Approximately 240,000 children worldwide die from tuberculosis each year, making it one of the top ten causes of death in children under five. One of the main reasons is that tuberculosis is often misdiagnosed or not diagnosed in a timely manner, particularly in resource-limited areas. An international research consortium led by Laura Olbrich and Norbert Heinrich of the University of Munich conducted a large-scale study in five countries, testing a novel diagnostic tool that provides crucial information for diagnosing pediatric tuberculosis.
As is well known, the most common method for detecting tuberculosis is based on the microbiological analysis of sputum (mucus extracted from the lower respiratory tract). However, obtaining such samples is challenging in pediatric patients. Additionally, pediatric tuberculosis often exhibits low bacterial load and nonspecific symptoms. Therefore, the development of tests suitable for pediatric detection is urgently needed.
In this study, researchers established a simple and rapid blood test. The test is based on the activity of three specific genes, which can be measured in capillary blood. These three genes are DUSP, GBP5, and KLF2. Simultaneously, an innovative semi-automated system enables healthcare professionals to identify the so-called transcriptomic features of these genes. These transcriptomic features can aid in diagnosing tuberculosis. The advantage of this test is that it can conveniently collect blood samples from the fingertip, and results can be obtained quickly.
Researchers tested the diagnostic accuracy of the new tool, the Mycobacterium tuberculosis host response (MTB-HR) box, which is a candidate test measuring three gene transcriptome features from finger blood. As part of the RaPaed-TB comprehensive tuberculosis study led by Heinrich, the research collaborated with partners in South Africa, Mozambique, Tanzania, Malawi, and India. The study included a total of 975 children under 15 years suspected of having tuberculosis. To determine the accuracy of the test, researchers also used standardized reference tests based on sputum and bacterial culture analysis to investigate the tuberculosis status of the children.
Compared to culture detection, this test identified nearly 60% of pediatric tuberculosis cases with a specificity of up to 90%. This positions the test to be comparable to or better than all other biomarker-based tests. Bacterial cultures serve as a reference that can yield stable results, but it takes up to eight weeks, and is often impractical in the locations where children with pulmonary tuberculosis are typically found.
