Immunoglobulin G4-Related Disease, A Diagnosis to Take into Account: About a Case

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated and multisystemic condition associated with developing fibroinflammatory lesions in any organ. The diagnosis is made based on the sum of clinical, serological, radiological, and histopathological criteria; however, this is often difficult due to its similarity to neoplasms, infections, or other immune-mediated diseases. Treatment is based on corticosteroids, in a possible combination with immunomodulators. The present case concerns a 59-year-old man with a history of jaundice syndrome and weight loss, admitted for suspected malignant neoplasia of the bile duct. Imaging revealed stricture with dilation of the intrahepatic bile ducts, prominent pancreas, pancreatic duct stricture, and nodular renal lesions. Due to the history of left submandibulectomy two years before the current disease and histology compatible with Küttner's tumor, plus the high IgG4 serum values, the diagnosis of IgG4-RD was established. He started treatment with corticosteroids and was asymptomatic during follow-up.

La enfermedad relacionada con inmunoglobulina G4 (ER-IgG4) es una condición inmunomediada y multisistémica asociada al desarrollo de lesiones fibroinflamatorias en cualquier órgano. El diagnóstico se realiza bajo la suma de criterios clínicos, serológicos, radiológicos e histopatológicos; sin embargo, este suele ser difícil debido a su similitud con neoplasias, infecciones u otras enfermedades inmunomediadas. El tratamiento se basa en corticosteroides, en una posible combinación con inmunomoduladores. El presente caso trata de un varón de 59 años con historia de síndrome ictérico y baja de peso, admitido por sospecha de neoplasia maligna de la vía biliar. Las imágenes revelaron estenosis con dilatación de las vías biliares intrahepáticas, páncreas prominente, estenosis del conducto pancreático y lesiones nodulares renales. Debido al antecedente de submandibulectomía izquierda 2 años antes de la enfermedad actual e histología compatible con tumor de Küttner, más los valores elevados de IgG4 sérico, se estableció el diagnóstico de ER-IgG4. Inició tratamiento con corticosteroides y cursó asintomático durante el seguimiento.

Una inusual causa de estrechez de la vía aérea laringotraqueal / An unusual cause of laryngotracheal airway narrowing

La enfermedad relacionada con inmunoglobulina (Ig) G4 es una enfermedad de reciente conocimiento que puede comprometer cualquier órgano teniendo preferencias por ciertas regiones del cuerpo, donde la región de cabeza y cuello es uno de sus principales puntos afectados, pudiendo comprometer tanto la órbita, glándulas salivales, glándulas lagrimales, glándula tiroides, cavidades paranasales, hueso temporal, faringe y laringe. Este último órgano es infrecuentemente comprometido, solo existiendo 12 casos registrados en la literatura antes de la publicación de este escrito. Presentamos un caso de una mujer de 49 años con historia de disnea frente a esfuerzo, diagnosticándose una estenosis subglótica la cual fue manejada quirúrgicamente con una reconstrucción laringotraqueal. En el estudio histopatológico se evidenció histología compatible con enfermedad relacionada con IgG4, por lo que se inició tratamiento médico con corticotera- pia oral por un lapso de 2 meses en conjunto con inmunología. Paciente luego de 4 años de seguimiento, no ha presentado recaídas, manteniendo un lumen subglótico adecuado.

Immunoglobulin (Ig) G4-related disease is a medical condition of recent knowledge that can compromise any organ, having preferences for certain regions of the body, where the head and neck region is one of the main affected points, being able to affect orbit, salivary glands, lacrimal glands, thyroid gland, paranasal cavities, temporal bone, pharynx and larynx. The latter is infrequently compromised, with only 12 cases registered in the literature before the publication of this writing. We present a case of a 49-year-old woman with a history of exertional dyspnea, diagnosed with a sub- glottic stenosis which was managed surgically with laryngotracheal reconstruction. The histopathological study revealed histology compatible with IgG4-related disease, so medical treatment with oral corticosteroid therapy was started for a period of 2 months in conjunction with immunology. After 4 years of follow-up, the patient has not presented relapses, maintaining an adequate subglottic lumen.

