BackgroundChronic rhinosinusitis (CRS) can be classified into CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRSwNP displays more intense eosinophilic infiltration and the presence of Th2 cytokines. Mucosal eosinophilia is associated with more severe symptoms and often requires multiple surgeries because of recurrence; however, even in eosinophilic CRS (ECRS), clinical course is variable. In this study, we wanted to set objective clinical criteria for the diagnosis of refractory CRS.MethodsThis was a retrospective study conducted by 15 institutions participating in the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC). We evaluated patients with CRS treated with endoscopic sinus surgery (ESS), and risk of recurrence was estimated using Cox proportional hazard models. Multiple logistic regression models and receiver operating characteristics curves were constructed to create the diagnostic criterion for ECRS.ResultsWe analyzed 1716 patients treated with ESS. To diagnose ECRS, the JESREC scoring system assessed unilateral or bilateral disease, the presence of nasal polyps, blood eosinophilia, and dominant shadow of ethmoid sinuses in computed tomography (CT) scans. The cutoff value of the score was 11 points (sensitivity: 83%, specificity: 66%). Blood eosinophilia (>5%), ethmoid sinus disease detected by CT scan, bronchial asthma, aspirin, and nonsteroidal anti‐inflammatory drugs intolerance were associated significantly with recurrence.ConclusionWe subdivided CRSwNP in non‐ECRS, mild, moderate, and severe ECRS according to our algorithm. This classification was significantly correlated with prognosis. It is notable that this algorithm may give useful information to clinicians in the refractoriness of CRS before ESS or biopsy.

Sublingual immunotherapy (SLIT) has been considered to be a painless and efficacious therapeutic treatment of allergic rhinitis which is known as type I allergy of nasal mucosa. Nevertheless, its mechanisms need to be further investigated. In this study, we constructed an effective murine model of sublingual immunotherapy in allergic rhinitis, in which mice were sublingually administered with ovalbumin (OVA) followed by intraperitoneal sensitization and nasal challenge of OVA. Sublingually treated mice showed significantly decreased specific IgE responses as well as suppressed Th2 immune responses. Sublingual administration of OVA did not alter the frequency of CD4+CD25+ regulatory T cells (Tregs), but led to upregulation of Foxp3- and IL-10-specific mRNAs in the Tregs of cervical lymph nodes (CLN), which strongly suppressed Th2 cytokine production from CD4+CD25− effector T cells in vitro. Furthermore, sublingual administration of plasmids encoding the lymphoid chemokines CCL19 and CCL21-Ser DNA together with OVA suppressed allergic responses. These results suggest that IL-10-expressing CD4+CD25+Foxp3+ Tregs in CLN are involved in the suppression of allergic responses and that CCL19/CCL21 may contribute to it in mice that received SLIT.

OK-432, a preparation of a low-virulence strain (Su) of Streptococcus pyogenes (Group A) killed by a penicillin and lyophilized, is a stiff inducer of Th1 cytokines, and exerts anti-cancer effects in tumor-bearing mice. OK-432 has been reported to consist of many bacterial components, such as peptidoglycan, M-protein, etc. However, it is yet to be ascertained which bacterial component induces T helper 1 (Th1) responses. For the last decade, Toll-like receptor (TLR) family proteins are well elucidated to play a role in recognizing bacterial components and inducing interleukin (IL)-12 from macrophages. Above all, peptidoglycan seems to be the agonist of TLR2 rather than the obverse. In our present study, the role of TLR2 for the recognition of OK-432 by macrophages and the effects of OK-432 are examined on murine allergic rhinitis model. Interestingly, results show IL-12 production by macrophages derived from TLR2 knock-out (ko) mice was significantly decreased, in comparison with that of macrophages derived from wild-type mice. Moreover, in TLR2 ko mice, no regulatory effect of OK-432 was observed on an allergic rhinitis model. These data indicate that TLR2 signaling is involved in regulating OK-432-induced anti-T helper 2 (Th2) immunity, and may offer a new prophylactic and therapeutic approach using OK-432 to downregulate allergic disorders, such as allergic rhinitis.

Sublingual immunotherapy has been considered to be a painless and effective therapeutic treatment for allergic rhinitis, and is known as type 1 allergy of the nasal mucosa. So far, its mechanism of action has been elucidated employing peripheral blood serum and lymphocytes in an antigen-specific fashion. Because of the limitations in sampling human materials, there is still controversy among many reports between clinical efficacy and laboratory data. Therefore, its mechanism of action needs to be investigated further by using promising animal models such as rodents and monkeys. Bearing this in mind, in our present study, we successfully constructed an effective murine model for sublingual immunotherapy in allergic rhinitis in which mice were administered ovalbumin (OVA) sublingually followed by intraperitoneal sensitization and nasal challenge.