Tissue IgG4-positive plasma cells in inflammatory bowel disease: a study of 88 treatment-naive biopsies of inflammatory bowel disease

Systemic diseases affecting the GI tract: A review of clinical and histopathologic manifestations

A variety of systemic diseases may affect the gastrointestinal (GI) tract. Since the GI tract responds to injury in limited ways, identifying these processes may be challenging, especially on small endoscopic biopsies. This article reviews the clinicopathologic features of commonly encountered systemic diseases affecting the tubular GI tract: sarcoidosis, graft vs. host disease, mast cell disorders, systemic sclerosis, and IgG-4 related disease. In addition, we offer guidance in differentiating them from their mimics.

Case report and review of literature: IgG4-gastroduodenitis in upper GI Crohn's disease: two separate entities or just a marker of disease severity?

A 20-year-old man was presented with ulcerative gastritis and duodenitis complicated by pyloric stenosis. Helicobacter pylori infection was excluded, and the lesions did not respond to treatment with proton pump inhibitors. No other parts of the intestinal tract showed signs of inflammation. Histopathological review showed signs of chronic inflammation with granuloma formation. A tentative diagnosis of isolated upper gastrointestinal (UGI) Crohn's disease was performed. However, additional work-up revealed significantly positive IgG4 staining as well as elevated IgG4 serum levels. Since granulomatous disease is unlikely in IgG4-related disease, an eventual diagnosis of overlapping IgG4-related disease and Crohn's disease (CD) was performed. Treatment with systemic steroids and anti-TNF in combination with azathioprine led to rapid symptomatic improvement. In this article, we review the available literature on IgG4-related gastroduodenitis, granulomatous gastritis, and upper GI CD. We suggest the possibility that IgG4-infiltration may be a marker of severely active inflammatory bowel disease rather than a separate disease entity.

Challenges and pitfalls in the diagnosis of IgG4-related disease

IgG4-related disease (IgG4-RD) is a relatively novel fibroinflammatory condition characterized typically by dense lymphoplasmacytic inflammation, storiform fibrosis and obliterative venulitis, together with prominent IgG4+ plasma cells and an IgG4+/IgG+ plasma cell ratio of >40 %. The diagnosis is usually made on a combination of clinical and serological features together with characteristic radiological and histological appearances. The condition may be limited to a single tissue/organ (e.g., autoimmune pancreatitis) or may be multicentric in nature - four clinical 'patterns' of disease distribution have recently been described. The diagnosis of IgG4-RD can be challenging, particularly when the clinical presentation is unusual and/or when the histological features are not typical. A diagnosis of IgG4-RD may still be achieved in these situations, after careful clinicopathological discussion e.g., at a specialist multidisciplinary team meeting. However, a wide range of other conditions (neoplastic and non-neoplastic) can mimic IgG4-RD, clinically and/or on histological examination. The relationship between IgG4-RD and non-IgG4-RD associated conditions in some clinical situations is particularly complex. This review describes the role of histological examination in the diagnosis of IgG4-RD, discusses some of the practical difficulties that may be encountered and provides an insight into the range of non-IgG4-RD associated conditions that can mimic IgG4-RD on clinical and/or histological grounds. The requirement for interpretation of histological features in the context of the global clinical picture of the patient is highlighted and emphasized.

Prevalence and clinical features of patients with autoimmune pancreatitis and inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Autoimmune pancreatitis (AIP) and inflammatory bowel disease (IBD) are categorized into immune-mediated inflammatory disorders (IMIDs). While AIP is a pancreato-biliary IMID with an increased incidence and prevalence among patients with IBD, its features are still unclear. This systematic review and meta-analysis aims to assess the prevalence and clinical characteristics of AIP-IBD patients.

METHODS

Electronic databases were searched to identify observational studies assessing AIP and IBD. The primary outcome was the prevalence of IBD among AIP patients, and vice versa. Secondary outcomes included clinical findings and outcomes of each IMID in AIP-IBD patients. The pooled rate of each outcome was determined using a random effects model.

