IgG4-related disease of the central and peripheral nervous systems

Disorders with Ophthalmic and Thoracic Involvement

A variety of systemic conditions involve the thorax and the eyes. While subtle or nonspecific eye symptoms can be the initial clinical manifestation of some disorders, there can be additional manifestations in the thorax that lead to a specific diagnosis and affect patient outcomes. For instance, the initial clinical manifestation of Sjögren syndrome is dry eye or xerophthalmia; however, the presence of Sjögren lung disease represents a fourfold increase in mortality. Likewise, patients with acute sarcoidosis can initially present with pain and redness of the eye from uveitis in addition to fever and parotitis. Nearly 90% of patients with sarcoidosis have thoracic involvement, and the ophthalmologic symptoms can precede the thoracic symptoms by several years in some cases. Furthermore, a diagnosis made in one system can result in the screening of other organs as well as prompt genetic evaluation and examination of family members, such as in the setting of Marfan syndrome or Ehlers-Danlos syndrome. Multimodality imaging, particularly CT and MRI, plays a vital role in identification and characterization of these conditions. While it is helpful for ophthalmologists to be knowledgeable about these conditions and their associations so that they can order the pertinent radiologic studies, it is also important for radiologists to use the clues from ophthalmologic examination in addition to imaging findings to suggest a specific diagnosis. Systemic conditions with thoracic and ophthalmologic manifestations can be categorized as infectious, inflammatory, autoimmune, neoplastic, or hereditary in origin. The authors describe a spectrum of these conditions based on their underlying cause. ©RSNA, 2024.

Neurological Involvement in a Portuguese Cohort of IgG4-Related Disease

INTRODUCTION

Neurological involvement in immunoglobulin G4-related disease (IgG4-RD) is increasingly recognized. Its diagnosis can be challenging due to clinical mimics and difficulty in obtaining nervous system biopsies. The aim of this study was to describe a cohort of neurological IgG4-RD patients.

METHODS

Patients were recruited from a neuroimmunology tertiary center. Clinical, laboratory, neuroimaging and histological data were reviewed.

RESULTS

Fifteen patients (60% women), with a median age of 53 years (48.5 - 65.0) were included: 13 (86.7%) classified as possible IgG4-RD, one (6.7%) as probable and one (6.7%) as definitive. The most common neurological phenotypes were meningoencephalitis (26.7%), orbital pseudotumor (13.3%), cranial neuropathies (13.3%), peripheral neuropathy (13.3%), and longitudinally extensive transverse myelitis (LTEM) (13.3%). Median serum IgG4 concentration was 191.5 (145.0 - 212.0) mg/dL. Seven in 14 patients had CSF pleocytosis (50.0%) and oligoclonal bands restricted to the intrathecal compartment, while most cases presented elevated CSF proteins (64.3%). Magnetic resonance imaging abnormalities included white matter lesions in four (26.7%), hypertrophic pachymeningitis in two (13.3%), and LETM in two (13.3%). Two patients had biopsy-proven IgG4-RD in extra-neurological sites.

CONCLUSION

This study highlights the phenotypical variability of the neurological IgG4-RD. Biopsy inaccessibility reinforces the importance of new criteria for the diagnosis of this subset of patients.

Secondary hypophysitis associated with Rathke's cleft cyst resembling a pituitary abscess

Background

Although rare, cases of hypophysitis resembling a pituitary abscess (PA) have been reported. Differential diagnosis between hypophysitis and PA is crucial as the two diseases require different treatments.

Case Description

A 38-year-old woman with headaches underwent head magnetic resonance imaging (MRI), which revealed an 11-mm mass lesion in the sella turcica. Due to breastfeeding, contrast-enhanced MRI was avoided. Pituitary adenomas and Rathke's cleft cyst (RCC) were suspected, and she was initially treated conservatively. Five months later, she acquired syndrome coronavirus two infections, and while the fever subsided with acetaminophen, the headache persisted. One month later, the headache worsened, followed by fever and diabetes insipidus. MRI revealed a pituitary cystic mass with ring-shaped contrast enhancement on T1-weighted MRI and increased signal intensity on diffusion-weighted imaging (DWI). PA was suspected, and emergency endoscopic transsphenoidal surgery was performed. The microbiological examination of the yellowish-brown content drained from the cystic mass was negative. Microscopically, the cystic lesion was covered with ciliated columnar epithelium and stratified squamous epithelium, with a dense inflammatory cell infiltrate consisting mainly of lymphocytes and plasma cells observed around the cyst. This supported the diagnosis of secondary hypophysitis associated with RCC without PA.

Conclusion

We report a case of hypophysitis secondary to RCC resembling PA with ring-shaped contrast enhancement on MRI and increased signal intensity on DWI. This case emphasizes the need for cautious diagnosis of secondary hypophysitis due to RCC in individuals with MRIs and clinical manifestations resembling an abscess.

IgG4-related pachyleptomeningitis with inflammatory pseudotumor

•We report the first case of IgG4-related pachyleptomeningitis.•Our case showed also an inflammatory pseudotumor on the side ipsilateral to the pachyleptomeningitis.•The pachyleptomeningitis is probably due to inflammation from the dural pseudotumor spreading along the adjacent meninges.

Ophthalmoplegia With Isolated Extraocular Muscle Hypertrophy

A 60-year-old man is experiencing diplopia but no problems with visual acuity, pain, or other symptoms. A magnetic resonance image of the head shows abnormal thickening and T2 hyperintensity of the right lateral rectus muscle. What is your diagnosis?

