Gastric IgG4-related disease mimicking a gastrointestinal stromal tumor in a child: A case report

BACKGROUND Gastric IgG4-related disease(IgG4-RD)is rarely encountered in clinical practice,and especially more so among pediatric patients.To our knowledge,this is the first report of IgG4-RD presenting as a calcifying gastric mass in a child.We describe how this entity was difficult to differentiate from a gastrointestinal stromal tumor(GIST)imaging-based approaches.Therefore,this case highlights the importance of considering IgG4-RD in the differential diagnosis of gastric tumor before performing surgical resection,especially to distinguish it from malignancy to avoid unnecessary surgery.CASE SUMMARY The patient suffered from epigastric pain for several days.Panendoscopy and computed tomography scan revealed a submucosal tumor.Differential diagnoses included GIST,leiomyoma,teratoma,and mucinous adenocarcinoma.However,laparoscopic proximal gastrectomy allowed for the definitive diagnosis of IgG4-related stomach disease.CONCLUSION We emphasize the importance of considering IgG4-RD in the differential diagnosis of gastric submucosal tumors before performing surgical resection.

CT and MR imaging findings of ocular adnexal mucosa-associated lymphoid tissue lymphoma associated with IgG4-related disease: multi-institutional case series

AIM:To report CT and MR imaging findings of ocular adnexal mucosa-associated lymphoid tissue lymphoma associated with IgG4-related disease(IgG4-MALT lymphoma),a rare but clinically important complication of ocular adnexal IgG4-related disease.METHODS:We retrospectively reviewed all cases of histologically confirmed ocular adnexal IgG4-related disease at three ter tiary and one secondary referral centers,between February 2003 and December 2016.Seven cases of histopathologically diagnosed IgG4-MALT lymphoma were identified.CT and MR images were analyzed by consensus of two experienced head and neck radiologists.RESULTS:Lacrimal glands were the main site of involvement in all seven patients.The lesions typically showed well-demarcated margins,iso-to hyperattenuation on precontrast CT,T2 hypo-to isointensity,T1 isointensity,and homogenous internal architecture with homogenous enhancement pattern.Lesions were mostly hyperdense and isointense to normal extraocular muscles on postcontrast CT and MR images,respectively.CONCLUSION:Unlike in typical ocular adnexal IgG4-related disease,T2 isointensity and hyperattenuation on precontrast CT images were noted in some IgG4-MALT lymphoma cases.Although the findings may be nonspecific,the possibility of accompanying MALT lymphoma may need to be considered,when ocular adnexal lesions in patients clinically suspected of having IgG4-related disease are refractory to glucocorticoids and show T2 isointensity and hyperattenuation on precontrast CT for the optimal management of the patients.However,this is a case series of a very rare complication of ocular adnexal IgG4-related disease,and thus caution is warranted to generalize the conclusion.

Multi-organ IgG4-related disease continues to mislead clinicians: A case report and literature review

BACKGROUND Immunoglobulin G4-related disease(IgG4-RD)is a multisystemic mass forming immune-mediated disease that affects almost every organ and is a diagnostic challenge for every clinician.There is a lack of adequate epidemiological data worldwide,and evidence-based treatment recommendations are not yet established.We report the first case of IgG4-RD from Lithuania and the Baltic Sea region presented with thyroiditis,orbital myositis,orbitopathy,uveitis,scleritis,sialadenitis,autoimmune pancreatitis and prostatitis.CASE SUMMARY A 54-year-old Caucasian male was admitted to our tertiary Centre complaining of severe weight loss,diarrhoea,abdominal pain,salivary gland swelling,sicca symptoms and diplopia.On examination,bilateral palpable masses in the projection of major salivary glands,severe protrusion of the left eyeball and cachexia were noted.The patient was previously diagnosed with autoimmune thyroiditis and endocrine ophthalmopathy.The magnetic resonance imaging(MRI)of the head revealed enlarged extraocular muscles indicating orbital myositis.The biopsy from the salivary gland mass indicated sialadenitis.Abdominal MRI showed signs of autoimmune pancreatitis,and a serological test revealed the elevated serum IgG4 concentration.The patient was then diagnosed with IgG4-RD and successfully treated with prednisolone.There was a significant clinical,serological and radiological improvement after one month of treatment and no signs of relapse within twenty months.However,it took almost 18 years and the efforts of eight different medical specialists to establish the correct diagnosis.CONCLUSION A comprehensive approach to the patient is essential to improving the recognition of rare immune system conditions,such as IgG4-RD.