RESULTS

For primary outcomes, 40 observational studies with 4031 AIP patients were included and the pooled prevalence of IBD was 10.5% (95% CI 7.2-15.0%). Meanwhile, five studies with 10,551 IBD patients were included and the pooled prevalence of AIP was 0.6% (95% CI 0.2-1.9%). For secondary outcomes, 53 observational studies with 469 AIP-IBD patients were assessed. The rates of type 2 AIP and ulcerative colitis were 79.2% (95% CI 69.1-86.6%) and 74.8% (95% CI 68.2-80.4%), respectively. We also demonstrated AIP-IBD patients were at a significant increased risk of AIP recurrence and colectomy compared with patients with either AIP or IBD (RR = 1.9, 95% CI 1.1-3.1 and P = 0.014 and RR = 3.7, 95% CI 1.9-6.9, P < 0.001, respectively).

CONCLUSIONS

Our meta-analysis reported the prevalence of AIP-IBD patients and demonstrated patients with both IMIDs had a high risk of poor outcomes.

Colonic Mucosal Infiltration of IgG4 Plasma Cells and Ulcerative Colitis: Determinant of Presence, Activity, Extension, and Duration of Disease

BACKGROUND Infiltration of IgG4 positive plasma cells has been detected in the colonic mucosa of patients with ulcerative colitis (UC). The aim of the study was to investigate the association between colonic mucosal infiltration of IgG4 plasma cells and the presence, activity, extension, and duration of UC. METHODS In this case-control study (2009-2014), 102 subjects (84 with UC/18 controls) were enrolled. Clinical records and rectosigmoid biopsies of UC patients were selected, and biopsies were stained with IgG4 monoclonal antibodies. IgG4 positive plasma cells were counted by a single pathologist. RESULTS Amongst 84 patients with UC, 73.8% had UC without primary sclerosing cholangitis (PSC), and 26.2% had UC with PSC. IgG4 plasma cells were seen in 35 (41.7%) patients with UC and 0% of controls (p = 0.001). The mean amount of IgG4 containing plasma cells was significantly different between active and inactive patients with UC, although it was not significantly different between UC patients with and without PSC. The presence of IgG4 infiltration was significantly associated with the extension and duration of the disease. Furthermore, IgG4 count had a sensitivity/specificity of 78.6%/83.3% for the diagnosis of UC. CONCLUSION Our study revealed the diagnostic role of IgG4 plasma cells in the colonic mucosa of patients with UC and its association with activity, extension, and duration of disease.

IgG4-related disease as a rare cause of gastric outlet obstruction: a case report and literature review

Background

IgG4-related disease involvement of the digestive tract is very rare. In few reported cases of isolated gastric/duodenal IgG4-related disease, none of which resulted in luminal obstruction.

Case presentation

A 59 years old female presented with longstanding gastrointestinal symptoms. CT showed mural thickening of the proximal duodenum. Gastroscopy showed antral ulcer extending into the duodenum with outlet obstruction and biopsy showed acute on chronic duodenitis. Whipple’s procedure was performed and IgG4-related disease was diagnosed on final pathology. Symptoms were revolved on mycophenolate mofetil and prednisone with no recurrence.

Conclusions

Our case is the only reported case with gastric outlet obstruction secondary to gastroduodenal IgG4-related disease. The diagnosis should be considered in the differential diagnosis of unexplained duodenal stricture, gastric outlet obstruction or gastrointestinal ulceration. IgG4-related disease usually responds to steroids but long-term response rates to steroid-sparing agents, especially in the subset of patients with luminal IgG4-related disease remains to be determined.

A reappraisal of sclerosing nodular and/or polypoid lesions of the gastrointestinal tract rich in IgG4-positive plasma cells

AIMS

To describe additional cases of nodular and polypoid sclerosing lesions of the gastrointestinal tract (GIT) that are associated with numerous IgG4-positive plasma cells, review the pertinent literature to ascertain the relationship with systemic IgG4-related disease, and provide a reporting framework for such lesions.

