A clinical study of olfactory dysfunction in patients with Mikulicz's disease

Effects of Corticosteroid Treatment on Olfactory Dysfunction in LATY136F Knock-In Mice

OBJECTIVE

Immunoglobulin G4-related disease (IgG4-RD) is a systemic inflammatory condition affecting multiple organs, including the pancreas, salivary glands, lungs, kidneys, skin, and lymph nodes. Clinically, it is characterized by elevated serum IgG and IgG4 levels and tissue infiltration by IgG4-positive plasma cells, lymphocytes, fibrosis, and phlebitis obliterans. IgG4-RD is linked to increased Th2-dominant cytokines, contributing to eosinophilia, elevated serum IgG4, and fibrosis. A notable feature is its good response to corticosteroid therapy. To investigate the effects of corticosteroid treatment on olfactory dysfunction in LATY136F knock-in mice, which exhibited increased production of Th2-type IgG1 (the murine homolog of human IgG4) and developed multiorgan tissue lesions similar to those observed in IgG4-RD patients.

METHODS

LATY136F knock-in mice (n=24) were divided into groups that received prednisolone or saline at different ages. Olfactory function was assessed using a behavioral test with cycloheximide. Histological and immunohistochemical analyses were performed to evaluate the olfactory epithelium thickness as well as the presence of mature and immature olfactory neurons.

RESULTS

Corticosteroid-treated mice exhibited significantly improved olfactory function compared to the controls. Histological analysis revealed a significant increase in olfactory epithelium thickness and mature (olfactory marker protein-positive) and immature (growth-associated protein 43-positive) olfactory neurons in the treated groups compared with the control group.

CONCLUSION

Corticosteroid treatment effectively improved olfactory dysfunction and promoted olfactory epithelium regeneration in LATY136F knock-in mice, suggesting the potential therapeutic benefits of corticosteroid treatment for patients with IgG4-RD experiencing olfactory dysfunction. However, further research on topical nasal steroid therapy in untreated patients is warranted. The results support further investigation into topical nasal steroid therapies for treating olfactory dysfunction in untreated patients, potentially influencing clinical practice and patient management strategies for IgG4-RD globally.

New insights into chronic rhinosinusitis associated with IgG4-related disease

IgG4-related disease (IgG4-RD) is a chronic inflammatory disorder characterized by elevated IgG4 serum levels, abundant IgG4-positive plasmacyte infiltration, and fibrosis of various organs, including the head and neck. We aimed to provide an overall review of IgG4-RD in the sinonasal region and propose a novel entity and criteria of chronic rhinosinusitis (CRS) associated with IgG4-RD as "IgG4-CRS," a distinct manifestation of IgG4-RD in the sinonasal region. Sinonasal involvement has been increasingly recognized; however, this region is not included in the classic IgG4-RD-affected organs. The clinical features of IgG4-CRS, including its prevalence and relationship with allergies and olfactory disturbances, have also been explored. Serum IgG4 levels and IgG4-positive plasma cell infiltrations, crucial diagnostic factors, have been discussed in association with IgG4-CRS pathogenesis. Fibrosis, a hallmark of IgG4-RD, is observed in sinonasal tissues; however, typical fibrosis, such as storiform fibrosis, is not usually found. Mimics or complications in eosinophilic CRS (ECRS) and antineutrophil cytoplasmic antibody-associated vasculitis (AAV) are highlighted. Treatment often involves typically effective glucocorticoids. Organ-specific diagnostic criteria for the sinonasal region have not currently been established. Hence, this review aims to foster awareness and understanding of IgG4-CRS among ENT physicians and to provide a basis for future research and diagnostic refinement.