Chronic Inflammatory Demyelinating Polyneuropathy and Evaluation of the Visual Evoked Potentials: A Review of the Literature

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare autoimmune disorder characterised by the progressive demyelination of peripheral nerves, resulting in motor and sensory deficits. While much research has focused on clinical and electrophysiological aspects of CIDP, there is an emerging interest in exploring its impact on the visual system through visual evoked potentials (VEPs). This comprehensive review synthesises existing literature on VEP findings in CIDP patients, shedding light on their potential diagnostic and prognostic value. The review thoroughly examines studies spanning the last two decades, exploring VEP abnormalities in CIDP patients. Notably, VEP studies have consistently revealed prolonged latencies and reduced amplitudes in CIDP patients compared to healthy controls. These alterations in VEP parameters suggest that the demyelinating process extends beyond the peripheral nervous system to affect the central nervous system, particularly the optic nerve and its connections. The correlation between VEP abnormalities and clinical manifestations of CIDP, such as visual impairment and sensory deficits, underscores the clinical relevance of VEP assessment in CIDP management. Furthermore, this review addresses the potential utility of VEPs in aiding CIDP diagnosis and monitoring disease progression. VEP abnormalities may serve as valuable biomarkers for disease activity, helping clinicians make timely therapeutic decisions. Moreover, this review discusses the limitations and challenges associated with VEP assessment in CIDP, including variability in recording techniques and the need for standardised protocols. In conclusion, this review highlights the evolving role of VEPs as a non-invasive tool in CIDP evaluation. The consistent VEP abnormalities observed in CIDP patients suggest the involvement of the central nervous system in this demyelinating disorder. As our understanding of CIDP and its pathophysiology continues to evolve, further research in this area may lead to improved diagnostic accuracy and monitoring strategies, ultimately enhancing the clinical management of CIDP patients.

IgG4-associated hypophysitis coexisting with MALT lymphoma and gangliocytoma: first case report and literature review

IgG4-related or IgG4-associated hypophysitis is a rare disease characterized by the infiltration of IgG4-positive plasma cells into pituitary gland tissue. Gangliocytomas in the sellar region are also extremely rare and are associated with pituitary adenomas in the majority of cases. Sellar mucosa-associated lymphoid tissue (MALT) lymphoma is an exceedingly rare condition. In this study, we present a case of IgG4-associated hypophysitis coexisting with MALT lymphoma and gangliocytoma. However, to elucidate the potential pathophysiological relationship, it is imperative to gather additional cases of IgG4-related hypophysitis accompanied by MALT lymphoma and gangliocytoma.

Treatment of IgG4-related disease-associated hypertrophic pachymeningitis with intrathecal rituximab: a case report

IgG4-related disease-associated hypertrophic pachymeningitis (IgG4RD-HP) is a fibroinflammatory autoimmune disorder in which diagnosis is difficult without biopsy. Guidance on management of disease refractory to glucocorticoids and intravenous rituximab is limited. We present the case of a 68-year-old woman with IgG4RD-HP who developed sensorineural hearing loss with associated bulky basilar pachymeningeal enhancement. Her cerebrospinal fluid was inflammatory and had an elevated IgG4 concentration, strongly suggestive of IgG4RD-HP. Biopsy of involved meninges was not possible due to surgical risk. Over years she developed bilateral optic neuropathies and hydrocephalus, requiring intravenous rituximab and ventriculoperitoneal shunt. Her disease was refractory to glucocorticoids. Despite maintenance intravenous rituximab, she developed slowly progressive symptoms of intracranial hypertension and hydrocephalus with persistently inflammatory spinal fluid. Switching to intrathecal rituximab therapy led to dramatic improvement in gait and headache and reduced pachymeningeal bulk and metabolic activity. In patients with IgG4RD-HP refractory to glucocorticoids and intravenous rituximab, intrathecal rituximab may be an efficacious therapy.

Anatomic and Functional Imaging of Immunoglobulin G4-related Disease and Its Mimics

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is an immune-mediated fibrosclerosing disease with tumefactive lesions infiltrated by IgG4-positive plasma cells. Initially described as autoimmune pancreatitis, IgG4-RD is now recognized as a discrete entity and is found to affect virtually any organ in the body. Common extrapancreatic sites include the biliary tree, salivary glands, periorbital tissue, lungs, kidneys, lymph nodes, aorta, retroperitoneum, and thyroid gland. Diagnosis-which relies on histopathologic, serologic, and radiologic features-can be challenging with the disease underdiagnosed, as IgG4-RD often mimics malignancy, infectious processes, or other immune-mediated conditions. Patients may present with signs of compression of nearby structures due to mass effect or with organ failure when the disease is left untreated. The clinical course is complex, with single- or multiorgan involvement and metachronous or synchronous occurrence of lesions. IgG4-RD responds well to glucocorticoid therapy, disease-modifying antirheumatic drugs, and B-cell-depleting biologic agents; prompt diagnosis is important to avoid delay in treatment and unnecessary pharmacologic or surgical intervention. While imaging features may not be specific for IgG4-RD, functional whole-body imaging with fluorine 18-fluorodeoxyglucose PET/CT is a useful adjunct for localizing extrapancreatic sites for biopsy, monitoring therapeutic response, and demonstrating disease relapse. The authors describe the pancreatic and extrapancreatic sites of involvement in IgG4-RD, with imaging features and patterns to aid in distinguishing IgG4-RD from its mimics through a multimodality approach with emphasis on functional imaging evaluation. ^©RSNA, 2023 Quiz questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Immune-mediated diseases involving central and peripheral nervous systems

BACKGROUND AND PURPOSE

In addition to combined central and peripheral demyelination, other immune diseases could involve both the central nervous system (CNS) and peripheral nervous system (PNS).

METHODS

To identify immune-mediated diseases responsible for symptomatic combined central/peripheral nervous system involvement (ICCPs), we conducted a multicentric retrospective study and assessed clinical, electrophysiological, and radiological features of patients fulfilling our ICCP criteria.

RESULTS

Thirty patients (20 males) were included and followed during a median of 79.5 months (interquartile range [IQR] = 43-145). The median age at onset was 51.5 years (IQR = 39-58). Patients were assigned to one of four groups: (i) monophasic disease with concomitant CNS/PNS involvement including anti-GQ1b syndrome (acute polyradiculoneuropathy + rhombencephalitis, n = 2), checkpoint inhibitor-related toxicities (acute polyradiculoneuropathy + encephalitis, n = 3), and anti-glial fibrillary acidic protein astrocytopathy (subacute polyradiculoneuropathy and meningoencephalomyelitis with linear gadolinium enhancements, n = 2); (ii) chronic course with concomitant CNS/PNS involvement including paraneoplastic syndromes (ganglionopathy/peripheral hyperexcitability + limbic encephalitis, n = 4); (iii) chronic course with sequential CNS/PNS involvement including POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) syndrome (polyradiculoneuropathy + strokes, n = 2), histiocytosis (polyradiculoneuropathy + lepto-/pachymeningitis, n = 1), and systemic vasculitis (multineuropathy + CNS vasculitis/pachymeningitis, n = 2); and (iv) chronic course with concomitant or sequential CNS/PNS involvement including combined central and peripheral demyelination (polyradiculoneuropathy + CNS demyelinating lesions, n = 10) and connective tissue diseases (ganglionopathy/radiculopathy/multineuropathy + limbic encephalitis/transverse myelitis/stroke, n = 4).

