Autoimmune pancreatitis

IgG4-related hypophysitis

Hypophysitis is a rare pituitary inflammatory disorder classified in different ways. Immunoglobulin G4-related disease (IgG4-RD), also a rare disease is a systemic fibro-inflammatory condition characterized by infiltration of tissue with IgG4-positive plasma cells; however prevalence of both of them probably is underestimated. In this paper, we present an Iranian patient with biopsy-proven IgG4-related hypophysitis and then review the clinical characteristics, laboratory, imaging, pathologic findings and therapeutic management as well as prognosis of 115 published cases of hypophysitis secondary to IgG4-related disease.

IgG4 hypophysitis: Diagnosis and management

IgG4-related hypophysitis is a rare disease, due to a lymphoplasmocytic IgG4 positive infiltration of the pituitary. Literature data are scarce, even though the description of cases has drastically increased over the last years. The aim of this review is to better characterize the natural history, the diagnosis and the management of IgG4-related hypophysitis, based on a clinical case, an exhaustive Pubmed research, and a reappraisal of the criteria for diagnosis. We will specifically focus on the differences with other etiologies of hypophysitis, in the aim of improving the diagnostic procedures for all the physicians who could have to take care of such patients.

IgG4-related hypophysitis in patients with autoimmune pancreatitis

PURPOSE

IgG4-related disease involves various organs including the pituitary and pancreas. The prevalence of IgG4-related hypophysitis is relatively rare compared with IgG4-related pancreatitis (autoimmune pancreatitis). Although several cases demonstrating both autoimmune pancreatitis and hypophysitis have been reported, the prevalence of IgG4-related hypophysitis in patients with autoimmune pancreatitis remains unknown. This study aimed at screening for IgG4-related hypophysitis to accurately determine its prevalence in patients with autoimmune pancreatitis.

METHODS

In this cohort study, we screened IgG4-related hypophysitis via pituitary magnetic resonance imaging (MRI) and endocrinological examination in 27 patients who were undergoing follow-up for autoimmune pancreatitis at Kobe University Hospital between 2014 and 2018.

RESULTS

Among 27 patients with autoimmune pancreatitis, 5 patients exhibited morphological abnormalities in the pituitary (18.5%). Among them, one patient (3.7%) met the criteria for hypophysitis with an enlarged pituitary and stalk concomitant with hypopituitarism. After glucocorticoid treatment, the enlarged pituitary shrank and became empty sella during the clinical course. Four patients (14.8%) revealed empty sella without obvious pituitary dysfunction. Four of 5 patients with morphological pituitary abnormalities showed multiple organ involvement in addition to pancreatic and pituitary involvement. Accordingly, multiple organ involvement was more prevalent in patients with morphological pituitary abnormalities (80%) compared to those without (48%).

CONCLUSIONS

Although a large-scale study is necessary to validate these results, these data suggest that the prevalence of hypophysitis in patients with autoimmune pancreatitis may be underestimated. Based on our findings, we recommend screening for hypophysitis, especially in patients with multiple organ involvement.

Management of Autoimmune Pancreatitis

Type 1 autoimmune pancreatitis (AIP) is an IgG-4-related systemic disease that can manifest as a pancreatic disorder or another disorder of presumed autoimmune origin. Type 2 disease is typically characterized by absent IgG-4-positive cells. As patients often present with acute pancreatitis, obstructive jaundice, or pancreatic mass, it is imperative to exclude malignancy, a more common diagnosis. AIP may respond to corticosteroids, and has a strong association with other immune-mediated diseases. Recent literature suggests the benefit of immune-modulating therapy, including rituximab, although no consensus exists. This review covers the essentials of diagnosis, but focuses primarily on management of AIP.

Rituximab was used to treat recurrent IgG4-related hypophysitis with ophthalmopathy as the initial presentation: A case report and literature review

RATIONALE

Immunoglobulin G4 (IgG4)-related hypophysitis is a type of IgG4-related disease (IgG4-RD), which is characterized by plasma cells infiltration in the pituitary causing functional changes and (or) space-occupying effect in the pituitary. IgG4-related hypophysitis is sensitive to hormone therapy in most patients, but recurrence is very likely.

