Clinical features of 10 patients with IgG4-related retroperitoneal fibrosis

A review of the current treatment methods for retroperitoneal fibrosis with obstructive uropathy

Introduction and aims

Retroperitoneal fibrosis (RPF) is a fibroinflammatory disease in which patients may suffer obstructive uropathy (OU). The optimum treatment strategy for RPF with secondary OU is currently unclear, and the aim of this literature review is to assess the methods used to treat this patient cohort.

Methods

Medline, Embase, Cinahl, the Cochrane Library and PubMed were systematically searched to find studies assessing treatment outcomes in this patient cohort. After reviewing the studies' titles, abstracts and full texts, 12 were found that matched our search aims. Data from these publications were analysed and reported.

Results

The demographic and symptomatic features of patients across the 12 studies were representative of the general RPF population. No randomised control trials (RCTs) were found, and just one study formally compared outcomes between patients who underwent different treatment strategies. Many of the studies concluded that using medical and surgical methods in combination led to positive outcomes; whereas, others found positive outcomes following a variety of regimens. Many studies also highlighted, however, that significant minorities required further treatment after initial therapy. Conclusions regarding optimum treatment methods were limited as most publications did not formally compare outcomes following different strategies and had an observational study design.

Conclusion

Although positive outcomes were commonly seen following medical, surgical and a combination of treatments, the literature currently lacks research formally comparing outcomes after assigning specific treatment protocols to groups of RPF patients. More research is therefore required to determine how to best manage RPF leading to secondary OU.

Extravertebral low back pain: a scoping review

BACKGROUND

Low back pain (LBP) is one of the most common reasons for consultation in general practice. Currently, LBP is categorised into specific and non-specific causes. However, extravertebral causes, such as abdominal aortic aneurysm or pancreatitis, are not being considered.

METHODS

A systematic literature search was performed across MEDLINE, Embase, and the Cochrane library, complemented by a handsearch. Studies conducted between 1 January 2001 and 31 December 2020, where LBP was the main symptom, were included.

RESULTS

The literature search identified 6040 studies, from which duplicates were removed, leaving 4105 studies for title and abstract screening. Subsequently, 265 publications were selected for inclusion, with an additional 197 publications identified through the handsearch. The majority of the studies were case reports and case series, predominantly originating from specialised care settings. A clear distinction between vertebral or rare causes of LBP was not always possible. A range of diseases were identified as potential extravertebral causes of LBP, encompassing gynaecological, urological, vascular, systemic, and gastrointestinal diseases. Notably, guidelines exhibited inconsistencies in addressing extravertebral causes.

DISCUSSION

Prior to this review, there has been no systematic investigation into extravertebral causes of LBP. Although these causes are rare, the absence of robust and reliable epidemiological data hinders a comprehensive understanding, as well as the lack of standardised protocols, which contributes to a lack of accurate description of indicative symptoms. While there are certain disease-specific characteristics, such as non-mechanical or cyclical LBP, and atypical accompanying symptoms like fever, abdominal pain, or leg swelling, that may suggest extravertebral causes, it is important to recognise that these features are not universally present in every patient.

CONCLUSION

The differential diagnosis of extravertebral LBP is extensive with relatively low prevalence rates dependent on the clinical setting. Clinicians should maintain a high index of suspicion for extravertebral aetiologies, especially in patients presenting with atypical accompanying symptoms.

IgG4-related retroperitoneal fibrosis: A case report of a challenging disease

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a multi-organ immune-mediated fibroinflammatory disorder that may imitate malignancy, infectious or any other inflammatory disorder. IgG4-related retroperitoneal fibrosis (IgG4-RPF) is a rare form of IgG4-RD, diagnosis of which is often relied on radiological technology. Herein, we describe a case of 60 year old male, presenting with low back pain and weight loss for a period of 2 months and 15 days. Imaging studies showed a retroperitoneal tumorous mass along with bilateral hydroureteronephrosis, which was later confirmed to be IgG4-related retroperitoneal fibrosis on the basis of extensive histopathological analysis. Immunosuppressive therapy resulted in a decrease in fibrosis and restoration of renal function.