CONCLUSIONS

We diagnosed nine ICCPs. The timing of central and peripheral manifestations and the disease course help determine the underlying immune disease. When antibody against neuroglial antigen is identified, CNS and PNS involvement is systematically concomitant, suggesting a common CNS/PNS antigen and a simultaneous disruption of blood-nerve and blood-brain barriers.

A unique presentation of IgG4 disease with ocular, neurologic and mastoid involvement

A man in his 20s presented with headache and acute deterioration in visual acuity. He was found to have panuveitis and raised intracranial pressure with papilloedema. MRI and F-fluorodeoxyglucose positron emission tomography confirmed a subclinical, but active, inflammatory mastoid process. Histology of the mastoid showed immunoglobulin G4 (IgG4) cells, plasma cells and storiform fibrosis.This presentation of IgG4 disease has not been previously described.Treatment with high-dose steroids was initiated, followed by long-term immunosuppressive therapy. The patient's symptoms improved, although he remains dependent on azathioprine and low dose oral steroids for symptom control. To date, there has been no progression of the disease.

Pachymeningitis in Biopsy-Proven Sarcoidosis

Background and Objectives

Meningeal inflammation is one of the most common manifestations of neurosarcoidosis, occurring in 16%–69% of affected patients. While the clinical and radiographic features of leptomeningitis in neurosarcoidosis are well known, those of pachymeningitis are far less clear. Our primary aim was to study the clinicoradiographic features of pachymeningeal involvement in neurosarcoidosis and its evolution over time in response to treatment.

Methods

Patients with a diagnosis of neurosarcoidosis seen at Emory University (January 2011–August 2021) were included if pachymeningeal involvement was evident by MRI and the patient's sarcoidosis was pathologically confirmed (from a CNS or non-CNS site).

Results

Twenty-six of 215 (12.1%) patients with neurosarcoidosis qualified for inclusion. Pathologic confirmation came from CNS tissue in 50%. The median age of onset was 43.5 years; most were male (16/26, 61.5%). Symptoms were primarily related to pachymeningitis in 20/26 (76.9%). Headache (19/26, 73.1%), visual dysfunction (12/26, 46.2%), and seizures (7/26, 26.9%) were the most common symptoms. All patients had cranial pachymeningitis; only a single patient undergoing spinal imaging (1/11, 9.1%) had spinal pachymeningitis. The falx cerebri (16/26, 61.5%) was the most commonly affected dural structure, but the anterior and middle cranial fossae and tentorium cerebelli were frequently involved (12/26 each, 46.2%). The pachymeningeal lesions were unifocal (11/26, 42.3%) or multifocal (15/26, 57.7%) in distribution, nodular morphologically (23/25, 92.0%), and homogeneously enhancing (24/25, 96.0%). Symptomatic improvement occurred with steroids initially in 22/25 (88.0%). Ultimately, 23/26 (88.5%) required initiation of steroid-sparing immunosuppressants, including 8/26 (30.8%) eventually undergoing TNF inhibition. Pachymeningeal relapses occurred in 7/26 (26.9%). The median clinical follow-up was 48 months. The median modified Rankin scale score at last follow-up improved to 1.0 from 2.0 at presentation.

Discussion

Pachymeningitis due to sarcoidosis often presents with headaches, visual dysfunction, and seizures; it usually affects the dura of the falx cerebri, anterior and middle cranial fossae, and tentorium cerebelli and tends to require steroid-sparing immunosuppressants. It has the potential to relapse, but the prospect for recovery is good.

IgG4-related Inflammatory Pseudotumor with Imaging Findings Similar to Meningioma: A Case Report

IgG4-related inflammatory pseudotumor is a feature of IgG4-related disease and develops in various organs. Intracranial IgG4-related inflammatory pseudotumor is rare, and data on the clinical course and response to treatment are insufficient in the literature. We herein report a patient with IgG4-related inflammatory pseudotumor who had magnetic resonance imaging findings similar to meningioma. Tumorectomy was discontinued because of the intraoperative rapid diagnosis, which revealed the infiltration of lymphocytes and plasma cells. She received oral prednisolone therapy for IgG4-related inflammatory pseudotumor, and the tumor size had significantly decreased after six months of treatment.

Case report: IgG4-related intracranial lesions mimicking multiple sclerosis in a 14-year-old girl

Objectives

IgG4-related disease (IgG4-RD) is distinguished by the infiltration of IgG4-positive plasma cells in a variety of tissues and organs. Even so, central nervous system lesions associated with IgG4-RD are scarce. We present a case of IgG4-related brain parenchymal lesions that mimics multiple sclerosis in a young girl.

Methods

The patient was followed by our neurology and rheumatology teams. Clinical information was recorded, and the brain was screened using magnetic resonance imaging (MRI). During follow-up, we examined serum IgE, IgG and IgG4 and lymph node biopsy.

Results

Here, we presented details of a 14-year-old Chinese girl suffering from diplopia, left eyelid ptosis, right facial numbness, and right lower limb weakness admitted to our institute. Brain MRI revealed multiple sclerosis-like lesions in the brain parenchyma and spinal cord. During the follow-up, she developed lymphadenopathy. Elevation of serum, IgG, IgG4 and IgE and lymph node biopsy favors a diagnosis of IgG4-RD. The patient had a good response to glucocorticoids and mycophenolate mofetil. The literature review summarized eight previously reported IgG4-RD involving brain parenchyma.

Discussion

Our case expands the known age spectrum of IgG4-RD. The intracranial IgG4-RD is rare and could mimic multiple sclerosis. Careful examination and dynamic review of disease history are crucial in the differential diagnosis.

Imaging findings of immunoglobin G4-related hypophysitis: A case report

BACKGROUND

Immunoglobin G4 (IgG4)-related hypophysitis (IgG4-RH) is a rare form of IgG4-related disease (IgG4-RD), which often manifests as a single organ disease and is easily misdiagnosed as a pituitary tumor clinically and by imaging. There are few reports of imaging findings of IgG4-RH. Therefore, we describe a case of IgG4-RH, which mimicked a pituitary macroadenoma, that was detected by computed tomography (CT) and magnetic resonance imaging (MRI), and review the previous literature in order to further the understanding of IgG4-RH.

