Biomarkers are needed to monitor tuberculosis (TB) treatment and predict treatment outcomes. We evaluated the Xpert MTB/RIF (Xpert) assay as a biomarker for TB treatment during and at the end of the 24 weeks therapy.
Sputum from 108 HIV-negative, culture-positive pulmonary TB patients was analyzed using Xpert at time points before and during anti-TB therapy. Results were compared against culture. Direct Xpert cycle-threshold (Ct), a change in the Ct (delta Ct), or a novel "percent closing of baseline Ct deficit" (percent closing) were evaluated as classifiers of same-day and end-of-treatment culture and therapeutic outcomes.
Xpert was positive in 29/95 (30.5%) of subjects at week 24; and positive one year after treatment in 8/64 (12.5%) successfully-treated patients who remained free of tuberculosis. We identified a relationship between initial bacterial load measured by baseline Xpert Ct and time to culture conversion (hazard ratio 1.06, p = 0.0023), and to the likelihood of being among the 8 treatment failures at week 24 (AUC = 72.8%). Xpert Ct was even more strongly associated with culture conversion on the day the test was performed with AUCs 96.7%, 99.2%, 86.0% and 90.2%, at Day 7, Week 4, 8 and 24, respectively. Compared to baseline Ct measures alone, a combined measure of baseline Ct plus either Delta Ct or percent closing improved the classification of treatment failure status to a 75% sensitivity and 88.9% specificity.
Genome loads measured by Xpert provide a potentially-useful biomarker for classifying same day culture status and predicting response to therapy.
Pharmacology, Toxicology and Pharmaceutical Science
5
4%
Biochemistry, Genetics and Molecular Biology
4
3%
Other
14
11%
Unknown
44
35%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 5. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 04 September 2018.
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#7,159,782
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#111,216
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#1,431
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Altmetric has tracked 25,306,238 research outputs across all sources so far. This one has received more attention than most of these and is in the 71st percentile.
So far Altmetric has tracked 219,562 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 15.7. This one has gotten more attention than average, scoring higher than 54% of its peers.
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We're also able to compare this research output to 4,346 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 66% of its contemporaries.
