The clinical characteristics of patients with IgG4-related disease with infiltration of the labial salivary gland by IgG4-positive cells

18F-fluorodeoxyglucose PET and PET/computed tomography for the evaluation of immunoglobulin G4-related disease: a systematic review

BACKGROUND

In the last years, 18F-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) has demonstrated its utility for the evaluation of immunoglobulin G4 (IgG4)-related disease (IgG4RD). The studies are, however, really heterogeneous and different. The aim of this review is, therefore, to analyze the diagnostic performance of 18F-FDG PET and PET/CT for the assessment of IgG4RD.

METHODS

A wide literature search of the PubMed/MEDLINE, Scopus, Embase and Cochrane library databases was made to find relevant published articles about the diagnostic performance of 18F-FDG PET or PET/CT for the evaluation of IgG4RD.

RESULTS

The comprehensive computer literature search revealed 779 articles. On reviewing the titles and abstracts, 756 articles were excluded because the reported data were not within the field of interest. Twenty-three studies were included in the review.

CONCLUSION

Despite some limitations that affect our review, 18F-FDG PET or PET/CT demonstrated the ability to assess IgG4RD both at initial evaluation and after therapy. In general, no correlation between PET/CT parameters and IgG4 serum levels has been reported. A possible role for 18F-FDG PET/CT to drive differential diagnosis with other disease is starting to emerge.

Oral and maxillofacial manifestations of IgG4-related disease: A clinicopathological study

BACKGROUND

IgG4-related disease is a fibroinflammatory and immune-mediated condition, which has extremely variable clinical manifestations. In this study, we aim to investigate the clinicopathological features of IgG4-related disease involving the oral and maxillofacial region.

METHODS

Cases of IgG4-related disease manifesting in the oral and maxillofacial region were retrieved from three Brazilian institutions. Clinical and serological data were obtained from the patients' medical charts, while microscopic and immunohistochemical findings were revised by oral pathologists. Diagnosis followed the American College of Rheumatology/European League against Rheumatism criteria.

RESULTS

Seven patients diagnosed with IgG4-related disease were included in this study. Women were affected in all analysed cases, with a mean age of 55.4 years. Two patients presented with the clinical involvement of more than one oral and maxillofacial anatomic site. Therefore, our sample comprised nine oral and maxillofacial anatomic sites affected by IgG4-related disease. The submandibular gland was affected in four cases, the tongue and the parotid gland in two cases each, and the palate in one case. In a few cases, exploratory lower lip biopsy was used as a diagnostic approach. A moderate-to-severe lymphoid infiltrate containing plasma cells and lymphocytes, with an increased IgG4/IgG ratio, was common. Treatment varied and steroids were the most frequently used (57.4%). Six patients remained alive, while one died from unknown causes.

CONCLUSION

Although major salivary glands are commonly affected by IgG4-related disease, the oral cavity can also be involved, and lower lip biopsy may be an auxiliary diagnostic tool.

Abnormal [18F]fluorodeoxyglucose accumulation to tori tubarius in IgG4-related disease

OBJECTIVES

Tubarial glands (TGs) are recently refocused gland tissues localized near the tori tubarius in the nasopharynx and their clinical relevance is not clear yet. IgG4-related disease (IgG4-RD) is a progressive fibrosing condition and salivary glands are well-affected lesions. The aim of the present study is to examine [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) accumulation to the tori tubarius in IgG4-related disease (IgG4-RD).

METHODS

48 patients with IgG4-RD who underwent positron emission tomography (PET) scanning with [¹⁸F]FDG were included and semi-quantitative analysis of [¹⁸F]FDG accumulation to tori tubarius was performed along with the clinical features and histopathological analysis.

RESULTS

Of the 48 patients, abnormal [¹⁸F]FDG accumulation (metabolic tumour volume ≥ 1) to tori tubarius was observed in 15 (31.3%), all of whom had lesions in other head and neck glands. IgG4-RD patients with abnormal [¹⁸F]FDG accumulation to tori tubarius showed swollen nasopharyngeal walls around tori tubarius and forceps biopsy of the lesion revealed acinar cells and IgG4-positive plasma cells histologically. Abnormal [¹⁸F]FDG accumulation (maximum standard uptake value, metabolic tumour volume and total lesion glycolysis) to tori tubarius correlated with higher IgG4 and lower IgA serum concentrations.