CASE SUMMARY

A 47-year-old man presented with a history of blurred vision for more than 2 mo, without other symptoms. A preoperative unenhanced CT scan revealed a slightly hyperdense mass in the sellar region measuring 2.5 cm × 2.3 cm × 1.8 cm, with a CT value of 45 HU. T1-weighted imaging (T1WI) and T2-weighted imaging showed iso-hypointensity, and gadolinium contrast-enhanced T1WI showed obvious homogeneous enhancement. The MRI revealed involvement of the pituitary gland and stalk. Preoperative laboratory tests revealed abnormal pituitary hormone levels, including an increased prolactin level, and decreased levels of insulin-like growth factor, dehydroepiandrosterone, and testosterone. The lesion was surgically resected. Postoperative histopathological examination of a tissue sample and an elevated serum IgG4 level confirmed the diagnosis of IgG4-RH. The patient was treated with cortisone acetate postoperatively and made a good recovery without developing any neurological deficit.

CONCLUSION

An elevated serum IgG4 concentration is the main clue for diagnosis of IgG4-RD. Imaging combined with laboratory testing is useful for preoperative diagnosis of IgG4-RH.

IgG4 ‐related disease associated with the primary manifestation of recurrent cerebral venous thrombosis: A rare case report

Nervous system involvement in IgG4‐related systemic disease (IgG4‐RD) is rarely reported and manifests as hypertrophic pachymeningitis and hypophysitis. In this report, a 33‐year‐old woman with neurological manifestations was diagnosed with IgG4‐RD by biopsy. The patient showed improvement in symptoms after treatment.

Refractory IgG4-related disease complicated with organising pneumonia and hypertrophic pachymeningitis

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) involves multiple organs, including the lungs and central nervous system. Lung lesions are frequently reported as mass lesions or non-specific interstitial pneumonia, whereas organising pneumonia (OP) due to IgG4-RD is rare. Furthermore, limited information is currently available on hypertrophic pachymeningitis (HP). We herein report a case of IgG4-RD complicated with OP and HP. The diagnosis was confirmed based on the serum concentration of IgG4 and the results of salivary gland and transbronchial lung biopsies. HP did not respond to steroid monotherapy and was also resistant to rituximab and intravenous cyclophosphamide; however, the combination therapy of methotrexate and dexamethasone was effective.

It's Not All in Your Head: Thoracic Manifestations of Neurologic Diseases and Disorders

Myriad conditions may affect both the neurologic system and the thorax, while other diseases primarily affecting the thorax may manifest with neurologic abnormalities. Correlation of signs, symptoms, and imaging findings in the neurological system with those in the thorax can help diagnose certain conditions and/or guide further diagnostic work-up and treatment. We will review and illustrate the imaging appearance of several systemic/neurological diseases with thoracic manifestations as well as discuss conditions in the thorax that can lead to neurologic symptoms.

Immunoglobulin G4-related disease involving multiple systems: A case report

BACKGROUND

IgG4-related disease (IgG4-RD), an immune-mediated chronic progressive fibroinflammatory disease, can affect the functions of several organs. Some common characteristics can be observed in different IgG4-RDs, such as higher prevalence in middle-aged and elderly male patients, raised serum IgG4 levels, abundant infiltration of IgG4-positive cells and fibrosis, diffuse or localized swelling of the affected organs, and good response to glucocorticoids treatment.

CASE SUMMARY

A 72-year-old man complained of left upper abdominal pain 3 mo ago, and he was diagnosed with acute onset of chronic cholecystitis and acute pancreatitis in the local hospital. Pain improved after relevant treatment. Several days ago, his abdominal pain worsened, and he was admitted to our hospital for further treatment. Doppler ultrasound showed that the pancreas presented with sausage-like swelling and the parenchymal echo was diffusely reduced. Gallbladder volume was increased, while the wall was rough and thickened with bilateral signs. Furthermore, the left submandibular gland was enlarged, accompanied with significantly increased blood flow signals. Finally, we found that the adventitia of the abdominal aorta and right iliac artery was thickened locally. Serum IgG4 was elevated to 12600 mg/L. Therefore, the patient was diagnosed with IgG4-RD. After treatment with methylprednisolone, he had an uneventful course and was discharged in good condition.

CONCLUSION

IgG4-RD can involve almost any organs. Ultrasound has a significant role in timely and accurately diagnosis.

Studies on anti-rabphilin-3A antibodies in 15 consecutive patients presenting with central diabetes insipidus at a single referral center

Central diabetes insipidus (CDI) is a rare condition caused by various underlying diseases including inflammatory and autoimmune diseases, and neoplasms. Obtaining an accurate definitive diagnosis of the underlying cause of CDI is difficult. Recently, anti-rabphilin-3A antibodies were demonstrated to be a highly sensitive and specific marker of lymphocytic infundibuloneurohypophysitis (LINH). Here, we report a detailed case series, and evaluated the significance of anti-rabphilin-3A antibodies in differentiating the etiologies of CDI. A prospective analysis was conducted in 15 consecutive patients with CDI from 2013 to 2020 at a single referral center. Anti-rabphilin-3A antibodies were measured and the relationship between antibody positivity and the clinical/histopathological diagnoses was evaluated. Among 15 CDI patients, the positive anti-rabphilin-3A antibodies were found in 4 of 5 LINH cases, 3 of 4 lymphocytic panhypophysitis (LPH) cases, one of 2 sarcoidosis cases, and one intracranial germinoma case, respectively. Two Rathke cleft cyst cases and one craniopharyngioma case were negative. This is the first report of anti-rabphilin-3A antibodies positivity in CDI patients with biopsy-proven LPH. Measurement of anti-rabphilin-3A antibodies may be valuable for differentiating CDI etiologies.

IgG4-Related Disease: Mimickers and Diagnostic Pitfalls

BACKGROUND

The tendency of IgG4-related disease (IgG4-RD) to form pseudotumors, as well as its multisystemic nature, makes it the perfect mimicker of many conditions. Moreover, some clinical, serological, radiological, or histological features of the disease might be shared with some mimickers.Recently, 4 clinical phenotypes have been identified, and patients grouped in each phenotype have distinctive demographic, clinical, and serological features and outcomes, and, as expected, for each phenotype, a set of differential diagnoses should be considered.