METHODS AND RESULTS

Five new cases of sclerosing polyps or nodules were collected over a 10-year period, occurring in four females and one male ranging in age from 32 years to 56 years (mean, 41.6 years). Patients were asymptomatic or had epigastric pain, and one had rectal bleeding. None had autoimmune or other obvious IgG4-related disease, and serum IgG4 levels were normal. All were solitary nodules in the stomach (two cases), ileum, caecum, and rectum. Four lesions were submucosal and one was subserosal; all were well circumscribed, composed of hyalinised, keloidal fibrous tissue with lymphoplasmacytic inflammation. Obliterative phlebitis was not seen. Lineage-specific immunomarkers were negative. In excess of 10 IgG4-positive plasma cells per high-power field were seen, and the IgG4/IgG ratios were >0.4.

CONCLUSIONS

Very few IgG4-related lesions in the tubular GIT are associated with disease at other sites and/or elevated serum IgG4 levels. The majority may represent a lesion in the spectrum of IgG4-related disease. The use of the term 'IgG4-positive nodule or polyp with probable histological features of IgG4-related disease' is advocated for nodular and/or polypoid lesions in the GIT with ≥10 IgG4-positive plasma cells in a high-power field and an IgG/IgG4 ratio of >0.4.

Pancreatic endosonographic findings and clinical correlation in Crohn's disease

OBJECTIVES

We aimed to evaluate the incidence of pancreatic alterations in Crohn's disease using endoscopic ultrasound (EUS) and to correlate the number of alterations with current clinical data.

METHODS

Patients diagnosed with Crohn's disease (n=51) were examined using EUS, and 11 variables were analyzed. A control group consisted of patients with no history of pancreatic disease or Crohn's disease. Patients presenting with three or more alterations underwent magnetic resonance imaging (MRI). Pancreatic function was determined using a fecal elastase assay.

RESULTS

Two of the 51 patients (3.9%) presented with four EUS alterations, 3 (5.9%) presented with three, 11 (21.5%) presented with two, and 13 (25.5%) presented with one; in the control group, only 16% presented with one EUS alteration (p<0.001). Parenchymal abnormalities accounted for 39 of the EUS findings, and ductal abnormalities accounted for 11. Pancreatic lesions were not detected by MRI. Low fecal elastase levels were observed in 4 patients, none of whom presented with significant pancreatic alterations after undergoing EUS. Ileal involvement was predictive of the number of EUS alterations.

CONCLUSION

A higher incidence of pancreatic abnormalities was found in patients with Crohn's disease than in individuals in the control group. The majority of these abnormalities are related to parenchymal alterations. In this group of patients, future studies should be conducted to determine whether such morphological abnormalities could evolve to induce exocrine or endocrine pancreatic insufficiency and, if so, identify the risk factors and determine which patients should undergo EUS.

Reduced CD27-IgD- B Cells in Blood and Raised CD27-IgD- B Cells in Gut-Associated Lymphoid Tissue in Inflammatory Bowel Disease

The intestinal mucosa in inflammatory bowel disease (IBD) contains increased frequencies of lymphocytes and a disproportionate increase in plasma cells secreting immunoglobulin (Ig)G relative to other isotypes compared to healthy controls. Despite consistent evidence of B lineage cells in the mucosa in IBD, little is known of B cell recruitment to the gut in IBD. Here we analyzed B cells in blood of patients with Crohn's disease (CD) and ulcerative colitis (UC) with a range of disease activities. We analyzed the frequencies of known B cell subsets in blood and observed a consistent reduction in the proportion of CD27^-IgD^- B cells expressing all Ig isotypes in the blood in IBD (independent of severity of disease and treatment) compared to healthy controls. Successful treatment of patients with biologic therapies did not change the profile of B cell subsets in blood. By mass cytometry we demonstrated that CD27^-IgD^- B cells were proportionately enriched in the gut-associated lymphoid tissue (GALT) in IBD. Since production of TNFα is a feature of IBD relevant to therapies, we sought to determine whether B cells in GALT or the CD27^-IgD^- subset in particular could contribute to pathology by secretion of TNFα or IL-10. We found that donor matched GALT and blood B cells are capable of producing TNFα as well as IL-10, but we saw no evidence that CD27^-IgD^- B cells from blood expressed more TNFα compared to other subsets. The reduced proportion of CD27^-IgD^- B cells in blood and the increased proportion in the gut implies that CD27^-IgD^- B cells are recruited from the blood to the gut in IBD. CD27^-IgD^- B cells have been implicated in immune responses to intestinal bacteria and recruitment to GALT, and may contribute to the intestinal inflammatory milieu in IBD.

