A study carried out at the Michael G. DeGroote Institute for Infectious Disease Research at McMaster University demonstrated that antibiotics might not be sufficient to treat pneumonia in aging patients. Researchers reported that inflammation that occurs naturally with aging includes a higher risk of developing pneumonia.

The study was published in the journal PLOS Pathogens under the title “TNF Drives Monocyte Dysfunction with Age and Results in Impaired Anti-pneumococcal Immunity,” and was funded by the Canadian Institutes for Health Research (CIHR), an Ontario Early Researcher Award and a Pfizer-Aspire Research Award.

Aging is associated with a chronic and basic level of inflammation, also known as “inflamm-aging.” This basic level of inflammation is highly associated with diseases like dementia, cardiovascular disease, and infections, especially pneumonia. In older people, when inflammation is required to fight an infection, the already enhanced inflammatory state of the patient increases even further and may remain afterwards. Exposure to these high levels of inflammation seems to impair the capacity of white blood cells to fight the infection.

Using animal models, Dr. Dawn Bowdish and co-workers found that the elevated levels of inflammation in old mice caused white blood cells to enter the bloodstream in an immature form, leading to an even greater level of inflammation. Lowering the level of inflammation in the young mice had no effect, but reducing the levels in the old ones helped them fight the infection.

“It sounds counter-intuitive to limit inflammatory responses during a bacterial infection, but clinical observations and our research indicates anti-bacterial strategies need to be tailored to the age of the patient,” Bowdish, the study’s senior author and associate professor for pathology and molecular medicine, said in a press release.

The research was based on a previous study reporting that older adults with pneumonia got better after treatment with antibiotics combined with corticosteroids to reduce inflammation.

“Our study in mice is consistent with clinical studies that recommend using anti-inflammatories as part of treatment to improve older adults’ defense against pneumonia, and that points to the development of better care,” Bowdish said.