Smell and Taste Function and Their Disturbances in Sjögren's Syndrome

Chemosensory disorders are a possible disturbance in Sjögren's syndrome (SS). The aim of the study is to comprehensively present chemosensory disorders in SS and to indicate their possible causes. The possible causes of taste and smell disorders in SS are changes in the structure of exocrine glands and their dysfunction, damage to receptors and weakening of their ability to regenerate, and neurological changes in the form of peripheral neuropathy and impaired cognitive function. Other postulated causes of chemosensory disorders are autoimmune mechanisms, adverse effects of drugs used in SS, and primary potentially SS-triggering viral infections. They are multifactorial and may occur independently of each other. The time of their onset and correlation with other disease symptoms may facilitate the determination of their primary cause in each patient. Awareness of chemosensory disorders in SS may help to ease their progress and eliminate other factors responsible for their more severe manifestation. In the prevention and treatment of chemosensory disorders in SS, the most important thing is to alleviate xerostomia and dryness in the nasal cavity and their effects in the form of chronic local inflammations, counteract receptor atrophy, and an implementation of appropriate neurological diagnosis and treatment.

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

Olfactory dysfunction in primary Sjogren's syndrome and its correlation with dry eye

Objective

To evaluate the olfactory function in primary Sjögren’s syndrome (pSS) patients and investigate its correlation with dry eye parameters.

Methods

Thirty-eight pSS patients (49.47 ± 10.06 years) and 20 healthy volunteers (47.40 ± 8.92 years) were enrolled in the study. All participants underwent ENT and eye examinations including a modified Connecticut Chemosensory Clinical Research Center (CCCRC) test, tear break-up time (TBUT), ocular surface staining (OSS) and Schirmer test. The parameters were compared between the two groups using Student-t test, and Pearson test was used to evaluate the correlations.

Results

Mean Schirmer and TBUT values were 2.39 ± 1.48 mm/5 min and 3.66 ± 1.5 sec in pSS and 18.30 ± 6.16 mm/5 min and 14.60 ± 3.64 sec in healthy subjects (p < 0.001, both). There was a significant decrease in mean odour threshold, odour identification, CCCRC and VAS scores in the pSS group (p < 0.001). Dry eye parameters showed moderate correlations with CCCRC parameters (r = 0.4-0.6, p < 0.001) and olfaction VAS score (r = 0.4-0.75, p < 0.05).

Conclusions

There is a mild clinical impairment in smell sense in patients with pSS which seems to be correlated with dry eye parameters. Therefore, smell complaints should be queried in pSS patients suffering from severe dry eye.

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.

Increased Expression of Activation-Induced Cytidine Deaminase in Sinus Mucosa from IgG4-Related Disease Patients with Comorbid Chronic Rhinosinusitis

OBJECTIVE

IgG4-related disease (IgG4-RD) is a systemic condition characterized by an elevated serum IgG4 level, localized infiltration of IgG4-positive plasma cells, and lesions in various organs. IgG4-RD also shows high rates of complication with allergic diseases and is often accompanied by elevated serum IgE levels. Reports in recent years have also shown high rates of complication with chronic rhinosinusitis (CRS) and its characteristic nasal manifestations. Accordingly, we speculate that there may be a distinct form of CRS that, as an IgG4-RD, differs from other CRS. Here, we investigated whether the elevated levels of factors that are thought to be important in the pathogenesis of IgG4-RD are also seen in the sinus mucosa of IgG4-RD-associated CRS patients.

METHODS

Ethmoid sinus mucosa specimens from 9 IgG4-RD (6 Mikulicz disease and 3 Küttner's tumor) patients with elevated serum IgG4 and IgE and from 22 control CRS patients were examined immunohistochemically for Treg cytokines (IL-10 and TGF-β), activation-induced cytidine deaminase (AID), and immunocompetent cells. The 22 control CRS patients were divided into 3 subgroups based on the serological findings for IgG4 and IgE. Quantitative real-time PCR was performed to examine the expression of AID.