Immunoglobulin G4-related Disease: A New Systemic Disease Emerging in Japan

Immunoglobulin G4-related disease (IgG4-RD) is a fibro-inflammatory disease characterized by organ enlargement and elevated serum IgG4 levels. In 2003, IgG4-RD was proposed as a distinct form of IgG4-related systemic disease based on a histopathological study involving patients with autoimmune pancreatitis. IgG4-RD occurs mainly in older men and can affect almost any organ simultaneously or metachronously. Pathophysiologically, IgG4-RD occurs when an autoantigen triggers an immune response characterized by Th2 predominance with increased production of cytokines, such as interleukin 4 (IL-4), IL-5, IL-10, IL-13, and tumor growth factor-β (TGF-β), in the affected organ. IL-10 and TGF-β produced by the increased number of regulatory T cells induce a switch from B cells to IgG4-producing plasma cells and fibrosis, respectively. The characteristic histological features consist of dense infiltration of lymphocytes and IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis. IgG4-RD is diagnosed based on a combination of clinical, serological, radiological, and histopathological findings. Differentiating IgG4-RD from malignant tumors or similar inflammatory diseases in the affected organs is important. The 2019 America College of Rheumatology/European League against Rheumatism classification criteria for IgG4-RD have high diagnostic sensitivity and specificity. IgG4-RD generally responds well to treatment with steroids, and a swift response is reassuring and provides further diagnostic confirmation. However, relapses are common during tapering or after cessation of steroids. In Japan, low-dose steroid maintenance therapy is usually given to prevent a relapse. B-cell depletion with rituximab is effective in patients resistant to or dependent on steroids. Most patients with IgG4-RD who receive steroid therapy show good short-term clinical, morphological, and functional outcomes. However, long-term outcomes, such as relapse, fibrosis development, and associated malignancies, have not been clearly defined. Therefore, novel treatment strategies, including rituximab, need to be tested in international randomized controlled clinical trials.

Retroperitoneal fibrosis is still underdiagnosed entity with poor prognosis

BACKGROUND

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the presence of inflammatory and fibrous retroperitoneal tissue that often encircles abdominal organs including aorta and ureters. Data on the incidence of this disease are limited.

SUMMARY

The disease may be idiopathic or secondary to infections, malignancies, drugs or radiotherapy. Idiopathic form is an immune-mediated entity and a part of the broader spectrum of idiopathic diseases termed chronic periaortitis, characterized by a morphologically similar fibroinflammatory changes in aorta and surrounding tissues. Taking into account the dominant symptoms and clinical charac-teristics of patients with periaortitis, two subtypes of disease could be distinguished. Vascular subtype include patients with non-dilated aorta or with inflammatory abdominal aortic aneu-rysm, both with and without involvement of adjacent structures and with numerous risk factors for atherosclerosis. In renoureteral subtype obstructive uropathy manifesting with hydronephro-sis and acute kidney injury is predominant finding. Due to the variety of symptoms, diagnosis of RPF remains challenging, difficult and often delayed. A series of diagnostic tests should be performed, in order to confirm the diagnosis idiopathic RPF. Laboratory work-up include eval-uation of inflammatory indices and immunological studies. A biopsy and histopathological evaluation may be necessary to confirm diagnosis and differentiate the disease. Computed to-mography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) are the modalities of choice for the diagnosis and follow-up of this disease. Management of ureteral obstruction, hydronephrosis, and aortic aneurysms often requires surgical evaluation and treatment. The pharmacological treatment of RPF has been evaluated in a few randomized trials and is mainly based on observational studies. Steroid therapy remains the gold standard of treatment. Key messages: Nowadays multidisciplinary team approach with clinical and diagnos-tic experience in both primary and secondary RPF as well as two major subtypes should be offered. Centers specialized in rare diseases with collaboration with other units and referral sys-tem yield the best possible outcomes.

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.

Renal Involvement in Retroperitoneal Fibrosis: Prevalence, Impact and Management Challenges

Retroperitoneal fibrosis (RPF) is a rare disorder consisting of idiopathic and various secondary forms and characterized by chronic inflammatory infiltrates and marked fibrosis in the retroperitoneal space. In idiopathic RPF (IRPF), 35–60% of cases have been reported to be IgG4-related RPF, the retroperitoneal lesions of IgG4-related disease (IgG4-RD). IRPF can frequently lead to renal insufficiency mediated by urinary tract obstruction and hydronephrosis irrespective of being IgG4-related or not. Clinical pictures, laboratory and imaging findings, and location of the urinary tract obstruction are generally similar in IgG4-related and non-IgG4-related IRPF although multiple organ involvement and serum IgG4 elevation may be characteristic of the IgG4-related forms. Periaortic/periarterial lesions are the most frequent cause of renal insufficiency. Although the response to glucocorticoids is generally good, relapse does occur in a considerable proportion of patients, and may require an additional immunosuppressive agent and/or urological intervention in cases with multiple relapses or refractory obstructive uropathy. In general, the prognosis of patients with IRPF is good, but careful attention needs to be paid to chronic kidney disease as a major complication and rupture of the affected aorta/artery as a life-threatening one. Further studies are necessary to better understand the pathogenesis of the disease and to establish the optimal diagnostic and therapeutic strategies for it.