IgG4-Related Disease Presenting as a Soft Tissue Tumor Affecting Skeletal Muscle: A Case Report

Background: IgG4-related disease is a systemic lymphoproliferative syndrome that shows IgG4-producing plasma cell expansion in affected organs with fibrotic or sclerotic changes. The lacrimal glands, salivary glands and pancreas are typically affected. We report a case of IgG4-related disease presenting a soft tissue tumor affecting skeletal muscle. Case Report: A 32-year-old man presented a soft tissue mass in his left arm. Magnetic resonance imaging revealed a spindle like, peripheral mass, in the lateral head of the triceps of his left arm. Tru-Cut Biopsy provided the diagnosis of IgG4-related disease affecting skeletal muscle. Glucocorticoid treatment was effective. Conclusion: To our knowledge, this is the first reported case of IgG4-related disease affecting skeletal muscle and presenting a soft tissue mass.

Autoimmune pancreatitis in the context of IgG4-related disease:Review of imaging findings

Current understanding of autoimmune pancreatitis(AIP) recognizes a histopathological subtype of the disease to fall within the spectrum of IgG4-related disease.Along with clinical,laboratory,and histopathological data,imaging plays an important role in the diagnosis and management of AIP,and more broadly,within the spectrum of IgG4-related disease.In addition to the defined role of imaging in consensus diagnostic protocols,an array of imaging modalities can provide complementary data to address specific clinical concerns.These include contrast-enhanced computed tomography(CT) and magnetic resonance(MR) imaging for pancreatic parenchymal lesion localization and characterization,endoscopic retrograde and magnetic resonance cholangiopancreatography(ERCP and MRCP) to assess for duct involvement,and more recently,positron emission tomography(PET) imaging to assess for extra-pancreatic sites of involvement.While the imaging appearance of AIP varies widely,certain imaging features are more likely to represent AIP than alternate diagnoses,such as pancreatic cancer.While nonspecific,imaging findings which favor a diagnosis of AIP rather than pancreatic cancer include:delayed enhancement of affected pancreas,mild dilatation of the main pancreatic duct over a long segment,the "capsule" and "penetrating duct" signs,and responsiveness to corticosteroid therapy.Systemic,extra-pancreatic sites of involvement are also often seen in AIP and IgG4-related disease,and typically respond to corticosteroid therapy.Imaging by CT,MR,and PET also play a role in the diagnosis and monitoring after treatment of involved sites.

Autoimmune hepatitis and IgG4-related disease

IgG4-related disease(IgG4-RD) is a chronic-fibroinflammatory disorder affecting a wide range of organs. Elevation of serum IgG4 concentrations and abundant infiltration of IgG4-expressing plasma cells are key diagnostic features of this autoimmune disease. Although common organ involvement of IgG4-RD includes the salivary glands, pancreas, and bile duct, hepatic involvement is less well established. Recently, five studies identified a subtype of autoimmune hepatitis(AIH), called IgG4-associated AIH(IgG4-AIH). IgG4-AIH is diagnosed based on significant accumulation of IgG4-expressing plasmacytes in the liver in patients who met the diagnostic criteria for classical AIH. Although four of the five reports regarded IgG4-AIH based on hepatic accumulation of IgG4-positive cells alone, one report diagnosed IgG4-AIH based on both hepatic accumulation of IgG4-positive cells and elevated serum concentrations of IgG4. IgG4-AIH diagnosed based on the latter criteria may be a hepatic manifestation of IgG4-RD whereas IgG4-AIH diagnosed based on the former criteria may be a subtype of AIH. In this review article, we summarize and discuss clinicopathological features of IgG4-AIH.

