Advancements in diagnosing IgG4-related disease of the head and neck: Navigating diagnostic pitfalls

IgG4-related disease (IgG4-RD) is an immune-mediated condition affecting nearly any organ. This review focuses on the nuances of diagnosing IgG4-RD affecting the head and neck. Salivary gland involvement, especially of the submandibular glands, often permits a definitive diagnosis on biopsy. However, elevated IgG4+ plasma cells are nonspecific and can be seen in chronic sialadenitis, lymphoma, and other mimics. Careful correlation of clinical and pathological findings is essential. Given the significant overlap with chronic sinusitis, IgG4-RD of the sinonasal region is difficult to diagnose histologically. Laryngeal and pharyngeal involvement appears rare as an isolated finding of IgG4-RD. Mastoid disease is uncommon and remains a diagnosis of exclusion. Thyroid manifestations pose challenges given unclear diagnostic criteria - Riedel's thyroiditis likely represents IgG4-RD, but the fibrosing variant of Hashimoto's thyroiditis as a form of the so-called 'IgG4-related thyroiditis' requires better characterisation. Eosinophilic angiocentric fibrosis, despite histologic similarities, only partially overlaps with IgG4-RD. This review aims to guide diagnosing IgG4-RD in the head and neck through a systematic, organ-focused discussion of the clinical context, the utility of immunostaining, histological mimics, and controversial issues that pose diagnostic pitfalls. Increased awareness of the nuances and difficulties diagnosing IgG4-RD affecting the head and neck will improve recognition of this protean disease.

A Rare Manifestation of IgG4-Related Disease and Secondary Hypereosinophilic Syndrome: A Case Report

We report a case of IgG4-related disease with marked eosinophilia. A 79-year-old woman was admitted due to diarrhea, and weight loss. Cervical lymphadenopathy, bilateral submandibular glands swelling, anemia (Hb8.5g/dl), hypereosinophilia (9,750/μL), and elevated serum creatinine (1.57 mg/dL), pancreatic amylase (191 IU/L), and IgG4 (3,380 mg/dL) were found. Diffusion-weighted image on MRI showed high intensity signals inside of both the pancreas and the kidney. The echogram of submandibular glands revealed cobblestone pattern. Kidney biopsy revealed acute tubulointerstitial nephritis. Biopsies of lip, gastrointestinal tract and bone marrow showed infiltration of lymphoplasmacytic cells and IgG4 positive plasma cells (30-67/HPF). Gastrointestinal and bone marrow biopsies also showed eosinophilic infiltration. Adrenal insufficiency, rheumatic disease, tuberculosis, parasite infection, drug induced eosinophilia, and eosinophilic leukemia were all ruled out. We started treatment with 40mg of prednisolone and her general condition rapidly improved. The eosinophil count, serum IgG4, and serum creatinine decreased. We gradually tapered prednisolone and maintained 5mg/day. During the 5 years of treatment, she had no recurrence of the symptom. According to the 2019 American College of Rheumatology/European League Against Rheumatism classification criteria for IgG4-related disease, eosinophils > 3000/μL is one of the exclusion criteria. If we comply this criterion, the diagnosis of IgG4-related disease should be avoided. However, our case fit the diagnostic criteria of type I autoimmune pancreatitis, IgG4-related sialadenitis and global diagnosis of IgG4-related disease. We finally diagnosed our case as IgG4-related disease with secondary hypereosinophilic syndrome. This case suggests that IgG4-related disease with eosinophils > 3000/μL does exist in the real world.

A Case of Isolated Central Nervous System Rosai-Dorfman Disease

Rosai-Dorfman disease (RDD) is a benign histiocytosis with unknown etiology. It generally occurs in cervical lymph nodes. Isolated central nervous system (CNS) RDD is very rare in the literature. We reported a case of no systemic involvement Rosai-Dorfmann which is rarely seen and shows CNS involvement by mimicking meningioma. A 32-year-old man presented with diplopia and a headache he has been experiencing for the past two years. His neurological examination showed left facial paresthesia, consistent with trigeminal nerve trace. Tendon reflexes were increased at the right side and the right plantar reflex was extensor. Brain magnetic resonance imaging demonstrated irregularly shaped, tumor-like lesions in the bilateral cerebellopontin area that were compressing pons. Rosai-Dorfman disease can be differentiated from IgG4 related disease (IgG4-RD) by its characteristic features such as plasma cell density and emperipolesis seen in its histopathology. Rosai-Dorfman disease can be confused with other diseases radiologically and histopathologically, especially the IgG4-RD, so be careful about differential diagnosis.

Immunoglobulin G4-related Dacryoadenitis Successfully Treated with Baricitinib

A 48-year-old woman visited our hospital because of bilateral lacrimal gland enlargement. Her serum immunoglobulin G4 (IgG4) level was high, and positron emission tomography-computed tomography showed significant positive findings in the bilateral lacrimal gland. A biopsy revealed a considerable increase in IgG4/CD138, leading to a diagnosis of IgG4-related dacryoadenitis. The disease did not respond to steroid therapy, so treatment was started with baricitinib because of exacerbation of the original atopic dermatitis and dacryoadenitis after the second dose of the coronavirus disease 2019 (COVID-19) vaccine. Baricitinib was effective for resolving both dermatitis and dacryoadenitis, and steroids were able to be discontinued. The IgG4 level also improved.

A rare case: IgG4-related chronic inflammatory disease with kidney involvement

IgG4-related disease is an inflammatory, multisystemic disease that affects the immune system. The disease progresses to fibrosis due to inflammation. Retroperitoneal fibrosis is a serious complication. Pancreas, biliary tract, glands, thyroid, lymph nodes, etc. may be involved. Prognosis is usually subacute, and seen in middle age and advanced men. It is characterized histopathologically by IgG4 positive plasma cells, lymphoplasmocytic cell infiltration, and storiform fibrosis. In our case, we evaluated a patient who referred to our clinic from an external center with the complaints of generalized pain, itching, tearing and redness in eyes, involvement of bilateral large joints, and impaired renal function. Diagnosis, treatment and management of the disease are important. Response to glucocorticoid therapy is good.

The Onset of IgG4-related Retroperitoneal Fibrosis under Administration of a TNF Inhibitor in a Rheumatoid Arthritis Patient

An 80-year-old woman with rheumatoid arthritis during treatment with etanercept, a tumor necrosis factor (TNF) inhibitor, showed swelling of the salivary glands and retroperitoneal fibrosis, which was diagnosed as IgG4-related disease. Although some reports have shown the efficacy of TNF inhibitors for IgG4-related disease or retroperitoneal fibrosis, TNF inhibitors sometimes cause paradoxical reactions like psoriasis, and the mechanisms are considered to involve the upregulation of plasmacytoid dendritic cells and IFN-α, which is also common in patients with IgG4-related disease. This is a case report of IgG4-related retroperitoneal fibrosis with the possibility of a rare paradoxical reaction by a TNF inhibitor.

Roles of IgG4 and IgG4/IgG ratio to IgG4-related disease in patients with elevated serum IgG4 level

OBJECTIVE

To evaluate the performance of elevated serum IgG4 and IgG4/IgG in IgG4-related disease (IgG4-RD) and other diseases.

METHODS

Seven hundred seventy-three patients with elevated serum IgG4 level (> 2.01 g/L) were reviewed in Zhongda Hospital of Southeast University from 1 July 2016 to 31 December 2021. Demographic, disease distribution and the role of elevated serum IgG4 and IgG4/IgG in IgG4-RD and other diseases were analysed. The alteration of IgG4 and IgG4/IgG in pre-therapy and post-treatment were also assessed in IgG4-RD.

