EC Pulmonology and Respiratory Medicine

Background: Dysphagia has been shown to trigger recurrent aspiration pneumonia in elderly persons. It is well known that abnormal cytokine production by innate immune disorders is involved in the pathogenesis of aspiration pneumonia. Elderly persons with repeated episodes of silent aspiration can develop chronic lung inflammation by producing inflammatory cytokines. Swallowing disorder scores and serum and/or induced-sputum cytokine levels were compared in elderly patients.

Methods: The subjects were 108 patients aged 70 years or older (51 males, 57 females; age 76.09 ± 8.15 years) who underwent videofluoroscopic swallowing examinations from April 1, 2015 to March 31, 2018. A total of 37 cases (18 males, 19 females; 78.5 ± 4.1 years) were included in this analysis. Serum and induced-sputum concentrations of neutrophil elastase (NE), osteopontin, interleukin (IL)-17A, hypoxia- induced factor-1alpha, and IL-36 gamma were measured by enzyme-linked immunosorbent assays. Overall, 29 patients had dysphagia, and the control group without dysphagia had 8 cases. These patients’ health status was followed for 2 years after the measurements.

Results: Induced-sputum NE, IL-36 gamma, IL-17A, and osteopontin levels were higher in the dysphagia group than in the control group. There was a weak positive correlation between dysphagia scores and induced-sputum osteopontin and NE levels. Of the 37 patients, 7 developed aspiration pneumonia during the 2-year follow-up period. The sputum osteopontin level was higher in recurrent aspiration pneumonia cases.

Conclusion: These findings suggest that higher induced-sputum NE and osteopontin levels might correlate with micro-aspiration and pneumonia in elderly persons.

Keywords: osteopontin, elderly, aspiration pneumonia, swallowing disorder, neutrophil elastase

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