Clinical features of IgG4-related retroperitoneal fibrosis among 407 patients with IgG4-related disease: a retrospective study

OBJECTIVES

IgG4-related disease (IgG4-RD) is recently recognized as a fibro-inflammatory condition featured by tumefactive lesions in multiple organs, and the retroperitoneum is one of the common involved sites. We undertook this study to compare detailed demographic, clinical and laboratory characteristics of IgG4-RD patients with retroperitoneum lesion (IgG4-RD RPF+) and retroperitoneum free IgG4-RD (IgG4-RD RPF-) in a large cohort.

METHODS

We carried out a retrospective review of the medical records of 407 cases of IgG4-RD diagnosed at Peking University People's Hospital between March 2009 and May 2019.

RESULTS

Among 407 patients, 58 had retroperitoneum affected. As compared with IgG4-RD RPF- patients, IgG4-RD RPF+ patients showed older age at disease onset and diagnosis. IgG4-RD RPF+ group involved more male patients. In terms of organ involvement, IgG4-RD RPF+ group was more frequently presented with kidney involvement, while salivary gland, lacrimal gland and pancreas were more prominent in the IgG4-RD RPF- group. In addition, the CRP, ESR level and creatinine level were significantly higher in IgG4-RD RPF+ patients, and hypocomplementemia were more common in this group.

CONCLUSION

We have revealed demographic, clinical and laboratory differences between IgG4-RD RPF+ and RPF- patients, which indicated potential differences in pathogenesis and important implications for the diagnosis and management of these two phenotypes.

Marfan syndrome resulting from a rare pathogenic FBN1 variant, ascertained through a proband with IgG4-related arteriopathy

A 57-year-old man with a family history of aortic aneurysm was found, during assessment of unexplained fever, to have an infrarenal aortic aneurysm requiring immediate repair. Dilatation of popliteal and iliac arteries was also present. Progressive aortic root dilatation with aortic regurgitation was documented from 70 years leading to valve-sparing aortic root replacement at 77 years, at which time genetic studies identified a likely pathogenic FBN1 missense variant c.6916C > T (p.Arg2306Cys) in exon 56. The proband's lenses were normally positioned and the Marfan syndrome (MFS) systemic score was 0/20. Cascade genetic testing identified 15 other family members with the FBN1 variant, several of whom had unsuspected aortic root dilatation; none had ectopia lentis or MFS systemic score ≥ 7. Segregation analysis resulted in reclassification of the FBN1 variant as pathogenic. The combination of thoracic aortic aneurysm and dissection (TAAD) and a pathogenic FBN1 variant in multiple family members allowed a diagnosis of MFS using the revised Ghent criteria. At 82 years, the proband's presenting abdominal aortic aneurysm was diagnosed retrospectively to have resulted from IgG4-related inflammatory aortopathy.

IgG4 related disease as a cause of isolated retroperitoneal fibrosis with no other organ involvement; Case report

Introduction and importance

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the replacement of normal tissue with fibrosis and inflammation. We present the case of a 40-years-old gentleman with RPF whose presenting complaints were bilateral flank pain and weight loss and was found to have IgG4 related disease. To the best of our knowledge, IgG4-related disease with isolated retroperitoneal involvement is a very rare occurrence.

Case presentation

The diagnosis of IgG4-Related retroperitoneal fibrosis was made based on clinical, radiological and histopathological criteria. Imaging revealed isolated retroperitoneal involvement and the patient was started on oral steroids with a good clinical response after ten days. Repeated imaging months later showed significant regression in the fibrosis.

Clinical discussion

RPF can occur due to many etiologies and is categorized to idiopathic and secondary. Factors associated with secondary RPF include medications, autoimmune disease, malignancy and IgG4 related disease. Almost all the reported cases of IgG4 related disease had evidence of multifocal involvement such as the pancreas, aorta and kidneys. Our patient was diagnosed with isolated RPF due to IgG4 disease. He met all the suggested diagnostic criteria, was started on oral steroids and had an excellent clinical outcome.

Conclusion

IgG4 related disease can present with isolated retroperitoneal fibrosis without involvement of other organ systems. The diagnosis should be based on specific criteria. Treatment with corticosteroids can lead to remission both clinically and radiographically.

Relapse patterns and predictors of IgG4-related diseases involved with autoimmune pancreatitis: A single-center retrospective study of 115 patients

OBJECTIVE

Autoimmune pancreatitis is an autoimmune disorder accompanied by clinicopathological manifestations that have been established as immunoglobulin (IgG)4-related diseases (IgG4-RD). Other IgG4-RD are often involved with autoimmune pancreatitis. They sometimes relapse despite a favorable response to steroid therapy. This study aimed to clarify the patterns and risk factors for extrapancreatic relapse.

