The new tool that the researchers have now tested is based on the activity of three specific genes that can be analyzed in capillary blood. An innovative, semi-automated system is used to determine a so-called transcriptional signature of these genes. This transcription signature can help to diagnose tuberculosis. The test has the advantage that the blood sample can simply be taken from the fingertip and the result can be determined very quickly: "The result is available in just over an hour. With most other tests, you first have to send the samples to other laboratories," says Olbrich.
The researchers tested the new tool as part of the extensive RaPaed TB tuberculosis study led by Heinrich together with cooperation partners in South Africa, Mozambique, Tanzania, Malawi and India. A total of 975 children under the age of 15 who were suspected of having tuberculosis were included in the study. To determine the accuracy of the test, the researchers also examined the children's tuberculosis status using a standardized reference test based on the examination of sputum and cultivation of the bacteria.
"The results were encouraging," says Olbrich. "The test identified almost 60 percent of children with tuberculosis compared to cultural detection, with a 90 percent specificity. This makes the new test comparable to or better than all other tests that work with biomarkers. The bacterial culture is always the reference because it provides the most stable results. But it takes up to eight weeks and is usually not available locally." Since the reference signature was largely determined on adults, the researchers also assume that the test results can be further improved if the signature used for the test is adapted for children.
Original announcement: LMU, 31.10.2023