RESULTS

Patients with elevated serum IgG4 were principally observed in older males. Chronic diseases of various organs (21.7%), rheumatic immune diseases (19.4%), bacterial infection disease (11.5%) and malignant tumor (5.2%) were the common diseases with elevated serum IgG4, but only 3.2% was IgG4-RD. The level of IgG4 and IgG4/IgG in IgG4-RD was significantly higher than that in various diseases except for eosinophilia group. Serum IgG4 and IgG4/IgG manifested a similar diagnostic capacity for IgG4-RD among this study cohort and the optimal cut-off values were 3.345 g/L and 0.295 respectively. The sensitivity and specificity were 96% and 71% for the optimal cut-off value of IgG4, and 80% and 88.8% for the optimal cut-off value of IgG4/IgG4. IgG4 and IgG4/IgG both were remarkably reduced in IgG4-RD after therapy compared with prior treatment (P < 0.05).

CONCLUSIONS

Elevated serum IgG4 was found in a variety of diseases, especially in chronic diseases of various organs. IgG4 and IgG4/IgG manifest a great value for IgG4-RD diagnosis, and are available for the treatment evaluation of IgG4-RD. Key Points • Elevated serum IgG4 level was not a specific marker to IgG4-related disease and can be observed in various diseases. • Patients with IgG4-related disease or eosinophilia manifest a higher level of serum IgG4 and IgG4/IgG. • Both of IgG4 and IgG4/IgG are available for the diagnosis and the clinical treatment evaluation of IgG4-related disease.

[When a rear-end collision turns out to be a revelation: a case of IgG4 related kidney desease]

IgG4 related renal disease represents a frequent manifestation of the wider IgG4 related disease, a fibroinflammatory disorder with a not fully understood etiology that affects several organs. Through the clinical case presented, we will focus attention on this pathology and on the diagnostic difficulties that may arise, and on the investigations necessary for the diagnosis. Finally, the main therapeutic options will be discussed.

A report of Rosai-Dorfman disease with systemic multiple lymphadenopathy and high IgG4 plasma cell infiltration

The Rosai-Dorfman disease (RDD) is a kind of sinus histiocytosis with massive lymphadenopathy and is remarkably rare. RDD is characterized by large histiocytes with emperipolesis. However, the cause of RDD is unknown, and most cases are relieved spontaneously. In rare cases, patients may have onset and remission of lymph nodes and extranodal involvement. This report showed an RDD case in a 67-year-old male patient with systemic superficial lymphadenopathy and high IgG4 plasma cell infiltration. We showed that a possible RDD diagnosis should be kept in mind when encountering a systemic multiple lymphadenopathy and high IgG4 plasma cell infiltration. Also, an overlap between RDD and IgG4-related disease might be present, which might help in clinical recognition of RDD.

Successful therapy of retroperitoneal fibrosis due to IgG4-related disease with rituximab, cyclophosphamide and glucocorticoids followed by maintenance therapy wit ritutixmab

Idiopathic retroperitoneal fibrosis (IRF) is a rare condition characterized by the development of a peri-aortic and peri-iliac tissue showing chronic inflammatory infiltrates and pronounced fibrosis. Ureteral entrapment with consequent obstructive uropathy is one of the most common complications, which can lead to acute renal failure and, in the long term, to varying degrees of chronic kidney disease. Common symptoms at onset include lower back, abdominal or flank pain, and constitutional symptoms such as malaise, fever, and anorexia and weight loss. Pain is frequently referred to the hip, to the groin and to the lateral regions of the leg, with nocturnal exacerbations, and typically does not modify with position. We report a case of 56 year-old male with recurrent lower back pain and lower abdominal pain. Contrast-enhanced computed tomography and was suggestive of retroperitoneal fibrosis and unilateral ureteral occlusion. Histologic examination with immunohistochemical staining for IgG4 demonstrate IgG4-related retroperitoneal fibrosis. Therapy was started with prednison 1 mg/kg, but the tolerance of this dose was poor. Therefore the therapy was switched to combination of rituximab 375 mg/ m2 on day 1, cyclophosphamide 300 mg/m2 mg infusion and dexamethasone 20 mg total dose infusion on day 1 and 15 in 28 days cycle. FDG-PET/CT control in fourth month showed residual accumulation of FDG in retroperitoneal fibrotic mass, and therefore the therapy was prolonged to 8 month. The subjective symptoms of this diseases disappeared in the 8th month. Then the maintenance therapy, administration of rituximab in 6 month interval, was started. The activity of this disease be further evaluated by FDG-PET/CT imagination. Glucocorticoids are considered the cornerstone of therapy. The use of other immunosuppressive agents, including cyclophosphamide, azathioprine, methotrexate, mycophenolate mofetil and biological agents such as rituximab, tocilizumab and infliximab and sirolimus have been reported as a valuable option mostly in case reports, cases series and small studies. This agents allowed to reduce cumulative dose of glucocorticoids and its adverse effects. Therefore in our patients we preferred combination of rituximab cyclophosphamide s dexamethasone with lover dose of prednisonem. This combination is preferable for patients who cannot tolerate glucocorticoids or who are likely to suffer from significant glucocorticoids -related toxicity.

Large lung mass lesion with spontaneous regression in a patient with IgG4-related lung disease

IgG4-related lung disease (IgG4-RLD) may present with a variety of radiological findings, but large lung mass lesion are rare. Although steroid therapy is strongly recommended for IgG4-RLD with or without symptoms, respirologists should be aware that some patients may not need steroid therapy.

Igg4 Related Disease of Skull Base-A Diagnostic Challenge

IgG4 related disease (IgG4-RD) is a fibro-inflammatory disease, with tendency to affect any organ of the body. However, few cases affecting the skull base have been reported in literature. We report one such case in an elderly male, who presented us with a mass lesion in the skull base that mimicked nasopharyngeal malignancy. On thorough clinical history, examination, and investigations, IgG4 Related disease was diagnosed and treatment was started for it. The patient responded well to the treatment and is on follow up.

IgG4-related disease diagnosed in a paratesticular pseudotumor simulating malignancy, in a patient with retroperitoneal fibrosis

IgG4 related disease is a term used to describe a fibroinflammatory condition characterized by storiform fibrosis, inflammation with a dense lymphoplasmocytic infiltrate rich in plasma cells expressing IgG4, and often, if not always, raised serum levels of IgG4. We report a case of a patient with a past history of retroperitoneal fibrosis presenting with a swollen left testicle, who underwent an orchidectomy due to suspicion of malignancy. The surgical specimen revealed a paratesticular pseudotumor with histopathological and immunohistochemical characteristics of IgG4 related disease. To the best of our knowledge, just nine such cases have previously been reported, of which only three were manifestations of systemic disease, as in the present case. Whilst it is important to recognize the clinical and radiological features of this entity, histopathology is often essential in order to confirm the diagnosis.