IgG4-Related Disease:A Retrospective Chinese Study of Features and Treatment Response of 98 Patients Including 4 Rare Cases

The features and treatment of 98 Chinese patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD) referred to a single tertiary referring centre were reviewed. Patientsdiagnosed with IgG4-RD according to the comprehensive diagnostic criteria (CDC) were includedin the retrospective study from May 2012 to March 2019. We collcted data on clinical, laboratory,imaging, histological features and treatment. Totally, 98 patients with IgG4-RD were enrolled.The common clinical manifestations included abdominal pain, salivary gland swelling andlymphadenopathy. 51% of the patients had multiple organs involvement. Lymph nodes, pancreasand salivary glands were most commonly involved. Four rare sites including ulna, cerebellum,scalp, and mammary gland were found. The serum IgG4 level was increased by 85.7%. The serumIgG4 level was positively correlated with the number of involved organs, IgG and IgG4/IgG. LowC3 and C4 levels were observed in 37.5% and 12.2% patients respectively, and all patients withkidney involvement had hypocomplementemia. A total of 54 patients underwent tissue biopsies,and 55.6%, 31.5% and 11.1% cases were diagnosed as definite, probable and possible IgG4-RD,respectively. Eighty-eight patients received glucocorticoids (GCs) therapy. Five patients underwentradical surgery to remove the lesion. 73% of them presented a complete or partial remission. IgG4-RD is a systemic fibroinflammatory disease with involvement of multiple organs throughout thebody including some rare sites. Most IgG4-RD patients had increased serum IgG4 levels andpatients with kidney involvement showed bypocomplementermia. GCs therapy is effective. Moreresearch is needed to provide a more reliable basis for the diagnosis and treatment of patients.

Roles of plasmablasts in IgG4-related disease and various immune-based diseases

IgG4-related disease(IgG4-RD) is a systemic fibroinflammatory disease with multiple organ disorders.Recently,in IgG4-RD,increased circulating plasmablasts have been found.The subsets of plasmablasts are negative for RP105(CD180).A large population of B cells lacking RP105(RP105-negative B cells) are found inpatients with active with systemic lupus erythematosus and other systemic autoimmune diseases,including dermatomyositis,and Sj?gren's syndrome.In other conditions,such as neuromyelitis optica,Kawasaki's disease,primary biliary cirrhosis and aging,RP105 expression on B cells and monocytes also alters.We review the basic science and clinical significance of RP105-negative B cells including plasmablasts in various immune-based diseases.RP105-negative B cells,especially plasmablasts,play crucial roles in both systemic and organ-specific autoimmune and inflammatory disorders.

Highlighting the importance of early diagnosis in progressive multi-organ involvement of IgG4-related disease: A case report and review of literature

IgG4-related disease(IgG4-RD)is an increasingly recognized pathological entity that tends to involve multiple organs with an elevated level of serum IgG4,which is easily misdiagnosed owing to sharing common clinical features with a variety of other diseases.Here,we report an interesting IgG4-RD case of a woman with progressive multi-organ involvement for over 19 years,started with swollen eyelids,dry eye and mouth,and polydipsia and hydruria.Imaging diagnosis revealed diffuse enlargement of the parotid glands,enlargement of the head of the pancreas,pulmonary infection and interstitial lung.Serological tests showed a remarkable elevation of the serum IgG4,and cytological analysis further revealed a large amount of lymphoplasmacytic infiltration into the focal lobule,and IgG 4-positive cell infiltration in bladder mucosa.Therapeutically,the patient responded well to steroid therapy,and thus,she was diagnosed as IgG 4-RD suspicious.This report highlights the importance of an early diagnosis in this autoimmune disease and suggests that patients with a clinically unclear cause of inflammation,swelling and refractory glands,rhinitis,pancreatitis,hypophysitis,and/or interstitial pneumonia should be considered for IgG 4-RD.The plasma IgG4 level and lymphoplasmacytic infiltration may be useful indexes for screening,and a low dose of steroid maintaining therapy may offer benefits for patients with IgG4-RD.