High level of IgG4 as a biomarker for a new subset of inflammatory bowel disease

The roles of B and plasma cells in the pathogenesis of inflammatory bowel disease (IBD) are largely unrevealed. Data on the characteristics of IgG4 in patients with IBD are scarce. In this case-control study, serum IgG4 levels were comparable between patients with IBD and healthy individuals, whereas patients with IBD had dramatically higher mucosal IgG4 counts than healthy individuals. In patients with UC, mucosal IgG4 counts were positively correlated with serum IgG4 levels, serum IgG4/IgG ratios, and the Mayo Index; serum IgG4 levels and IgG4/IgG ratios were associated with a history of intestinal surgery and medications. A significant mucosal IgG4 count was found in 33.3% of patients with IBD, whereas, elevated serum IgG4 levels were found in only 9.9% of patients with IBD. Lesions were more severe and extensive in IBD patients with high levels of serum and mucosal IgG4. High levels of serum and mucosal IgG4 decreased after treatment with glucocorticoids or other immunosuppressants. High IgG4 level may be a biomarker for a new subset of IBD. More studies are warranted to explore this new subset of IBD for personalized therapy in the future.

Intrapancreatic distal common bile duct carcinoma: Analysis, staging considerations, and comparison with pancreatic ductal and ampullary adenocarcinomas

Distal common bile duct carcinoma is a poorly characterized entity for reasons such as variable terminology and difficulty in determining site of origin of intrapancreatic lesions. We compared clinicopathologic features of pancreatobiliary-type adenocarcinomas within the pancreas, but arising from the distal common bile duct, with those of pancreatic and ampullary origin. Upon careful review of 1017 pancreatoduodenectomy specimens with primary adenocarcinoma, 52 (5%) qualified as intrapancreatic distal common bile duct carcinoma. Five associated with an intraductal papillary neoplasm were excluded; the remaining 47 were compared to 109 pancreatic ductal adenocarcinomas and 133 ampullary carcinomas. Distal common bile duct carcinoma patients had a younger median age (58 years) than pancreatic ductal adenocarcinoma patients (65 years) and ampullary carcinoma patients (68 years). Distal common bile duct carcinoma was intermediate between pancreatic ductal adenocarcinoma and ampullary carcinoma with regard to tumor size and rates of node metastases and margin positivity. Median survival was better than for pancreatic ductal adenocarcinoma (P=0.0010) but worse than for ampullary carcinoma (P=0.0006). Distal common bile duct carcinoma often formed an even band around the common bile duct and commonly showed intraglandular neutrophil-rich debris and a small tubular pattern. Poor prognostic indicators included node metastasis (P=0.0010), lymphovascular invasion (P=0.0299), and margin positivity (P=0.0069). Categorizing the tumors based on size also had prognostic relevance (P=0.0096), unlike categorization based on anatomic structures invaded. Primary distal common bile duct carcinoma is seen in younger patients than pancreatic ductal adenocarcinoma or ampullary carcinoma. Its prognosis is significantly better than pancreatic ductal adenocarcinoma and worse than ampullary carcinoma, at least partly because of differences in clinical presentation. Use of size-based criteria for staging appears to improve its prognostic relevance. Invasive pancreatobiliary-type distal common bile duct carcinomas are uncommon in the West and have substantial clinicopathologic differences from carcinomas arising from the pancreas and ampulla.