METHODS

We reviewed the data of 115 patients diagnosed with definite autoimmune pancreatitis type 1 and followed up for > 1 year. We analyzed two items: the timing and pattern of extrapancreatic relapse, and risk factors for relapse with three common manifestations: IgG4-related sclerosing cholangitis (SC), IgG4-related dacryoadenitis and sialadenitis (DS), and IgG4-related retroperitoneal fibrosis (RF).

RESULTS

Remission was achieved in all patients, except one. The extrapancreatic relapse rates were 11.0%, 19.7%, and 40% within 3, 5, and 10 years, respectively. Of 26 patients with extrapancreatic relapse, nine (34.6%) relapsed with a new IgG4-RD. Based on multivariate analysis, the interval between symptom onset and steroid initiation, and the presence of RF at onset were significant risk factors for relapse with SC and RF, respectively.

CONCLUSIONS

Our results indicate that they may be various extrapancreatic relapse patterns especially in autoimmune pancreatitis with other organ involvement. Patients with a delayed initiation of steroids or RF at onset should be carefully followed up as high-risk groups for SC and RF relapse.

Clinical Manifestations and Long-term Outcomes of IgG4-Related Kidney and Retroperitoneal Involvement in a United Kingdom IgG4-Related Disease Cohort

INTRODUCTION

IgG4-related disease (IgG4-RD) is a relapsing multisystem fibro-inflammatory disease, which may involve the kidney (IgG4-related kidney disease [IgG4-RKD]) and retroperitoneum (IgG4-related retroperitoneal fibrosis [IgG4-RPF]). The aim of this study was to describe IgG4-RKD and IgG4-RPF in the United Kingdom.

METHODS

We conducted a retrospective observational study of patients with IgG4-RKD and IgG4-RPF in a multicenter IgG4-RD cohort. Data were collected through review of medical records. We describe clinical parameters at baseline, histological and radiological findings, treatment, and patient outcomes.

RESULTS

Of 154 patients with IgG4-RD, 14 (9.1%) had IgG4-RKD, 10 (6.5%) had IgG4-RPF, and 4 (2.6%) had both. Patients were aged 58.2 ± 14.2 years, and 26 (92.9%) were male. Creatinine at presentation was worse in those with intrinsic renal disease (229 μmol/l vs. 110 μmol/l; P = 0.0076). Serum IgG4 was elevated in the majority of patients (87.5%), and hypocomplementemia was present in half of those with IgG4-RKD. Fifteen patients underwent renal biopsy; tubulointerstitial nephritis with abundant IgG4+ plasma cells was the most common finding (n = 14; 93.3%), and 4 (26.7%) patients had membranous nephropathy. Most patients (89.3%) were treated with corticosteroids, and 4 (16.0%) with additional azathioprine as initial management. Thirteen patients (46.4%) relapsed over 60 ± 48 months of follow-up, at median 18 (12-36) months after renal/RPF diagnosis; 61.5% of relapses were in the kidney. Renal function deteriorated in 5 patients (20.8%), including 2 (8.3%) who reached end-stage renal disease (ESRD).

CONCLUSION

IgG4-RKD and IgG4-RPF represent major organ manifestations of IgG4-RD, and should be identified early with prompt treatment to prevent progression to ESRD.

Imaging appearance of fibrosing diseases of the retroperitoneum: can a definitive diagnosis be made?

PURPOSE

To assess the frequency with which previously reported characteristic findings of retroperitoneal fibrosis (RPF) (a circumferential or almost circumferential peri-aortic mass centered at L4, which does not displace the abdominal aorta or proximal common iliac arteries) are present in patients with RPF, in patients with other fibrosing diseases, and in cancer patients referred to a subspecialty clinic with a suspected diagnosis of RPF, in order to determine whether diagnostic percutaneous biopsy can be avoided in some patients.

METHODS

This HIPAA-compliant Institutional Review Board-approved retrospective study assessed clinical and CT and MR imaging abnormalities on imaging studies in 92 patients referred to a subspecialty clinic with suspected RPF over a 14-year period. Two reviewers, in consensus, determined the frequency of different CT and MRI findings in three groups of patients (Group 1: those with an eventual diagnosis of RPF, Group 2: those with a fibrosing disease associated with vascular or urologic abnormalities, and Group 3: those with cancer). Assessed imaging features included the presence of retroperitoneal masses, whether masses were single or multiple, whether such masses were circumferential or nearly circumferential, whether they displaced the aorta away from the spine (with the degree of such displacement measured), and whether there were abnormalities outside of the peri-aortic region of the retroperitoneum. The frequency with which findings previously reported as characteristic of RPF were present was determined for each of the three groups. Imaging results were correlated with the final diagnoses.

