Tuesday, April 2, 2013
A clinical picture of recalcitrant chronic rhinosinusitis
Dr. Daniel Hamilos [p1263-1264] discusses the importance of microbes (viruses, bacteria and fungi) in chronic rhinosinusitis [CRS] in this month’s issue [Journal of Allergy and Clinical Immunology 2013; 131(4):1263-1264] Starting with a case report, the author reviews the current state of knowledge of CRS with [CRSwNP] and without [CRSsNP] nasal polyposis and further discusses the definitions of refractory and recalcitrant CRS. CME questions are included at the end of the article.
Dr. Hamilos notes that eosinophilic inflammation is present to some degree in both CRSwNP and CRSsNP patients, whereas neutrophilia is more common in CRSsNP. While there is little evidence for persistent viral infection in CRS, there is evidence for persistent infection with Staphylococcus aureus and/or Pseudomonas aeruginosa in sinus tissue in roughly 80% of refractory CRS cases. The presence of these bacteria is often found in association with “biofilm” formation. The author discusses biofilm and studies showing that its presence is associated with more severe disease and poorer outcomes. The fungus Alternaria is also more frequently detected in CRS tissues than in tissues from healthy patients.
The author discusses the various components of innate and adaptive immunity that function in response to microbial colonization or infection in CRS patients. Examples of key observations include the presence of a Th2 inflammatory bias in CRSwNP that negatively impacts TLR-9 function. Dr. Hamilos wraps up commenting that more precise clinical characterization of CRS patients based on their microbial and immunological phenotype is needed to assist clinicians in designing more effective treatment strategies.