Heightened microbial translocation is a prognostic biomarker of recurrent tuberculosis

Background
Microbial translocation is a known characteristic of pulmonary tuberculosis (PTB). Whether microbial translocation is also a biomarker of recurrence in PTB is not known.

Methods
We examined the presence of microbial translocation in a cohort of newly diagnosed, sputum smear, and culture positive individuals with drug-sensitive PTB. Participants were followed up for a year following the end of anti-tuberculosis treatment. They were classified as cases (in the event of recurrence, n = 30) and compared to age and gender matched controls (in the event of successful, recurrence free cure; n = 51). Plasma samples were used to measure the circulating microbial translocation markers. All the enrolled study participants were treatment naïve, HIV negative and with or without diabetes mellitus.

Results
Baseline levels of lipopolysaccharide (LPS) (P = .0002), sCD14 (P = .0191), and LPS-binding protein (LBP) (P < .0001) were significantly higher in recurrence than controls and were associated with increased risk for recurrence, whereas intestinal fatty acid binding protein (I-FABP) and Endocab showed no association. Receiver operating characteristic (ROC) curve analysis demonstrated the utility of these individual microbial markers in discriminating recurrence from cure with high sensitivity, specificity, and area under the curve (AUC).

Conclusions
Recurrence following microbiological cure in PTB is characterized by heightened baseline microbial translocation. These markers can be used as a rapid prognostic tool for predicting recurrence in PTB.