RESULTS

Of 68 subjects eventually diagnosed with retroperitoneal fibrosis (RPF) (Group 1), 47 had peri-aortic retroperitoneal masses, 18 of which displaced the aorta anteriorly away from the spine. Of 12 subjects with fibrosing abnormalities related to vascular or urologic disease (Group 2), six had retroperitoneal masses, none of which displaced the aorta away from the spine. Of 12 subjects with malignancies (Group 3), six had peri-aortic retroperitoneal masses only two of whom had aortic displacement. Only 34 of 68 Group 1 subjects had peri-aortic masses characteristic of RPF, compared with six Group 2 subjects and one Group 3 subject. Subjects with characteristic retroperitoneal masses were significantly more likely to have benign disease than cancer (p = 0.009).

CONCLUSION

Many patients with RPF do not have characteristic imaging findings. Contrary to prior publications, absence of aortic displacement is not seen in all patients with RPF and is seen in some cancer patients. Nonetheless, when infiltrative peri-aortic retroperitoneal soft tissue that does not displace the aorta is encountered on CT or MRI, RPF can be diagnosed with a high degree of confidence, obviating the need for biopsy.

Rituximab for retroperitoneal fibrosis due to IgG4-related disease: A case report and literature review

Retroperitoneal fibrosis (RPF) is a progressive fibroinflammatory disease that can be complicated by urinary obstruction. RPF can be the only manifestation of IgG4-related disease (IgG4-RD). Treatment of IgG4-related RPF is challenging and mostly consists of long-term glucocorticoids leading to significant side effects and treatment intolerance. Recent exploration of the role of rituximab as a B-cell depleting therapy in the treatment of IgG4-RD provides therapeutic potential as a well-tolerated alternative to glucocorticoids. We present a case of IgG4-related RPF for which rituximab was instituted as a steroid-sparing treatment strategy. Following 4 doses, kidney function partially recovered, and the disease went into remission. We discuss the potential merit of rituximab for the treatment of patients with IgG4-related RPF.

Inferior vena cava thrombosis as the initial presentation of IgG4-related retroperitoneal fibrosis: Case report and literature review

IgG4-related disease is an immune-mediated deposition of fibro-inflammatory tissue with IgG4-positive plasma cells and dense fibrosis in a single or multiple organs. It often raises concern for malignancy requiring biopsy for diagnosis. Presentation may vary according to organ involved. IgG4-related retroperitoneal fibrosis accounts for two-thirds of the previously considered idiopathic retroperitoneal fibrosis cases. In IgG4-related retroperitoneal fibrosis, computed tomography scan or magnetic resonance imaging shows periaortic soft tissue that extends from below the kidneys to iliac arteries and entrap ureters causing hydronephrosis and renal failure. We present a rare case of IgG4-related retroperitoneal fibrosis presenting with leg swelling and pain due to inferior vena cava compression and thrombosis, and we review current concepts on disease pathogenesis, diagnosis and treatment.

Clinical features and prognostic factors of ten patients with renal failure caused by IgG4-related retroperitoneal fibrosis

IgG4-related retroperitoneal fibrosis (IgG4-RPF) is a newly recognized entity which often mimics cancer. We aimed to investigate the clinical features and the causes of renal failure, as well as to explore the factors affecting the prognosis of renal function by analysis of the clinical data of patients with IgG4-RPF. We reviewed clinical features of 10 patients with renal failure caused by IgG4-RPF, which was confirmed by pathology review and clinic-pathologic correlations. All patients were male, and the mean age at onset was 64.2 ± 10.0 years. Five patients were revealed with acute renal failure (ARF), while the other five ones with ARF on chronic kidney disease (CKD) (A on C) at diagnosis. Initial favorable responses obtained in 90% of the patients who underwent steroid therapy. The serum creatinine (SCr) level returned to normal in six patients including five with ARF and one with A on C, while those of the rest four patients with A on C restored to baseline levels (GFR remained below 60 ml/min/1.73 m² however) after therapy. These four unrecovered patients had a history of CKD, a longer period of persistently elevated SCr, a thinner total renal parenchyma thickness, and continuous elevated serum IgG4 levels after steroid therapy, compared with those recovered patients (P < 0.05). We concluded that recovery and long-term prognosis of the disease were primarily associated with timely diagnosis and proper treatment.

[Diseases of connective tissue in IgG4-associated autoimmune diseases]

The IgG4-associated diseases of connective tissue are caused by allergen-mediated autoimmune processes. The retroperitoneum, mesentery and mediastinum as well as other less common localizations, such as the neck, orbit and periarticular connective tissue can be affected. Inflammatory fibrosis is initially dominated by a lymphocytic and plasma cell-rich infiltrate and later by cell-poor storiform fibrosis. Stenosis and occlusion of vessels, ureters and intestines can cause severe complications. Computed tomography (CT) and magnetic resonance imaging (MRI) can be implemented in the diagnostic algorithm to narrow the differential diagnosis, delineate the distribution of fibrosis and reveal complications.

