Polymorphisms in Beta-2 Adrenergic Receptor Gene and Association with Tuberculosis

A differential DNA methylome signature of pulmonary immune cells from individuals converting to latent tuberculosis infection

Tuberculosis (TB), caused by Mycobacterium tuberculosis, spreads via aerosols and the first encounter with the immune system is with the pulmonary-resident immune cells. The role of epigenetic regulations in the immune cells is emerging and we have previously shown that macrophages capacity to kill M. tuberculosis is reflected in the DNA methylome. The aim of this study was to investigate epigenetic modifications in alveolar macrophages and T cells in a cohort of medical students with an increased risk of TB exposure, longitudinally. DNA methylome analysis revealed that a unique DNA methylation profile was present in healthy subjects who later developed latent TB during the study. The profile was reflected in a different overall DNA methylation distribution as well as a distinct set of differentially methylated genes (DMGs). The DMGs were over-represented in pathways related to metabolic reprogramming of macrophages and T cell migration and IFN-γ production, pathways previously reported important in TB control. In conclusion, we identified a unique DNA methylation signature in individuals, with no peripheral immune response to M. tuberculosis antigen who later developed latent TB. Together the study suggests that the DNA methylation status of pulmonary immune cells can reveal who will develop latent TB infection.

Spatiotemporal epidemiology of, and factors associated with, the tuberculosis prevalence in northern China, 2010-2014

BACKGROUND

Tuberculosis (TB) is an important public health issue worldwide. However, evidence concerning the impact of environmental factors on TB is sparse. We performed a retrospective analysis to determine the spatiotemporal trends and geographic variations of, and the factors associated with, the TB prevalence in Inner Mongolia.

METHODS

We performed a retrospective analysis of the epidemiology of TB. A Bayesian spatiotemporal model was used to investigate the spatiotemporal distribution and trends of the TB prevalence. A spatial panel data model was used to identify factors associated with the TB prevalence in the 101 counties of Inner Mongolia, using county-level aggregated data collected by the Inner Mongolia Center for Disease Control and Prevention.

RESULTS

From January 2010 to December 2014, 79,466 (6.36‱) incident TB cases were recorded. The TB prevalence ranged from 4.97‱ (12,515/25,167,547) in 2014 to 7.49‱ (18,406/ 24,578,678) in 2010; the majority of TB cases were in males, and in those aged 46-60 years; by occupation, farmers and herdsmen were the most frequently affected. The Bayesian spatiotemporal model showed that the overall TB prevalence decreased linearly from 2010 to 2014 and occupation-stratified analyses yielded similar results, corroborating the reliability of the findings. The decrease of TB prevalence in the central-western and eastern regions was more rapid than that in the overall TB prevalence. A spatial correlation analysis showed spatial clustering of the TB prevalence from 2011 to 2014 (Moran's index > 0, P < 0.05); in the spatial panel data model, rural residence, birth rate, number of beds, population density, precipitation, air pressure, and sunshine duration were associated with the TB prevalence.

CONCLUSIONS

The overall TB prevalence in Inner Mongolia decreased from 2010 to 2014; however, the incidence of TB was high throughout this period. The TB prevalence was influenced by a spatiotemporal interaction effect and was associated with epidemiological, healthcare, and environmental factors.

Human genetic factors in tuberculosis: an update

Tuberculosis (TB) is a major threat to human health, especially in many developing countries. Human genetic variability has been recognised to be of great relevance in host responses to Mycobacterium tuberculosis infection and in regulating both the establishment and the progression of the disease. An increasing number of candidate gene and genome-wide association studies (GWAS) have focused on human genetic factors contributing to susceptibility or resistance to TB. To update previous reviews on human genetic factors in TB we searched the MEDLINE database and PubMed for articles from 1 January 2014 through 31 March 2017 and reviewed the role of human genetic variability in TB. Search terms applied in various combinations were 'tuberculosis', 'human genetics', 'candidate gene studies', 'genome-wide association studies' and 'Mycobacterium tuberculosis'. Articles in English retrieved and relevant references cited in these articles were reviewed. Abstracts and reports from meetings were also included. This review provides a recent summary of associations of polymorphisms of human genes with susceptibility/resistance to TB.