A Case of Acute Renal Failure Associated with IgG4-Related Disease Presenting Both Tubulointerstitial Nephritis and Retroperitoneal Fibrosis

We report a case of IgG4-related disease presenting both tubulointerstitial nephritis and retroperitoneal fibrosis causing acute renal failure in a 63-year-old male. He was admitted to our hospital because of acute renal failure requiring emergent hemodialysis. Computed tomography showed a soft-tissue density mass with an irregular border in the retroperitoneum. The mass involved bilateral ureters and had caused acute renal failure by bilateral hydronephrosis. Because of a history of uveitis and high IgG4 levels, we considered a diagnosis of retroperitoneal fibrosis, IgG4-related disease. Kidney biopsy revealed IgG4-related kidney disease with interstitial nephritis. After relief of urinary obstruction by inserting ureteral catheters into the bilateral ureters, renal function recovered.

Comparison of clinical features and outcomes of proliferative,fibrotic,and mixed subtypes of IgG4-related disease:A retrospective cohort study

Background:Immunoglobulin G4-related disease(IgG4-RD)is a recently recognized immune-mediated disorder that can affect almost any organ in the human body.IgG4-RD can be categorized into proliferative and fibrotic subtypes based on patients’clinicopathological characteristics.This study aimed to compare the clinical manifestations,laboratory findings,and treatment outcomes of IgG4-RD among different subtypes.Methods:We prospectively enrolled 622 patients with newly diagnosed IgG4-RD at Peking Union Medical College Hospital from March 2011 to August 2021.The patients were divided into three groups according to their clinicopathological characteristics:proliferative,fibrotic,and mixed subtypes.We compared demographic features,clinical manifestations,organ involvement,laboratory tests,and treatment agents across three subtypes.We then assessed the differences in treatment outcomes among 448 patients receiving glucocorticoids alone or in combination with immunosuppressants.Moreover,risk factors of relapse were revealed by applying the univariate and multivariate Cox regression analysis.Results:We classified the 622 patients into three groups consisting of 470 proliferative patients,55 fibrotic patients,and 97 mixed patients,respectively.We found that gender distribution,age,disease duration,and frequency of allergy history were significantly different among subgroups.In terms of organ involvement,submandibular and lacrimal glands were frequently involved in the proliferative subtype,while retroperitoneum was the most commonly involved site in both fibrotic subtype and mixed subtype.The comparison of laboratory tests revealed that eosinophils(P=0.010),total IgE(P=0.006),high-sensitivity C-reactive protein(P<0.001),erythrocyte sedimentation rate(P<0.001),complement C4(P<0.001),IgG(P=0.001),IgG1(P<0.001),IgG4(P<0.001),and IgA(P<0.001),at baseline were significantly different among three subtypes.Compared with proliferative and mixed subtypes,the fibrotic subtype showed the lowest rate of relapse(log-rank P=0.014).Conclusions:Our study revealed the differences in demographic characteristics,clinical manifestations,organ involvement,laboratory tests,treatment agents,and outcomes across proliferative,fibrotic,and mixed subtypes in the retrospective cohort study.Given significant differences in relapse-free survival among the three subtypes,treatment regimens,and follow-up frequency should be considered separately according to different subtypes.Trial Registration:ClinicalTrials.gov,NCT01670695.

IgG4-related kidney disease complicated with retroperitoneal fibrosis:A case report

BACKGROUND IgG4-related disease(IgG4-RD)is a chronic fibrotic disease mediated by immunity recognized by clinicians in recent years.When the kidney is involved,it is called IgG4-related kidney disease(IgG4-RKD).IgG4-related tubulointerstitial nephritis(IgG4-TIN)is a representative manifestation of IgG4-RKD.IgG4-TIN can cause obstructive nephropathy complicated by retroperitoneal fibrosis(RPF).Cases of IgG4-TIN complicated with RPF are rare.Glucocorticoids are the firstline therapeutic medication for IgG4-RD and can significantly improve renal function.CASE SUMMARY Herein,we report the case of a 56-year-old man with IgG4-RKD complicated with RPF.The patient presented to the hospital with complaints of elevated serum creatinine(Cr),nausea,and vomiting.During hospitalization,Cr was 1448.6μmol/L,and serum IgG4 was increased.A total abdominal computed tomography(CT)scan and enhanced CT scan obviously indicated RPF.Although this patient had a long course and renal insufficiency,we performed a kidney biopsy.Renal biopsy showed that the renal tubulointerstitium had focal plasma cell infiltration and increased lymphocyte infiltration accompanied by fibrosis.After combining the biopsy results with immunohistochemistry,it was found that the absolute number of positive IgG4+cells per high power field exceeded 10,and the ratio of IgG4/IgG was over 40%.Finally,the patient was diagnosed with IgG4-TIN complicated with RPF and given glucocorticoids as long-term maintenance therapy,helping him keep out of dialysis.After a follow-up of 19 mo,the patient had recovered well.Previous literature on IgG4-RKD and RPF was retrieved from PubMed to characterize the clinical and pathological features and to identify the diagnosis and treatment of IgG4-RKD.CONCLUSION Our case report demonstrates the clinical characteristics of IgG4-RKD complicated with RPF.Serum IgG4 is a favorable indicator for screening.Performing renal biopsy actively plays a vital role in diagnosis and treatment,even if the patient has a long course and manifests with renal insufficiency.It is remarkable to treat IgG4-RKD with glucocorticoids.Hence,early diagnosis and targeted therapy are essential for reversing renal function and improving extrarenal manifestations in patients with IgG4-RKD.

