IgG4-related sclerosing cholangitis associated with essential thrombocythemia:A case report

BACKGROUND The complexity of immunoglobulin G4(IgG4)-related diseases and their potential connection to hematologic malignancies remains unclear.This article provided a review of the diagnosis and treatment of a patient with IgG4-related sclerosing cholangitis(SC)and essential thrombocythemia(ET),along with an analysis of relevant literature to enhance comprehension of this disease.CASE SUMMARY A 56-year-old male was admitted to two hospitals with deteriorating jaundice and pruritus prior to hospitalization.Beyond our expectations,the patient was first diagnosed with IgG4-SC and ET with the Janus kinase 2 V617F mutation.Interestingly,the administration of acetate prednisone significantly resulted in improvements in both IgG4-SC and ET.Clinicians need to pay attention to immune disorders and inflammation as they contribute to the development of various disease phenotypes.CONCLUSION When IgG4-SC is suspected without histopathological evidence,diagnostic therapy and long-term regular follow-up can lead to positive treatment outcomes.Clinicians should be mindful of the potential presence of concurrent hematologic diseases in patients with immune disorders.

Journey to diagnosis:An unfinished exploration of IgG4-related sclerosing cholangitis

IgG4-related sclerosing cholangitis(IgG4-SC)is an inflammatory disease that leads to bile duct stricture,characterized by the infiltration of IgG4-positive plasma cells into the bile duct wall,thickening of the bile duct wall,and narrowing of the lumen.The differential diagnosis of IgG4-SC mainly includes primary sclerosing cholangitis,cholangiocarcinoma,and pancreatic cancer.IgG4-SC is often associated with autoimmune pancreatitis and can be accurately diagnosed based on clinical diagnostic criteria.However,isolated IgG4-SC is difficult to distinguish from biliary tumors.Given the significant differences in biological behavior,treatment,and prognosis between these diseases,accurately identifying isolated IgG4-SC has very important clinical significance.

Diagnosis of IgG4-related sclerosing cholangitis

IgG4-related sclerosing cholangitis(IgG4-SC)is often associated with autoimmune pancreatitis.However,the diffuse cholangiographic abnormalities observed in IgG4-SC may resemble those observed in primary sclerosing cholangitis(PSC),and the presence of segmental stenosis suggests cholangiocarcinoma(CC).IgG4-SC responds well to steroid therapy,whereas PSC is only effectively treated with liver transplantation and CC requires surgical intervention.Since IgG4-SC was first described,it has become a third distinct clinical entity of sclerosing cholangitis.The aim of this review was to introduce the diagnostic methods for IgG4-SC.IgG4-SC should be carefully diagnosed based on a combination of characteristic clinical,serological,morphological,and histopathological features after cholangiographic classification and targeting of a disease for differential diagnosis.When intrapancreatic stenosis is detected,pancreatic cancer or CC should be ruled out.If multiple intrahepatic stenoses are evident,PSC should be distinguished on the basis of cholangiographic findings and liver biopsy with IgG4 immunostaining.Associated inflammatory bowel disease is suggestive of PSC.If stenosis is demonstrated in the hepatic hilar region,CC should be discriminated by ultrasonography,intraductal ultrasonography,bile duct biopsy,and a higher cutoff serum IgG4 level of 182 mg/dL.

Isolated intrapancreatic Ig G4-related sclerosing cholangitis

Immunoglobulin G4-related sclerosing cholangitis(Ig G4-SC) is frequently associated with type 1 autoimmune pancreatitis(AIP). Association with AIP can be utilized in the diagnosis of Ig G4-SC. However, some cases of Ig G4-SC are isolated from AIP, which complicates the diagnosis. Most of the reported cases of isolated Ig G4-SC displayed hilar biliary strictures, whereas isolated Ig G4-SC with intrapancreatic biliary stricture is very rare. Recently, we have encountered 5 isolated intrapancreatic Ig G4-SC cases that were not associated with AIP, three of which were pathologically investigated after surgical operation. They all were males with a mean age of 74.2 years. The pancreas was not enlarged in any of these cases. No irregular narrowing of the main pancreatic duct was found. Bile duct wall thickening in lesions without luminal stenosis was detected by abdominal computed tomography in all five cases, by endoscopic ultrasonography in two out of four cases and by intraductal ultrasonography in all three cases. In three cases, serum Ig G4 levels were within the normal limits. The mean serum Ig G4 level measured before surgery was 202.1 mg/d L(4 cases). Isolated intrapancreatic Ig G4-SC is difficult to diagnose, especially if the Ig G4 level remains normal. Thus, this type of Ig G4-SC should be suspected in addition to cholangiocarcinoma and pancreatic cancer if stenosis of intrapancreatic bile duct is present.