Elevated Serum Levels of IgG4 in Patients with Heart Failure with Reduced Ejection Fraction: A Prospective Controlled Study

(1) Background: Immunoglobulin gamma subclass 4 (IgG4) is a serum protein belonging to the immunoglobulin superfamily. It has a central role in certain immune-mediated conditions defined as IgG4-related disease. There is a paucity of data regarding the potential association of IgG4 and cardiovascular diseases. Our aim is to study the serum levels of IgG4 in patients with ischemic and non-ischemic dilated cardiomyopathy (DCM). (2) Methods: patients with ischemic and non-ischemic DCM were included in this study. Non-ischemic DCM was defined as a left ventricular ejection fraction (LVEF) < 40% without coronary artery disease (CAD). Ischemic DCM was defined as a LVEF < 40% and proven CAD. The serum concentrations of IgG4 were measured by turbidimetry. (3) Results: Overall 98 patients with cardiomyopathy had significantly higher levels of IgG4 compared with the control group (77.4 ± 64.0 vs. 50.3 ± 28.8 mg/dL, p < 0.01). Although there was no difference in the total IgG levels in patients with ischemic DCM, the serum concentrations of IgG4 were significantly higher than the corresponding values in the control group (89.8 ± 67.3 vs. 50.3 ± 28.8 mg/dL; interquartile ranges: 40.4−126.5 vs. 31.8−66.8 mg/dL, p < 0.01). This was altered by gender and smoking. (4) Conclusions: The patients with ischemic DCM had increased serum concentrations of IgG4. Future studies are warranted to explore the potential role of an IgG4-mediated process in patients with heart failure with reduced LVEF.

Lacrimal Gland and Orbital Lesions in LatY136F Knock-in Mice, a Model for Human IgG4-Related Ophthalmic Disease

PURPOSE

Lat^Y136F knock-in mice were recently proposed as an animal model for immunoglobulin G4 (IgG4)-related disease. In this study, we investigated whether Lat^Y136F knock-in mice exhibit ophthalmic lesions, specifically in the lacrimal and Harderian glands.

METHODS

Lacrimal glands, Harderian glands, and adherent lymphoid follicle lesions were dissected from Lat^Y136F knock-in mice and wild type (WT) C57BL/6 mice between 6 and 24 weeks of age. Tissues were stained with hematoxylin-eosin, immunoglobulin G (IgG), and anti-IgG1, a homologue of human IgG4, for histopathological analysis.

RESULTS

In Lat^Y136F knock-in mice, IgG1-positive cells infiltrated the space between the lacrimal gland acinar cells at 6, 9, 12, and 20 weeks or order, and the number of IgG1-positive cells did not differ significantly between these age groups. Infiltration of IgG1-positive inflammatory cell was also observed in the Harderian glands of Lat^Y136F knock-in mice at all ages. The ratio of IgG1/IgG-positive cells averaged 80 and 67% in the lacrimal and Harderian glands, respectively. Dense IgG1-positive lesions were also seen in tissues adjacent to the lacrimal and Harderian glands in some Lat^Y136F knock-in mice. In contrast, there were almost no IgG1-positive cell infiltrates in the lacrimal and Harderian glands of WT mice.

CONCLUSION

IgG1-positive cells infiltrate the lacrimal and Harderian glands of Lat^Y136F knock-in mice, indicating that Lat^Y136F knock-in mice could be a representative animal model for IgG4-related ophthalmic disease.

[A CASE OF IgG4-RELATED DISEASE OF THE URETER DIAGNOSED BY TRANSVAGINAL ULTRASOUND-GUIDED BIOPSY]

IgG4-related disease (IgG4-RD) is a chronic inflammatory disorder that systemically causes tissue fibrosis due to infiltration of IgG4-positive plasma cells. Here, we reported a rare case of ureteral IgG4-RD that formed a nodular lesion and diagnosed by trans-vaginal ultrasound-guided needle biopsy.A 72-year-old woman presented with loss of appetite. The patient underwent Computed Tomography (CT), and she was pointed out the thickening of the left side bladder wall. So we performed a transurethral bladder biopsy under lumber anesthesia, but histopathological findings were almost normal. After that, she developed pyelonephritis repeatedly. We performed CT again. A CT revealed a nodular lesion at the end of her left ureter and hydronephrosis. The tumor was gradually getting larger. So we performed placement the ureteral stent for urinary tract obstruction. Left ureteral urine cytology was classIIIa. We performed transvaginal ultrasound needle biopsy for the nodular lesion of the left ureter. Histopathological findings showed infiltration of lymphocytes and fibrosis and infiltration of IgG4 positive plasma cells: the ratio of IgG4/IgG positive cells>0.6, 30>IgG4 positive plasma cells/high power field. The serum IgG and IgG4 levels were also elevated 1,943 and 210 mg/dl. We finally diagnosed IgG4-RD of the ureter and started using steroid for her treatment. One month later, the tumor had reduced after steroid treatment. The ureteral stent was removed. Since then, recurrent ureteral obstruction of the left ureter has not occurred.IgG4-RD of the ureter with nodular type is rare, and the imaging findings are similar to malignant tumors. Accurate diagnosis is very important to rule out malignancy. In our case, transvaginal needle biopsy was helpful to reach final diagnosis.

Retroperitoneal fibrosis - diagnosis and treatment

Idiopathic retroperitoneal fibrosis (IRF) is a rare condition characterized by the development of a peri-aortic and peri-iliac tissue showing chronic inflammatory infiltrates and pronounced fibrosis. Ureteral entrapment with consequent obstructive uropathy is one of the most common complications which can lead to acute renal failure and, in the long term, to varying degrees of chronic kidney disease. Common symptoms at onset include lower back, abdominal or flank pain. Pain is frequently referred to the hip, to the groin and to the lateral regions of the leg, often with nocturnal exacerbations and not responding to position changes. The disease is commonly associated with signs of systemic inflammatory response (malaise, fever, and anorexia and weight loss). Glucocorticoids are considered the cornerstone of the therapy. The use of other immunosuppressive agents, including cyclophosphamide, azathioprine, methotrexate, mycophenolate mofetil and biological agents such as rituximab, tocilizumab and infliximab have been reported as a valuable option mostly in case reports, cases series and small studies. These agents allowed to reduce cumulative dose of glucocorticoids and their adverse effects. Combined therapy is preferable for all patients who suffer from significant glucocorticoid- related toxicity or in cases where glucocorticoids alone are insufficient to treat the condition.

IgG4-related disease. Clinical manifestation differential diagnosis and recent International Diagnostic Criteria for IgG4-related disease

Immunoglobulin G4- related disease (IgG4-RD) is a rare systemic fibro-inflammatory disorder. Autoimmune pancreatitis is the most frequent manifestation of IgG4-RD. However, IgG4-RD can affect any organ such as salivary glands, orbits, retroperitoneum, prostate and many others. Recent research enabled a clear clinical and histopathological description of IgG4-RD and in 2019 four Clinical phenotypes of IgG4-related disease were described. Diagnosis is based on morphological examination with typical findings of lymphoplasmocellular inflammation, storiform fibrosis and obliterative phlebitis in IgG4-RD biopsies and the tissue invading plasma cells largely produce IgG4. Elevated serum IgG4 levels are found in many but not all patients. New diagnostic criteria for IgG4-RD have been published recently in 2019 and 2021. This review summarizes current knowledge on pathophysiology, clinical manifestations, diagnosis and differential diagnosis of IgG4-RD from the point of view 2022 and in next article brings overview of the IgG4-RD therapy.

Uncommon Tumors and Uncommon Presentations of Cancer in the Breast

Purpose of review

The purpose is to present a case series of rare diagnoses and unusual presentations of breast lesions with radiologic-pathologic correlation from a major cancer center, and to review the recent literature on each entity with a focus on radiology-pathology concordance. We present our findings and experience from cases of metastatic small cell lung carcinoma to the breast, IgG-4 related breast disease, breast implant associated anaplastic large cell lymphoma, granular cell tumor, pleomorphic sarcoma, adenomyoepithelioma, post-radiation angiosarcoma, and breast carcinoma after risk-reducing total mastectomy.