IgG4-related hypertrophic pachymeningitis: a case report / 中华神经科杂志

A case of IgG4-related hypertrophic pachymeningitis was reported. The patient was an elderly female, with the course of disease more than 8 years. Clinical manifestations included recurrent headache, vision and hearing loss, exophthalmos and thyroid dysfunction. Finally, she was diagnosed as IgG4-related disease and IgG4-related hypertrophic pachymeningitis by PET-CT and dural biopsy. After treatment with methylprednisolone and mycophenolate mofetil, the patient′s clinical symptoms improved.

A case of duodenal ulcer as prominent manifestation of IgG4-related disease / 北京大学学报(医学版)

A case of IgG4-related disease presented with a duodenal ulcer to improve the understan-ding of IgG4-related diseases was reported. A 70-year-old male presented with cutaneous pruritus and abdominal pain for four years and blackened stools for two months. Four years ago, the patient went to hospital for cutaneous pruritus and abdominal pain. Serum IgG4 was 3.09 g/L (reference value 0-1.35 g/L), alanine aminotransferase 554 U/L (reference value 9-40 U/L), aspartate aminotransferase 288 U/L (reference value 5-40 U/L), total bilirubin 54.16 μmol/L (reference value 2-21 μmol/L), and direct bilirubin 29.64 μmol/L (reference value 1.7-8.1 μmol/L) were all elevated. The abdominal CT scan and magnetic resonance cholangiopancreatography indicated pancreatic swelling, common bile duct stenosis, and secondary obstructive dilation of the biliary system. The patient was diagnosed with IgG4-related disease and treated with prednisone at 40 mg daily. As jaundice and abdominal pain improved, prednisone was gradually reduced to medication discontinuation. Two months ago, the patient developed melena, whose blood routine test showed severe anemia, and gastrointestinal bleeding was diagnosed. The patient came to the emergency department of Beijing Hospital with no improvement after treatment in other hospitals. Gastroscopy revealed a 1.5 cm firm duodenal bulb ulcer. After treatment with omeprazole, the fecal occult blood was still positive. The PET-CT examination was performed, and it revealed no abnormality in the metabolic activity of the duodenal wall, and no neoplastic lesions were found. IgG4-related disease was considered, and the patient was admitted to the Department of Rheumatology and Immunology of Beijing Hospital for further diagnosis and treatment. The patient had a right submandibular gland mass resection history and diabetes mellitus. After the patient was admitted to the hospital, the blood test was reevaluated. The serum IgG4 was elevated at 5.44 g/L (reference value 0.03-2.01 g/L). Enhanced CT of the abdomen showed that the pancreas was mild swelling and was abnormally strengthened, with intrahepatic and extrahepatic bile duct dilation and soft tissue around the superior mesenteric vessels. We pathologically reevaluated and stained biopsy specimens of duodenal bulbs for IgG and IgG4. Immunohistochemical staining revealed remarkable infiltration of IgG4-positive plasma cells into duodenal tissue, the number of IgG4-positive cells was 20-30 cells per high-powered field, and the ratio of IgG4/IgG-positive plasma cells was more than 40%. The patient was treated with intravenous methylprednisolone at 40 mg daily dosage and cyclophosphamide, and then the duodenal ulcer was healed. IgG4 related disease is an immune-medicated rare disease characterized by chronic inflammation and fibrosis. It is a systemic disease that affects nearly every anatomic site of the body, usually involving multiple organs and diverse clinical manifestations. The digestive system manifestations of IgG4-related disease are mostly acute pancreatitis and cholangitis and rarely manifest as gastrointestinal ulcers. This case confirms that IgG4-related disease can present as a duodenal ulcer and is one of the rare causes of duodenal ulcers.