SUMMARY OF THE LITERATURE

The main differential diagnoses for the pancreato-hepato-biliary phenotype are pancreatic adenocarcinoma and cholangiocarcinoma. Other differential diagnoses include type 2 autoimmune pancreatitis and primary sclerosing cholangitis. In patients with retroperitoneal/aortic phenotype, inflammatory conditions such as idiopathic retroperitoneal fibrosis and large vessel vasculitides should be ruled out, and most of the time, a biopsy will be needed to exclude malignancies. In head and neck limited phenotype, autoimmune conditions (eg, granulomatosis with polyangiitis, Graves orbitopathy, sarcoidosis), malignancies, and histiocytosis should be ruled out, whereas the main differential diagnoses of the Mikulicz/systemic phenotype are Sjögren syndrome, granulomatosis with polyangiitis, and multicentric Castleman disease.

CONCLUSIONS

Approaching a patient with probable IgG4-RD through a clinical phenotype framework will ease the diagnostic algorithm and facilitate the prompt recognition of the disease. There are certain clinical, serological, radiological, and histological features in each clinical phenotype that, if present, increase the likelihood that a patient may have IgG4-RD instead of the mimicker condition. Those clues that point toward IgG4-RD diagnosis should be actively sought in the workup of patients.

Optic perineuritis: A Canadian case series and literature review

BACKGROUND

Optic perineuritis (OPN) is a rare orbital inflammatory disorder that primarily involves the optic nerve sheath (ONS). This study aimed to describe the clinical features of idiopathic OPN as well as OPN secondary to other infectious and inflammatory conditions in a Canadian case series as current literature on secondary OPN in Western countries is mostly limited to case reports.

METHODS

Retrospective case series of all patients seen in a tertiary neuro-ophthalmology practice with a diagnosis of OPN from 2014 to 2020.

RESULTS

A total of 21 patients (14 women, mean age 55.8) corresponding to 29 eyes with OPN were identified. Fifteen cases were associated with inflammatory or infectious conditions and only 6 were idiopathic. All idiopathic cases were unilateral. The most common secondary causes of OPN were anti-myelin oligodendrocyte glycoprotein (MOG) antibody disease (n = 4), syphilis (n = 3), sarcoidosis (n = 3), and giant cell arteritis (n = 3). At initial presentation, best-corrected visual acuity (BCVA) was 20/20 or better in 24% (n = 7) and visual field mean deviation (VF MD) was better than -5 dB in 34% of eyes (10/29). Treatment consisted of intravenous penicillin for syphilitic OPN and high-dose corticosteroids followed by oral taper with or without immunosuppressive therapy for non-syphilitic OPN. BCVA improved in 34% (10/29) and VF MD improved in 45% (13/29) eyes.

CONCLUSION

OPN primarily occurred in association with systemic inflammatory conditions, especially in bilateral cases. Syphilis must be ruled out in all patients. Anti-MOG antibody disease is an important, newly recognized secondary cause of OPN, and serologic testing should be included in the investigation of all patients with OPN.

Clinical Manifestations, Pathogenesis, Diagnosis and Treatment of Peripheral Neuropathies in Connective Tissue Diseases: More Diverse and Frequent in Different Subtypes than Expected

Purpose of review: To discuss and summarize recent findings in peripheral neuropathy (PN) related to connective tissue diseases (CTD) including its prevalence, clinical manifestations, pathogenesis, diagnosis and treatment. Recent findings: Although PN is a common complication in CTD and has been well studied, recent research has shown that PN is more diverse and frequent in different subtypes of CTD than was expected. The incidence of PN in Sjögren’s syndrome and rheumatoid arthritis (RA) varies according to different disease subtypes, and the pathogenesis of neuropathic pain in different subtypes of eosinophilic granulomatosis with polyangiitis (EGPA) may also differ. Neurogenic inflammation, autoantibody-mediated changes, ischemia of the vascular wall and metabolic mechanisms have been shown to contribute to the pathogenesis of PN in CTD. Moreover, allergic inflammation has been recently identified as a possible new mechanism producing peripheral neuropathic pain associated with MPO-ANCA negative EGPA patients. Glucocorticoids are routinely used to relieve pain caused by PN. However, these steroids may cause hyperalgesia, exacerbate neuropathic pain, and activate the early phase of pain induction and produce hyperalgesia. Recently, neuroactive steroids, such as progesterone, tetrahydroprogesterone and testosterone, have been shown to exert protective effects for several PN symptoms, and in particular neuropathic pain. Neuroactive steroids will be an interesting topic for future research into PN in CTD. Summary: It is essential for the diagnosis and treatment of PN in CTD to be updated. Timely diagnosis, appropriate treatments, and multidisciplinary care are essential to minimize morbidity and decrease the risk of permanent neurologic deficits. Further studies are needed to guide diagnosis and treatment.

Clinical Perspectives on IgG4-Related Disease and Its Classification

Immunoglobulin G4-related disease (IgG4-RD) is a systemic immune-mediated fibroinflammatory disease. Since its discovery nearly two decades ago, our understanding of its pathophysiology and clinical manifestations has grown substantially. Early diagnosis and treatment of this elusive disease can prevent substantial organ damage from end-stage fibrosis, emphasizing the need for prompt recognition and accurate characterization of IgG4-RD. The classification criteria endorsed by the American College of Rheumatology and the European Alliance of Associations for Rheumatology in 2019 provide a framework for establishing the diagnosis in the clinical setting. This process involves recognizing the typical manifestations of the disease and incorporating clinical, radiological, serological, and histopathological information as well as excluding disease mimickers. Glucocorticoids and rituximab are effective at inducing remission in IgG4-RD in most patients, but the optimal approach to long-term management of IgG4-RD remains an area of active clinical research. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Autoimmune diseases of the brain, imaging and clinical review

There is an extensive spectrum of autoimmune entities that can involve the central nervous system, which has expanded with the emergence of new imaging modalities and several clinicopathologic entities. Clinical presentation is usually non-specific, and imaging has a critical role in the workup of these diseases. Immune-mediated diseases of the brain are not common in daily practice for radiologists and, except for a few of them such as multiple sclerosis, there is a vague understanding about differentiating them from each other based on the radiological findings. In this review, we aim to provide a practical diagnostic approach based on the unique radiological findings for each disease. We hope our diagnostic approach will help radiologists expand their basic understanding of the discussed disease entities and narrow the differential diagnosis in specific clinical scenarios. An understanding of unique imaging features of these disorders, along with laboratory evaluation, may enable clinicians to decrease the need for tissue biopsy.