PATIENT CONCERNS

Here, we report a 57-year-old male patient with bilateral eye redness as the initial presentation. He later presented with pituitary hypofunction that involved multiple organs, including eyes, lacrimal gland, pituitary, lung, gall bladder, and intestine. There was an elevation of C-reactive protein and blood sedimentation, but the IgG and IgG4 levels of the serum and the cerebrospinal fluid did not increase obviously following irregular glucocorticoid therapy. Magnetic resonance imaging revealed enlarged pituitary and obviously thickened pituitary stalk. IgG4-related hypophysitis was confirmed by biopsy of the pituitary.

DIAGNOSES

The patient was diagnosis of IgG4-related hypophysitis with ophthalmopathy by pathological and molecular tests.

INTERVENTIONS

The patient responded to methylprednisolone pulse therapy but relapsed during the maintenance therapy using small-dose hormones combined with azathioprine. Methylprednisolone pulse therapy was given for 3 days followed by rituximab injection for 4 weeks.

OUTCOMES

After use methylprednisolone pulse therapy with rituximab the patient achieved complete remission.

LESSONS

Rituximab achieved good effect for recurrent IgG4-related hypophysitis after glucocorticoid therapy combined with immunosuppressant in this case. Moreover, comparative analysis was carried out with other reported cases of IgG4-related hypophysitis in terms of clinical features, treatment, and follow-up.

Critical review of IgG4-related hypophysitis

PURPOSE

IgG4-related hypophysitis is a rare disease, with only 34 cases published in English (2015). Available short reviews may not present complete details of IgG4-related hypophysitis. We aimed to survey case reports of IgG4-related hypophysitis, including abstracts of scientific meetings, in English and Japanese.

METHODS

We searched for information about IgG4-related hypophysitis in PubMed and Igakuchuozasshi (Japan Medical Abstracts Society). Among 104 case reports found, we reviewed 84 fulfilling Leporati's diagnostic criteria.

RESULTS

The mean ±  SD age of onset was 64.2  ±  13.9, 67.5  ±  9.8, and 56.4  ±  18.6 years for all subjects, men, and women, respectively. Men:women was 2.4:1. On magnetic resonance imaging, pituitary, stalk, and pituitary-stalk mass were observed at frequencies of 14.3, 21.4, and 64.3%, respectively. Manifestations were anterior hypopituitarism in 26.2% (22 cases), central diabetes insipidus in 17.9% (15 cases), and panhypopituitarism in 52.4% (44 cases). The median level of serum IgG4 was 264.5 mg/dL for all subjects, 405 mg/dL for men, and 226 mg/dL for women. The mean number of IgG4-related systemic diseases was 2.7  ±  1.5 in all subjects, 3.0  ±  1.5 in men, and 1.8  ±  1.1 in women. Among the IgG4-related diseases, retroperitoneal fibrosis was the most frequent (26.2%), followed by salivary gland diseases (25%). Glucocorticoid therapy was generally effective, except for two cases that received replacement doses. There were significant differences between sexes in terms of age, serum IgG4 levels, and number of IgG4-related diseases.

CONCLUSION

IgG4-related hypophysitis may have different clinical characteristics between genders. This survey may lack some information because the Japanese abstracts did not contain certain details.

IgG4-related hypophysitis is highly prevalent among cases of histologically confirmed hypophysitis

IgG4-related disease is an immune-mediated disease with manifestations in most organ systems among them the pituitary gland. To date, few cases of histologically confirmed cases of IgG-related hypophysitis have been reported. The aim of this study was to retrospectively determine the prevalence of IgG4-related hypophysitis among cases previously diagnosed as primary hypophysitis (lymphocytic hypophysitis, granulomatous hypophysitis and hypophysitis not otherwise specified). Histological and immunohistochemical analysis revealed that 12 of 29 cases (41.4%) previously diagnosed as primary hypophysitis fulfilled the criteria for IgG4-related disease and, thus, IgG4-related hypophysitis should always be considered in the differential diagnosis of primary hypophysitis. All cases of IgG4-related hypophysitis showed a dense lymphoplasmacytic infiltrate with more than 10 IgG4-positive cells per high power field and a ratio of IgG4/IgG-positive cells of more than 40%, whereas storiform fibrosis was an inconsistent histological feature and was also seen in few cases of non-IgG-related hypophysitis, thus lacking sensitivity and specificity. Obliterative phlebitis was not seen in any case. Thus, histological criteria defined for IgG4-related disease in other organs should be modified for IgG4-related hypophysitis, accordingly.