First case of IgG4-related sclerosing cholangitis associated with autoimmune hemolytic anemia

To our knowledge,patients with immunoglobulin G4-related sclerosing cholangitis(IgG4-SC)associated with autoimmune hemolytic anemia(AIHA)have not been reported previously.Many patients with IgG4-SC have autoimmune pancreatitis(AIP)and respond to steroid treatment.However,isolated cases of IgG4-SC are difficult to diagnose.We describe our experience with a patient who had IgG4-SC without AIP in whom the presence of AIHA led to diagnosis.The patient was a73-year-old man who was being treated for dementia.Liver dysfunction was diagnosed on blood tests at another hospital.Imaging studies suggested the presence of carcinoma of the hepatic hilus and primary sclerosing cholangitis,but a rapidly progressing anemia developed simultaneously.After the diagnosis of AIHA,steroid treatment was begun,and the biliary stricture improved.IgG4-SC without AIP was thus diagnosed.

IgG4-related sclerosing cholangitis and chronic sclerosing sialadenitis mimicking cholangiocarcinoma and neck malignancy

To the Editor:IgG4-related sclerosing cholangitis（IgG4-SC）has re cently been recognized as a biliary manifestation of IgG4-related disease（IgG4-RD）.Type 3 IgG4-SC pre sented biliary strictures in both the porta hepatis and the distal common bile duct（CBD）.;Its manifestation especially in the absence of autoimmune pancreatitis,is extremely rare and very similar to that of cholangiocarci noma（CC）.

Immunosuppressant treatment for IgG4-related sclerosing cholangitis: A case report

BACKGROUND Immunoglobulin G4-related disease(IgG4-RD)is a multi-system fibroinflammatory disorder that can involve any organ,including the salivary glands,pancreas,and biliary tree.Treatment of immunoglobulin G4-related sclerosing cholangitis(IgG4-SC)is similar to that for IgG4-RD,but progression is irreversible in some cases.We present a case of IgG4-SC in which an immuno-suppressant induced marked clinical and radiologic improvement.CASE SUMMARY A 63-year-old male presented with a prominent itching sensation and wholebody jaundice.He showed obstructive-pattern jaundice,an elevated IgG4 level,and infiltration of a large number of IgG4-positive cells in the ampulla of Vater.The imaging findings of intrahepatic duct(IHD)and common bile duct dilation,an elevated serum IgG4 level,and characteristic histological findings led to diagnosis of IgG4-SC that compatible with the 2019 ACR/EULAR classification criteria.We planned to treat the patient with high-dose glucocorticoid(GC),followed by cyclophosphamide pulse therapy.After treatment with high-dose GC and an immunosuppressant,imaging studies showed that IHD dilatation had completely resolved.CONCLUSION Prompt diagnosis and appropriate treatment of IgG4-SC are important.Because there is a risk of relapse of IgG4-SC,the GC dose should be gradually reduced,and a maintenance immunosuppressant should be given.

Usefulness of ultrasonography to assess the response to steroidal therapy for the rare case of type 2b immunoglobulin G4-related sclerosing cholangitis without pancreatitis:A case report

BACKGROUND A type 2b immunoglobulin G4(IgG4)-related sclerosing cholangitis(SC)without autoimmune pancreatitis is a rare condition with IgG4-SC.While the variety of the imaging modalities have tested its usefulness in diagnosing the IgG4-SC,however,the usage of ultrasonography for the assessment of the response to steroidal therapy on the changes of bile duct wall thickness have not been reported in the condition.Therefore,the information of our recent case and reported cases have been summarized.CASE SUMMARY We report the case of an 82-year-old Japanese man diagnosed with isolated IgG4-related SC based on the increase of serum IgG4,narrowing of the bile duct,its wall thickness,no complication of autoimmune pancreatitis,and IgG4 positive inflammatory cell infiltration to the wall with the fibrotic changes.The cholangiogram revealed type 2b according to the classification.Corticosteroid treatment showed a favorable effect,with the smooth decrease in serum IgG4 and the improvement of the bile duct wall thickness.CONCLUSION As isolated type 2b,IgG4-SC is rare,the images,histological findings,and clinical course of our case will be helpful for physicians to diagnose and treat the new cases appropriately.

