News briefs

Lung damage in ventilated pre-term infants may vary with gestational age

Assisted ventilation is crucial to supporting very pre-term babies, but the treatment often leads to chronic lung disease. While survival of pre-term babies has increased over the past 30 years, rates of chronic lung disease have remained static. Researchers from the Murdoch Children’s Research Institute have found that the type of injury caused by ventilation depends on the gestational age of the lungs. The findings, published in Scientific Reports, suggest that individualised respiratory support could reduce risks to infants. In a study undertaken in lambs, the investigators mapped protein changes in blood plasma following ventilation of lambs born at term, pre-term (less than 32 weeks), and very pre-term (less than 26 weeks). By examining blood samples taken during the first 60 minutes of life, the researchers found significant changes in coagulant and complement protein expression in the pre-term lambs. The researchers noted that these changes indicated the potential for progressive lung injury, and would inhibit the effectiveness of some treatments options, such as surfactant administration. In the study’s next phase, the investigators will examine the changes in the lungs of pre-term human infants.

https://www.nature.com/articles/s41598-018-30868-x

Natural killers may help keep tuberculosis in check

Higher levels of natural killer cells are associated with tuberculosis (TB) latency, according to research by a team including investigators from the University of Queensland and Stanford University School of Medicine, published in Nature. The findings raise the question of whether natural killer cells might play an active role in controlling TB infections. Most TB infections are latent; that is, they are manifested as a clinically asymptomatic, contained state. It is estimated that a quarter of the world’s population has latent TB, and fewer than 10% of latent TB infections eventually progress to an active state. The immune system factors that influence the outcome for an individual, however, are poorly understood. To investigate the immune state underlying latency and how it changes when the disease progresses, the investigators studied a number of human cohorts, combining high-dimensional mass cytometry analysis with an examination of gene expression datasets to identify differences in immune cell populations between uninfected people and those with latent or active TB. They found that latent TB was associated with higher numbers of natural killer cells — white blood cells that kill certain pathogens — with more marked antitoxin responses than uninfected individuals. In people with active infections, natural killer cell levels were lower, but returned to baseline levels when the infection was cured. However, the findings do not establish a causal relationship between natural killer cells and TB latency. Additionally, the authors found that measuring natural killer cell levels can indicate the activity level and burden of TB infection in a patient’s lungs, a finding that could help in assessing disease progression and optimising treatment.

https://www.nature.com/articles/s41586-018-0439-x