IgG4-related disease: what a hematologist needs to know

CT surveillance for type 1 autoimmune pancreatitis: cumulative radiation dose and diagnostic performance for disease relapse

OBJECTIVES

Long-term follow-up is essential for type 1 autoimmune pancreatitis (AIP) patients due to high relapse rates. The cumulative radiation dose from repeated CT scans during follow-up should not be ignored. We aim to investigate the cumulative radiation dose in AIP patients undergoing CT surveillance and the diagnostic performance of CT in detecting disease relapse. The diagnostic performance of MRI from a secondary cohort during the same period was also investigated.

METHODS

This retrospective single-institutional study included 247 type 1 AIP patients with one or more follow-up CT scans, and 120 patients with MR follow-ups. Four metrics were utilized to report the radiation dose, including the volume computed tomography dose index, the dose length product, size-specific dose estimate and effective dose. The diagnostic performance for AIP relapse was assessed, taking the final clinical diagnosis in retrospect as the reference standard.

RESULTS

With a median 2.3-year follow-up period, AIP patients followed up with CT exhibited a median cumulative radiation dose of 37.5 mSv. 11.3% of patients have accumulated doses exceeding 100 mSv. For the 169 patients followed over a year, 30.8% sustained an average annual radiation dose surpassing 20 mSv. The sensitivity/specificity/accuracy of CT for detecting abdominal organ relapse was 64.1%/99.6%/97.0%. For AIP patients followed up with MRI, the sensitivity for detecting disease relapse was 90.5%.

CONCLUSION

Considering the accumulation of radiation dose in AIP patients and the insufficient sensitivity in detecting disease relapse with CT, safer and more sensitive imaging follow-up strategies should be explored.

KEY POINTS

Question CT, as the primary imaging modality for autoimmune pancreatitis (AIP) follow-up, raises concerns regarding radiation exposure and lacks reported diagnostic performance in detecting AIP relapse. Findings CT in AIP follow-up causes significant cumulative radiation exposure and exhibits insufficient sensitivity in relapse detection. Clinical relevance Type 1 AIP necessitates long-term imaging follow-up, yet current guidelines lack consensus regarding the prioritization of CT or MRI for such follow-up. CT is widely used but has radiation concerns and limited sensitivity, calling for safer, efficient strategies.

Rosai-Dorfman-Destombes disease in adults: a single center experience

Recent advances in Rosai-Dorfman-Destombes disease (RDD), notably molecular testing, targeted therapy, and PET-CT imaging, hold promise for better recognition and improved outcomes. This study presents patients diagnosed and treated in a "real world" setting, where navigating limited resources must be considered. This retrospective single-center review includes 15 adult patients diagnosed with RDD at Vancouver General Hospital between November 2015 and October 2023. The cohort comprised five males and ten females with a median age 53 years (range 19-80 years). All 15 patients had extra-nodal disease; 11 patients exclusively had extra-nodal disease, and four patients also had lymph node involvement. Seven patients had tissue next-generation sequencing, identifying MAP2K1 mutations in four cases and a KRAS p.K117N mutation in one case that was treated with targeted therapy using trametinib. PET-CT was used for disease staging in four cases. Six patients with refractory disease tolerated lenalidomide and dexamethasone without significant toxicity; three patients achieved complete response, and three had partial response. This study highlights RDD's diverse extra-nodal manifestations. Lenalidomide combined with dexamethasone is an effective and well-tolerated treatment option for select patients, especially those with refractory disease. Broad utilization of NGS and PET-CT can positively influence management decisions.

Volume-Based Quantitative Measurement of [18F]AlF-NOTA-FAPI-04 PET/CT Uptake Reflects the Disease Activity of IgG4-Related Disease

BACKGROUND

To investigate the potential utility of quantitative parameters obtained by 18F-fibroblast activation protein inhibitor positron emission tomography/computed tomography ([18F]AlF-NOTA-FAPI-04 PET/CT) in the assessment of organ involvement and disease activity in IgG4-related disease (IgG4-RD).

METHODS

This study enrolled patients who underwent [18F]AlF-NOTA-FAPI-04 PET/CT scans at the Department of Rheumatology, The First Affiliated Hospital, Zhejiang University School of Medicine from August 2021 to August 2022. The PET/CT images of the included patients were re-evaluated by PET center technicians, and the maximal standardized uptake value (SUVmax), metabolic lesion volume (MLV), and total lesion FAPI (TL-FAPI) were used to evaluate the involved organs and tissues that abnormally accumulated [18F]AlF-NOTA-FAPI-04. The clinical and laboratory data of patients are also systematically collected and analyzed.