CONCLUSIONS

Abnormal [¹⁸F]FDG accumulation to tori tubarius can be observed in patients with IgG4-RD and the abnormal [¹⁸F]FDG accumulation to tori tubarius can be a clue of TG involvement in IgG4-RD.

Application of Lip Biopsy for the Histological Diagnosis of Immunoglobulin G4-Related Disease

We describe the case of a 51-year-old woman with immunoglobulin G4-related disease (IgG4-RD) diagnosed using lip biopsy. She reported having bilateral submandibular nodules for a month. Magnetic resonance imaging showed diffuse swelling in the bilateral submandibular glands (SMGs), suggesting inflammatory changes. Laboratory data revealed an elevated level of serum IgG4. Fine needle aspiration cytology of the SMG showed a considerable number of lymphocytes with degeneration but did not demonstrate specific findings for a definitive diagnosis of IgG4-RD. Lip biopsy was performed, and a biopsy specimen from the labial salivary gland showed abundant lymphoplasmacytic infiltration with a large number of IgG4-positive cells. The patient was diagnosed with IgG4-RD based on histological and laboratory findings. Findings of further examinations revealed that the patient had autoimmune pancreatitis, confirming our diagnosis. Four months after prednisolone administration, improvement of the submandibular and pancreatic lesions was observed. One year after the initial presentation, the serum IgG4 level was normalized. In cases of IgG4-RD with salivary gland involvement, lip biopsy might be one of the options for the histological diagnosis of IgG4-RD.

Five Cases of IgG4-related Disease with Nasal Mucosa and Sinus Involvement

We herein report five patients with nasal mucosa and sinus involvement who were diagnosed with immunoglobulin G4-related disease (IgG4-RD). In all cases, the lacrimal, parotid, and submandibular glands were swollen; biopsies of these glands were risky, so the labium and nasal mucosa were instead targeted. All patients tested positive through these biopsies, suggesting alternative sites for confirming IgG4-RD. These five patients had first been diagnosed and unsuccessfully treated for allergic rhinitis or chronic sinusitis. After the IgG4-RD diagnosis, they were administered corticosteroid therapy, which drastically improved the nasal mucosa and sinus involvement. When refractory allergic rhinitis or sinusitis is detected, IgG4-RD should be considered.

[Dental-craniofacial manifestation and treatment of rare diseases in China]

Rare diseases are genetic, chronic, and incurable disorders with relatively low prevalence. Thus, diagnosis and management strategies for such diseases are currently limited. This situation is exacerbated by insufficient medical sources for these diseases. The National Health and Health Committee of China recently first provided a clear definition of 121 rare diseases in the Chinese population. In this study, we summarize several dental-craniofacial manifestations associated with some rare diseases to provide a reference for dentists and oral maxillofacial surgeons aiming at fast-tracking diagnosis for the management of these rare diseases.

Dental-craniofacial manifestation and treatment of rare diseases

Rare diseases are usually genetic, chronic and incurable disorders with a relatively low incidence. Developments in the diagnosis and management of rare diseases have been relatively slow due to a lack of sufficient profit motivation and market to attract research by companies. However, due to the attention of government and society as well as economic development, rare diseases have been gradually become an increasing concern. As several dental-craniofacial manifestations are associated with rare diseases, we summarize them in this study to help dentists and oral maxillofacial surgeons provide an early diagnosis and subsequent management for patients with these rare diseases.