Medical visit status and clinical features in patients with IgG4 related disease / 北京大学学报(医学版)

OBJECTIVE@#To understand the medical treatment and clinical characteristics of patients with IgG4-related disease (IgG4-RD) with complex clinical manifestations and easy to be misdiagnosed and missed, and to improve the recognition of this disease among doctors from relevant medical departments.@*METHODS@#A retrospective analysis was conducted on the medical records of patients diagnosed with IgG4-RD who were hospitalized and discharged from Peking University Third Hospital from January 1, 2012 to December 31, 2022. The patient' s medical visit status, clinical manifestations, laboratory examinations, diagnosis, and treatment information were summarized.@*RESULTS@#A total of 116 patients diagnosed with IgG4-RD were included in this study, with a male to female ratio of 2. 52∶ 1 and an average age of (61.83±10.80) years. The departments for initial visits were gastroenterology, general surgery, and ophthalmology. While the departments responsible for definitive diagnosis were gastroenterology, rheumatology and immunology, and respiratory medicine. Twenty-one patients (18. 10%) required consultation and treatment from three or more departments before receiving a definitive diagnosis. The median time from symptom onset to the initial clinic visit was 2 (1, 7) months, and the median time from symptom onset to diagnosis was 1 (1, 12) month. Twenty-four patients (20.69%) underwent surgical resection of the affected sites before diagnosis. According to the classification criteria of IgG4-RD, sixty-eight (58.62%) cases were diagnosed definitively, eight (6.9%) cases were likely to be diagnosed, and 40 (34.48%) cases were suspected to be diagnosed. In the 68 definitively diagnosed patients, the most commonly affected organs were submandibular gland, the pancreas, biliary tract, parotid in sequence. The median serum IgG4 (IgG4, immunoglobulin G4) level was 6.16 (3. 61, 12. 30) g/L. Fifty-seven patients (83.82%) were treated with glucocorticoids, and 14 patients (20.59%) were treated with immunosuppressants. The use of immunosuppressants was mainly in the rheumatology and immunology department (78. 57%).@*CONCLUSION@#IgG4-RD is more common in elderly males, with submandibular gland, the pancreas, biliary tract, and parotid being most commonly affected. The distribution of initial visit departments in patients is wide. The proportion of definitive diagnosis based on pathology is relatively low. In terms of treatment, the main approach is steroid treatment, while the use of immunosuppres-sants is not widespread.

Isolated external iliac artery aneurysm: a rare case presentation of IgG4-related disease / Aneurisma isolado de artéria ilíaca externa - uma apresentação de caso raro de doença relacionada à IgG4

Abstract Isolated external iliac artery aneurysm is a rare occurrence. These aneurysms have varied presentations depending on size and proximity. Both open surgical and endovascular modalities can be used for treatment depending upon presentation, aneurysmal anatomy, and patient condition. Preservation of at least one internal iliac artery is important to prevent post-repair hypogastric ischemia. There are no previous reports of IgG4-related disease (IgG4-RD) as etiology of these aneurysms. A 32-year-old male patient presented with a left lower abdominal lump and was found to have a left external iliac artery aneurysm on computed tomography angiography. The patient underwent iliofemoral bypass with an 8 mm polyester graft. Histopathological examination of the aneurysm wall suggested IgG4-RD. The patient fulfilled the 2020 Revised Comprehensive Diagnostic Criteria for IgG4-RD. An 18-Fluorodeoxyglucose-Positron Emission Tomography scan performed in the postoperative period showed no active disease, hence medical therapy was not instituted. The patient is doing well at 1 year.

Resumo O aneurisma isolado da artéria ilíaca externa é uma ocorrência rara. Esses aneurismas têm apresentações variadas, dependendo do tamanho e da proximidade. Ambas as modalidades cirúrgicas aberta e endovascular podem ser usadas para o tratamento, dependendo da apresentação, anatomia do aneurisma e condição do paciente. A preservação de pelo menos uma artéria ilíaca interna é importante para prevenir isquemia hipogástrica pós-reparação. A doença relacionada à imunoglobulina G4 (IgG4-RD) nunca havia sido encontrada como etiologia desse aneurisma. Um paciente do sexo masculino de 32 anos que apresentava um nódulo no abdome inferior esquerdo foi diagnosticado com aneurisma da artéria ilíaca externa esquerda na angiotomografia computadorizada. O paciente foi submetido a bypass iliofemoral com enxerto de poliéster de 8 mm. O exame histopatológico da parede do aneurisma era indicativo de IgG4-RD. O paciente cumpriu os Critérios Abrangentes Revisados ​​para IgG4-RD de 2020. A tomografia por emissão de pósitrons com 18-fluorodesoxiglicose no pós-operatório não evidenciou doença ativa, não sendo instituída terapia medicamentosa. Após seguimento de 1 ano, o paciente está bem.

