Photo by Elise Amendola
Blood for transfusion
A new study has revealed a previously unknown link between gastrointestinal flora and transfusion-related acute lung injury (TRALI).
“We observed that the composition of the gastrointestinal flora drives the pathogenic immune response in the lungs during TRALI,” said Rick Kapur, PhD, of Lund University in Lund, Sweden.
Dr Kapur and his colleagues described this discovery in Blood Advances.
The researchers compared 2 groups of mice. One group was kept in a strictly sterile environment, allowing the gastrointestinal flora to be minimally affected by external factors. The other group was raised in a normal, less sterile environment.
“We saw that the mice kept in a more sterile environment were resistant to TRALI development, while the less sterile-raised mice developed severe TRALI,” said study author John W. Semple, PhD, of Lund University.
The composition of the gastrointestinal flora was significantly different between the 2 groups of mice, as determined by genetic sequencing of stool.
When the researchers wiped out the gastrointestinal flora with several types of antibiotics, they found that mice in the less sterile environment did not develop TRALI.
The researchers also transplanted stool from mice that developed TRALI into TRALI-resistant mice. After the stool transplant, the resistant mice were also able to develop TRALI, which confirmed the link between the composition of the gastrointestinal flora and the onset of TRALI.
The researchers still need to clarify which specific gut bacteria are directly involved, but the knowledge that intestinal bacteria may affect the lungs could facilitate diagnostics and the development of potential new drugs.
The ability to easily assess the risk for TRALI via analysis of gastrointestinal flora is equally important, according to the researchers.
“Knowing the composition of the gastrointestinal flora of people who will receive blood transfusions, an analysis which can be easily performed today, would allow you to assess who may be at increased risk for developing TRALI,” Dr Kapur said.
“The TRALI model in mice is very similar to the condition in humans, and the next step will be to validate these findings in humans,” Dr Semple said. “It’s not often that these types of findings in mice can lead directly to clinical studies in humans, but that will be our aim.”