RESULTS

The ethmoid sinus mucosa from patients with IgG4-RD-associated CRS showed, in comparison with the 3 CRS control subgroups, significantly elevated AID production. Their mucosa also showed significantly increased infiltration of CD-20-positive immunocompetent cells compared with the controls. On the other hand, immunohistochemical examination found no significant differences in the number of IL-10- or TGF-β-positive cells.

CONCLUSION

Ethmoid sinus mucosa from IgG4-RD-associated CRS patients showed clearly increased AID production, suggesting AID involvement in class-switching to IgG4 in those local sites. This implies the existence of a distinct form of CRS that is an IgG4-RD.

The prevalence of extra-salivary gland complications in immunoglobulin G4-related sialadenitis

OBJECTIVES

To estimate the prevalence of extra-glandular lesions in patients with immunoglobulin G4-related sialadenitis (IgG4-RS).

METHODS

Six electronic databases (PubMed, EMBASE, Science Direct, Scopus, Web of Science, and China National Knowledge Infrastructure) were systematically searched from the date of inception of each database to March 2021. The Strengthening the Reporting of Observational Studies in Epidemiology statement was used to conduct methodological quality assessment, and a random-effect meta-analysis model was applied to estimate the prevalence. Publication bias was visually assessed using a funnel plot and calculated via Begg's and Egger's tests. The Stata 15 software was used to perform data analysis.

RESULTS

A total of 43 articles comprising 1,864 patients with IgG4-RS were considered to be eligible for this study. The pooled prevalence of extra-salivary gland lesions in IgG4-RS was 76.53% with a confidence interval (CI) of (69.39%, 83.04%). A higher prevalence was associated with studies published before or during 2015 (84.38%, CI [74.23%, 92.58%]) than those published after 2015 (68.55%, CI [58.44%, 77.88%]). Lacrimal gland involvement (54.68%, CI [45.61%, 63.60%]) and lymph node swelling (56.96%, CI [48.16%, 65.56%]) were the most frequent lesions.

CONCLUSIONS

Extra-glandular lesions were common in patients with IgG4-RS. More high-quality prospective studies with less heterogeneity are required to determine the accurate prevalence.

Systemic diseases and disorders

Alterations in the ability to smell or taste are of considerable consequence, impacting quality of life, safety, nutrition, and dietary activities. These primary senses are influenced by a wide range of systemic diseases and disorders that commonly involve the entire body. These include viral, bacterial, fungal, protozoal, cestode, and nematode infections that can spread throughout the gastric, lymphatic, neural, or circulatory systems as well as classic autoimmune disorders, collagen diseases, diabetes, and hypertension, and others. Although a considerable literature has evolved in which the function of both taste and smell has been assessed in a number of such disorders, quantitative chemosensory testing is still relatively rare with many disorders not receiving empirical assessment. Incongruent findings are not uncommon. This chapter reviews what is known about the influences of a wide spectrum of systemic diseases and disorders on the abilities to taste and smell.

Olfactory function in systemic lupus erythematosus and systemic sclerosis. A longitudinal study and review of the literature

BACKGROUND/PURPOSE

To evaluate olfactory function in systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and healthy controls over a 2-year period, and to determine the association of olfactory dysfunction with age, disease activity, disease damage, treatment, anxiety and depression symptoms and limbic structures volumes.

METHODS

Consecutive SLE and SSc patients were enrolled in this study. Clinical, laboratory disease activity and damage were assessed according to diseases specific guidelines. Olfactory functions were evaluated using the Sniffin' Sticks test (TDI). Volumetric magnetic resonance imaging (MRI) was obtained in a 3T Phillips scanner. Amygdalae and hippocampi volumes were analyzed using FreeSurfer® software.