IgG4 related sclerosing encapsulating peritonitis with cocoon formation: An unusual and undescribed presentation

IgG4-related sclerosing mesenteritis is a rare disease of mesentery of an unknown etiology which shows a constellation of histopathologic findings of lymphoplasmacytic inflammation with IgG4-positive plasma cells and marked fibrosis. This chronic inflammatory condition of mesentery forming an abdominal cocoon has never been described before to the best of our knowledge. Here, we report a patient with a history of subacute small bowel obstruction who was found to have an intra-abdominal encapsulating mass in the right iliac fossa and was finally diagnosed as IgG4-related sclerosing encapsulating peritonitis (abdominal cocoon) based on peroperative findings, histology and immunohistochemistry.

Hallazgos histológicos de glándulas salivales mayores y menores en pacientes con enfermedad relacionada a IgG4 / Histological findings of major and minor salivary glands in patients with IgG4 related disease

Introducción: la enfermedad relacionada con IgG4 (ER-IgG4) es una afección inmunomediada, asociada con lesiones fibroinflamatorias que pueden ocurrir en casi cualquier órgano. Ante su sospecha clínica es fundamental realizar el examen histopatológico para excluir malignidad y otras enfermedades. El objetivo principal de este estudio fue describir los hallazgos histológicos de la biopsia de glándulas salivales labiales (GSL) en pacientes con diagnóstico de ER-IgG4 y, posteriormente, comparar estos hallazgos con la histología e inmunohistoquímica de la glándula salival mayor (GSM). Materiales y métodos: estudio retrospectivo, observacional y descriptivo sobre una cohorte de 40 pacientes con diagnóstico de ER-IgG4. Se incluyeron 26 pacientes con diagnóstico de ER-IgG4 que presentaron biopsias de GSL. Resultados: el 73% de la muestra tuvo un infiltrado linfoplasmocitario y el 11%, fibrosis con patrón no estoriforme. En ningún caso se halló arteritis obliterativa ni ninguna forma de flebitis. Al realizar la comparación con los hallazgos de las biopsias de GSM, no hubo significancia estadística. El 65% de los pacientes manifestó compromiso extraglandular y fueron los sistemas pancreato hepato biliar y las adenopatías los más afectados. Conclusiones: la biopsia incisional de glándula submandibular sería más útil y apropiada que la biopsia de GSL para un diagnóstico definitivo de ER-IgG4.

Introduction: IgG4-related disease (IgG4-RD) is an immune-mediated condition associated with fibroinflammatory lesions that can occur in almost any anatomical site. Histopathological examination is essential when suspected to diagnose it to exclude malignancy and other diseases. The objective of this study was to describe the histological findings of the minor salivary gland biopsy (GSL) in patients diagnosed with IgG4-RD, and subsequently to correlate these findings with the histology and immunohistochemistry of the major salivary gland (GSM). Materials and methods: retrospective, observational and descriptive study on a cohort of 40 patients diagnosed with RD-IgG4. Twenty-six patients diagnosed with IgG4-RD who presented SLG biopsies were included. Results: the 73% of the samples presented a lymphoplasmacytic infiltrate and 11% of them fibrosis with a non-storiform pattern. In no case was obliterative arteritis or any form of phlebitis found. When comparing the findings of the GSM biopsies, there was no statistical significance. Sixty-five percent of the patients presented extraglandular involvement; the pancreato-hepato-biliary system and the adenopathies were the most affected. Conclusions: incisional biopsy of the submandibular gland would be more useful and appropriate than LSG for a definitive diagnosis of IgG4-RD.