Salivary Gland Pathology in IgG4-Related Disease: A Comprehensive Review

IgG4-related disease (IgG4-RD) is a rare fibroinflammatory condition that can affect almost any organ, characterized by swollen lesions and often by eosinophilia and elevated serum IgG4 concentrations. The diagnosis of IgG4-RD is a challenging task: in fact, single or multiple organs can be affected and clinical, serological, and histological findings can be heterogeneous. In IgG4-RD, the involvement of salivary glands is observed in 27% to 53% of patients. Several organ-specific conditions, now recognized as different manifestations of IgG4-related sialadenitis (IgG4-RS), were viewed in the past as individual disease entities. The study of salivary glands may sometimes be complex, because of the number of pathological conditions that may affect them, often with overlapping clinical pictures. Integration of different imaging techniques is often required in the case of swelling of salivary glands, even though biopsy remains the gold standard for a definite diagnosis of IgG4-RS. Thus, in this review, we discuss new insights in the pathogenesis of IgG4-RD, focusing on its clinical aspects and the tools that are currently available for a correct differential diagnosis when the salivary glands are involved.

Soluble Interleukin-2 Receptor: A Potential Marker for Monitoring Disease Activity in IgG4-Related Disease

BACKGROUND

IgG4-related disease (IgG4-RD) is a fibroinflammatory condition. T-cells play a crucial role in the pathogenesis, and therefore, serum soluble interleukin-2 receptor (sIL-2R) may be a potential biomarker.

METHOD

We studied the levels of sIL-2R in 26 histologically proven IgG4-RD patients with available serum sIL-2R and compared them to those in newly diagnosed and untreated sarcoidosis patients (n = 78) and controls (n = 101) and the serum sIL-2R levels in patients after treatment of IgG4-RD (n = 15). The disease activity was measured using the IgG4-Related Disease Responder Index (IgG4-RD RI).

RESULTS

Median serum sIL-2R in IgG4-RD patients was 4667 pg/ml compared to 1515 pg/ml in controls (P < 0.001) and 6050 pg/ml in sarcoidosis patients (P = 0.004 compared to IgG4-RD). All IgG4-RD patients had elevated serum sIL-2R levels compared to the reference value of <2500 pg/ml in controls and 85% elevated serum IgG4; however, these did not correlate with each other. Both serum sIL-2R and IgG4 levels declined significantly after treatment (P = 0.001 and P = 0.01, resp.). Before treatment, serum sIL-2R level and IgG4-RD RI did not correlate with each other. However, the decrease in serum sIL-2R upon treatment did correlate significantly (P = 0.04) with the decrease in disease activity assessed by IgG-RD RI.

CONCLUSION

Serum sIL-2R is elevated in IgG4-RD reflecting the inflammatory process with enhanced T-cell activation. Furthermore, serum sIL-2R might serve as a potential marker of response to treatment in IgG4-RD.

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.

IgG4-related sialadenitis and Sjögren's syndrome

IgG4-related disease (IgG4-RD) has emerged as a new entity in the last decade. It comprises numerous conditions previously thought to be unrelated. Macroscopically, these diseases cause diffuse organ swelling and formation of pseudotumorous masses. Histopathologically, they are characterized by a lymphoplasmacytic infiltrate with increased IgG4+ plasma cells and storiform fibrosis. Despite rapid progress within the last years, our knowledge on these conditions is still fragmented. To date, more than forty organs have been reported to be included in IgG4-RD, and salivary gland involvement is amongst the most common organs affected [IgG4-related sialadenitis (IgG4-RS)]. Interestingly, IgG4-RS shares commonalities with Sjögren's syndrome (SS), like glandular enlargement, sicca symptoms, arthralgias, hypergammaglobulinemia, hypocomplementemia, and circulating antinuclear antibodies. Nonetheless, they differ in that the incidence of anti-Ro and anti-La reactivity is not frequently found in patients with IgG4-RS, their salivary glands are infiltrated by a large number of IgG4+ plasma cells and IgG4-RS symptoms respond promptly to steroids. The aim of this review was to describe the clinical, serological, histopathological and pathophysiological aspects of IgG4-RS in the context of IgG4-RD and highlight the differences between IgG4-RS and SS.

Enhanced IgG4 production by follicular helper 2 T cells and the involvement of follicular helper 1 T cells in the pathogenesis of IgG4-related disease

Background

The aim of this study was to elucidate the function of circulating follicular helper T (Tfh) cell subsets in helping B cells in patients with active, untreated IgG4-related disease (IgG4-RD) and determine their relationship with disease activity.