RESULTS

We included 143 SLE, 57 SSc and 166 healthy volunteers. Olfactory dysfunction was observed in 78 (54.5%) SLE, 35 (59.3%) SSc patients and in 24 (14.45%) controls (p<0.001) at study entry. SLE and SSc patients had significantly lower mean in all three phases (TDI) of the olfactory assessment when compared with healthy volunteers. In SLE, the presence of olfactory dysfunction was associated with older age, disease activity, higher anxiety and depression symptoms score, smaller left hippocampus volume, smaller left and right amygdalae volume and the presence of anti-ribosomal P (anti-P) antibodies. In SSc the presence of olfactory impairment was associated with older age, disease activity, smaller left and right hippocampi volumes and smaller right amygdala volume. Olfactory function was repeated after a 2-year period in 90 SLE, 35 SSc and 62 controls and was stable in all three groups.

CONCLUSION

Both SLE and SSc patients with longstanding disease had significant reduction in all stages of TDI that maintained stable over a 2-year period. Olfactory dysfunction was associated with age, inflammation and hippocampi and amygdalae volumes. In SLE, additional association with anti-P, anxiety and depression symptoms was observed.

Increased number of IgG4-positive plasma cells in chronic rhinosinusitis

CONCLUSION

High levels of IgG4-positive plasma cells were observed in tissue samples from ∼30% of patients with chronic rhinosinusitis who satisfied the comprehensive diagnostic criteria for IgG4-related disease. Detection of increased numbers of IgG4-positive plasma cells in the nasal cavity or paranasal sinuses might not be sufficient to make a diagnosis of IgG4-related rhinosinusitis, and a comprehensive evaluation is required.

OBJECTIVES

This study aimed to clarify the clinicopathological characteristics of IgG4-positive plasma cells in patients with chronic rhinosinusitis.

METHOD

This study examined nasal mucosal specimens from 35 patients and assigned them to high-IgG4 and low-IgG4 groups based on infiltration of IgG4-positive plasma cells. It compared the pathological characteristics of the two groups, including the presence of fibrosis, phlebitis, hyperplasia of the nasal glands and infiltration of inflammatory cells.

RESULTS

No cases of chronic rhinosinusitis showed storiform fibrosis or obliterative phlebitis. The mean number of IgG4-positive plasma cells in samples from all patients was 29.8 ± 40.3/high-power field. Eleven of the 35 cases (31.4%) were classified as high-IgG4. Hyperplasia of the nasal glands was observed significantly more frequently in the high-IgG4 group than in the low-IgG4 group (p = .03).

Recent advances in knowledge regarding the head and neck manifestations of IgG4-related disease

IgG4-related disease (IgG4-RD) is a chronic inflammatory disorder, characterized by elevated serum IgG4 levels as well as abundant infiltration of IgG4-positive plasmacytes and fibrosis in various organs, including the head and neck region. In particular, the salivary glands, orbit, and thyroid are common sites of disease involvement. IgG4-RD is diagnosed based on various clinical, serological, and histopathological findings, none of which are pathognomonic. Hence, various differential diagnoses, which exhibit elevated serum IgG4 levels and infiltration of IgG4-postive cells into tissues, need to be excluded, especially malignant diseases and mimicking disorders. Systemic corticosteroids are generally effective in inducing IgG4-RD remission; however, recurrent or refractory cases are common. In addition, although the pathogenic mechanisms of IgG4-RD remain unclear, an antigen-driven inflammatory condition is believed to be involved. Recent studies have indicated the important pathogenic role of B cell/T cell collaboration and innate immunity in this disease. Nevertheless, additional research and discussions are needed to resolve many remaining questions. In this review, we provide an overview of the recent insights on the history, clinical features, diagnosis, and treatment of IgG4-RD in the head and neck region. Furthermore, we have also addressed the pathogenesis of this disease.