Sialoadenitis esclerosante asociada a enfermedad por IgG4: reporte de un caso / Sclerosing sialadenitis associated with IgG4 disease: case report

Las enfermedades relacionadas con IgG4 (ER-IgG4) son entidades fibroinflamatorias e inmunomediadas, caracterizadas por la afección multiorgánica, con la formación de pseudotumores que provocan lesión tisular y daño orgánico subsecuente. Se describe el caso de un paciente de 43 años que presentó sialoadenitis esclerosante y cumplió todos los criterios diagnósticos de enfermedad relacionada con IgG4.

IgG4-related diseases (IgG4-RD) are fibroinflammatory immune-mediated entities characterized by multiorgan involvement with the development of pseudotumors that cause tissue injury and subsequent organ damage. We describe the case of a 43-year-old man who presented sclerosing sialadenitis and fulfilled the diagnostic criteria for IgG4-related disease.

Analysis of the characteristics of IgG4-related membranous nephropathy with literature review / 中华风湿病学杂志

Objective:By retrospectively analyzing 6 cases of IgG4-related membranous nephropathy (IgG4-MN), combined with literature review, to explore the clinical and renal pathological characteristics of the disease, and improve clinicians' understanding of the disease.Methods:The data of six patients with biopsy-proven IgG4-MN in the nephrology center of our hospital during April 2017 to January 2021 were collected. At the same time, we reviewed the literature systematically and summarized the clinicopathological characteristics.Results:Six male patients with the age ranged fom 55 to 75 years old were described. Urine protein level was (3.1±2.1) g/24 h, 3 cases (50%) showed nephrotic syndrome and 4 cases (67%) had elevated serum creatinine. The median creatinine level was (103±24) μmol/L. Six cases (100%) had elevated serum immunoglobulin (Ig)E level, and 4 cases (67%) had elevated IgG4. M-type phospholipase A2 receptor (PLA2R) was positive in 1 case (17%) and tubulointerstitial nephritis (TIN) was present in 6 cases. The review of the literature suggested that a total of 49 cases with IgG4-MN were reported, including 6 cases in this report. There were 40 males (40/46, 87%), with a age range of (61±12) years old, 32 cases (32/49, 65%) showed nephrotic syndrome range proteinuria, and the proportion of serum IgG and IgG4 increase was 61%(20/33) and 88% (36/41), respectively, 13 cases (13/15, 87%) had elevated serum IgE level, 47% (14/30) had low-complement C3 and 44%(12/27) had low-complement C4 level. The main organs involved were pancreas (15/37) and lymph nodes (16/37). Renal pathology showed TIN in 74%(36/49). Electron dense deposition was mainly subepithelial deposits. 7%(2/28) were positive for anti-PLA2R antibody in serum, 17%(3/18) were positive for PLA2R in kidney tissue, 6%(1/18) were suspected positive for PLA2R in kidney tissue, and 8%(1/12) were dual positive in blood and kidney tissue.Conclusion:IgG4-MN usually presents with nephrotic range proteinuria or nephrotic syndrome in middle-aged and elderly patients. Most of them are complicated with TIN and other organ involvement. A certain proportion of patients are PLA2R positive in IgG4-MN, and whether it is primary or secondary MN needs further study.

Advances in diagnosis and treatment of IgG4-related hepatobiliary and pancreatic diseases / 临床肝胆病杂志

IgG4-related hepatobiliary and pancreatic diseases are a part of the IgG4-related disease multiorgan fibroinflammatory disorder, including IgG4-related autoimmune pancreatitis, IgG4-related sclerosing cholangitis, and IgG4-related hepatic involvement. The main pathological features include IgG4 + plasma cell/lymphocyte infiltration, storiform fibrosis, obliterative phlebitis, and eosinophil infiltration. The diagnosis of this disease is often based on the comprehensive diagnostic criteria for IgG4-related diseases and organ-specific diagnostic criteria. However, it is difficult to differentiate IgG4-related hepatobiliary and pancreatic diseases from neoplastic diseases, and novel diagnostic biomarkers are expected to improve the sensitivity and specificity of diagnosis. To date, glucocorticoids remain the first-line drug for this disease, and biological agents, especially anti-CD20 monoclonal antibody, may be an alternative therapy for patients with corticosteroid contraindication/intolerance or recurrent/refractory disease.

