High Beclin-1 Expression in Human Alveolar Macrophage Significantly Correlate with the Bacteriologic Sterilization in Pulmonary Tuberculosis Patients.

BACKGROUND: Tuberculosis (TB) continues to be a major health problem, and there are few biomarkers for predicting TB progression and anti-TB outcome. Recently, studies suggested that autophagy may link the multistep process of intracellular MTB clearance. So we hypothesized that autophagy level might indicate anti-TB prognostic significance.

METHODS: Sixty-five pulmonary tuberculosis (PTB) patients and 15 healthy controls were included in the study. Laboratory examinations were determined in all subjects. Beclin-1 level, which was highly related with autophagy process, was determined using RT-PCR and western blotting assay in human alveolar macrophages. We divided the patients into Beclin-1 high group and Beclin-1 low group and treated them with the same anti-TB regimens. The predictive ability of Beclin-1 on the treatment outcome was further studied.

RESULTS: In this study, we found Beclin-1 was markedly increased in alveolar macrophages in PTB patients. Sterilization of the sputum culture was achieved faster in the Beclin-1 high group, as demonstrated either by the percentage of negative smear findings or by the colony-forming unit (CFU) assay. Furthermore, Beclin-1 high group demonstrated faster relief of respiratory symptoms.

CONCLUSIONS: Our results suggested the expression of Beclin-1 could be a novel biomarker for predicting anti-TB outcomes.