A new Rutgers New Jersey Medical School study shows that most people at high risk for tuberculosis (TB) relapse can be identified by testing the Mycobacterium tuberculosis bacteria that causes TB before the patient begins treatment.
The study, led by Roberto Colangeli, assistant professor in the Department of Medicine, and David Alland, professor and chief of infectious disease in the Department of Medicine, appears in the New England Journal of Medicine.
“The most important signal of a successful treatment for TB is the relapse rate,” said Alland. “Approximately five percent of patients with drug-susceptible tuberculosis, or TB that can be effectively treated, have a relapse six months after the first time they are treated. Approximately 20 percent of patients have a relapse four months after therapy.”
According to Alland, their research showed the current approach of dividing M. tuberculosis bacteria into “drug-susceptible” and “drug-resistant” is overly simplistic. Even among the drug susceptible group, there is a range of resistance that is critical for predicting TB treatment outcomes. This finding suggests that standard criteria, also called “break points” used to define drug resistance may need to be updated.
“Characteristics natural to the bacteria combined with easily obtainable clinical information relating to each infected patient can be used to predict treatment outcomes,” said Colangeli. “This further suggests that the strength of a TB drug is just as important as the mechanism of action in treating TB.”
Insights gathered from the study reveal a way to identify which patients can be treated for TB for four months instead of six months. They also identify which patients should be treated for more than six months to achieve a cure.
“The standard six-month, multi-drug therapy increases the risks of toxic effects, treatment non-adherence and development of drug resistance, and it also puts a burden on health systems,” said Alland. “Reducing treatment times, by even two months, would potentially mean dramatic savings for public health programs as well as better treatment results among people infected with TB.”