Olfactory Dysfunction in IgG4-Related Disease.

IgG4-related disease is a newly recognized systemic disease, and its elucidation is progressing. However, little is known about its sinonasal manifestations. The aim of this study was to assess the olfaction of patients with IgG4-related disease. Twenty-five patients with IgG4-related disease underwent T&T olfactometry to measure olfactory function. We analyzed the clinical features, including serum IgG4 and IgE levels, involved organs, and sinonasal computed tomography scores to explore the etiology of olfactory dysfunction. Thirteen patients with IgG4-related disease were found to have moderate to severe olfactory dysfunction (52%). There were no differences in the clinical features between the olfactory dysfunction group and the normal group. In 7 patients, the inferior turbinate was biopsied to study the correlation between olfaction score and the number of IgG4-positive cells, but no such correlation was found. Six hyposmia patients recovered to a normal state. Five patients recovered after corticosteroid treatment and 1 recovered spontaneously. We found that the prevalence of olfactory dysfunction was high in patients with IgG4-related disease and that it could be reversed. Olfactory dysfunction appears to be a novel important manifestation of IgG4-related disease.

Olfactory dysfunction in LATY136F knock-in mice.

OBJECTIVE: This study examined olfactory dysfunction in LATY136F knock-in mice and its pathogenic mechanism. METHODS: The olfactory function of LATY136F knock-in mice was assessed by a behavioral test using cycloheximide solution, which has been used as a mice repellant because of its peculiar smell and unpleasant taste. The tests were administered to each group of LATY136F knock-in mice and WT mice at 8, 12, 16, 20, and 24 weeks of age. After the behavioral tests to evaluate olfactory function, the mice were sacrificed for evaluations by immunohistochemistry. RESULTS: Behavioral tests to evaluate olfactory function showed that the LATY136F knock-in mice had a statistically significant level of olfactory dysfunction (P < 0.05). Histological analysis showed that the thickness of the olfactory epithelium in these mice was thinner than that in the age-matched wild type mice. There was no IgG4-RD like lesion in the olfactory epithelium of LATY136F knock-in mice. Olfactory marker protein and growth-associated protein 43 expressions in the olfactory epithelium of the LATY136F knock-in mice were markedly lesser than those in the wild type mice (P < 0.05). CONCLUSION: The present study demonstrated that olfactory disturbances occurred in LATY136F knock-in mice. Furthermore, the mechanism was suggested to be reduced regeneration of the olfactory epithelium.

Immunoglobulin class switching to IgG4 in Warthin tumor and analysis of serum IgG4 levels and IgG4-positive plasma cells in the tumor.

We previously reported a case of immunoglobulin (Ig)G4-related immune inflammation in Warthin tumor. Increased serum IgG4 levels and tissue infiltration of IgG4-positive plasma cells are characteristics of IgG4-related disease (IgG4-RD), a newly emerging clinicopathological entity. However, the relationship between IgG4-RD and Warthin tumor remains to be elucidated. We aimed to investigate the involvement of systemic and local IgG4 production and class-switch recombination in Warthin tumor. We examined serum IgG4 levels and also analyzed the involvement of IgG4-positive plasma cells in Warthin tumors (18 cases) compared with those of pleomorphic adenomas (19 cases) as controls. Furthermore, in specimens of Warthin tumors (3 cases), pleomorphic adenomas (2 cases), and IgG4-RDs (2 cases), we examined messenger RNA expression of activation-induced cytidine deaminase, IgG4 germline transcripts and productive IgG4 by reverse transcription polymerase chain reaction. Serum IgG4 levels were increased in 5 of 18 Warthin tumors and not in any of the 19 pleomorphic adenomas. Infiltration of IgG4-positive plasma cells was detected in 4 Warthin tumors and none in the pleomorphic adenomas. Moreover, activation-induced cytidine deaminase, IgG4 germline transcripts, and productive IgG4 messenger RNA were found to be expressed in 2 of 3 Warthin tumors as well as IgG4-RDs by reverse transcription polymerase chain reaction, but not in pleomorphic adenomas. In conclusion, immunoglobulin class switching to IgG4 may be involved in the pathogenesis of Warthin tumor, and it is possible that certain inflammatory background with an immune reaction is involved in the pathogenesis of Warthin tumor.

Expression of interleukin-33 is correlated with poor prognosis of patients with squamous cell carcinoma of the tongue.

OBJECTIVE: The aim of this study was to clarify the role of IL-33 in tumor progression. METHODS: Surgical specimens from 81 patients with squamous cell carcinoma of the tongue were studied using immunohistochemistry. Primary tumor sections were analyzed for IL-33 and ST2 expression. To examine the influence of IL-33 on the microenvironment of the tumor, we determined the mast cell density (MCD) and microvessel density of the stroma. RESULTS: Patients with high IL-33 expression had a significantly worse prognosis (p=0.004). IL-33 expression was significantly elevated in patients with local and nodal recurrence (p=0.014 and p=0.019). ST2 expression was also associated with a worse prognosis (p=0.024) and was significantly elevated in patients with nodal recurrence (p=0.004). MCD was associated with worse prognosis (p=0.038) and correlated significantly with IL-33 expression (r=0.626, p<0.001). Micovessels in the stroma were significantly increased in the high IL-33 group (p<0.001). CONCLUSION: These data suggest that the IL-33/ST2 axis contributes to tumor aggressiveness and affects the tumor microenvironment. Immunohistochemical evaluation of IL-33 and ST2 is useful for identifying patients at a high risk for poor prognosis.

Warthin's tumor associated with IgG4-related disease.

Immunoglobulin G4-related disease (IgG4-RD) is an inflammatory condition associated with elevated serum IgG4 levels and tissue infiltration by IgG4-expressing plasma cells. Several inflammatory conditions associated with IgG4-RD have been reported. Warthin's tumor is a benign parotid gland tumor consisting of oncocytic epithelial cells and lymphoid stroma containing lymphoid follicles with reactive germinal centers. This is the first report describing a case of Warthin's tumor with possible involvement of IgG4-RD. The patient was a 71-year-old man presenting with swollen right parotid and bilateral submandibular glands. He had a history of a Warthin's tumor of the left parotid gland, autoimmune pancreatitis, and an inflammatory abdominal aortic aneurysm. Laboratory tests revealed a high serum IgG4 level. Histological examination of the resected parotid gland showed a Warthin's tumor and a nodule showing severe lymphocytic infiltration containing many IgG4-positive plasma cells. This case shows the possible involvement of Warthin's tumor with IgG4-RD.