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.

A case of retroperitoneal fibrosis responding to steroid therapy

A 69-year-old man presented at the hospital with complaints of prolonged stomach pain extending from the week prior. Enhanced computed tomography (CT) revealed a low density area in the retroperitoneal space. A radiologist diagnosed the patient with retroperitoneal fibrosis. One week later, an enhanced CT revealed an exponential increase of the low density area and slight right hydronephrosis. Upon admission, prednisolone administration was initiated at a dose of 40mg/day. The size of the retroperitoneal soft tissue mass decreased gradually. Although the dose of prednisolone was tapered to 5mg, the patient is doing well without any sign of recurrence.

Elevated serum IgG4 levels in diagnosis and treatment response in patients with idiopathic retroperitoneal fibrosis

Idiopathic retroperitoneal fibrosis (iRPF) may be a manifestation of IgG4-related disease. Measuring serum IgG4 (sIgG4) may be of value in monitoring iRPF, but this has scarcely been evaluated. It is unknown if tamoxifen (TMX) affects sIgG4 levels. We performed a prospective inception cohort study of 59 patients with untreated (re)active iRPF stratified by elevated (>1.4 g/L) or normal sIgG4 level. Changes in sIgG4 levels following TMX initiation and, if treatment failed, during subsequent corticosteroid (CS) treatment were analyzed. The median sIgG4 level was 1.1 g/L (interquartile range (IQR) 0.4-2.2); 24 patients (40%) had elevated sIgG4 level. Patients with elevated sIgG4 tended to present with higher ESR (46 vs. 34 mm/h; P = 0.08) and more frequent locoregional lymphadenopathy adjacent to the mass (41.7 vs. 20.0%; P = 0.08). sIgG4 also correlated with ESR (ρ = 0.26; P = 0.05) and serum creatinine (SC) (ρ = 0.26; P = 0.04). Following TMX initiation, sIgG4 level decreased, particularly when achieving treatment success (P < 0.01). Odds ratio for TMX treatment success in patients with elevated sIgG4 level was 0.77 (95% CI 0.53-1.14; P = 0.19). After adjusting for age, sex, and SC, the odds ratio was 0.78 (95% CI 0.51-1.18; P = 0.24). ROC curve analyses of sIgG4 on a continuous scale and treatment success showed an AUC of 0.62. Treatment success and concurrent sIgG4 decrease (P < 0.01) were achieved in 78% of patients who converted to CS therapy. Patients with elevated sIgG4 level may be more inflammatory than patients with normal sIgG4 level, but this needs further study. TMX affects sIgG4 levels, but to a lesser extent than CSs. sIgG4 cannot be used as an outcome prediction tool, irrespective of which cutoff value was chosen.

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.

Detection of Polyclonal Increases in Immunoglobulin G4 Subclass by Distinct Patterns on Capillary Serum Protein Electrophoresis: Diagnostic Pitfalls and Clinical Observations in a Study of 303 Cases

OBJECTIVES

Autoimmunity, hypersensitivity, and the recently recognized set of syndromes collectively termed immunoglobulin G4-related disease (IgG4-RD) may be associated with increased serum IgG4 levels. We reviewed our experience detecting increased IgG4 by distinct serum protein electrophoresis (SPEP) patterns.

METHODS

We studied 303 capillary SPEP cases with dome-like anodal γ changes and increased measured serum IgG4.

RESULTS

IgG4 ranged from 208 to 6,670 mg/dL (normal, <201 mg/dL). Seventeen of 91 cases evaluated by immunosubtraction appeared monotypic (16 κ, 1 λ), but all five cases further analyzed by isoelectric focusing appeared polyclonal. Six cases with markedly increased IgG4 had presumptive evidence of IgG4-RD. Sixteen of 45 assessed patients had autoantibodies.

CONCLUSIONS

Increased polyclonal IgG4 has a characteristic SPEP pattern that may mimic monoclonal gammopathy, even on immunosubtraction. κ Pseudo-restriction might reflect the naturally high κ/λ ratio of the IgG4 subclass. Autoantibodies were common, and the greatest IgG4 increases had clinical features of IgG4-RD.