Recent findings

It is essential for physicians to have knowledge of rare breast diagnoses and unusual breast disease presentations to formulate a complete differential diagnosis, recognize radiological-pathological concordance of these entities and provide appropriate patient care.

Summary

Current literature on these rare described entities exists mainly as case reports, case series and small-scale studies. By sharing our findings, we hope to educate trainees in radiology, pathology and other fields across the continuum of care in radiologic-pathologic correlation, while also augmenting the existing literature on these rare entities.

Phenotype, function and clinical significance of innate lymphoid cells in immunoglobulin G4-related disease

OBJECTIVE

Innate immune system participates in immunoglobulin G4 related disease (IgG4-RD). While the role of innate lymphoid cells (ILCs) in IgG4-RD remains to be elucidated, we aimed to evaluate the phenotype, function and clinical significance of ILCs in IgG4-RD patients.

METHODS

Sixty-seven untreated IgG4-RD patients, age and sex matched healthy controls (HCs) were enrolled. Circulating and tissue infiltration of ILCs were detected by flow cytometry. Serum suppression of tumorigenicity 2 (sST2) was detected by ELISA and membrane-bound ST2 (ST2L) was detected by flow cytometry. Tissue infiltration of IL-33 was measured by immunohistochemistry staining. RT-qPCR was performed to analyze the expression pattern of ILC2 associated genes between HCs and IgG4-RD patients. In addition, correlation analysis was performed in order to evaluate clinical significance of ILCs in IgG4-RD.

RESULTS

The frequency of circulating pan ILCs in IgG4-RD patients was lower than in HCs. ILC2s was higher in IgG4-RD compared with HCs, whereas ILC1s was lower in IgG4-RD. sST2 and ST2L were increased in IgG4-RD than HC. Infiltration of ILC1s in submandibular glands of IgG4-RD was more prominent than ILC2s. Intracellular secretion of IL-9 was increased in ILC2s of IgG4-RD than in HCs. Circulating ILC2s correlated positively with Treg cells, the surface expression of CD154, PD-1 and CXCR5 in ILC2s correlated positively with CD19+B cells, serum IgG4 level and serum IgE, respectively.

CONCLUSION

ILCs and their subsets were significantly altered in IgG4-RD. We demonstrated the dysfunction of ILC2s in IgG4-RD by phenotype, correlation analysis, and function investigation, revealing ILC2s participated in the pathogenesis of IgG4-RD.

IgG4 Related Disease is characterized by the overexpression of Immunomodulatory proteins

INTRODUCTION

IgG4 related disease (IgG4-RD) is a multisystem disease, characterized by tumefactive lesions and a swift response to immunosuppressive therapy. Although elevated serum and tissue IgG4 are characteristic, T-cells appear to be the primary driver of this immunologically mediated disease. The overarching goal was to examine the role of immunomodulatory cells in IgG4-RD.

METHODS

Biopsies from patients with IgG4-RD (n=39) and mimics of this disease (n=78) were evaluated for IgG4, IgG, CD8, PD-L1 and a subset (n=18) evaluated for CD4, PU.1, Foxp3, PD-L1, PD-1, IDO1 and LAG3. Data pertaining to demographics and laboratory findings at baseline evaluation was extracted from electronic medical records.

RESULTS

When compared to mimics, IgG4-RD showed increased numbers of PD-L1 (p=0.0001), PD-1 (p=0.001), IDO1 (p=0.03), LAG3 (p=0.04) and Foxp3 (p=0.04) positive immune cells. The PD-L1 positive cells were enriched within aggregates of CD4 and CD8 positive T-cells. 31 of 39 (80%) IgG4-RD cases showed greater than 5 PD-L1 positive cells per HPF, while 4 of 78 (5%) mimics of this disease exceeded this cut point. In IgG4-RD PD-L1 positive macrophages correlated with PD-1 (p=0.002), LAG3 (p=0.001) and IDO1 positive cells (p=0.001); a positive correlation was also noted between IgG4/IgG ratio and PD-L1, PD-1, and IDO1 positive cells.

CONCLUSIONS

IgG4-RD shows expansion of mechanisms that maintain peripheral tolerance. The spatial and temporal relationship between T-cells and the PD-L1-PD1 axis, and the upregulation of multiple immunomodulatory proteins suggests that these immunoregulatory mechanisms play a significant role in IgG4-RD.

Comprehensive analysis of protein-expression changes specific to immunoglobulin G4-related disease

BACKGROUND AND AIMS

Immunoglobulin 4 (IgG4)-related disease (IgG4-RD) is a lymphoproliferative disorder characterized by elevated serum IgG4 levels and tissue infiltration of IgG4-positive plasma cells. We analyzed the serum proteins, whose levels varied based on the disease state and treatment.

MATERIALS AND METHODS

Serum proteins from patients with IgG4-related disease and healthy subjects were resolved using two-dimensional electrophoresis, silver-stained, and scanned. Alternatively, the proteins were labeled with Cy2, Cy3, and Cy5 before electrophoresis. The proteins, whose expression differed significantly between patients and healthy individuals, and between before and after steroid treatment, were identified and validated using enzyme-linked immunosorbent assays.

RESULTS

Pre-treatment sera from patients with IgG4-related disease was characterized by increased levels of immunoglobulins such as IgG1, IgG4; inflammatory factors such as α-1 antitrypsin (A1AT); and proteins associated with immune system regulation such as clusterin and leucine-rich α-2-glycoprotein (LRG-1). The serum levels of A1AT, LRG-1 and clusterin, during treatment with prednisolone for up to 12 months revealed that LRG-1 levels were halved after 1 month of treatment, comparable to those in healthy subjects; LRG-1 levels remained normal until the end of treatment.

CONCLUSION

LRG-1 could serve as a novel biomarker of IgG4-related diseases.

A Unique Case of Encephalopathy with an Elevated IgG-4 and Extremely High Interleukin-6 Level and Delayed Myelodysplastic Syndrome

We herein report a 75-year-old man who developed disturbed consciousness with polynuclear cell dominant pleocytosis and low glucose and extremely high interleukin (IL)-6 levels in his cerebrospinal fluid. The biopsy specimen from his right supraclavicular lymph node showed the infiltration of inflammatory cells positive for IgG, IgG4 and IL-6. Prednisolone and azathioprine administered under suspicion of IgG4-related disease (IgG4-RD) or multicentric Castleman's disease (MCD) successfully remitted the symptoms. However, he developed myelodysplastic syndrome (MDS) and died 18 months later. The extremely high IL-6 may have been related to the rare neurological manifestations and development of MDS in the present case.

IgG4 related lung disease- a rare and novel mimic of malignancy and infections-a case series of three patients with a brief review of updated literature

IgG4-related lung disease is an extremely rare and novel entity which is still poorly understood. We reviewed the 16 patients diagnosed with IgG4-related disease from October 2014 through December 2019 at our institution. The three cases that showed pulmonary involvement are included in this series. Of these, two patients had cavitary lung disease and developed aspergilloma and chronic cavitating aspergillosis after a prolonged course of steroid therapy, and one had isolated pulmonary nodule and ground glass opacity. We reviewed the updated literature and briefly described disease epidemiology, clinical characteristics, diagnostic approaches, and management strategies for IgG4-related lung disease.

[A case of IgG4-related disease with initial clinical manifestation of neck lymph nodes enlargement and literature review]

A 58 years old male came to our hospital with chief compliant of a persistent neck mass on his right neck.The size of this neck mass was 5 cm×3 cm.After a surgery of removing two largest lymph nodes in his neck，as well as immunohistochemistry staining，the diagnosis of IgG4 related disease was reached.

