DETROIT - Researchers at the Wayne State University School of Medicine have developed a novel screening tool that can differentiate between sarcoidosis and tuberculosis antigens. It could lead to earlier reliable diagnosis and treatment of both diseases, and may aid in the development or evaluation of a tuberculosis vaccine.
The non-invasive technique is now pending patent and answers the need to develop accurate tests to diagnose sarcoidosis and TB reliably and quickly.
"We show for the first time that immuno-screening of a library derived from sarcoidosis tissue, which we developed at Wayne State in Detroit, can differentiate between sarcoidosis and tuberculosis antigens. These results are extremely exciting and we believe these findings can revolutionize the fields of both TB and sarcoidosis," said study principal investigator Lobelia Samavati, M.D., associate professor of medicine and director of the Center for Sarcoidosis and Interstitial Lung Diseases.
The scientists spent two years developing the sarcoidosis library and two years completing the study. Study participants were from the Detroit area and included patients with tuberculosis being cared for by the Detroit Department of Health and Wellness Promotion.
"Sarcoidosis is an inflammatory granulomatous disease of unknown etiology affecting multiple organs, and is highly prevalent in Michigan and especially in Detroit. It affects younger adults, especially African-Americans, and can lead to severe morbidity and mortality," Dr. Samavati said.
The condition strikes between 20 and 50 of every 100,000 Americans annually, most of them between the ages of 20 and 40. Sarcoidosis attacks African-Americans at least 10 times more often than Caucasians, and women more often than men. Common symptoms include chest pain, a dry cough and shortness of breath. Researchers have not yet identified a cause or a cure for sarcoidosis, an inflammatory disorder of unknown origin. The condition, which manifests as abnormal clumps of immune cells called granulomas, can affect a number of organs such as lungs, brain, eyes and the skin. In some cases, the condition can go into remission without treatment. Extreme cases can require a heart or lung transplant. Physicians can only use invasive procedures such as tissue biopsy to diagnose sarcoidosis.
Tuberculosis remains a major global health problem. The World Health Organization estimates that more than one-third of the global population is infected with and/or carries M. tuberculosis, or Mtb, a typically dormant infection. Those infected are asymptomatic and non-contagious. Five percent to 10 percent of latent Mtb carriers will develop active TB, Dr. Samavati said.
"Therefore, it is important to appropriately diagnose and treat both latent TB infection and active TB disease, as well as to discriminate between non-infectious granulomatous such as sarcoidosis and TB. It is not only locally important but also it is important to control the level of contagion in the environment, and ultimately the health of the global population," she said. "Current available tests have low yield, especially in developing countries. The current mode of detection and diagnosis of Mtb is generally confirmed through a combination of three different diagnostic tools, such as tuberculin skin test, blood-based interferon-gamma or release assays, or IGRA. Most importantly, to diagnose active disease patients need to have a positive sputum culture to confirm Mtb infection. However, generally this gold standard diagnostic test takes about six weeks to get culture results back. This may lead to late diagnosis, late treatment and spreading of the bacteria."
Dr. Samavati and team outline their method in "Development of a T7 Phage Display Library to Detect Sarcoidosis and Tuberculosis by a Panel of Novel Antigens," an open-access article published in March in EBioMedicine, a new journal affiliated with The Lancet and Cell.
The scientists have now contacted the WHO to obtain a large collection of sera from patients with tuberculosis and those with latent TB from various countries.
The work is supported by a grant from the National Heart, Lung, and Blood Institute (R21 HL104481).
About Wayne State University School of Medicine
Founded in 1868, the Wayne State University School of Medicine is the largest single-campus medical school in the nation, with more than 1,000 medical students. In addition to undergraduate medical education, the school offers master's degree, doctoral and M.D.-Ph.D. programs in 14 areas of basic science to about 400 students annually. Connect with us on Facebook, Twitter @wsu_med_school and Pinterest.
Wayne State University is a premier urban research institution offering more than 380 academic programs through 13 schools and colleges to nearly 28,000 students.