Researchers at Nationwide Children’s Hospital, Columbus, Ohio, have identified specific changes tuberculosis makes to a patient’s blood. The findings, published in the journal Nature, may make it possible to identify patients who will develop the disease.
The researchers used microarray technology to develop blood profiles in patients with the disease. Gene expression microarray technology can be used to help develop blood transcriptional signatures.
“Each infectious agent, be it a virus or a bacterium, interacts with human immune cells in unique ways by triggering proteins on white blood cells,” said Asuncion Mejias, MD, an investigator at the Center for Vaccines and Immunity in The Research Institute at Nationwide Children’s Hospital. “We can identify patterns among the white blood cell’s activated proteins and identify a unique ‘signature’ for each infectious agent.”
The study examined and compared blood drawn from patients in London and Cape Town, South Africa who had active TB, latent TB, or who did not have TB. The researchers developed genome-wide transcriptional profiles for each of the patients and discovered a distinct characteristic, or “signature,” of the blood from patients with active TB. Patient x-rays with this signature were consistent with signs of active TB.
The research team also found that a subset of latent TB patients had signatures similar to those in active TB patients.
“The signature of active TB, which was observed in 10-20% of latent TB patients, may identify those individuals who will develop disease, but longitudinal studies are needed to assess this,” said Octavio Ramilo, MD, also an investigator at the Center for Vaccines and Immunity in The Research Institute at Nationwide Children’s Hospital.
The transcriptional signature was diminished in active TB patients after two months and completely extinguished by 12 months after treatment. According to the researchers, these findings suggest that blood transcriptional signature of active TB patients could be used to monitor the effectiveness of a patient’s treatment.
Source: Nationwide Children’s Hospital