Pulmonary Sarcoidosis (SA) is a chronic inflammatory disease with no known aetiology that often results in a skin rash, shortness of breath and a persistent cough. A major clinical problem in hospitals is the diagnosis of sarcoidosis because the disease shares symptomatic, radiological and immune-pathological features with the more common disease, Tuberculosis (TB), which results from infection by Mycobacterium tuberculosis and affects a third of the world’s population. As Sarcoidosis is unresponsive to Tuberculosis therapy, a rapid and affordable diagnostic test which could discriminate between the two conditions would dramatically improve time to diagnosis and treatment for individuals with either condition.
- Using high-resolution mass spectrometry, the inventors quantitatively assessed serum profiles of people suffering from pulmonary forms of both SA and TB
- Proteomic screening identified 5 proteins that were statistically significant in SA and 122 in TB
- The protein CSF1R was found to be highly specific to SA and has not been reported as a serum marker for SA previously
- The in-patient ratio of SA biomarker (CSF1R) and TB biomarker (S100A8/A9) provided high diagnostic accuracy when explored by ELISA methods (AUC = 0.96) (Fig. 1a)
- A simple ELISA-based test has been developed that correlates well with MS data (Fig. 1b)
- This method appears to be more sensitive compared to transcriptomic signatures from whole blood
- The CSFR1/S100A8/A9 marker pair shows better differentiation when compared to a pair of markers composed of a known sarcoidosis marker (Chitotriosidase-1) and a known tuberculosis marker (Matrix metalloproteinase-9).