Published Online March 7, 2013
Chronic rhinosinusitis (CRS) is characterized by chronic inflammation of the sinonasal mucosa that persists for at least 12 weeks despite medical therapy, and affects up to 10% of the US population. CRS is often divided into two clinically and phenotypically distinct classifications: CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). Despite the high incidence of this disease, the pathology of CRS is not well understood, and treatment options are limited resulting in a significant loss in quality of life and a large financial burden on the health care system. It is clear, however, that defects in innate immunity along with chronic activation of a variety of inflammatory cells are two factors that play roles in the pathogenesis of CRS.
A new study in a recent issue of The Journal of Allergy and Clinical Immunology (JACI) by Hulse et al. theorized that B cells may play an important role in the pathogenesis of CRS. They used flow cytometry to analyze B lineage cell populations from uncinate tissues (UT) from control and CRS patients, and nasal polyps (NP) from CRSwNP patients. The authors also measured levels of a variety of antibody isotypes, expression of the polymeric immunoglobulin receptor (pIgR), and expression of Epstein Barr Virus-induced protein 2 (EBI2), which has been shown to play an important role in the development of antibody responses.
The authors found significant elevations of B cells and plasma cells in NP, compared to control UT. Interestingly, most antibody isotypes were also highly significantly elevated in NP, suggesting local production. However, pIgR expression was diminished in NP, and antibody levels were not significantly increased in nasal lavage fluid from patients with CRS. Finally, EBI2 expression was highly elevated in NP and correlated with expression of plasma cell markers.
These data suggest that B lineage cells, and their antibody products, may play an important role in the pathogenesis of CRS. The high levels of antibodies found in NP may activate local innate immune cells and exacerbate local inflammation. Furthermore, elevated levels of EBI2 may play a role in promoting the activation and maturation of B cells into antibody-secreting cells, and may present a novel target for the design of new therapeutic strategies for the treatment of CRS. Taken together, these findings indicate that B cell inflammatory responses occur locally in NP, may play a critical role in the pathogenesis of CRSwNP, and may provide novel insights for the development of improved therapeutic interventions.
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.