Clinical analysis of 21 cases of IgG4-related diseases / 口腔疾病防治

Objective@# To summarize the clinical manifestations of IgG4-related diseases in the head and neck, explore treatment methods.@*Methods @#The clinical data of 21 patients diagnosed with IgG4-related diseases were retrospectively analyzed. The clinical data and the results of glucocorticoid and immunosuppressive therapy were studied retrospectively.@* Results@#All patients had swollen sclerotic masses, and CT showed irregular high-density masses with uniform enhancement in the enlarged glands. Some patients had mucosal thickening and mass-like changes in theoral cavity, nose, sinuses, throat and other tissues, and most of the patients had cervical lymphadenopathy and elevated serum IgG4 levels (≥ 1.35 g/L). Histopathological examination of affected exosine glands and affected mucosa and lymph nodes in all patients showed infiltration of lymphocytes, plasma cells and IgG4+ plasma cells. In 21 patients, the mass in the affected glands and mucosa (including head, neck and other tissues) disappeared, and the clinical symptoms were relieved after the application of glucocorticoids. However, with a reduction in glucocorticoids, the mass recurred or even worsened.@*Conclusion @#For patients with a single mass in the submandibular gland, parotid gland and other salivary glands, as well as lymph node enlargement, CT is the first choice to identify the nature of gland neoplasms. Combined with pathological examination, related auxiliary examination and peripheral blood examination are also needed to obtain a definitive diagnosis. Glucocorticoid therapy is used to achieve a good prognosis, and long-term follow-up and timely adjustment of medication regimens are required.

Guidelines on the diagnosis and management of primary sclerosing cholangitis (2021) / 中华肝脏病杂志

In 2015, the first Chinese consensus on the diagnosis and management of primary sclerosing cholangitis was issued. In the past years, more data have emerged from the literature. Herein, the Autoimmune Liver Disease Group of the Chinese Society of Hepatology organized an expert group to review the evidence and updated the recommendations to formulate the guidelines. There are 21 recommendations on PSC clinical practice. To facilitate the differentiation between PSC and IgG4-related sclerosing cholangitis, 10 recommendations on IgG4-SC are also attached. These guidelines aim to provide a working reference for the management of PSC and IgG4-SC.

IgG4 related disease involving the adrenal glands: a case report / 中华泌尿外科杂志

IgG4-related diseases have a low incidence and are easily misdiagnosed as tumors in clinical treatments. A 26-year-old male patient was admitted to the hospital because of a left adrenal tumor found in health examination for more than 5 months. The tumor in the left adrenal region could be seen from abdominal CT, and the retroperitoneal laparoscopic resection of the left adrenal tumor was performed. Postoperative pathology was consistent with IgG4-related diseases, and serum IgG4 was abnormally high. After 2 months’ follow-up, serum IgG4 returned to normal, and no special discomfort.

Progress on the pathogenesis and treatment of IgG4-related disease / 药学学报

IgG4-related disease (IgG4-RD) is a newly recognized fibro-inflammatory condition of autoimmune etiology in recent twenty years, mainly manifesting as mass-forming lesions in single or multiple organs. In the past, it was often missed or misdiagnosed as inflammation or tumor. Patients may die from multiple organ failure due to end-stage fibrosis if they are not treated promptly. However, the number of clinically confirmed cases has gradually increased with the improvement of diagnostic level in recent years, and these patients have benefited greatly after receiving early treatment. Although patients generally respond well to traditional immunosuppressors including glucocorticoids and disease-modifying anti-rheumatic drugs, refractory and recurrent cases, even patients with glucocorticoid contraindication are common. Important mechanistic insights have been derived from studies of B-cell depletion therapy, but greater awareness of the pathophysiology of IgG4-RD is still badly needed to identify novel therapeutic targets. In this article, we reviewed the pathogenesis progress and promising therapy of IgG4-RD to seek better clinical management of IgG4-RD.