Methods

Seventeen consecutive patients with active, untreated IgG4-RD, 20 with primary Sjögren syndrome (pSS), 5 with multicentric Castleman’s disease (MCD), and 12 healthy controls (HC) were enrolled. Tfh cell subset function was evaluated by co-culture with naïve B cells in vitro. Activated Tfh cell subsets were defined as a CCR7^lowPD-1^high subset among Tfh cell subsets. Disease activity was evaluated by IgG4-RD responder index (IgG4-RD RI) score.

Results

The number of Tfh2 cells was significantly higher in IgG4-RD compared to pSS, MCD, or HC, and correlated with serum IgG4 level or the number of plasmablasts. In vitro, Tfh2 cells more efficiently induced the differentiation of naïve B cells into plasmablasts compared to Tfh1 or Tfh17 cells. Of note, while IgG production in culture supernatants of Tfh2 cells was comparable between IgG4-RD and HC, IgG4 production was significantly higher with Tfh2 cells from patients with IgG4-RD than in those from HC. Accordingly, the IgG4:IgG ratio in culture supernatants was also significantly higher with Tfh2 cells from IgG4-RD compared to HC. Moreover, the number of activated Tfh2 cells was higher in IgG4-RD compared to pSS, MCD, or HC, and strongly correlated with IgG4-RD RI score in the baseline active phase. Particularly, the number of activated Tfh2 cells was associated with the number of affected organs and serum IgG4 level. Importantly, the number of activated Tfh2 cells was decreased after glucocorticoid treatment and paralleled disease improvement. Moreover, the number of activated Tfh1 cells was also increased in IgG4-RD compared to pSS, MCD, or HC, correlating with IgG4-RD RI score, but not with serum IgG4 level.

Conclusions

Tfh2 cells, but not Tfh1 or Tfh17 cells, induce the differentiation of naïve B cells into plasmablasts and enhanced production of IgG4 in patients with active, untreated IgG4-RD. Furthermore, activated Tfh2 cells reflect disease activity, suggesting the involvement of this T cell subset in the pathogenesis of IgG4-RD. Interestingly, the number of activated Tfh1 cells was also increased in IgG4-RD, correlating with disease activity but not with serum IgG4 level, suggesting the involvement of Tfh1 cells but not in the process of IgG4 production in patients with IgG4-RD.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1064-4) contains supplementary material, which is available to authorized users.

IgG4-related disease involving vital organs diagnosed with lip biopsy: A case report and literature review

Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized new disease entity characterized by elevated serum IgG4 and infiltration of IgG4 plasma cells in affected tissues. Histological examination is essential for definitive diagnosis, as other pathological conditions can also present with serum IgG4 elevation. However, IgG4-RD frequently involves vital or internal organs that are difficult to perform biopsies. We herein report a unique case of IgG4-RD involving vital organs that could be successfully diagnosed by alternative lip biopsy, an accessible, little invasive procedure, despite no apparent manifestation demonstrating the involvement in labial salivary gland.A 60-year-old man with swelling of both submandibular glands and elevated serum creatinine level visited our hospital. His labial salivary glands appeared normal. His blood test showed high serum IgG4, and positron-emission computed tomography revealed abnormal uptake in submandibular glands, periaorta, and left kidney with hydronephrosis. We suspected him of IgG4-RD; however, the involved organs were difficult to approach for histological examination. Alternatively, we performed lip biopsy and proved massive infiltration of IgG4 plasma cells leading to the diagnosis with IgG4-RD. Treatment with prednisolone resulted in the remarkable improvement of organ involvements and the normalization of serum IgG4 level after 3 months. Prednisolone was gradually tapered without the relapse of disease.The early recognition and diagnosis of IgG4-RD is clinically important because delay in the treatment initiation leads to fibrosis with irreversible organ damage. Our case highlights the possibility that lip biopsy is a promising option for histological examination in patients with IgG4-RD in whom affected organs are difficult to access, leading to early diagnosis with appropriate treatment.