Pulmonary manifestations of IgG4‑related disease in a South African patient

Immunoglobin 4-related disease (IgG4-RD) is an auto-immune, multisystem inflammatory disorder characterised by storiform fibrosis, lymphoplasmacytic infiltration and obliterative phlebitis on histology. Its pathophysiology is not well understood, but is thought to occur due to complex interactions between T helper 2 cells, their cytokines, chemokines, and B lymphocytes that become dysregulated and produce dysfunctional immunoglobulins. Here, we present a case report of a 54-year-old man who was initially suspected of having lung cancer on imaging, but was ultimately diagnosed with IgG4-RD on histological analysis of a pneumonectomy specimen. Treatment with glucocorticoids can establish disease remission, with a small proportion of patients relapsing, if the diagnosis is made before significant fibrosis occurs.

IgG4 related disease as a cause of isolated retroperitoneal fibrosis with no other organ involvement; Case report

Introduction and importance

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the replacement of normal tissue with fibrosis and inflammation. We present the case of a 40-years-old gentleman with RPF whose presenting complaints were bilateral flank pain and weight loss and was found to have IgG4 related disease. To the best of our knowledge, IgG4-related disease with isolated retroperitoneal involvement is a very rare occurrence.

Case presentation

The diagnosis of IgG4-Related retroperitoneal fibrosis was made based on clinical, radiological and histopathological criteria. Imaging revealed isolated retroperitoneal involvement and the patient was started on oral steroids with a good clinical response after ten days. Repeated imaging months later showed significant regression in the fibrosis.

Clinical discussion

RPF can occur due to many etiologies and is categorized to idiopathic and secondary. Factors associated with secondary RPF include medications, autoimmune disease, malignancy and IgG4 related disease. Almost all the reported cases of IgG4 related disease had evidence of multifocal involvement such as the pancreas, aorta and kidneys. Our patient was diagnosed with isolated RPF due to IgG4 disease. He met all the suggested diagnostic criteria, was started on oral steroids and had an excellent clinical outcome.

Conclusion

IgG4 related disease can present with isolated retroperitoneal fibrosis without involvement of other organ systems. The diagnosis should be based on specific criteria. Treatment with corticosteroids can lead to remission both clinically and radiographically.

[SIGNIFICANCE OF IgG4 IN IDIOPATHIC RETROPERITONEAL FIBROSIS]

(Objective)Retroperitoneal fibrosis is largely divided into the idiopathic and secondary types. Some idiopathic cases include IgG4-related diseases, which are often similar to malignant diseases, such as lymphoma and sarcoma. The diagnostic criteria for IgG4-related disease are used and pathologic examination is necessary for a definitive diagnosis of IgG4-related retroperitoneal fibrosis. The first choice of treatment for IgG4-related retroperitoneal fibrosis is steroid administration, but no consensus has been established regarding its dose and tapering schedule. We investigated the significance of IgG4 in diagnosis and treatment of idiopathic retroperitoneal fibrosis. (Patients and methods)We examined 14 cases diagnosed as idiopathic retroperitoneal fibrosis between April 2013 and March 2019. Serum IgG4 was measured at the time of diagnosis in 13 cases, and changes over time in serum IgG4 before and after the induction of steroid therapy were measured in 6 cases. Computed tomography-guided biopsy was performed on 4 cases. (Results)Of all cases, 1 patient was diagnosed as IgG4-related retroperitoneal fibrosis and 5 patients were classified as possible group. Ten patients were administered steroid therapy. Percutaneous nephrostomy tube was placed in 3 patients and was removed in 2 of these patients after steroid therapy. The serum high levels of IgG4 were confirmed in all 4 patients who were classified into the possible group and who were treated with steroids. (Conclusion)Although histologic examination is necessary for the diagnosis of retroperitoneal fibrosis, tissue collection by open or laparoscopic surgery is highly invasive. CT-guided biopsy may be useful in high-risk cases, such as elderly patients on anticoagulation. After excluding other diseases in high-risk cases, response to empiric steroid therapy may be diagnostic. In the possible group, changes in serum IgG4 levels may reflect the disease condition and might be useful in determining the maintenance dose of steroids.

Role of Quantitative Spectral CT Analysis for Differentiation of Orbital Lymphoma and Other Orbital Lymphoproliferative Disease

PURPOSE

To investigate the value of quantitative parameters from spectral computed tomography for the differentiation of orbital lymphoma from other lymphoproliferative disease, including idiopathic orbital inflammatory disease (IOID) and IgG4-related disease (IgG4-RD).

METHODS

Patients with orbital masses who underwent pre-treatment contrast-enhanced spectral CT were enrolled in this retrospective study. The subjects were divided into lymphoma and other orbital lymphoproliferative disease groups. Qualitative imaging features (margin, location, enhancement pattern, cranial nerves, soft tissue, and bone involvement) were reviewed. Quantitative parameters (iodine density and spectral attenuation curve slope) derived from spectral CT were measured.

RESULTS

Eleven patients had orbital lymphoma and 11 had other orbital lymphoproliferative diseases (idiopathic orbital inflammatory disease (IOID), n = 5; IgG4-related disease (IgG4-RD), n = 6). Qualitative analysis showed no significant difference between the two groups. There was significantly higher iodine density in orbital lymphoma (1.24 ± 0.24 mg/ml) than in IOID/IgG4-RD (0.83 ± 0.23 mg/ml; P = 0.001). An iodine density threshold of 1.0 mg/ml gave sensitivity, specificity, and accuracy of 81.8%, with an area under the curve of 0.876 (P = 0.0003). Orbital lymphoma had a significantly higher iodine spectral attenuation curve slope (2.44 ± 0.51 HU/keV) than IOID/IgG4-RD (1.66 ± 0.47 HU/keV; P = 0.001). A threshold of 1.99 HU/keV for the spectral attenuation curve slope of 40-70 keV gave sensitivity, specificity, and accuracy of 81.8%, with an area under the curve of 0.884 (P = 0.0002).

CONCLUSIONS

Quantitative spectral CT parameters can help differentiate orbital lymphoma from other orbital lymphoproliferative disease, with lymphoma having a significantly higher iodine density value and spectral attenuation curve slope than IOID/IgG4-RD.

Axillary lymphadenopathy with IgG4 positive plasma cell infiltration as differential diagnosis of metastatic lung adenocarcinoma

Immunoglobulin type G4 -related disease (IgG4-RD) is known as a chronic systemic inflammatory disease, which is sometimes associated with lung cancer. However, the detailed association between IgG4-RD and lung cancer in clinical settings is still poorly understood. An 80-year-old man was diagnosed with progressive lung adenocarcinoma carrying an EGFR point mutation at L858R, and osimertinib treatment was administered. Two months later, although osimertinib treatment showed good response to the primary tumor, fever and anorexia appeared, and multiple lymph nodes, in particular in the left axillary, became swollen. Ultrasonography-guided biopsy of the axillary lymph node revealed infiltration of lymphocytes with IgG4-positive plasma cells and fibrosis. Serum IgG4 levels were also increased. These results suggested that the multiple swollen lymph nodes were not metastasis, but IgG4-related disease. Based on these results, therapy using prednisolone was initiated. Multiple lymphadenopathy gradually decreased, and his symptoms improved. Currently, his good responses to osimertinib treatment have been maintained. Like in our case, multiple lymphadenopathy with IgG4-positive plasma cell infiltration during successful anti-cancer treatment is quite rare. In this case, it was hypothesized that anti-cancer treatment with osimertinib induced IgG4-positive plasma cell infiltration in multiple lymph nodes. When lymphadenopathy occurs during lung cancer treatment, IgG4-RD has to be considered other than lung cancer metastasis.

