"About one-third of the world's population is infected by Mycobacterium tuberculosis--the bacteria responsible for tuberculosis," says Dr. Erwin Schurr, a molecular geneticist at the Centre for the Study of Host Resistance at the MUHC, and the study's principal investigator. "Of the estimated two billion people infected, only 5%-10% actually develop tuberculosis disease in their lifetime--the other 90%-95% appear to be able to contain the infection in a dormant state, so that they do not become ill." Dr. Schurr has spent the past 5 years researching why and how this happens.
The new research focused on NRAMP1--a gene already known to be involved in many other illnesses, including diseases as diverse as leprosy and rheumatoid arthritis. "We discovered that variants (alleles) of the NRAMP1 gene control the speed at which tuberculosis develops, rather than whether or not it will develop at all," says Dr. Schurr. "This is the first time a gene has been shown to control the time frame between initial infection and the disease." Certain factors are already known to increase the speed at which people develop tuberculosis. "HIV and tuberculosis are synergistic partners in crime for example," says Dr. Schurr. "They appear to accelerate disease progression when they occur together."
"Understanding the basic pathways of pathogenesis offers new targets and policies for disease prevention," notes Dr. Emil Skamene, Scientific Director of the Research Institute of the MUHC. "Academic hospitals such as the MUHC combine scientific research, technology and clinic expertise, enabling scientific breakthroughs to be developed into treatments and cures that directly benefit patients."
The Research Institute of the McGill University Health Centre (RI MUHC) is a world-renowned biomedical and health-care hospital research centre. Located in Montreal, Quebec, the institute is the research arm of the MUHC, a university health center affiliated with the Faculty of Medicine at McGill University. The institute supports over 500 researchers, nearly 1000 graduate and post-doctoral students and operates more than 300 laboratories devoted to a broad spectrum of fundamental and clinical research. The Research Institute operates at the forefront of knowledge, innovation and technology and is inextricably linked to the clinical programs of the MUHC, ensuring that patients benefit directly from the latest research-based knowledge. For further details visit: www.muhc.ca/research.
The McGill University Health Centre (MUHC) is a comprehensive academic health institution with an international reputation for excellence in clinical programs, research and teaching. The MUHC is a merger of five teaching hospitals affiliated with the Faculty of Medicine at McGill University––the Montreal Children's, Montreal General, Royal Victoria, and Montreal Neurological Hospitals, as well as the Montreal Chest Institute. Building on the tradition of medical leadership of the founding hospitals, the goal of the MUHC is to provide patient care based on the most advanced knowledge in the health care field, and to contribute to the development of new knowledge. www.muhc.ca
Journal
Proceedings of the National Academy of Sciences