Advances in the diagnosis and treatment of Ig G4-related sclerosing cholangitis: a review

Immunoglobulin G4-related sclerosing cholangitis （IgG4-SC） is an IgG4-related disease characterized by bile duct fibroinflammatory wall-thickening and stenosis, resulting in obstruction jaundice, weight loss. Dif- ferent regions of the bile duct can be involved, with the distal region being the most common. IgG4-SC can also have other organ involvement, such as the pancreas, urinary tract, salivary glands and lacrimal glands. In clinical practice, the manifestation of IgG4-SC is very similar to cholangiocarcinoma （CC） and primary sclerosing cholangiUs （PSC）, as well as pancreatic malignancies, while the treatment and prognosis are totally different. Japanese researchers ever established the clinical diagnostic criteria in 2012： （1） charac- teristic biliary imaging findings; （2） elevated serum IgG4 concentrations; （3） the coexistence of IgG4-related diseases except those of the biliary tract; and （4） characteristic histopathological features. According to our observations, IgG4-SC can be distinguished from CC with 100% specificity only at a cutoff of six times the upper normal limit. Imaging findings have low specificity for diagnosis, with the exception of intraductal ultrasonography, which can reflect the lesion with relatively high specificity. IgG4 plasma cell infiltration can be found in bile duct biopsy tissue, although this procedure is difficult. According to recent studies, the treatment of IgG4-SC relies mainly on corticosteroids. Following steroid treatment, most IgG4-SC patients can recover and their symptoms are resolved although a few patients relapse after steroid withdrawal. Maintenance of steroid therapy or alternative drugs is necessary in such cases. There is, however, no stronq evidence for malignant transformation in I qG4-SC.

IgG4-related sclerosing disease

Based on histological and immunohistochemical exami- nation of various organs of patients with autoimmune pancreatitis （AIP）, a novel clinicopathological entity of IgG4-related sclerosing disease has been proposed. This is a systemic disease that is characterized by extensive IgG4-positive plasma cells and T-lymphocyte infiltration of various organs. Clinical manifestations are apparent in the pancreas, bile duct, gallbladder, salivary gland, retroperitoneum, kidney, lung, and prosrate, in which tissue fibrosis with obliterative phlebitis is pathologically induced. AlP is not simply pancreatitis but, in fact, is a pancreatic disease indicative of IgG4- related sclerosing diseases. This disease includes AlP, sclerosing cholangitis, cholecystitis, sialadenitis, retro-peritoneal fibrosis, tubulointerstitial nephritis, interstitial pneumonia, prostatitis, inflammatory pseudotumor and lymphadenopathy, all IgG4-related. Most IgG4-related sclerosing diseases have been found to be associated with AlP, but also those without pancreatic involvement have been reported. In some cases, only one or two organs are clinically involved, while in others, three or four organs are affected. The disease occurs predominantly in older men and responds well to steroid therapy. Serum IgG4 levels and immunos-taining with anti-IgG4 antibody are useful in making the diagnosis. Since malignant tumors are frequently suspected on initial presentation, IgG4-related sclerosing disease should be considered in the differential diagnosis to avoid unnecessary surgery.

Review of primary sclerosing cholangitis with increased IgG4 levels

Primary sclerosing cholangitis(PSC) is a chronic progressive liver disease. Subtypes of PSC have been described, most recently PSC with elevated serum and/or tissue IgG4 subclass. We aim to summarise the clinical phenotype,disease associations, differential diagnosis, response to therapy and pathogenic mechanisms underlying PSC-high IgG4 subtype. We reviewed Pub Med,MEDLINE and Embase with the search terms "primary sclerosing cholangitis","IgG4", and "IgG4-related sclerosing cholangitis(IgG4-SC)". Elevated serum IgG4 are found in up-to one-quarter, and abundant IgG4-plasma cell infiltrates in the liver and bile ducts are found in up-to one-fifth of PSC patients. This group have a distinct clinical phenotype, with some studies reporting a more aggressive course of liver and associated inflammatory bowel disease, compared to PSCnormal IgG4 and the disease mimic IgG4-SC. Distinguishing PSC-high IgG4 from IgG4-SC remains challenging, requiring careful assessment of clinical features,organ involvement and tissue morphology. Calculation of serum IgG4:IgG1 ratios and use of a novel IgG4:IgG RNA ratio have been reported to have excellent specificity to distinguish IgG4-SC and PSC-high IgG4 but require validation in larger cohorts. A role for corticosteroid therapy in PSC-high IgG4 remains unanswered, with concerns of increased toxicity and lack of outcome data. The immunological drivers underlying prominent IgG4 antibodies in PSC are incompletely defined. An association with PSC-high IgG4 and HLA class-II haplotypes(B*07, DRB1*15), T-helper2 and T-regulatory cytokines(IL4, IL10,IL13) and chemokines(CCL1, CCR8) have been described. PSC-high IgG4 have a distinct clinical phenotype and need careful discrimination from IgG4-SC,although response to immunosuppressive treatments and long-term outcome remains unresolved. The presence of IgG4 likely represents chronic activation to persistent antigenic exposure in genetically predisposed individuals.

Inflammatory bowel disease of primary sclerosing cholangitis:A distinct entity?

