When can tuberculosis therapy be stopped without the risk of relapse? Doctors are faced with this question time and again because of the lack of detection of the tuberculosis pathogen mycobacterium tuberculosis is no guarantee for a permanent cure of the lung infection.
Patients who respond to the standard therapy may be out of treatment after six months but for resistant causes, more than eighteen months of treatment duration is currently advised. “ This is a very long time for those affected who often have to take more than four antibiotics every day and suffer from side effects explained Prof. Dr. Christoph Lange, clinical director at the research centre Borstel and director of the study conducted at the German centre for infection research (DZIF) in cooperation with the German Centre for lung research (DZL).” We urgently need a biomarker that enables the implementation of an individualised treatment duration” he emphasizes after all, not every patient needs so long to recover.
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Since the absence of bacteria in the sputum does not justify a safe stop in therapy, the team around Christoph Lange set out to find alternative biomarker in the patient. In collaboration with the international tuberculosis centre, on the basis of a patient cohort, a model for the end of therapy could be developed that is based on an RNA determination in the blood.
For many thousand of gene, twenty-two have been identified whose activity correlates with the course of the disease. The production of RNA of these twenty-two genes in human blood can tell us whether the patient is cured, Dr Jan Heyckendorf from the FZ Brostel sums it up. It is an RNA signature from twenty-two genes identified on two cohorts and validated on another three cohorts adds the scientist.” No other published transcription marker shows comparable properties so far.
To identify this individual biomarker, the scientists within the DZIF have established five different patient cohorts. In all cases, these were adults who had contracted pulmonary TB, Partly from resistant forms. In addition to cohorts in Germany, patients in Bucharest ( Romania) were also included where the DZIF supports the study centre.
“The individualisation of the treatment duration is an important milestone on the road to precision medicine for tuberculosis “ affirms Christoph Lange. Even without progression value, one could risk stopping a patient’s treatment on the basis of this RNA determination. As a next step, the researchers are planning a prospective study at the DZIF.
The aim is for patients in one study arm to receive for as long as the biomarker suggests, while patients in the arm receive treatment for as long as the national tuberculosis program recommends. The scientists then want to see whether the biomarker makers a shorter treatment duration possible, the team around Christoph Lange is confident. “Hopefully it will then be possible for patients with multidrug-resistant tuberculosis to save about one-third of treatment on average says, Lange.
By: Peace Chigozie