Lung nodules and IgG4 related disease: a single-center based experience

BACKGROUND

This study was undertaken in an attempt to characterize the frequency and clinical features of lung nodules in IgG4 related disease (IgG4-RD) patients as an insight for help with the diagnosis of lung nodules.

METHODS

A retrospective study was carried out in West China Hospital, Sichuan University from January 2012 to December 2018, 89 patients with definite IgG4-RD were enrolled.

RESULTS

Fifty of 89 patients with definite IgG4-RD had radiologically confirmed lung nodules, 6 of whom were diagnosed with definite IgG4 related lung disease. Lung nodules detected in more than 40 patients were small and solid, always with regular margins. Multiple (41/50) and bilateral (34/50) distributions was also a major characteristic of these lung nodules. Lobulation and speculation were simultaneously detected in 3 patients, including 2 patients combined with pleural indentation. Calcification of nodules was detected in only one patient. Thirty-seven patients also had additional radiological abnormalities of lungs, including ground-glass opacity (21/50), thickening of pleura (9/50), thickening of interlobular septa (4/50), thickening of bronchial wall (3/50), pleural effusion (4/50), mass (3/50), interstitial changes (5/50), and mediastinal or hilar lymphadenopathy (32/50). Most patients (44/50) were treated with glucocorticoids alone or combined with immunosuppressive agents. Sixteen patients received a re-examination by chest computed tomography (CT) scan after treatment, 10 of whom showed a decrease in the size and/or the number of nodules.

CONCLUSIONS

The incidence of lung nodules in IgG4-RD patients can be high. For an IgG4-RD patient with lung nodules, the possibility that the lung nodules related to IgG4-RLD is high. It is hard to differentiate IgG4 related lung nodules from other lung diseases, in particular, lung cancer. Radiological characteristics and positive responses to glucocorticoids and immunosuppressive agents can help with the differential diagnosis. For these patients, regular follow-up is also important.

Constrictive Pericarditis Caused by IgG4-Related Disease Requiring Pericardiectomy After Partial Response to Corticosteroids

Immunoglobulin G4-related disease is a systemic fibroinflammatory disease; pericardial involvement has occasionally been reported in publications. A 79-year-old man with biopsy-proven immunoglobulin G4-related disease with pleural involvement was admitted in acute heart failure, with imaging and hemodynamic studies consistent with constrictive pericarditis. He was treated with corticosteroids for 2 months with partial response manifest by decreases in pericardial thickening and immunoglobulin G4 levels. However, persistent constriction required pericardiectomy, leading to significant symptomatic improvement. (Level of Difficulty: Intermediate.).

La fibrose rétropéritonéale idiopathique

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the presence of fibro-inflammatory tissue around the aorta entrapping the adjacent structures. RPF can be idiopathic or secondary to many disorders. The physiopathology is unknown but can be part of the spectrum of IgG4 related diseases. Imaging studies and inflammatory markers are essential for initial evaluation and follow-up. Biopsy is usually not recommended. The first line of treatment is corticosteroids associated or not with immunosuppressive drugs. In case of ureteral obstruction with renal failure, ureteral stent placement or nephrostomies are recommended. Initial response to treatment is usually good but relapses are frequent.

Inflammatory Demyelinating Pseudotumor With Liver Dysfunction: IgG4 Related Disease With Primary Biliary Cholangitis

Immunoglobulin G4 related disease (IgG4-RD) is a recently recognized immune-mediated disease which is far from understanding. A case of inflammatory demyelinating pseudotumor had been confirmed as IgG4-RD according to pathology features and clinical context. Combined with liver dysfunction, IgG4 related sclerotic cholangitis was suspected. However, primary biliary cholangitis was finally diagnosed by immune marks and histopathological findings. This is the first report in which mass lesions in the brain parenchyma were caused by IgG4-RD while liver dysfunction was due to primary biliary cholangitis. The clinical features of IgG4-RD are miscellaneous, and the accumulation of case reports might enrich clinicians experience and broaden their horizons about this condition.

PEGylated Liposomal Methyl Prednisolone Succinate does not Induce Infusion Reactions in Patients: A Correlation Between in Vitro Immunological and in Vivo Clinical Studies

PEGylated nanomedicines are known to induce infusion reactions (IRs) that in some cases can be life-threatening. Herein, we report a case study in which a patient with rare mediastinal and intracardiac IgG4-related sclerosing disease received 8 treatments of intravenously administered PEGylated liposomal methylprednisolone-succinate (NSSL-MPS). Due to the ethical requirements to reduce IRs, the patient received a cocktail of premedication including low dose of steroids, acetaminophen and H2 blockers before each infusion. The treatment was well-tolerated in that IRs, complement activation, anti-PEG antibodies and accelerated blood clearance of the PEGylated drug were not detected. Prior to the clinical study, an in vitro panel of assays utilizing blood of healthy donors was used to determine the potential of a PEGylated drug to activate complement system, elicit pro-inflammatory cytokines, damage erythrocytes and affect various components of the blood coagulation system. The overall findings of the in vitro panel were negative and correlated with the results observed in the clinical phase.

Identification of canine IgG and its subclasses, IgG1, IgG2, IgG3 and IgG4, by immunofixation and commercially available antisera

Immunofixation is a diagnostic and research tool used for characterizing the electrophoretic location of immunoglobulin fractions in serum and urine. Commercially available polyclonal antisera which discriminate two IgG subclasses (IgG1 and IgG2) are available and commonly used. More recently, four IgG subclasses have been defined in the dog based on cDNA data. Archived serum from 16 dogs with naturally occurring monoclonal or biclonal gammopathies were characterized using routine serum protein electrophoresis, routine immunofixation and LCMS/MS as 3 IgA, 3 IgM, 2 IgG2, 7 IgG3 and 2 IgG4 heavy chain predominant cases. Immunofixation reactivity of a panel of commercially available antisera to these cases was characterized. The anti-human IgG antisera was the only tested antisera which bound all canine IgG restricted bands without also labelling IgA or IgM heavy chains or light chains. The tested polyclonal antisera labeled as reacting with canine IgG2 bound canine IgG2, IgG3, IgA and IgM and may label IgG1. The tested polyclonal antisera labeled as reacting with canine IgG1 bound the canine IgG4 bands but not those identified as IgA, IgM, IgG2 or IgG3 and likely did not bind IgG1. This data suggests that commercially available polyclonal IgG1 antisera (Bethyl A40 - 120A and Bio-Rad AHP947) can be used to positively but possibly not selectively identify canine IgG4 by immunofixation.

Risk factors and treatment of relapses in autoimmune pancreatitis: Rituximab is safe and effective

Background and aims

Steroid therapy is the first-line treatment for autoimmune pancreatitis but relapses are frequent. The aims were to assess the efficacy and the safety of immunomodulator treatments for relapsing autoimmune pancreatitis and rituximab in particular and to identify relapsing risk factors.

Methods

Patients followed for autoimmune pancreatitis from 2000 to 2016 were included. Data were retrospectively analysed regarding autoimmune pancreatitis treatment.