This is a review of the characteristic findings of inflammatory bowel disease(IBD)associated with primary sclerosing cholangitis(PSC)and their usefulness in the diagnosis of sclerosing cholangitis.PSC is a chronic inflammatory disease characterized by idiopathic fibrous obstruction and is frequently associated with IBD.IBDassociated with PSC(PSC-IBD)shows an increased incidence of pancolitis,mild symptoms,and colorectal malignancy.Although an increased incidence of pancolitis is a characteristic finding,some cases are endoscopically diagnosed as right-sided ulcerative colitis.Pathological studies have revealed that inflammation occurs more frequently in the right colon than the left colon.The frequency of rectal sparing and backwash ileitis should be investigated in a future study based on the same definition.The cholangiographic findings of immunoglobulin G4-related sclerosing cholangitis(IgG4-SC)are similar to those of PSC.The rare association between IBD and IgG4-SC and the unique characteristics of PSC-IBD are useful findings for distinguishing PSC from IgG4-SC.

Eosinophilic cholangitis is a potentially underdiagnosed etiology in indeterminate biliary stricture

To investigate presence and extent of eosinophilic cholangitis (EC) as well as IgG4-related disease in patients with indeterminate biliary stricture (IBS).METHODSAll patients with diagnosis of sclerosing cholangitis (SC) and histopathological samples such as biopsies or surgical specimens at University Hospital Frankfurt from 2005-2015 were included. Histopathological diagnoses as well as further clinical course were reviewed. Tissue samples of patients without definite diagnosis after complete diagnostic work-up were reviewed regarding presence of eosinophilic infiltration and IgG4 positive plasma cells. Eosinophilic infiltration was as well assessed in a control group of liver transplant donors and patients with primary sclerosing cholangitis.RESULTSone hundred and thirty-five patients with SC were included. In 10/135 (13.5%) patients, no potential cause of IBS could be identified after complete diagnostic work-up and further clinical course. After histopathological review, a post-hoc diagnosis of EC was established in three patients resulting in a prevalence of 2.2% (3/135) of all patients with SC as well as 30% (3/10) of patients, where no cause of IBS was identified. 2/3 patients with post-hoc diagnosis of EC underwent surgical resection with suspicion for malignancy. Diagnosis of IgG4-related cholangitis was observed in 7/135 patients (5.1%), whereas 3 cases were discovered in post-hoc analysis. 6/7 cases with IgG4-related cholangitis (85.7%) presented with eosinophilic infiltration in addition to IgG4 positive plasma cells. There was no patient with eosinophilic infiltration in the control group of liver transplant donors (n = 27) and patients with primary sclerosing cholangitis (n = 14).CONCLUSIONEC is an underdiagnosed benign etiology of SC and IBS, which has to be considered in differential diagnosis of IBS.

Clinical and pathological differences between serum immunoglobulin G4-positive and -negative type 1 autoimmune pancreatitis

AIM: To identify clinical and pathological differences between serum immunoglobulin G4 (IgG4)-positive (SIP) and IgG4-negative (SIN) type 1 autoimmune pancreatitis (AIP) in South Korea. METHODS: AIP was diagnosed by the international consensus diagnostic criteria. The medical records and pathology were retrospectively reviewed and IgG4-positive cells were counted in a high power field (HPF). Type I AIP was defined as a high serum level of IgG4or histological finding. SIN type 1 AIP was defined as a histological evidence of type 1 AIP and a normal serum IgG4 level. The clinical and pathological findings were compared between the two groups. The analysis was performed using Student's t test, Fischer's exact test and Mann-Whitney's U test. A P value of < 0.05 was considered statistically significant. As repeated com- parison was made, P values of less than 5% (P < 0.05) were considered significant. RESULTS: Twenty five patients with definite type 1 AIP (19 histologically and six serologically diagnosed cases) were enrolled. The mean tissue IgG4 concentrations were significantly higher in SIP than SIN group (40 cells per HPF vs 18 cells per HPF, P = 0.02). Among eight SIN patients, the tissue IgG4 concentrations were less than 15 cells per HPF in most of cases, except one. The sensitivity of serum IgG4 was 68% (17 SIP and eight SIN AIP). Other organ involvement was more frequent- ly associated with SIP than SIN AIP (59% vs 26%, P = 0.016). However, the relapse rate and diffuse swelling of the pancreas were not associated with serum IgG4 level. The concentrations of IgG4-positive cells per HPF were higher in SIP than SIN AIP (40 vs 18, P = 0.02). CONCLUSION: The sensitivity of serum IgG4 was 68% in type 1 AIP. High serum IgG4 level was associated with other organ involvement and tissue IgG4 concentration but did not affect the relapse rate in type 1 AIP.