IgG4-related hypothalamo-hypophysitis

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A patient exhibited IgG4-related hypothalamo-hypophysitis.

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Prominent high-signal areas of swelling were observed in the hypothalamus, tuber cinereum, infundibulum, and bilateral optic nerve systems.

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MRI T1WI with contrast media demonstrated enhanced neurohypophysis and cystic swelling, and compressed anterior pituitary.

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MRI findings improved rapidly after 4 days of steroid therapy.

Intrathecal activation of CD8+ memory T cells in IgG4-related disease of the brain parenchyma

IgG4-related disease (IgG4-RD) is a fibroinflammatory disorder signified by aberrant infiltration of IgG4-restricted plasma cells into a variety of organs. Clinical presentation is heterogeneous, and pathophysiological mechanisms of IgG4-RD remain elusive. There are very few cases of IgG4-RD with isolated central nervous system manifestation. By leveraging single-cell sequencing of the cerebrospinal fluid (CSF) of a patient with an inflammatory intracranial pseudotumor, we provide novel insights into the immunopathophysiology of IgG4-RD. Our data illustrate an IgG4-RD-associated polyclonal T-cell response in the CSF and an oligoclonal T-cell response in the parenchymal lesions, the latter being the result of a multifaceted cell-cell interaction between immune cell subsets and pathogenic B cells. We demonstrate that CD8⁺ T effector memory cells might drive and sustain autoimmunity via macrophage migration inhibitory factor (MIF)-CD74 signaling to immature B cells and CC-chemokine ligand 5 (CCL5)-mediated recruitment of cytotoxic CD4⁺ T cells. These findings highlight the central role of T cells in sustaining IgG4-RD and open novel avenues for targeted therapies.

Immunoglobulin G4-related Disease Accompanied by Peripheral Neuropathy: A Report of Two Cases

Due to its rarity and the limited literature, the clinicopathological characteristics of peripheral nerve involvement in immunoglobulin G4 (IgG4)-related disease are unknown. We present two cases of IgG4-related disease, accompanied by peripheral neuropathy, presenting as unilateral ptosis (case 1) and sclerosing cholangitis (case 2), respectively. In both cases, sural nerve biopsy indicated vasculitis as the underlying pathophysiology; the peripheral neuropathy was refractory to corticosteroid therapy. In contrast to the previously proposed pathomechanism of IgG4-related neuropathy (direct lymphoplasmacytic infiltration), the pathological findings in our cases suggest that vasculitis occurs secondary to systemic autoimmune conditions.

Neuroimaging findings in rheumatologic disorders

Patients with rheumatological diseases may present with neurological manifestations of peripheral and/or central nervous system (CNS). Symptoms may be related to underlying rheumatological disease or CNS effects of immune-modulating drugs. Early diagnosis and therapy may help prevent serious complications. Magnetic resonance imaging (MRI), given its excellent soft tissue details, is the preferred imaging modality when evaluating patients with rheumatological disease and suspected CNS involvement. We present a review of the neuroimaging manifestations of various rheumatic diseases with emphasis on the imaging findings on MRI.

Adrenal insufficiency

Adrenal insufficiency (AI) is a condition characterized by an absolute or relative deficiency of adrenal cortisol production. Primary AI (PAI) is rare and is caused by direct adrenal failure. Secondary AI (SAI) is more frequent and is caused by diseases affecting the pituitary, whereas in tertiary AI (TAI), the hypothalamus is affected. The most prevalent form is TAI owing to exogenous glucocorticoid use. Symptoms of AI are non-specific, often overlooked or misdiagnosed, and are related to the lack of cortisol, adrenal androgen precursors and aldosterone (especially in PAI). Diagnosis is based on measurement of the adrenal corticosteroid hormones, their regulatory peptide hormones and stimulation tests. The goal of therapy is to establish a hormone replacement regimen that closely mimics the physiological diurnal cortisol secretion pattern, tailored to the patient's daily needs. This Primer provides insights into the epidemiology, mechanisms and management of AI during pregnancy as well as challenges of long-term management. In addition, the importance of identifying life-threatening adrenal emergencies (acute AI and adrenal crisis) is highlighted and strategies for prevention, which include patient education, glucocorticoid emergency cards and injection kits, are described.

Histopathological findings in the landscape of IgG4-related pathology in patients with pituitary dysfunction: Review of six cases

IgG4-related hypophysitis (IgG4-RH) is increasingly being reported as an isolated entity or, less frequently, as a manifestation of a multiorgan IgG4-related disease (IgG4-RD), in which typical histopathology is a cornerstone for the diagnosis. We aimed to describe the histopathological changes in the surgical specimens from patients with clinical signs of pituitary disease that fulfilled the current diagnostic criteria for IgG4-RH. Histopathological features were correlated with clinical and radiological findings. Of 19 patients with pituitary dysfunction and inflammatory changes in the surgical pituitary specimen operated on during 2011-2019, we identified five patients with typical IgG4-related pathology (lymphoplasmacytic infiltration with more than 10 IgG4-positive plasma cells per one high power microscopic field, representing at least 40% of all plasma cells and at least focal storiform fibrosis). One patient with diabetes insipidus and pachymeningitis with IgG4-related changes in a biopsy from the dura was also included. Additional histopathological changes that typically are not part of the IgG4-RH were observed: Rathke's cleft cyst in four and granulomatous changes in two patients. One patient had an elevated serum IgG4 level and systemic manifestations that could be associated with the systemic IgG4-RD. Our findings indicate that pure IgG4-RH is uncommon. All patients with pituitary dysfunction, beyond typical IgG4-related pathology, had other pathological findings that could trigger the secondary IgG4-response. Both primary pathology and secondary IgG4-related features should be reported in patients with pituitary dysfunction because their co-occurrence may cause atypical clinical and imaging features, and unexpected response to surgical and pharmacological treatment. The current criteria for the diagnosis of IgG4-RH can lead to overdiagnosis of IgG4-RH if additional pathological changes are not taken into consideration. The classification criteria of IgG4-RD proposed by the American College of Rheumatology/European League Against Rheumatism could help classify patients more properly as IgG4-RH if applied to the pituitary gland.