New chemosensory component in the U.S. National Health and Nutrition Examination Survey (NHANES): first-year results for measured olfactory dysfunction

The U.S. NHANES included chemosensory assessments in the 2011-2014 protocol. We provide an overview of this protocol and 2012 olfactory exam findings. Of the 1818 NHANES participants aged ≥40 years, 1281 (70.5 %) completed the exam; non-participation mostly was due to time constraints. Health technicians administered an 8-item, forced-choice, odor identification task scored as normosmic (6-8 odors identified correctly) versus olfactory dysfunction, including hyposmic (4-5 correct) and anosmic/severe hyposmic (0-3 correct). Interviewers recorded self-reported smell alterations (during past year, since age 25, phantosmia), histories of sinonasal problems, xerostomia, dental extractions, head or facial trauma, and chemosensory-related treatment and changes in quality of life. Olfactory dysfunction was found in 12.4 % (13.3 million adults; 55 % males/45 % females) including 3.2 % anosmic/severe hyposmic (3.4 million; 74 % males/26 % females). Selected age-specific prevalences were 4.2 % (40-49 years), 12.7 % (60-69 years), and 39.4 % (80+ years). Among adults ≥70 years, misidentification rates for warning odors were 20.3 % for smoke and 31.3 % for natural gas. The highest sensitivity (correctly identifying dysfunction) and specificity (correctly identifying normosmia) of self-reported olfactory alteration was among anosmics/severe hyposmics (54.4 % and 78.1 %, respectively). In age- and sex-adjusted logistic regression analysis, risk factors of olfactory dysfunction were racial/ethnic minority, income-to-poverty ratio ≤ 1.1, education <high school, and heavy drinking. Moderate-to-vigorous physical activity reduced risk of impairment. Olfactory dysfunction is prevalent, particularly among older adults. Inexpensive, brief odor identification tests coupled with questions (smell problems past year, since age 25, phantosmia) could screen for marked dysfunction. Healthcare providers should be prepared to offer education on non-olfactory avoidance of hazardous events.

Nasal manifestations of IgG4-related disease: A report of two cases

IgG4-related disease (IgG4-RD) is a recently recognized clinical disease entity characterized by elevated serum IgG4, tumefaction, tissue infiltration of IgG4-positive plasma cells and fibrosis. IgG4-RD may occur, either synchronously or metachronously, in a variety of organs throughout the body. We describe herein two representative cases of the nasal manifestations of IgG4-RD, characterized by diffuse, crusty, erosive lesions on nasal mucosa. Oral steroid administration was effective in treating these nasal manifestations. We report a decrease in IgG4 positive plasma cell infiltrates in nasal mucosa biopsy specimens after steroid therapy, demonstrating that infiltration of IgG4-positive cells is reversible.

Smell and autoimmunity: a comprehensive review

The sense of smell is an ancient sensory modality vital for sampling and perceiving the chemical composition of surrounding environments. Olfaction involves a pathway of biochemical and electrophysiological processes, which allows the conversion of molecular information into sensations. Disturbances in the olfactory function have been investigated mainly in neurological/neurodegenerative disorders such as Alzheimer's and Parkinson's diseases; impaired sense of smell has been associated with depressed mood. Only recently, smell capability was tested in other diseases, particularly autoimmune diseases. Shoenfeld and colleagues opened this chapter showing that patients affected with systemic lupus erythematosus (SLE) have disturbances in their olfactory functions and revealed its association with neuropsychiatric manifestations of the disease. This evidence was confirmed in experimental models and replicated in other SLE populations. The connection between autoimmunity and the sense of smell was lately emphasized by studies on patients with Sjögren's syndrome and in patients with other autoimmune/immune-mediated diseases, such as polydermatomyositis, recurrent spontaneous abortion, and hereditary angioedema. Genetic susceptibility and hormonal and environmental factors may play a role in these conditions. Olfactory receptor gene clusters are located in proximity to key locus of susceptibility for autoimmune diseases such as the major histocompatibility complex, suggesting not only a physic linkage, but a functional association. Nonetheless, gender- and hormone-mediated effects are fundamental in the development of autoimmune diseases. The different connections between smell and autoimmunity, genes and hormones may suggest that this is another tessera of a mosaic which is waiting the answer of Oedipus.