Results

In total, 162 patients with autoimmune pancreatitis type 1 (n = 92) and type 2 (n = 70) were included (median follow-up: 3 years (0.5-14). Relapse occurred in 46.5% of patients with autoimmune pancreatitis type 1 (vs 19.3% in autoimmune pancreatitis 2; p < 0.001). Risk factors of relapse were cholangitis, initial use of steroids, other organ involvement and chronic pancreatitis in autoimmune pancreatitis type 1 and initial use of steroids, tobacco consumption and chronic pancreatitis for autoimmune pancreatitis type 2. Overall, 21 patients were treated with immunomodulators (azathioprine, n = 19, or methotrexate, n = 2) for relapses. The efficiency rate was 67%. A total of 17 patients were treated with rituximab, with two perfusions at 15 days apart. The efficacy was 94% (16/17), significantly better than immunomodulator drugs (p = 0.03), with a median follow-up of 20 months (11-44). Only two patients needed two supplementary perfusions.

Conclusion

In relapsing autoimmune pancreatitis, rituximab is more efficient than immunomodulator drugs and shows better tolerance.

[Advances in IgG4-related sinonasal diseases]

IgG4 related disease (IgG4-RD) is an independent clinical pathological entity which is different from common chronic inflammation and other autoimmune diseases in recent years. It often appears in the form of tumor like tissue-destructive lesions and may be accompanied by the increase of concentration of serum IgG4. Histopathology is characterized by a large number of lymphocytes and plasma cells infiltration, storiform fibrosis and occlusive phlebitis. The characteristics of IgG4-RD in nose and sinuses have not been widely investigated. The aim of the present study is to review the advances in IgG4 related sinonasal diseases from four aspects including pathogenesis, clinical features, treatment and future research directions.

[IgG4 related disease with exclusive sinonasal involvement: A case report and literature review]

IgG4 related disease (igG4-RD) is a pathological process which integrates a large number of diseases of unknown pathogenesis, considered as being exclusive to many different organs. Diagnosis is established through histological, radiological and serological criteria. Treatment is based on long term corticosteroids; rituximab being used only in refractory cases. It is unusual for this entity to be found exclusively in the head and neck, without systemic involvement; there are only a few reported cases to date. We present a case of a nasosinusal IgG4-RD orbital tumor with paranasal sinus involvement. The accurate diagnosis made early onset corticosteroid treatment possible and the patient is currently asymptomatic.

IgG4-related disease manifesting as an isolated gastric lesion- a literature review

INTRODUCTION

IgG4-related disease (IgG4-RD) is a newly recognised disorder of unknown etiology and pathogenesis, characterised by dense IgG4+ cells infiltration and fibrosis. IgG4-RD can affect various organs, but gastrointestinal tract involvement is rare. First case of isolated gastric IgG4-RD reported in polish population was diagnosed in our Clinic and became the reason for conducting a literature review.

MATERIALS AND METHODS

A literature review was performed using PubMed database. Eight studies of isolated gastric IgG4-RD, published between 2011 and 2017, and a case diagnosed by the authors were included.

RESULTS

Three out of nine analysed patients had gastrointestinal complaints. In other cases lesions were detected accidentally. The majority of them were submucosal tumors while only one was a gastric ulcer. The most commonly affected was the stomach body. In all cases malignancy had been suspected, and the lesions were surgically removed. Diagnosis was based on the histopathology image and immunohistochemical staining. Only one patient had elevated IgG4 serum level. No case of recurrence or other organ involvement was reported.

CONCLUSION

IgG4-related disease may manifest as an isolated gastric lesion and should be taken in consideration in differential diagnosis. Making an ultimate diagnosis without histopathological specimen examination seems to be difficult and can lead to misdiagnosis followed by inappropriate treatment. IgG4-RD responds well to steroid therapy. However, on this matter further studies are needed.

IgG4-related disease: Is rituximab the best therapeutic strategy for cases refractory to conventional therapy? Results of a systematic review

INTRODUCTION

IgG4 related disease is a fibroinflammatory condition characterised by lymphoplasmocytic infiltration with predominance of IgG4+ plasma cells, fibrosis, and in most cases elevated IgG4 serum levels. It can affect any organ and result in varying clinical manifestations. Steroids are the cornerstone of treatment, however there is a high percentage of relapse. Recent studies have demonstrated favourable effects with rituximab.

OBJECTIVE

To evaluate effectiveness related to the response to treatment with rituximab in patients with IgG4 related disease refractory to steroids and other immunosuppressant therapies.

MATERIALS AND METHODS

We undertook a systematic search of the specialist databases EMBASE, LILACS, PUBMED and OVID-Cochrane for publications up until December 2017.

RESULTS

After the quality analysis, we selected 27 articles (264 patients in total) for the final review, of which 23 were case reports and case series (105 patients), 3 were observational follow-up cohort studies (129 patients), and there was one clinical trial (30 patients). IgG4 related disease presents predominantly in male patients aged between 50 and 70 years on average. Multiple organs are compromised with an average of 3.5 compromised organs. Orbital, glandular and lymph-node compromise is most frequent. Patients in the different studies we included had received various treatments prior to starting rituximab, including glucocorticoids and disease-modifying anti-rheumatic drugs. There was 90.7% response in the cases where rituximab was used as second line therapy; rituximab was used as first line treatment for 10% of the patients with a 100% response rate.

CONCLUSION

The use of rituximab for patients refractory to first-line treatments was associated with a high response percentage and less dependence on glucocorticoids.

Does IgG4 level at the time of diagnosis correlate with disease outcome in IgG4-Related disease?

BACKGROUND/OBJECTIVES

Serum IgG4 level is used as a diagnostic criterion for immunoglobulin G4-related disease (IgG4-RD) but whether it predicts disease progression is unclear. Aim of the study was to investigate if serum IgG4 level at the time of diagnosis correlates with disease outcome.

METHODS

Patients with a definitive diagnosis of IgG4-RD were included in this study. They were divided into two groups - Group 1: Elevated serum IgG4 at diagnosis and Group 2: Normal serum IgG4 at diagnosis. Outcome parameters including multiple organ involvement, exocrine and endocrine dysfunction, relapse and mortality were compared. Data was subanalysed for outcomes on 2 levels of serum IgG4 cut-off - A: The upper limit of normal (ULN) and B: Twice the ULN.

RESULTS

Of 47 patients, 31 (66%) patients had elevated serum IgG4 at diagnosis. There was no statistically significant difference between the two groups in any of the outcome parameters. Data analysed with the serum IgG4 levels > ULN showed no difference between the 2 groups for any of the outcome parameters. However, when the serum IgG4 cut-off was set to twice the ULN, there was a significantly higher rate of disease relapse (42.9% vs 11.5%, p = 0.02) and pancreatic exocrine insufficiency (PEI) (76.2% vs 42.3%, p = 0.041).

CONCLUSION

Raised serum IgG4 greater than two times the ULN was significantly associated with disease relapse and PEI in patients with IgG4-RD. Larger multicentre studies with longer follow-up are required to corroborate these findings and define the role and cut-off value of serum IgG4 in outcomes of IgG4-RD.

IgG4-related disease mimicking pancreatic cancer: Case report and review of the literature

•

Pancreatic masses pose a diagnostic challenge, and cancer has to be always considered.

•

IgG4-related disease is a rare cause of pancreatic masses.

•

Biopsy from the pancreas is not always required if histopathology from a more accessible peripheral site lesion confirms the diagnosis.

•

Multiorgan involvement and aortitis should raise suspicion of IgG4-related disease.

Introduction

Most patients with pancreatic masses pose a diagnostic challenge when a benign lesion is suspected, and often, resection is needed before a benign diagnosis is confirmed.