Studies on newly recognized chronic sialadenitis / 北京大学学报(医学版)

Some kinds of chronic sialadenitis were recognized during the recent years. They have specific pathogenesis, clinical and histopathologic appearances, and require specific treatment. IgG4-related sialadenitis (IgG4-RS) is one of the immune-mediated diseases, characterized by tumefactive lesions. The incidence of IgG4-RS obviously increased during the past 30 years. The study on the potential relationship between occupational exposure to chemical substances and the incidence of IgG4-RS showed that subjects with occupational exposure to agents known to cause IgG4-RD had an increased risk for IgG4-RS. Surgical excision of involved SMG could not control the disease progression, which is not recommended for treatment of IgG4-RS. The combination of glucocorticoid and steroid-sparing agents is effective for treating IgG4-RS, and restores salivary gland function. Radioiodine induced sialadenitis (RAIS) is one of the common complications of postoperative adjuvant treatment of differentiated thyroid cancer by 131I. The incidence of the disease is related to radiation dosage. Clinically, the patients suffered from swelling and tenderness in the buccal or submandibular regions, especially during the mealtime. Imaging appearances are similar to those of chronic obstructive sialadenitis. Conservative managements, such as gland massage, sialagogues, are the mainstream methods in the treatment of RAIS. Sialendoscopy is feasible for RAIS, but not as effective as conventional obstructive sialadenitis (COS). Therefore the prevention of RAIS is crucial. Eosinophilic sialodochitis (ES) is a new type of chronic inflammatory disease of the salivary gland related to allergy. It has characteristics of swelling of multiple major salivary glands, strip-like gelatinous plugs discharged from the duct orifice of the gland, elevated level of serum IgE and eosinophils in peripheral blood, infiltration of eosinophils and IgE positive plasma cells in the tissues, allergic history, increased expression of allergy-related cytokines, such as IL-4, IL-5, IL-13, and eotaxin, which suggest allergic reactions as a potential pathogenesis of the disease. The clinical, laboratory, histological, and immunohistochemical characteristics of ES are significantly different from conventional obstructive sialadenitis (COS). Therefore, it is suitable to separate ES from COS. Conservative managements, such as self-maintenance therapy and anti- allergic modality are the choices of treatment for ES. Based on the results of our comprehensive studies a new classification of chronic sialadenitis is suggested.

Pacientes con compromiso orbitario y renal: Diagnósticos diferenciales poco frecuentes / Patients with orbitary and kidney commitment: Rare differential diagnoses

Se comunica una serie de tres casos clínicos que consultaron al servicio de Reumatología por compromiso orbitario y renal. Uno de ellos presentó pseudotumor orbitario con proteinuria en rango nefrótico; se realizó biopsia y se encontró infiltrado linfoplasmocitario denso y fibrosis estoriforme con inmunohistoquímica: 15 células IgG4+ por campo de alto poder y relación IgG/IgG4 ≤40%, concluyendo diagnóstico de enfermedad relacionada por IgG4. El segundo y tercer caso presentaron compromiso ocular con "ojos de mapache" y lesiones amarillentas en párpados, ambos con proteinuria >500 mg/24 h, con biopsia de piel rojo Congo positiva y birrefringencia verde manzana con luz polarizada. Se discuten distintos diagnósticos diferenciales poco frecuentes a tener en cuenta en estos pacientes.

A series of three cases that consulted the rheumatology service due to orbital and renal involvement is reported. One of them presented orbital pseudotumor with proteinuria in the nephrotic range, a biopsy was performed, finding dense lymphoplasmacytic infiltrate and storiform fibrosis with immunohistochemistry: 15 IgG4 positive cells per HPF and IgG/IgG4 ratio ≤40%, concluding diagnosis of IgG4 related disease. The second and third cases presented ocular involvement with raccoon eyes and yellowish lesions on the eyelids, both with proteinuria greater than 500 mg/24 h, with apple-green birefringence of amyloid on congo red staining. Different rare differential diagnoses to take into account in these patients are discussed.