IgG4-Related Hypophysitis: Case Report and Literature Review

IgG4-related hypophysitis is a rare, inflammatory process of the pituitary that mimics more commonly seen pituitary tumors. We report a case of IgG4-related hypophysitis in a 16-year-old female with diabetes insipidus who was found to have IgG4-related hypophysitis based on tissue diagnosis. This entity has not been previously described in a pediatric patient. Recognition of certain inflammatory processes of the pituitary may lead to alternative means of diagnosis and medical management without a biopsy.

Autoimmune Pancreatitis: An Update on Diagnosis and Management

There is an evolving understanding that autoimmune pancreatitis (AIP) is an immunoglobulin (Ig) G4 systemic disease. It can manifest as primarily a pancreatic disorder or in association with other disorders of presumed autoimmune cause. Classic clinical characteristics include obstructive jaundice, abdominal pain, and acute pancreatitis. Thus, AIP can be difficult to distinguish from pancreatic malignancy. However, AIP may respond to therapy with corticosteroids, and has a strong association with other immune mediated diseases. Although primarily a pathologic diagnosis, attempts have been made to reliably diagnose AIP clinically. AIP can be classified as either type 1 or type 2.

Clinical course of IgG4-related hypophysitis presenting with focal seizure and relapsing lymphocytic hypophysitis

BACKGROUND

This is the first case report of focal seizure as a manifestation of Immunoglobulin G4 (IgG4)-related hypophysitis. IgG4-related hypophysitis is a novel category of hypophysitis. The clinical presentations, imaging studies and initial pathology studies can mimic lymphocytic hypophysitis. Here we report additional clinical clues in differentiating these two conditions.

CASE PRESENTATION

A 43-year-old Thai male presented with focal seizure, headache, and anterior pituitary hypofunction. His MRI study showed typical hypophysitis lesion with abnormal cerebral parenchymal signal intensity at right frontal lobe. The pituitary biopsied was obtained and the patient was initially diagnosed with lymphocytic hypophysitis. Following initial low-dose steroid therapy, his seizure and headache resolved but his anterior pituitary hormones remained deficient. However, during steroid tapering, he developed new onset acute visual loss. Upon rigorous pathologic review, his diagnosis of IgG4-related hypophysitis with suspected CNS involvement was established. He was subsequently treated with high-dose steroid and rapidly regained his sight.

CONCLUSION

This case report highlights the important distinguishing features of IgG4-related hypophysitis from lymphocytic hypophysitis. These include the relapsing clinical course of hypophysitis after steroid decrement and concomitant pachymeningitis particularly in middle-aged to elderly Asian male who presented with hypophysitis. With appropriate dosage of steroids, medical treatment is usually sufficient to control the disease and surgical interventions are usually not required.

Cerebral involvement in IgG4-related disease

IgG4-related disease is a recently recognised multi-system disease. Common organ involvement includes the pancreas, biliary tree and salivary glands. Central nervous system involvement has been infrequently reported. In a single-centre cohort of 84 patients, we report cerebral involvement in three (4%) patients. Details of cerebral involvement in these patients are outlined, including pituitary involvement in two patients and a diffuse autoimmune-like encephalopathy in the other.

Hypophysitis due to IgG4-related disease responding to treatment with azathioprine: an alternative to corticosteroid therapy

PURPOSE

Fifteen cases of lymphocytic hypophysitis due to IgG4-related disease have been reported demonstrating marked improvement with corticosteroid therapy. This is the first case of IgG4-related hypophysitis demonstrating improvement with azathioprine, where corticosteroids were initially tried but ceased due to concern regarding enlargement of the pituitary infiltrate.

METHODS

Case description and review of 15 cases reported in the literature. A 40 year old male was diagnosed with IgG-4 related disease based on pituitary and lacrimal gland biopsies associated with raised serum concentration of IgG4. The patient was commenced on prednisolone 30 mg/day, as rapid response to prednisolone treatment has been described in the literature for other cases of IgG4-related hypophysitis. Over the next 3 months, prednisolone treatment resulted in a reduction of serum IgG4 levels, but repeat MRI scan showed an enlarging pituitary mass with new optic nerve compression. Azathioprine 75 mg twice daily was commenced and in the subsequent 3 months, IgG4 levels normalised (0.58 g/L) and MRI scan showed 50% shrinkage of the pituitary mass. After 10 months of azathioprine treatment the MRI showed a normal sized pituitary but persistence of the infraorbital nerve thickening.

CONCLUSIONS

Hypophysitis due to IgG4-related disease usually demonstrates prompt response to corticosteroids. This case highlights the need to image promptly after starting treatment to exclude an enlarging pituitary mass despite corticosteroid treatment. Alternative therapy with azathioprine can result in marked improvement. It should be remembered that IgG-4 related hypophysitis is part of a multi-organ disease.