IgG4-Related Disease and Innate Immunity

An increased number of clinicopathological studies on autoimmune pancreatitis, cholangitis, and sialoadenitis have led to the recognition of immunoglobulin G4-related disease (IgG4-RD) as a novel disorder, characterized by elevated levels of serum IgG4 and infiltration of IgG4-expressing plasma cells in the affected organs. Although the immunological background associated with the development of IgG4-RD remains poorly understood, recent studies have suggested involvement of the innate immune response in its pathogenesis. Peripheral blood innate immune cells, such as plasmacytoid dendritic cells and monocytes isolated from patients with IgG4-RD, promote IgG4 production by B cells. Activation of the innate immune response by microbe- and/or damage-associated molecular patterns stimulates production of type I interferon and B cell-activating factor by innate immune cells and results in IgG4 production by B cells. Elucidation of the innate immune response associated with IgG4-RD may help identify a new therapeutic target for this immune disorder.

Colorectal mucus non-invasively collected from patients with inflammatory bowel disease and its suitability for diagnostic cytology

Colorectal mucus is a key component of the protective gut barrier which is altered in inflammatory bowel disease (IBD). We aimed to cytologically characterize colorectal mucus non-invasively collected from IBD patients using our new sampling technique. Colorectal mucus was self-collected by 58 IBD patients comprising 31 ulcerative colitis (UC) and 27 Crohn's disease (CD) cases. The samples were examined cytologically, and immunocytochemically. Large numbers of well-preserved granulocytes were typically detected (neutrophils undergoing degradation were observed as well). Plasma cells and erythrophagocytosis were present in 18.2% and 29.1% of cases, respectively, predominantly in patients with UC and distal CD. Immunocytochemical visualization of calprotectin in neutrophils, eosinophil-derived neurotoxin in eosinophils and tumour necrosis factor-α in macrophages was also achieved. Correct cytological diagnosis was made in 61.8% of analysed IBD cases. Our new method of colorectal mucus sampling provides highly informative material for cytology. Findings of the presence of plasmocytes and erythrophagocytosis in colorectal mucus are unique and may reflect previously unknown mechanisms of IBD pathogenesis. Immunocytochemical detection of inflammation biomarkers demonstrates the suitability of this material for biomarker quantification. These promising results suggest a potential role for colorectal mucus cytology in the non-invasive diagnosis of IBD.

Hepatic nodular lymphoid lesion with increased IgG4-positive plasma cells associated with primary biliary cirrhosis: a report of two cases

The nodular lymphoid lesion of the liver known as reactive lymphoid hyperplasia or pseudolymphoma is rare and its pathogenesis is unknown. We report two cases of nodular lymphoid lesions of the liver with numerous IgG4-positive plasma cells in patients with primary biliary cirrhosis. Histologically, in both cases, the lesion showed a dense lymphoplasmacytic infiltrate with lymphoid follicles and granulomas. Fibrous tissue was scarce and without a storiform pattern. Obliterative phlebitis was not identified. The IgG4+ plasma cell counts were 82 and 76 per high power field, with an IgG4/IgG ratio of 75 and 64 %, respectively, which qualifies the lesions according to the diagnostic criteria for IgG4-related disease as « probable histological feature of IgG4-related disease ». There were no rearrangements of immunoglobulin heavy-chain genes and plasma cells had a polytypic pattern of kappa and lambda light-chain expression. The non-tumor liver showed primary biliary cirrhosis with destructive cholangitis without IgG4 plasma cells. In both cases, IgG4-related disease was not found in other organs neither at the time of diagnosis nor 3 years later. Serum IgG4 levels normalized after local ablation of the lesions. It seems unlikely that these lesions are a manifestation of IgG4-related disease. However, because the pathogenesis of both nodular lymphoid lesions and IgG4-related disease remains unclear, further studies are needed to elucidate a potential link between nodular lymphoid lesions of the liver and an increased number of IgG4 plasma cells. More definite conclusions will be possible when the pathogenesis of IgG4-related disease has been clarified.