Enfermedad relacionada con IgG4: reporte de un caso y revisión de la literatura / IgG4-related disease: a case report and literature review

Immunoglobulin G4 (IgG4-RD) -related disease is a regional or systemic fibroinflammatory disease of unknown etiology. It has a characteristic histopathological appearance of dense lymphoplasmacytic infiltrates with abundant IgG4 positive plasma cells, storiform fibrosis and obliterative phlebitis with the appearance of inflammatory swelling or swollen lesions. This entity frequently affects the pancreas, salivary glands, and lymph nodes, but it can compromise almost any structure in the human anatomy. This new disease entity includes a wide variety of diseases such as Mikulicz disease, autoimmune pancreatitis, Riedel's thyroiditis, interstitial nephritis, and retroperitoneal fibrosis. Glucocorticoid therapy can resolve clinical and pathologic abnormalities and impaired organ function. IgG4-RD was internationally recognized in 2011, and new evidence has accumulated on its pathogenesis, clinical characteristics, and treatment. However, much is still unknown about the behavior of IgG4 in vivo, the participation of this molecule in disease, and whether its role in IgG4-related disease is primary or secondary. The text below is based on a brief review of the most recent literature on this entity in relation to a clinical case.

IgG4-related kidney disease presenting as a cystic renal mass: a case report and literature review / 中华泌尿外科杂志

Objective:To investigate the clinical characteristics, differential diagnosis and treatment of IgG4-related kidney disease (IgG4-RKD) presenting as a cystic renal mass.Methods:A 42-year-old male patient was found having a tumor in the left kidney in an annual physical examination. Subsequent CTU scan revealed a round shadow in the lower pole of the left kidney, with slightly lower, uneven density and obscure boundaries, which was slightly enhanced on contrast-enhanced CT imaging, suggesting a cystic mass (Bosniak category Ⅲ). Contrast-enhanced MRI showed a long T1, long T2 signal lesion in the lower pole of the left kidney, which was not obviously enhanced in the cortical phase but exhibited continuous and separated enhancement in parenchymal and delayed phases, suggesting a cystic renal cell carcinoma. A preoperative diagnosis of a left renal mass was made, for which the patient underwent a laparoscopic partial nephrectomy.Results:The resected cystic mass was grey white with obscured boundaries. Microscopically, the mass showed lymphoplasmacytic hyperplasia with lymphoid follicles, cystic formation, fibrosis hyperplasia and vascular obstruction. Immunohistochemistry revealed that the number of IgG4 (+ ) plasma cells was more than 50/HPF, and over 40% IgG (+ ) plasma cells were IgG4 (+ ). By virtue of the radiologic and pathologic findings, the patient was diagnosed with IgG4-RKD. At 2 weeks after operation, serum IgG level was 0.71g/L (reference: 0.03-2.01 g/L). Chest and abdominal CT scans performed 3 months after operation showed no evidence of other organ involvement and serum IgG4 level was within the normal range. Therefore no adjuvant therapy was prescribed.Conclusions:It is usually difficult to differentiate IgG4-RKD presenting as a cystic renal mass by radiography alone. The presence of other organ involvement, serum IgG4 test and renal biopsy can help the diagnosis and so as to avoid unnecessary surgery.

Lung adenocarcinoma misdiagnosed as IgG4-related lung disease:A case report and literature review / 中南大学学报(医学版)

IgG4-related disease (IgG4-RD) is a recently recognized disorder characterized by elevated serum IgG4 levels and infiltration of IgG4 positive blood cells in the affected organs. However, other conditions like malignancy as well as connective tissue diseases, may show similar findings. A 56-year-old male patient visited Second Xiangya Hospital, Central South University for recurrent fever and chest pain for more than 1 month. Preliminary tests diagnosed as IgG4-related lung disease (IgG4-RLD). However, the improvement of symptoms was absent after the treatment with methylprednisolone. The patient underwent the second biopsy and the result eventually demonstrated lung adenocarcinoma. The role of IgG4 in the pathogenesis or prognosis for lung adenocarcinoma remains unclear. Therefore, a thorough evaluation of symptoms, test of specific serum markers and eventually pathological confirmation are required to avoid misdiagnosis.