Better chances of cure for patients with multidrug-resistant tuberculosis
Better chances of cure for patients with multidrug-resistant tuberculosis
Over a period of five years, an international team of scientists has documented in detail the treatment success of patients with severe tuberculosis. During this period, the team also reviewed the current WHO definition of “cure”. The study, which was conducted at 23 treatment centres in Europe, showed that the chances of cure are much higher than previously assumed—as soon as the experts used more simplified and more informative definitions than those of the WHO. DZIF scientists from the Research Center Borstel coordinated the study.
The number of patients who have been diagnosed with multidrug-resistant tuberculosis (MDR-TB) has been increasing over the last years, also in Europe. Up to now, the patient’s prospects of being successfully cured have been considered low. According to World Health Organisation criteria, only 31 percent of patients in Europe can be defined as cured. The WHO definition of cure includes three negative sputum tests for tuberculosis bacteria after the patient’s successful completion of intensive therapy.
International study with 380 patients
In an international study, the WHO criteria were reviewed and compared to newly developed criteria. Together with physicians from TBNET (Tuberculosis Network European Trials Group), scientists from the Research Center Borstel recorded the courses of treatment in 380 patients at 23 treatment centres in Europe over a period of five years—from the time of diagnosis up to one year after the end of treatment. “We ascertained that the WHO criteria are not applicable to the majority of patients in Western Europe because the requested tests are actually not conducted in clinical practice,” explains Dr Gunar Günther from the DZIF Clinical Center for Tuberculosis at the Research Center Borstel. The reason being: “During this phase of treatment, the majority of patients are no longer able to produce any sputum.”
Subsequently, the clinical scientists developed more simplified and stronger successful multidrug-resistant tuberculosis treatment criteria for patients in the study. According to these criteria, as the courses of treatment also showed, patients can be considered cured when the bacteria can no longer be detected six months after treatment initiation and when no relapse occurs within one year after treatment completion. “These criteria are not only easier to determine, the results are also more coherent,” explains study coordinator Prof Christoph Lange from the Research Center Borstel. Similar to the situation with cancer patients, no relapse is a very good criterion for cure. “Most relapses occur within one year after treatment completion,” explains Lange and criticises that, “the WHO criteria do not include a follow-up period.”
With the new, stronger criteria the scientists could show that a relapse-free cure occurred in 61 percent of the MDR-TB cases, i.e. overall, the chances of cure were around twice as high than the WHO criteria were applied. “This is very encouraging for the affected patients,” says Lange.
Hope yes, all-clear no
Even though these results are encouraging, the researchers do not give an all-clear regarding multidrug-resistant tuberculosis bacteria. Christoph Lange: “There is still a lot to do because at least a third of the patients are currently still incurable. However, we are optimistic that the chances of cure for these patients can be increased significantly in future through personalised medicine and individual treatment concepts.”
Publication
Günther et al.: Treatment Outcomes in Multidrug-Resistant Tuberculosis.
New England Journal of Medicine September 15, 2016.
DOI: 10.1056/NEJMc1603274
