The results seem to challenge the current approach endorsed by the World Health Organization. Under that method, directly observed therapy-short-course strategy (DOTS), TB that responds to medication is treated with a cocktail of drugs under the supervision of health care workers, who in many countries must travel to isolated villages – a costly and time-consuming process.
“Every TB patient is supposed to be watched as they swallow their pills in order to increase adherence and decrease emergence of drug resistance. This is the most expensive part of the program, but has been felt to be cost-effective since it improves compliance,” said Dr. Gumbo, administrative director of research programs for the Office of Global Health at UT Southwestern.
In this study, UT Southwestern researchers created a sophisticated system of high-tech test tubes, which they called a “glass mouse,” that mimicked standard therapy being given daily for 28 to 56 days, with dosing adherence varying between 0 percent and 100 percent. The threshold for defined non-adherence (failure to take a required dose of medication) was reached at 60 percent of the time or more.
“The first main finding in our laboratory model was that in fact non-adherence did not lead to multidrug resistance or emergence of any drug resistance in repeated studies, even when therapy failed. In fact, even when we started with a bacterial population that had been spiked with drug-resistant bacteria, non-adherence still did not lead to drug resistance,” he said.
In fact, using computer simulations based on 10,000 TB patients in Cape Town, South Africa, the researchers discovered that approximately 1 percent of all TB patients with perfect adherence still developed drug resistance because they cleared the drugs from their bodies more quickly.
The body sees drugs as foreign chemicals and tries to rid itself of them, Dr. Gumbo said. A population of individuals with a genetic trait that speeds the process has been found in one area of South Africa that has a high rate of multidrug-resistant TB. In that population, patients who receive standard doses of drugs end up with concentrations in their bodies that are too low to kill the TB bacillus and drug resistance develops, he said.
A Journal of Infectious Diseases editorial that accompanies the study suggests that monitoring the levels of TB drugs in a patient’s blood could be as important as monitoring compliance with therapy – in contrast to current WHO guidelines.
“These data, based on our preclinical model, show that non-adherence alone is insufficient for the emergence of multidrug-resistant TB,” Dr. Gumbo said. “It might be more cost-effective to measure patients’ drug concentrations during treatment and intervene with dosage increases in those who quickly clear the drugs from their systems.”
The work was supported by a grant from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health.
Other UT Southwestern investigators involved in the study are lead author Dr. Shashikant Srivastava, former postdoctoral researcher, and Dr. Jotam G. Pasipanodya, research scientist in internal medicine. Researchers from the School of Pharmacy at Texas Tech University Health Science Center, Dallas, also participated.
Deborah Wormser | EurekAlert!
Advanced analysis of brain structure shape may track progression to Alzheimer's disease
26.10.2016 | Massachusetts General Hospital
Indian roadside refuse fires produce toxic rainbow
26.10.2016 | Duke University
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
27.10.2016 | Materials Sciences
27.10.2016 | Physics and Astronomy
27.10.2016 | Life Sciences