Infrequent organ involvement in immunoglobulin G4-related prostate disease: A case report

BACKGROUND Immunoglobulin G4-related prostate disease(IgG4-RPD)characterized by a high count of IgG4-positive plasma cells has distinctive serological and radiological findings.Here we report a case of a patient who was successfully treated for IgG4-RPD,which manifested as frequent micturition,dysuric,and systemic lymphadenopathy.CASE SUMMARY The patient was a 33-year-old man who was referred to our hospital because of urinary tract symptoms that had persisted for 4 years.A physical examination revealed systemic lymphadenopathy and blood tests showed hyperglobulinemia with an IgG level of 18.90 g/L and an IgG4 level of 18.40 g/L.Computed tomography(CT)revealed bilateral lacrimal gland,right parotid gland and prostatic enlargement.Based on these findings,IgG4-RD was suspected,and further pathological examination and follow-up results showed expected results.Finally,the patient was diagnosed with IgG4-RPD based on clinical symptoms,pathological examination,therapeutic effects,and follow-up results.He received 50 mg oral prednisolone(the dose was gradually reduced and a low dose was used for long-term maintenance)in combination with cyclophosphamide 1.0 g via an intravenous drip for 6 mo.One year after the treatment was initiated,he was free of urinary or other complaints and his serum IgG4 level normalized.CONCLUSION In IgG4-RPD with severe urinary tract symptoms,radiological findings should be carefully examined.IgG4-RPD prognosis is good because the disease responds well to glucocorticoids.Furthermore,it is urgent for clinicians and pathologists to improve their understanding of IgG4-RPD.

IgG4-related autoimmune pancreatitis overlapping with Mikulicz's disease and lymphadenitis:A case report

Autoimmune pancreatitis(AIP)is a form of chronic pancreatitis that is categorized as type 1 or type 2according to the clinical profile.Type 1 AIP,which predominantly presents in a few Asian countries,is a hyper-IgG4-related disease.We report a case of IgG4-related AIP overlapping with Mikulicz’s disease and lymphadenitis,which is rare and seldom reported in literature.A 63-year male from Northeast China was admitted for abdominal distension lasting for one year.He presented symmetric swelling of the parotid and submandibular glands with slight dysfunction of salivary secretion for 6 mo.He had a 2-year history of bilateral submandibular lymphadenopathy without pain.He underwent surgical excision of the right submandibular lymph node one year prior to admission.He denied any history of alcohol,tobacco,or illicit drug use.Serological examination revealed high fasting blood sugar level(8.8 mmol/L)and high level of IgG4(15.2 g/L).Anti-SSA or anti-SSB were negative.Computed tomography of the abdomen showed a diffusely enlarged pancreas with loss of lobulation.Immunohistochemical stain for IgG4 demonstrated diffuse infiltration of IgG4-positive plasma cells in labial salivary gland and lymph node biopsy specimens.The patient received a dose of 30 mg/d of prednisone for three weeks.At this three-week follow-up,the patient reported no discomfort and his swollen salivary glands,neck lymph node and pancreas had returned to normal size.The patient received a maintenance dose of 10mg/d of prednisone for 6 mo,after which his illness had not recurred.

