Research in PLOS Medicine gives hope for the development of a blood test able to distinguish TB from other conditions prevalent in HIV-infected and -uninfected African adults.

For the study, investigators took blood samples from adults with suspected TB who were eventually diagnosed with either TB, latent TB infection or another disease (where TB was considered in the differential diagnosis but then excluded). The blood transcriptional profiles were analyzed to identify signatures that could be used to calculate a disease risk score capable of differentiating TB from other conditions prevalent in HIV-infected and -uninfected African adults.

They found the disease risk score (DRS) had a high sensitivity (95%) and specificity (90%) for distinguishing TB from latent TB, and for distinguishing TB from other diseases. In the independent validation cohort, the researchers found that patients with TB could be distinguished from patients with latent TB and also from patients with other diseases.

Though promising, researchers note the need for further research, adding that “from a clinical perspective, a simple transcriptome-based test that reliably diagnoses or excludes TB in the majority of patients undergoing investigation for suspected TB, using a single blood sample, would be of great value, allowing scarce hospital resources to be focused on the small proportion of patients where the result was indeterminate.”

“The challenge for the academic research community and for industry is to develop innovative methods to translate multi-transcript signatures into simple, cheap tests for TB suitable for use in African health facilities,” researchers wrote.