Presentation of case

A 57 years old male patient presented with a pancreatic head mass, obstructive jaundice and submandibular lymph node enlargement. He also had a history of recurrent eye pain and redness, skin lesions, and benign prostatic hypertrophy. MRI showed a pancreatic head mass with double duct sign, aortic thickening, bilateral renal lesions, diffuse lymph node enlargement, and prostatic enlargement. FDG-PET/CT demonstrated abnormal uptake corresponding to the MRI lesions, and there were elevated IgG4 levels on blood investigations. Biopsy of an inguinal lymph node revealed infiltrates with IgG4 plasma cells, consistent with the diagnosis of IgG4 disease. The patient was treated with IV steroids and showed significant improvement.

Discussion

IgG4 related disease is a rare entity that is characterized by lesions that show heavy infiltration with IgG4 positive plasma cells, storiform fibrosis, and obliterative phlebitis. The pancreas is the most commonly involved organ, but several other organ systems are involved, and this helps in clinical suspicion of the diagnosis. A biopsy from any easily accessible site that shows the characteristic histological features is sufficient for diagnosis. Patients respond quickly to steroids, but recurrence is frequent.

Conclusion

IgG4 related disease is a rare cause of pancreatic tumorous lesions that need a high index of suspicion for diagnosis and should be differentiated from pancreatic neoplastic lesions.

Paratesticular Fibrous Pseudotumor: A New Entity of IgG4-Related Disease?

INTRODUCTION

Paratesticular fibrous pseudotumor (PFP) represents a benign tumor-like lesion confined to intrascrotal, paratesticular areas. Due to its rarity, only less than 200 cases have been reported to date, of which both pathogenesis and clinical management are little understood. Recently, PFP has been postulated to be among the spectrum of so-called immunoglobulin G4-related diseases (IgG4-RD). Here we describe a case of PFP focusing on the clinical, morphological features and the utility of immunohistochemistry to support the theory that PFP might be a potential member of IgG4-RD family.

CASE PRESENTATION

A 41-year-old man presented with a slowly growing, right intrascrotal mass An MRI scan revealed a diffuse-proliferative nodular mass around the paratesticular area. The patient underwent right orchiectomy and a diffuse multinodular tumor with testicular compression was discovered without intratesticular infiltration. Postoperatively, the patient has been well for 2 years up to the recent follow up. On histological examination, the lesion consisted of hyalinized fibrotic tissue with storiform patterns. There were scattered germinal centers; lymphocytic vasculitis was also noted. The immunoglobulin G4 staining showed infiltration of positive plasma cells with highest count 52 per high-power field, whereas the mixed Kappa and Lambda immunoglobulin light chain expression indicated the polyclonality of the plasma cell population.

CONCLUSIONS

The morphological and immunohistochemical features in our case support the theory of PFP being part of IgG4-RD. Familiarity to this tumor-like lesion is crucial, since it may respond to corticosteroid therapy, which may save patients from more aggressive surgical procedures.

Lung Manifestations of IgG4-related Disease. A multifaceted disorder. Presentation of two cases and short review of the literature

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a recently described systemic inflammatory disease associated with elevated circulating levels of IgG4. IgG4-RD may affect one or more organs and lesions can present synchronously or metachronously in different organs. Pulmonary involvement of IgG4-related disease includes airway, lung parenchyma, pleura and mediastinum. In this article, we report two cases of IgG4-RD to show the multifaceted manifestations of this disease in the lungs. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 74-80).

[Clinical Evaluation of Diagnostic and Treatment Protocol of Idiopathic Retroperitoneal Fibrosis Incorporating Consideration of Possible IgG4-Related Disease]

About half of idiopathic retroperitoneal fibrosis might be classified as a IgG4-related disease, a newly characterized disease that is especially known to be sensitive to steroid therapy. We developed a new protocol for diagnosis and treatment of retroperitoneal fibrosis, which included aggressive diagnosis of IgG4- related disease. We retrospectively reviewed 22 cases with idiopathic retroperitoneal fibrosis that were diagnosed and treated according to our protocol. Of them, 10 patients (45.5%) had no evidence of IgG4- related disease (non-IgG4RD group), whereas 12 patients (54.5%) were diagnosed with IgG4-related disease (IgG4RD group). All patients received steroid therapy, and 13 patients (59.1%) underwent ureteral stenting or received prednisolone (PNS). There was no severe adverse event and planned steroid therapy was completed in all patients. In principle, maintenance steroid therapy was continued after induction therapy in the IgG4RD group, whereas steroid therapy was discontinued in the non-IgG4RD group. Regression of retroperitoneal plaque was achieved in all 22 patients. Four (57.1%) out of 7 patients and 3 (50.0%) out of 6 patients achieved freedom from ureteral stent or PNS in the non-IgG4RD group and IgG4RD group, respectively. All 3 patients with PNS became catheter-free after treatment, whereas only 4 (40.0%) of the 10 patients withureteral stent could become stent-free. Steroid therapy could be discontinued in 7 patients (70.0%) in the non-IgG4RD group. The results of this study suggest that similar efficacy of steroid therapy can be expected in the non-IgG4RD group and IgG4RD group.

Pathogenesis and clinical spectrum of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a disease of the biliary tract, which has been documented in the literature since 1867. This disease has a strong predilection for affecting men and can be seen in individuals as young as 2 years of age. PSC has a strong associated with inflammatory bowel disease, more commonly with ulcerative colitis, and is also part of the clinical spectrum of IgG4-related diseases. Small-duct PSC, a variant of PSC, also has an association with inflammatory bowel disease. The exact pathogenesis of PSC is not well understood at present, however, is likely a combination of a genetic predisposition with alteration of the molecular structure of the gut. Abnormal serum liver chemistry and presence of certain autoimmune markers are usually the first indicators leading to a diagnosis of PCS, however, these may often be normal in early stages of this disease. The diagnosis is made by cholangiography, which is now considered the gold standard. PSC is a known pre-malignant condition. Such patients have an increased risk of developing cholangiocarcinoma, gallbladder neoplasia, and colon cancer. Many new treatment modalities have emerged in the recent past, including anti-tumor necrosis factor- α and anti-integrins; however, liver transplantation is the only known cure for PSC. Despite past and present research, PSC remains an enigmatic biliary disease with few viable treatment options.

Immunoglobulin G4 related thyroid disorders: Diagnostic challenges and clinical outcomes

Ig-G4 related disease (IgG4RD) is a heterogeneous disorder with multi-organ involvement recognised as a separate entity at the start of this century only. It is currently one of the hottest areas of clinical and translational research across specialties. Thyroid involvement in IgG4RD is rare, believed to occur in less than 4% of cases, may be isolated or may be associated with other organ involvement. As of today Riedel's thyroiditis, fibrosing variant of Hashimoto's thyroiditis, and few patients of Graves' orbitopathy represent the types of IgG4-related thyroid disease (IgG4RTD). This disorder is frequently confused with malignancy due to the intense sclerosis of thyroid resulting in hard texture on palpation compounded by often-associated compressive symptoms. Diagnosis involves establishing high circulating levels of IgG4 > 135 mg/dL, increased serum IgG4 to IgG ratio of > 8%, immunohistochemistry showing dense lymphoplasmacellular inflammatory infiltrate consisting of IgG4-positive plasma cells with storiform fibrosis and obliterative phlebitis, and increased IgG4 positive plasma cell > 10 cells per high-power field when at least three fields are evaluated. Glucocorticoids are the primary form of therapy in IgG4RD. However, their role in IgG4RTD needs to be evaluated. As of today levothyroxine supplementation for resulting hypothyroidism, appropriate management of Graves' disease, and surgical excision of thyroid in case of compressive symptoms remain the primary treatment options. (Endokrynol Pol 2016; 67 (5): 520-524).