Simple Blood Test Quickly and Accurately Diagnoses Potentially Life-Threatening Inflammatory Disease

By LabMedica International staff writers
Posted on 23 Feb 2024

Image: Scientists have developed a simple blood test to quickly diagnose sarcoidosis (Photo courtesy of 123RF)

Sarcoidosis, a chronic inflammatory condition characterized by small lumps known as granulomas in the lungs and other organs, remains a medical mystery with its exact cause yet to be understood. Current theories suggest it might be an immune disorder triggered by specific antigens, usually foreign substances that provoke an immune response. Diagnosing sarcoidosis is currently a complex process that typically involves tissue removal and testing, accompanied by additional screenings to exclude other conditions like tuberculosis or lung cancer. Now, researchers have developed a tool that uses a simple blood test to rapidly and inexpensively diagnose sarcoidosis, potentially reducing the need for more invasive diagnostic techniques presently used to detect the disease.

In a research project supported by the National Institutes of Health (NIH, Bethesda, MD, USA), researchers at Wayne State University (Detroit, MI, USA) set out to identify antigens and determine which might be linked to sarcoidosis. They collected lung fluid and blood cell samples from patients with pulmonary sarcoidosis and extracted genetic material from these samples. Through a series of molecular techniques, the team successfully identified two novel antigen biomarkers specific to sarcoidosis, which bind only to antibodies found in sarcoidosis-positive patients.

Subsequently, the team developed a highly specific blood test that requires only a small blood sample to detect sarcoidosis accurately. To evaluate the effectiveness of their test, the researchers analyzed blood samples from a diverse group of 386 individuals, including patients diagnosed with sarcoidosis, tuberculosis, lung cancer, and healthy controls. Their findings confirmed that the test could effectively distinguish individuals with sarcoidosis from those with other respiratory diseases, marking a significant advancement in the diagnosis of sarcoidosis.

“Currently, diagnosing sarcoidosis isn’t a straightforward process, and requires tissue removal and testing with additional screenings to rule out other diseases, such as tuberculosis or lung cancer,” said James Kiley, Ph.D., Director of the Division of Lung Diseases at the National Heart, Lung, and Blood Institute, part of NIH. “Using a blood test will help diagnose faster, particularly in those organs that are more challenging to biopsy and with less harm to the patient.”

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