The prevalence of IgG4-related hypophysitis in 170 consecutive patients with hypopituitarism and/or central diabetes insipidus and review of the literature

OBJECTIVE

The prevalence and clinical characteristics of IgG4-related hypophysitis remain unclear due to the limited number of case reports. Therefore, in this study, we screened consecutive outpatients with hypopituitarism and/or diabetes insipidus (DI) to estimate its prevalence.

METHODS

A total of 170 consecutive outpatients with hypopituitarism and/or central DI were screened at Kobe University Hospital for detecting IgG4-related hypophysitis by pituitary magnetic resonance imaging, measuring serum IgG4 concentrations, assessing the involvement of other organs, and carrying out an immunohistochemical analysis to detect IgG4-positive cell infiltration.

RESULTS

Among the screened cases, 116 cases were excluded due to diagnosis of other causes such as tumors and congenital abnormalities. Additionally, 22 cases with isolated ACTH deficiency were analyzed and were found not to meet the criteria of IgG4-related hypophysitis. The remaining 32 cases were screened and seven were diagnosed with IgG4-related hypophysitis, of which three cases were diagnosed by analyzing pituitary specimens. IgG4-related hypophysitis was detected in 30% (seven of 23 patients) of hypophysitis cases and 4% of all hypopituitarism/DI cases. The mean age at the onset of IgG4-related hypophysitis was 61.8±8.8 years, and the serum IgG4 concentration was 191.1±78.3 mg/dl (normal values 5-105 mg/dl and values in IgG4-related disease (RD) ≥135 mg/dl). Pituitary gland and/or stalk swelling was observed in six patients, and an empty sella was observed in one patient. Multiple co-existing organ involvement was observed in four of the seven patients prior to the onset of IgG4-related hypophysitis.

CONCLUSION

These data suggest that the prevalence of IgG4-related hypophysitis has been underestimated. We should also consider the possibility of the development of hypopituitarism/DI caused by IgG4-related hypophysitis during the clinical course of other IgG4-RDs.

Occurrence of IgG4-related hypophysitis lacking IgG4-bearing plasma cell infiltration during steroid therapy

Eight years after an episode of multiple IgG4-related disease, a pituitary mass with panhypopituitarism and a visual disturbance developed in a 70-year-old man under low-dose steroid therapy. A pituitary biopsy revealed findings of lymphocytic hypophysitis with the absence of IgG4-positive plasma cell infiltration. The serum IgG4 level was unremarkable. Although performing a pituitary biopsy and measuring the serum IgG4 level is crucial for making a diagnosis of IgG4-related hypophysitis, it is occasionally difficult to diagnose the disease in patients treated with steroid therapy, as observed in the present case. Based on a review of the diagnosis, conducting a careful assessment is required, especially in men and elderly patients thought to have solitary hypophysitis.

A case of IgG4-related hypophysitis without pituitary insufficiency

CONTEXT

IgG4-related hypophysitis is a novel clinical disease entity, which is typically complicated by hypopituitarism.

OBJECTIVE

The objective of the study was to describe a novel case of IgG4-related hypophysitis without pituitary insufficiency and summarize the current relevant literature.

PATIENT AND METHODS

A 55-year-old Japanese man presented with an enlarged pituitary gland and bitemporal hemianopsia. Endocrine studies revealed normal pituitary function, although his serum IgG4 level was high. The patient underwent a transsphenoidal biopsy of the pituitary gland, and the pathological tissues were consistent with IgG4-related hypophysitis. Oral prednisolone therapy was started, and after 6 months, his serum IgG4 level decreased and visual field improved.

CONCLUSION

We described the first case of IgG4-related hypophysitis without pituitary insufficiency. However, further case collection is needed to characterize the pathophysiology of IgG4-related hypophysitis.

IgG4-related hypophysitis: a new addition to the hypophysitis spectrum

CONTEXT

Hypophysitis is a chronic inflammation of the pituitary gland that comprises an increasingly complex clinicopathological spectrum. Within this spectrum, lymphocytic and granulomatous hypophysitis are the most common forms, but newer variants have recently been reported.

OBJECTIVE

The aims of the study were to describe a new patient with IgG4-related hypophysitis, review the published literature, and provide diagnostic criteria.