Immunoglobulin G4-related disease presenting with peripheral neuropathy: a case report

Background

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibro-inflammatory condition characterized by high serum IgG4 concentrations and tissue infiltration by IgG4-positive plasma cells. Reports have demonstrated that IgG4-RD affects various organs, including the pancreas, kidney, lung, thyroid, and lacrimal and salivary glands. In the nervous system, hypertrophic pachymeningitis and hypophysitis are mainly related to IgG4-RD; however, the peripheral neuropathy involvement is unusual.

Case presentation

We report on a 69-year-old woman with multiple mononeuropathy, weight loss and kidney mass in the setting of IgG4-RD. Biopsies of the kidney mass showed lymphoplasmacytic sclerosing inflammation with numerous IgG4-positive plasma cells. IgG4 and IgG4/IgG ratios in the blood were elevated. The patient was treated with high dose methylprednisolone with improvement in her neuropathy.

Conclusions

IgG4-RD is a relatively recently reported systemic fibrous inflammatory disease caused by the infiltration of IgG4-positive plasma cells in various organs. In the nervous system, symptomatic peripheral nerve invasion is very rare. However, as demonstrated in our case, IgG4-RD may present with primarily peripheral nerve disease.

A clinical approach to hypertrophic pachymeningitis

IMPORTANCE

Hypertrophic pachymeningitis (HP) is a non-usual manifestation of rheumatologic, infectious, and neoplastic diseases. Etiological diagnosis is a challenge, but when made promptly it creates a window of opportunity for treatment, with the possibility of a total reversal of symptoms.

OBSERVATIONS

HP is an inflammatory process of the dura mater that can occur as a manifestation of sarcoidosis, granulomatosis with polyangiitis, and IgG4-related disease. The HP case evaluation is extensive and includes central nervous system imaging, cerebrospinal fluid analysis, serology, rheumatologic tests, and systemic survey for other manifestations sites. After systemic investigation, meningeal biopsy might be necessary. Etiology guides HP treatment, and autoimmune disorders are treated with corticosteroids alone or associated with an immunosuppressor.

CONCLUSION

HP is a manifestation of several diseases, and a precise etiological diagnosis is crucial because of the difference among treatments. An extensive investigation of patients with HP helps early diagnosis and correct treatment.

Combination of autoimmune pancreatitis and peripheral neuropathy on an IgG4-related disease patient with 4 years following-up

Type1 autoimmune pancreatitis (AIP) is the first recognized and the most common manifestation of IgG4-related disease. However, AIP patient presented with neuropathy in the extremities have not been reported previously. We reported a rare combination of autoimmune pancreatitis and peripheral neuropathy on an IgG4-related disease patient based on histological features to expand the clinical spectrum of IgG4-related disease.

Gender issues of antibody-mediated diseases in neurology: (NMOSD/autoimmune encephalitis/MG)

Neuromyelitis optica spectrum disorder (NMOSD), autoimmune encephalitis (AE), myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) are antibody-mediated neurological diseases. They have mostly female predominance, affecting many women during childbearing age. Interactions between the underlying disease (or necessary treatment) and pregnancy can occur in every of these illnesses. Herein, we present the characteristics of NMOSD, AE, MG and LEMS in general, and review published data regarding the influence of the different diseases on fertility, pregnancy, puerperium, treatment strategy during pregnancy and post-partum period, and menopause but also male factors. We summarise key elements that should be borne in mind when confronted with such cases.

Immunoglobulin G4-related spinal pachymeningitis

Immunoglobulin G4-related disease (IgG4-RD) is rare disease entity and has recently been recognized as an inflammatory disorder with the tendency to affect multiple organs. Pachymeningitis of spine caused by IgG4-related disease is extremely rare. Neck pain and spinal cord compression symptoms consist of usual presentation of IgG4-related spinal pachymeningitis; however, polyarthritis is an unusual presentation of this disease, and it was reported in only one case that mimicked psoriatic arthritis. In this report, we describe a case of IgG4-related spinal pachymeningitis in a middle-age male who presented initially with neck pain and rheumatoid arthritis-like symptoms and later on developed both right upper and lower limb weakness. He was found to had pachymeningeal thickening on a cervical magnetic resonance image (MRI) and elevated serum IgG4 levels. He was treated with glucocorticoids and rituximab, which led to a significantly positive radiological response.

Recurrent myelitis and asymptomatic hypophysitis in IgG4-related disease: case-based review

IgG4-related disease (IgG4-RD) is a disorder with various clinical manifestations. Central nervous system (CNS) involvement is well recognized, with hypertrophic pachymeningitis and hypophysitis being the most common manifestations. Spinal cord involvement is an extremely rare manifestation. We present the first case of an IgG4-RD patient with spinal cord parenchymal disease and concurrent hypophysitis. We review also the current literature about CNS parenchymal involvement in the context of IgG4-RD. A young female presented with clinical symptoms of myelitis. Cervical spinal cord magnetic resonance imaging (MRI) displayed features of longitudinally extensive transverse myelitis (LETM). Brain MRI showed a small number of high-intensity lesions in the deep white matter and enlargement of hypophysis with homogeneous gadolinium enhancement (asymptomatic hypophysitis). Diagnostic workup revealed elevated IgG4 serum levels (146 mg/dL). Our patient fulfilled the organ-specific diagnostic criteria of IgG4-hypophysitis. Treatment with intravenous glucocorticoids led to rapid clinical response, and to the substantial resolution of imaging findings. Azathioprine was used as a maintenance treatment. One relapse occurred 2 years after the initial diagnosis and patient was re-treated with glucocorticoids. Three years after relapse, patient is in remission with azathioprine. We present the first case of myelitis with radiological features of LETM associated with increased IgG4 serum levels and the simultaneous presence of asymptomatic IgG4-related hypophysitis.