A clinicopathological study on IgG4-related ophthalmic disease

AIM： To investigate clinicopathological features of immunoglobulin G4-related ophthalmic disease（IgG4-ROD）, and analyze the recurrence rates following systemic corticosteroid administration.METHODS： We retrospectively searched clinical features, laboratory and histological findings based on the medical records of 21 patients with IgG4-ROD. All the patients examined in this study underwent surgical resection in the ocular adnexal lesions and underwent histological evaluation. This study further investigated clinical and histopathological features of 15 patients who received systemic corticosteroid after the resection.RESULTS： The mean age of the patients consisting of 7 males（33%） and 14 females（67%） was 61y. Fourteen patients were diagnosed as definitive, and 2 and 5 patients were probable and possible IgG4-ROD, respectively. Eyelid swelling was an initial symptom in 11 patients（52%） who did not show systemic involvements at a diagnosis. Fifteen patients received systemic corticosteroid administration, and all showed remission of inflammation. Among them, 10 patients did not recur, whereas 5 patients（33%） recurred during tapering. There were no significant difference between patients with or without recurrence in clinicopathological features.CONCLUSION： In this study, female patients are more predominant in IgG4-ROD. While inflammation recurs in one-third of patients, this study do not identify factors associated with recurrence after systemic corticosteroid administration.

Biomarkers in autoimmune pancreatitis and immunoglobulin G4-related disease

Solitary organ autoimmune disorders,formerly known as autoimmune pancreatitis(AIP),autoimmune sialadenitis,and autoimmune sclerosing cholangitis,are now considered organ-specific manifestations of systemic immunoglobulin G4-related disease(IgG4-RD).AIP and IgG4-RD are characterized by elevated serum concentration of IgG4 antibody(Ab),accumulation of IgG4-expressing plasmacytes in the affected organs,and involvement of multiple organs.It is well established that enhanced IgG4 Ab responses are a hallmark of AIP and IgG4-RD for diagnosis and monitoring disease activity.However,a significant fraction of patients with AIP and IgG4-RD who develop chronic fibroinflammatory responses have normal serum concentrations of this IgG subtype.In addition,disease flare-up is sometimes seen even in the presence of normalized serum concentrations of IgG4 Ab after successful induction of remission by prednisolone.Therefore,it is necessary to identify new biomarkers based on the understanding of the pathophysiology of AIP and IgG4-RD.Recently,we found that activation of plasmacytoid dendritic cells producing both interferon-α(IFN-α)and interleukin-33(IL-33)mediate murine AIP and human IgG4-RD.More importantly,we provided evidence that serum concentrations of IFN-αand IL-33 could be useful biomarkers for the diagnosis and monitoring of AIP and IgG4-RD activity after induction of remission in these autoimmune disorders.In this Frontier article,we have summarized and discussed biomarkers of AIP and IgG4-RD,including Igs,autoAbs,and cytokines to provide useful information not only for clinicians but also for researchers.

Rare case of Helicobacter pylori-positive multiorgan Ig G4-related disease and gastric cancer

A 61-year-old male from Northeast China presented with a 2-mo history of abdominal distension,pruritus and jaundice.Laboratory testing revealed an elevated serum Ig G4 level.A computed tomography scan showed a typical feature of autoimmune pancreatitis(AIP) and cholecystocholangitis.Early gastric cancer was incidentally discovered when endoscopic untrasound-guided fine needle aspiration(EUSFNA) of the pancreas was carried out.The patient underwent radical subtotal gastrectomy for gastric cancer combined with cholecystectomy.Helicobacter pylori(H.pylori) and Ig G4-positive plasmacytes were detected in gastric cancer tissue,pancreatic EUSFNA sample and resected gallbladder specimen by immunohistochemistry.The patient was diagnosed with H.pylori-positive Ig G4-related AIP and sclerosing cholecystocholangitis as well as H.pylori-positive gastric cancer.He responded well to steroid therapy and remains healthy with no signs of recurrence at one year follow-up.We speculate that H.pylori might act as a trigger via direct or indirect action in the initiation of onset of gastric cancer and multiorgan Ig G4-related disease.