IgG4-related retroperitoneal fibrosis: a newly characterized disease

Retroperitoneal fibrosis (RPF) is a rare disease characterized by chronic, nonspecific inflammatory and sclerotic or fibrotic tissue in the periaortic or periiliac retroperitoneum that encases adjacent structures. There will be a series of clinical manifestations once the proliferated fibrous tissues encase the abdominal aorta, iliac arteries and urinary duct. RPF is generally divided into two types: idiopathic retroperitoneal fibrosis (IRPF) without identified pathogenesis, making up about two-thirds of cases, and secondary retroperitoneal fibrosis. Recent studies on Immunoglobulin G4-related disease (IgG4-RD) reveal that abundant infiltration of IgG4 positive plasma cells is found in biopsies on the mass of RPF of some IRPF patients, which is identified as one spectrum of IgG4-RD and is named IgG4-related RPF. IgG4-related RPF is often misdiagnosed as retroperitoneal visceral malignancy and is treated with surgery. In addition, because of its good response to glucocorticoid, early detection and treatment is important. We review the definition, epidemiology, clinical features, diagnostic criteria, treatment and prognosis of IgG4-related RPF in this article to raise awareness of this newly characterized disease.

Diagnosis and Treatment of IgG4-Related Disease

It is critical to differentiate IgG4-related disease (IgG4-RD) from malignant tumor and similar disease of the affected organ to apply appropriate therapy and avoid unnecessary surgery. IgG4-RD is diagnosed on combination of typical radiological findings; elevation of serum IgG4 levels; histopathological findings of abundant infiltration of IgG4-positive plasma cells and lymphocytes, storiform fibrosis , and obliterative phlebitis ; association with other IgG4-related diseases; and response to steroids. Histopathological approach is particularly recommended. Systemic glucocorticoids are currently the first-line approach for IgG4-RD, and the indications are symptoms. The initial recommended dose of oral prednisolone for induction of remission is 0.6 mg/kg/day, administered for 2-4 weeks. This dose is gradually tapered to a maintenance dose of 2.5-5 mg/day over a period of 2-3 months. As IgG4-RD sometimes relapses after steroids, maintenance therapy is usually performed in Japan. However, as IgG4-RD patients are typically elderly and are at high risk of developing steroid-related complications, cessation of the medication should be attempted at least within 3 years. For relapsed IgG4-RD, re-administration or dose up of steroid is effective, but the addition of immunomodulatory drugs such as azathioprine has been considered to be appropriate. B cell depletion with rituximab (an anti-CD20 antibody) is effective, even in many patients in whom treatment with immunomodulatory drugs was unsuccessful. The short-term clinical, morphological, and functional outcomes of most IgG4-RD patients treated with steroid therapy are good, but the long-term outcomes are less clear due to several unknown factors such as relapse, developed fibrosis, and associated malignancy.

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.

Organ Correlation in IgG4-Related Diseases

IgG4-related disease (IgG4-RD) is a potentially multiorgan disorder. In this study, clinical and serological features from 132 IgG4-RD patients were compared about organ correlations. Underlying pathologies comprised autoimmune pancreatitis (AIP) in 85 cases, IgG4-related sclerosing cholangitis (IgG4-SC) in 12, IgG4-related sialadenitis (IgG4-SIA) in 56, IgG4-related dacryoadenitis (IgG4-DAC) in 38, IgG4-related lymphadenopathy (IgG4-LYM) in 20, IgG4-related retroperitoneal fibrosis (IgG4-RF) in 19, IgG4-related kidney disease (IgG4-KD) in 6, IgG4-related pseudotumor (IgG4-PT) in 3. Sixty-five patients (49%) had multiple IgG4-RD (two affected organs in 36 patients, three in 19, four in 8, five in 1, and six in 1). Serum IgG4 levels were significantly higher with multiple lesions than with a single lesion (P<0.001). The proportion of association with other IgG4-RD was 42% in AIP, the lowest of all IgG4-RDs. Serum IgG4 level was lower in AIP than in other IgG4-RDs. Frequently associated IgG4-RDs were SIA (25%) and DAC (12%) for AIP; AIP (75%) for IgG4-SC; DAC (57%), AIP (38%) and LYM (27%) for IgG4-SIA; AIP (26%) and LYM (26%) for IgG4-DAC; SIA (75%), DAC (50%) and AIP (45%) for IgG4-LYM; SIA (58%), AIP (42%) and LYM (32%) for IgG4-RF; AIP (100%) and SIA (67%) for IgG4-KID; and DAC (67%) and SIA (67%) for IgG4-PT. Most associated IgG4-RD lesions were diagnosed simultaneously, but IgG4-SIA and IgG4-DAC were sometimes identified before other lesions. About half of IgG4-RD patients had multiple IgG4-RD lesions, and some associations were seen between specific organs.

