Objective

Community-acquired pneumonia (CAP) is a leading cause of hospitalisation in older adults and is associated with a high likelihood of adverse outcomes. Given the ageing population and lack of therapeutic advances in CAP, new strategies to manage the burden of this disease are needed. Neutrophil dysfunction has been widely demonstrated in CAP and is associated with poor outcomes. We hypothesised that impaired glycolytic metabolism was driving neutrophil dysfunction in older adults with CAP.

Setting

Adult acute hospital in England.

Design

This was a single-centre prospective observational study.

Participants

57 participants were recruited between November 2019 and August 2023.

Outcome

Participants with CAP and older adult controls were well matched for age, sex, ethnicity, clinical frailty score and major comorbidities known to influence neutrophil function.

Methods

To understand why neutrophils (a type of white blood cell) don’t work properly in older adults with community-acquired pneumonia (CAP) and sepsis, researchers compared them to both older adults without these conditions and healthy young adults. They looked at how well the neutrophil’s function and how they produce energy from sugar in the blood.

Results

It was found that neutrophils (a type of white blood cell) from older people with community-acquired pneumonia (CAP) have many problems, such as not moving correctly towards interleukin 8, having a weaker response to phorbol 12-myristate 13-acetate, and releasing their contents more often by themselves compared to healthy older people. The process of breaking down sugar for energy (glycolysis) didn’t show much difference between the older groups. However, the basic levels of this energy production were higher in both older people with CAP and healthy older adults compared to healthy young adults. When stimulated, young adults had a higher increase in glycolysis compared to older adults with or without CAP.

Conclusions

The findings suggest that neutrophil dysfunction in older adults with CAP may be implicated in poor outcomes, irrespective of glycolytic metabolism.