker alleles identify a subgroup of tuberculosis in a Mexican population

Pulmonary surfactant and its components are essential for normal lung function and are involved in local host defense. Surfactant protein (SP)-A and SP-D bind to and modulate phagocytosis of Mycobacteriurn tuberculosis by macrophages. Frequency comparisons of SP marker alleles in tuberculosis patients and healthy control subjects (tuberculin-skin test positive or general population) were performed. Regression analyses of the tuberculosis and the tuberculin-skin test positive groups revealed, on the basis of odds ratios, tuberculosis susceptibility (DA11-C and GATA-3) and protective (AAG-2) marker alleles. Similarly, between tuberculosis patients and general population control subjects, susceptibility 1A³, 6A⁴, and B1013-A and protective AAGG-1, and AAGG-7 marker alleles were observed. Moreover, interactions were seen between alleles 6A² and 1A³ (P = .0064) and between 1A³ and B1013-A (P = .036). The findings indicate a possible involvement of SP alleles in tuberculosis pathogenesis.