Retroperitoneal disorders associated with IgG4-related autoimmune pancreatitis

IgG4-related autoimmune pancreatitis is frequently accompanied by relevant lesions in the genitourinary tract and retroperitoneal organs, which cause various clinical problems, ranging from non-specific back pain or bladder outlet obstruction to renal failure. The diagnosis of IgG4-related retroperitoneal fibrosis requires a multidisciplinary approach, including serological tests, histological examination, imaging analysis, and susceptibility to steroid therapy. Radiological examinations are helpful to diagnose this condition, but surgical resection is occasionally unavoidable to exclude malignancy, particularly for patients with isolated retroperitoneal involvement. Steroid therapy is the treatment of choice for this condition, the same as for other manifestations of IgG4-related disease. For patients with severe ureteral obstruction, additional ureteral stenting needs to be considered prior to steroid therapy to preserve the renal function. Some papers have suggested that IgG4-related disease can affect male reproductive organs including the prostate and testis. IgG4-related prostatitis usually causes lower urinary tract symptoms, such as dysuria and pollakisuria. Patients sometimes state that corticosteroids given for IgG4-related disease at other sites relieve their lower urinary tract symptoms, which leads us to suspect prostatic involvement in this condition. Because of the limited number of publications available, further studies are warranted to better characterize IgG4-related disease in male reproductive organs.

Retroperitoneal fibrosis

Retroperitoneal fibrosis (RPF) is a rare disease that is marked by systemic inflammation and the development of a periaortic fibroinflammatory mass. The fibroinflammatory infiltration can encase the abdominal aorta, ureters, and other abdominal organs. The clinical presentation often includes constitutional symptoms, abdominal pain, and signs of renal insufficiency or renal failure related to ureteral obstruction. Less frequently, RPF may present with vascular complications, such as venous thrombosis or claudication. The idiopathic form of RPF is most common but secondary forms have been described and are associated with malignancy and a variety of different medications. The pathophysiology is uncertain, but RPF has been linked with periaortitis and IgG4-related disease. Treatment centers on the relief of symptoms and complications associated with mass effects. Corticosteroids and other immunosuppressant therapies can improve constitutional symptoms, reduce infiltrate mass, and achieve disease remission, but a chronic relapsing course is not uncommon.

Immunoglobulin G4-Related Retroperitoneal Fibrosis Treated with Hochuekkito, a Kampo Medicine, following Steroid Treatment

We report a case of immunoglobulin G4 (IgG4)-related retroperitoneal fibrosis (RF) with complete remission and no relapses after therapy with steroids and Hochuekkito, a Kampo (i.e. traditional Japanese herbal) medicine. A 62-year-old Japanese man was admitted to our hospital for treatment of a retroperitoneal mass detected by computed tomography. The mass had a maximum diameter of 11.0 cm; it involved the left ureter and was associated with left hydronephrosis. After inserting a ureteral stent, we performed a biopsy by laparotomy. Histopathology revealed IgG4-related RF. The lesion disappeared after 7 months of steroid therapy. We subsequently used Hochuekkito as an alternative maintenance treatment because of steroid-related complications. The patient has not relapsed in the 3 years since starting the medication. To the best of our knowledge, this is the first case of IgG4-related RF treated with Hochuekkito as a maintenance treatment.

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.

IgG4-related disease in the abdomen: a great mimicker

IgG4-related disease is a systemic disorder that can involve various abdominal organs. Abdominal manifestations include autoimmune pancreatitis, sclerosing cholangitis, gallbladder pseudotumours, multifocal renal abnormalities, retroperitoneal fibrosis, and sclerosing mesenteritis. Radiological appearances of the IgG4-related disease often resemble malignant tumors and other inflammatory processes, potentially leading to unnecessary invasive procedures. Moreover, a timely diagnosis of IgG4-related disease leads to an effective treatment with steroids. Therefore, it is important to understand the spectrum of imaging manifestations of IgG4-related disease and their differentiating features from other diagnoses.

Mechanisms and assessment of IgG4-related disease: lessons for the rheumatologist

Recognition of IgG4-related disease as an independent chronic inflammatory disorder is a relatively new concept; previously, the condition was thought to represent a subtype of Sjögren's syndrome. IgG4-related disease is characterized by elevated serum levels of IgG4 and inflammation of various organs, with abundant infiltration of IgG4-bearing plasma cells, storiform fibrosis and obliterative phlebitis representing the major histopathological features of the swollen organs. The aetiology and pathogenesis of this disorder remain unclear, but inflammation and subsequent fibrosis occur due to excess production of type 2 T-helper-cell and regulatory T-cell cytokines. The disease can comprise various organ manifestations, such as dacryoadenitis and sialadenitis (also called Mikulicz disease), type 1 autoimmune pancreatitis, kidney dysfunction and lung disease. Early intervention using glucocorticoids can improve IgG4-related organ dysfunction; however, patients often relapse when doses of these agents are tapered. The disease has also been associated with an increased incidence of certain malignancies. Increased awareness of IgG4-related disease might lead to consultation with rheumatologists owing to its clinical, and potentially pathogenetic, similarities with certain rheumatic disorders. With this in mind, we describe the pathogenic mechanisms of IgG4-related disease, and outline considerations for diagnosis and treatment of the condition.