Recent developments in steroid-responsive pancreatitides (autoimmune pancreatitis)

PURPOSE OF REVIEW

There are two distinct steroid responsive chronic fibro-inflammatory diseases of the pancreas, called type 1 and type 2 autoimmune pancreatitis (AIP). We review recent progress in this field.

RECENT FINDINGS

It has recently been suggested that the term AIP be used to describe type 1 AIP and the term idiopathic duct-centric chronic pancreatitis (IDCP) be used for type 2 AIP. Clinical features and long-term outcomes of AIP and IDCP are well characterized and prognosis of both diseases is excellent. Diagnostic strategies tailored to regional practice patterns have emerged with the application of International Consensus Diagnostic Criteria for AIP. Although corticosteroids remain the mainstay of treatment, management of relapses and strategies for preventing multiple relapses are better understood, including the role of maintenance therapy and B-cell depletion therapy with rituximab. Association studies with malignancies have yielded conflicting results regarding risk of cancer in AIP.

SUMMARY

The treatment, follow-up guidelines and associations continue to evolve with our increasing experience with both AIP and IDCP. In AIP, rituximab can be used for both induction and maintenance of remission. IDCP responds to steroids without need for maintenance therapy. Both AIP and IDCP have excellent prognosis.

Can IgG4 Levels Identify the Ulcerative Colitis Subtype of Inflammatory Bowel Disease?

Background

Pancreatitis and exocrine pancreatic insufficiency may occur as extraintestinal manifestations of inflammatory bowel disease. Recently, autoimmune pancreatitis and colitis have been described as presentations of IgG4-related disease. IgG4+ plasma cells have been identified in colon tissue from patients with refractory forms of inflammatory bowel disease. The presence of elevated serum/tissue levels of IgG4 and the frequency of exocrine pancreatic insufficiency in inflammatory bowel disease are still a source of controversy. Our aim was to investigate the meaning of elevated IgG4 levels in patients with inflammatory bowel disease.

Methods

A cross-sectional study analyzed 56 patients with a diagnosis of inflammatory bowel disease recruited by convenience sampling from two tertiary centers in Midwestern Brazil. All patients underwent fecal pancreatic elastase testing for detection of exocrine pancreatic insufficiency and serum IgG4 measurement. Findings were correlated with clinical and epidemiological data and disease activity.

Results

Elevated serum IgG4 levels were found in 10 patients, and were most frequent in ulcerative colitis (nine cases), with a prevalence ratio of 16.42 (95% CI: 3.32 - 79.58). Ten patients (10 of 56, 17.8%) were diagnosed with exocrine pancreatic insufficiency, which did not correlate with disease activity, and serum IgG4 levels.

Conclusion

Exocrine pancreatic insufficiency is prevalent in patients with inflammatory bowel disease, but it is not associated with elevated serum IgG4 levels. The high prevalence of elevated serum IgG4 in ulcerative colitis suggests that this parameter has potential for use as a diagnostic biomarker.

IgG4-related disease: a new kid on the block or an old aquaintance?

IgG4-related systemic disease is a recently recognized systemic condition characterized by unique pathological features that can affect a variety of organs. It includes a growing number of medical conditions which have the following features in common: diffuse organ swelling or focal mass formation, sclerosing storiforme (whirl-shaped) fibrosis with a lymphoplasmacytic infiltrate rich in IgG4-bearing plasma cells, as well as elevated levels of serum IgG4. It invariably responds to steroid treatment and is mostly diagnosed in elderly men. Well-known syndromes like Mikulicz's disease of the salivary or lacrimal gland, Küttner's tumour of the submandibular gland, Riedel's thyroiditis, or retroperitoneal fibrosis, as well as novel entities such as autoimmune pancreatitis type 1, are now regarded to be manifestations of this systemic disease. This article provides an overview of the epidemiology, concepts of pathogenesis, clinical presentation, proposed diagnostic approaches, treatment options, and differential diagnosis of IgG4-related disease.