Immunoglobulin G4-related kidney diseases: An updated review

This review will encompass definition, pathogenesis, renal clinical manifestations and treatment of immunoglobulin G4-related diseases( IgG4-RDs). IgG4-RD is a recently recognized clinical entity that often involves multiple organs and is characterized by high levels of serum immunoglobulins G4, dense infiltration of IgG4+ cells and storiform fibrosis. Cellular immunity, particularly T-cell mediated immunity, has been implicated in the pathogenesis of IgG4-RDs. The most frequent renal manifestations of IgG4-RD are IgG4-related tubulointerstitial nephritis, membranous glomerulopathy and obstructive nephropathy secondary to urinary tract obstruction due to IgG4-related retroperitoneal fibrosis. IgG4-RD diagnosis should be based on specific histopathological findings, confirmed by tissue immunostaining, typical radiological findings and an appropriate clinical context. The first line treatment is the steroids with two warnings: Steroid resistance and relapse after discontinuation. In the case of steroid resistance, B cell depleting agents as rituximab represent the secondline treatment. In the case of relapse after discontinuation, steroid treatment may be associated with steroid sparing agents. Since the disease has been only recently identified, more prospective, long-term studies are needed to an improved understanding and a more correct and safe treatment.

Ig G4-related disease manifesting as an acute gastric-pericardial fistula

Ig G4-related disease is a recently recognized entity linked initially to autoimmune pancreatitis and has been subsequently described in nearly every organ system. Men over the age of 50 represent the most affected demographic group and a comprehensive set of diagnostic criteria has been developed to aid treating clinicians. Though elevated levels of Ig G4 in the serum are suggestive of the disease, definitive diagnosis is made on histopathology. Treatment is tailored to the clinical presentation with corticosteroid therapy known to have proven efficacy. Gastric manifestations of the Ig G4-related disease primarily come in two varieties, notably chronic ulceration or pseudotumor formation. Autoimmune pancreatitis conveys increased risk for Ig G4-related disease of the stomach, which is independent of Helicobacter pylori status. In this case report, we present an acute gastric-pericardial fistula secondary to Ig G4-related disease that required urgent operative management. To our knowledge, this is the first report in the medical literature describing this complication of Ig G4-related disease.

Successful treatment of tubulointerstitial nephritis in immunoglobulin G4-related disease with rituximab: A case report

BACKGROUND Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated condition that consisted of disorders that share particular clinical,serologic and pathologic properties.The common presentation of disease includes tumor-like swelling of involved organs and the histopathological findings are a lymphoplasmacytic infiltrate enriched with IgG4-positive plasma cells,and a variable degree of fibrosis that has a characteristic "storiform" pattern in biopsy specimens of tumorlike masses.Major presentations of this disease,which often affects more than one organ,include autoimmune pancreatitis,salivary gland disease (sialadenitis),orbital disease and retroperitoneal fibrosis.The steroid treatment is essential for the treatment of the disease however,other immunosuppressive drugs including cyclophosphamide or rituximab could be an option in resistant cases.CASE SUMMARY Herein,we reported a 34-year-old woman whom previously had diagnosed with asthma,rheumatoid arthritis and Sj?gren’s syndrome (SS) referred our nephrology department due to acute kidney failure development at the last rheumatology visit.After kidney biopsy she has been diagnosed with IgG4-RD and tubuluointerstitial nephritis.She had been accepted resistant to steroid,mycophenolate mofetil,methotrexate and azathioprine therapies due to receiving in last two years.She refused to receive cyclophosphamide due to potential gonadotoxicity of the drug.Thus,rituximab therapy was considered.She received 1000 mg infusion,15 d apart and 6 mo later it has been administered same protocol.After one year from the last rituximab dose serum creatinine decreased from 4.4 mg/dL to 1.6 mg/dL,erythrocyte sedimentation rate decreased from 109 mm/h to 13 mm/h [reference range (RR) 0-20],and Creactive protein decreased from 55.6 mg/L to 5 mg/L (RR 0–6).All pathologic lymph nodes and masses were also disappeared.CONCLUSION Patients with IgG4-RD usually misdiagnosed with rheumatologic diseases including systemic lupus erythematous or SS and also they were screened for the presence of malignancy.Rituximab could be an important treatment option in cases with steroid resistant tubulointerstitial nephritis in IgG4-RD.