SETTING

A 75-yr-old man presented with a 1-yr history of frontal headache. Initial studies revealed panhypopituitarism and a mass in both the sella turcica and the sphenoidal sinus. The patient underwent transphenoidal surgery, initiated high-dose prednisone followed by hormone replacement therapy, and was closely monitored for 3 yr.

RESULTS

Symptoms improved after prednisone, along with shrinkage of the pituitary and sphenoidal masses, but recurred when prednisone dose was lowered. Histopathology showed a marked mononuclear infiltrate in both the pituitary and sphenoidal specimens, mainly characterized by increased numbers of plasma cells. Many of the infiltrating plasma cells (>10 per high-power field) were IgG4-positive. Review of the literature identified 11 cases of IgG4-related hypophysitis (two diagnosed based on pituitary histopathology).

CONCLUSIONS

We describe the first Caucasian patient with biopsy-proven IgG4-related hypophysitis and provide classification criteria for this disease.

Usefulness of serum IgG4 in the diagnosis and follow up of autoimmune pancreatitis: A systematic literature review and meta-analysis

High circulating serum immunoglobulin G4 (IgG4) levels have been proposed as a marker of autoimmune pancreatitis (AIP). The aim of the present study was to review the data existing in the English literature on the usefulness of the IgG4 serum levels in the diagnosis and follow up of patients with AIP. A total of 159 patients with AIP and 1099 controls were described in seven selected papers reporting the usefulness of serum IgG4 in diagnosing AIP. In total, 304 controls had pancreatic cancer, 96 had autoimmune diseases, and the remaining 699 had other conditions. The summary receiver-operating characteristic curve analysis was carried out by means of Meta-DiSc open-access software. Serum IgG4 showed good accuracy in distinguishing between AIP and the overall controls, pancreatic cancer and other autoimmune diseases (area under the curve [+/- SE]: 0.920 +/- 0.073, 0.914 +/- 0.191, and 0.949 +/- 0.024, respectively). The studies analyzed showed significantly heterogeneous specificity values in each of the three analyses performed. The analysis of the four studies comparing AIP and pancreatic cancers also showed significantly heterogeneous values of sensitivities and odds ratios. Regarding the usefulness of IgG4 as a marker of efficacy of steroid treatment, a decrease in the serum concentrations of IgG4 was found in the four available studies. The serum IgG4 subclass is a good marker of AIP, and its determination should be included in the diagnostic workup of this disease. However, the heterogeneity of the studies published until now means that more studies are necessary in order to better evaluate the true accuracy of IgG4 in discriminating AIP versus other autoimmune diseases.

Autoimmune pancreatitis: with special reference to a localized variant

In 2006, the Japan Pancreas Society revised the diagnostic criteria for autoimmune pancreatitis (AIP) so as to more clearly define its morphological, pathological, and immunological features, as follows: (1) diffuse or segmental narrowing of the main pancreatic duct with an irregular wall and diffuse or localized enlargement of the pancreas recognized by imaging studies; (2) high serum gamma globulin, IgG, or IgG4 levels, or the presence of autoantibodies; and (3) marked interlobular fibrosis and prominent infiltration of lymphocytes and plasma cells in the periductal area, occasionally with lymphoid follicles in the pancreas. Establishing a diagnosis of AIP has become easier with knowledge of its immunological abnormalities, including serum IgG4 levels. However, the localized form of AIP sometimes mimics pancreatic cancer. The rate of focal mass formation in patients with AIP is reportedly 24%-43%; however, there have been few reports on the histological findings of localized AIP, in contrast to mass-forming pancreatitis (MFP). Our review of patients who had undergone resection due to a preoperative diagnosis of MFP with possible cancer revealed 72% to be patients with localized AIP. For the discrimination of these conditions, it is important to recognize the characteristic ultrasonographic findings of AIP, i.e., (1) diffuse or localized enlargement and hypoechogenicity of the pancreas; (2) rarity of calcification, cystic lesions, and peripancreatic fluid collection; (3) thickened layer structure of the bile duct wall; (4) iso/hypervascularity in the swollen portion of the pancreas; (5) attenuation of pancreatic swelling and bile duct wall thickening after steroid therapy; and (6) multiple hypoechoic masses in various organs, including the pancreas. Contrast-enhanced endoscopic ultrasonography is potentially a useful tool in the differential diagnosis and for assessment of the efficacy of steroid therapy by enabling evaluation of the vascularity of the lesions. Along with the presence of IgG4-positive plasma cells, verification of obliterative phlebitis is highly specific for the histological diagnosis of AIP.