A case report of IgG4-related disease: an insidious path to the diagnosis through kidney, heart and brain

Background

IgG4-related disease, described around the years 2000 as a form of autoimmune pancreatitis, is now increasingly accepted as a systemic syndrome. The diagnosis is based on both comprehensive and organ-specific criteria. For the kidney, Mayo clinic classification and the guidelines of the Japanese Nephrology Society are used. Ultimately, together with parameters that characterize every organ or apparatus involved, the key element is the confirmation of growing levels of IgG4 in blood or in tissues.

Case presentation

We describe a male patient with chronic renal failure associated to hypertension without proteinuria. IgG4-related disease was diagnosed through renal biopsy. After an initial positive response to steroids, he presented tinnitus, and histological assessment showed cerebral and subsequently cardiac damage, both IgG4-related. This case appears unique for the type of histologically documented cardiac and neurological parenchymal involvement, and at the same time, exemplifies the subtle and pernicious course of the disease. Frequently, blurred and non-specific signs prevail. Here, kidney damage was associated with minimal urinary findings, slowly progressive renal dysfunction and other factors that can be equivocated in the differential diagnosis. Neurological involvement was represented by tinnitus alone, while cardiac alterations were completely asymptomatic.

Conclusions

This report is representative of the neurological and cardiac changes described in the literature for IgG4-related disease, which may be correlated or not with the renal form and highlights the need, in some cases, of targeted therapeutic approaches. In addition to glucocorticoids, as in this case, rituximab may be necessary.

Imaging in Neuro-ophthalmology

PURPOSE OF REVIEW

This article discusses an approach to imaging in patients with neuro-ophthalmologic disorders, with emphasis on the clinical-anatomic localization of lesions affecting afferent and efferent visual function.

RECENT FINDINGS

Advances in MRI, CT, ultrasound, and optical coherence tomography have changed how neuro-ophthalmic disorders are diagnosed and followed in the modern clinical era.

SUMMARY

The advantages, disadvantages, and indications for various imaging techniques for neuro-ophthalmologic disorders are discussed, with a view to optimizing how these tools can be used to enhance patient care.

[A case of hypertrophic pachymeningitis associated with probable sarcoidosis with increased serum IgG4]

We report a 54-year-old man, who presented with an acute onset of diplopia and ptosis on the left side. On admission, neurological examination showed left oculomotor and abducens nerve palsy. Brain MRI showed thickening of the left parieto-temporal dura mater with gadolinium enhancement. Whole-body CT revealed a mass lesion in the right submandibular gland, diffuse goiter, and bilateral hilar lymph node enlargement. Initially, IgG4-related disease was considered because of an elevated serum IgG4 level (240 mg/dl); however, biopsy of the submandibular gland showed non-caseating epithelioid cell granulomas that suggested sarcoidosis, which could be associated with the intracranial lesions causing his neurological manifestation. In cases of hypertrophic pachymeningitis, especially with increased serum IgG4 including our case, a careful assessment with pathological examination is critical for identifying various underlying conditions.

IgG4-related disease: Association with a rare gene variant expressed in cytotoxic T cells

BACKGROUND

Family screening of a 48-year-old male with recently diagnosed IgG4-related disease (IgG4-RD) revealed unanticipated elevations in plasma IgG4 in his two healthy teenaged sons.

METHODS

We performed gene sequencing, immune cell studies, HLA typing, and analyses of circulating cytotoxic CD4+ T lymphocytes and plasmablasts to seek clues to pathogenesis. DNA from a separate cohort of 99 patients with known IgG4-RD was also sequenced for the presence of genetic variants in a specific gene, FGFBP2.

RESULTS

The three share a previously unreported heterozygous single base deletion in fibroblast growth factor binding protein type 2 (FGFBP2), which causes a frameshift in the coding sequence. The FGFBP2 protein is secreted by cytotoxic T-lymphocytes and binds fibroblast growth factor. The variant sequence in the FGFBP2 protein is predicted to form a disordered random coil rather than a helical-turn-helix structure, unable to adopt a stable conformation. The proband and the two sons had 5-10-fold higher numbers of circulating cytotoxic CD4 + T cells and plasmablasts compared to matched controls. The three members also share a homozygous missense common variant in FGFBP2 found in heterozygous form in ~40% of the population. This common variant was found in 73% of an independent, well characterized IgG4-RD cohort, showing enrichment in idiopathic IgG4-RD.

CONCLUSIONS

The presence of a shared deleterious variant and homozygous common variant in FGFBP2 in the proband and sons strongly implicates this cytotoxic T cell product in the pathophysiology of IgG4-RD. The high prevalence of a common FGFBP2 variant in sporadic IgG4-RD supports the likelihood of participation in disease.

Immunoglobulin G4 related disease: a single-centre experience from South Australia

BACKGROUND

IgG₄ related disease (IgG4RD) is a newly described multisystem fibro-inflammatory disorder. There is a paucity of literature describing the Australian experience of this rare condition.

AIMS

To characterise the Royal Adelaide Hospital IgG4RD cohort with biopsy-proven disease.

METHODS

A search of the Frome Road SA Pathology database was performed for all tissue biopsies containing the phrase 'IgG₄ positive'. Case notes were reviewed for clinical details, laboratory and radiology results. Histological features according to the Boston Criteria were used. Patients with available case notes, highly suggestive or probable histology and clinical features to suggest IgG4RD were included.

RESULTS

Twenty patients had definite or probable IgG4RD and suggestive clinical features; median age 59 (20-76), male : female 1.5:1. There was considerable delay in diagnosis (median diagnosis at 64 months). Organ involvement included: 11 exocrine gland, seven pancreatobiliary, seven nodal, seven soft tissue, five retro-orbital, three retroperitoneal fibrosis and two renal. Systemic symptoms at diagnosis were seen in eight patients. Seven (35%) had an elevated serum IgG₄ (>1.35 g/L) at diagnosis. Only 12 (60%) required immunosuppressive treatment (corticosteroids); of these, four (20%) required a steroid-sparing agent and four (20%) required B-cell depleting therapy (rituximab). The median duration of follow up was 18 months.

CONCLUSIONS

This is the first characterised Australian cohort with generalised IgG4RD, a rare, relatively indolent and under-recognised multisystem disorder. Diagnosis is difficult given lack of awareness of this rare condition among physicians, its presentation as a great disease mimic, challenges with histopathological assessment and the absence of a suitable serum biomarker.