Inflammatory signatures in elderly CRS patients have significant treatment implications

Published online: November 20, 2018

Chronic rhinosinusitis (CRS) is a highly prevalent inflammatory disease that can affect individuals of any age group, although recent research suggests that it may be more common in older patients. As the population of the U.S. ages, treatment of these patients may present an impending challenge to health care providers and the greater health care economy. For example, common treatments for CRS such as antibiotics and corticosteroids are associated with increased risks of adverse complications in elderly patients, requiring practitioners to be more targeted when treating CRS in this group. Thus, there is an urgent need to develop more effective treatment options for CRS in the elderly population, a goal that will require improving both our general understanding of CRS pathophysiology and the aspects of the disease that are unique to older patients.   
 
In a recent study published in The Journal of Allergy and Clinical Immunology (JACI) Morse and colleagues assessed whether the type of inflammation in CRS varies with age. Patients with CRS who had failed medical management and elected to pursue endoscopic sinus surgery were prospectively enrolled in the study. Demographic and disease-specific data were recorded and levels of different inflammatory markers were measured in mucus collected from each patient at the time of surgery. The enrolled cohort was then clustered into groups (endotypes) based on similarities among the inflammatory markers identified in their mucus. The immune signatures of each endotype were then evaluated to identify potential relationships with age and other factors.   

Interestingly, one of the five identified endotypes was particularly enriched with older patients, with 70% aged 60 or older.  This cluster of patients was associated with elevated IL-1b, IL-6, IL-8, and TNF-a, cytokines linked with activation of the body’s innate immune system in the setting of both acute and chronic inflammation. A similar inflammatory pattern was identified in the overall cohort, with relatively consistent levels of these pro-inflammatory cytokines in younger patients, that subsequently increased longitudinally after age 60. Tissue eosinophils, which are key mediators of CRS in many patients, were reduced in aged patients, who instead were more likely to have neutrophilic tissue inflammation. Finally, older patients were more likely to have sinus cultures positive for pathogenic organisms and experience chronic bacterial colonization of the sinonasal tract. In older patients, this characteristic was closely linked to levels of the pro-inflammatory cytokines IL-1b and IL-8, while a similar relationship was not observed in their younger counterparts.

Overall, the authors showed that elderly CRS patients have a unique inflammatory signature characterized by select pro-inflammatory cytokines, neutrophilic tissue infiltration, and reduced ability to clear pathogenic bacteria from the sinonasal tract. Ultimately, this inflammatory pattern suggests that elderly patients may be less likely to respond to corticosteroids and may instead benefit from treatments targeting the innate immune response to microbial pathogens.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

Graphical Abstract

18-00901, Chronic rhinosinusitis in elderly patients is associated with an exaggerated neutrophilic pro-inflammatory response to pathogenic bacteria