RESULTS

Among the patients included in this study, 12 patients met the IgG4-RD classification criteria established by the American College of Rheumatology in 2019. Among them, 8 were males and 4 were females, with an average age of 59.3 ± 11.5 years. 50% of IgG4-RD patients were found with more organ involvement on PET/CT than physical examination, ultrasonography, and computed tomography. IgG4 levels (Rho = 0.594, p = 0.042) and IgG4-RI (Rho = 0.647, p = 0.023) were significantly positively correlated with TL-FAPI. After linear regression analysis, only TL-FAPI showed a predictive value of RI (R2 = 0.356, B = 0.008, p = 0.041).

CONCLUSIONS

[18F]AlF-NOTA-FAPI-04 PET/CT is a useful tool for identifying asymptomatic organ involvement and assessing disease activity. The TL-FAPI as an indicator was positively correlated with IgG4-RD disease activity.

Systemic Involvement in Immunoglobulin G4-Related Ophthalmic Disease

BACKGROUND

Immunoglobulin G4-related ophthalmic disease (IgG4-ROD) poses clinical challenges due to its heterogeneous ocular and systemic manifestations. We aim to report the systemic involvement and the clinical, serological and radiological associations of a cohort of Chinese patients.

METHODS

A territory-wide, biopsy-proven, Chinese cohort. A retrospective, masked chart review of medical records, orbital images, and histopathology reports.

RESULTS

A total of 122 (65 male) patients with a follow-up of 81 ± 49 (24 to 84) months were reviewed. Ninety (74%) patients presented bilaterally. Subacute upper eyelid swelling was the commonest presentation (82/122, 67%). During follow-up, 91/122 patients (75%) underwent extra-orbital imaging including computer tomography (692 films), ultrasonography (182 films), magnetic resonance imaging (76 films) and whole body FDG-PET scan (33 films). Eighty-six (95%) of these 91 patients had extra-orbital involvement radiologically (2.7 ± 1.6 regions, range: 0 to 9). Lymph node was the most prevalent (N = 60,66%), followed by salivary gland (N = 51,56%), lung (N = 49,54%), kidney (N = 22, 24%), hepatobiliary tree (N = 18, 20%) and pancreas (N = 17, 19%). Other organs include thyroid, aorta, meninges/brain and skin. Twenty-eight (23%) patients had allergic diseases (19 asthma, 16 allergic rhinitis, and 6 eczemas). Fifty-seven (48%) patients had paranasal sinusitis. Serum eosinophilia was associated with a higher number (3.24 versus 2.52, P = 0.0304) of organ involvement. Patients with deep organ involvement was associated with a higher age of IgG4-ROD onset (70 ± 12 versus 56 ± 13, P < 0.0001).

CONCLUSIONS

95% of the patients who underwent systemic imaging in our cohort had systemic organ involvement. An early physicians' assessment and radiological imaging are recommended after the diagnosis of IgG4-ROD.

Castleman Disease: A Rare Lymphoproliferative Disorder With Diverse Clinical Presentation, Diagnosis, and Treatment Approach

Castleman disease (CD) includes rare and intricate lymphoproliferative disorders characterized by the abnormal growth of lymph nodes and immune system disturbances. It primarily presents in two forms: unicentric Castleman disease (UCD), which affects a single lymph node area, and multicentric Castleman disease (MCD), which involves multiple lymph nodes and systemic manifestations. The disease's underlying mechanisms are often linked to immune system irregularities, especially involving interleukin-6 (IL-6). The condition was first documented by Dr. Benjamin Castleman in 1954, laying the groundwork for understanding this complex disorder. MCD can be further divided into idiopathic MCD (iMCD), which includes thrombocytopenia, ascites, fibrosis, renal impairment, and organ enlargement (TAFRO) syndrome, and human herpesvirus-8 (HHV-8)-associated MCD, which can occur in individuals with or without HIV. The prevalence of CD shows a higher occurrence of UCD, with the disease typically presenting in individuals in their fifth to seventh decades of life and being more common in areas with high HIV prevalence. The clinical presentation of CD can include symptoms such as swollen lymph nodes, fever, anemia, and systemic inflammation. Diagnostic challenges arise due to the disease's rarity, and its symptoms overlap with other conditions. Treatment approaches differ based on the subtype. UCD generally responds favorably to the surgical removal of the affected lymph nodes, while MCD often requires antiviral treatments, interleukin-6 (IL-6) inhibitors, and new biologic therapies. Recent advances in treatment, including innovative biologic agents and combination therapies, offer promising prospects for improving patient outcomes. Accurate diagnosis and customized treatment strategies are essential for the effective management of this complex disease.

Elevated polyclonal IgG4 mimicking a monoclonal gammopathy in IgG4-related disease-a case-based review

IgG4-related diseases (IgG-RDs) are a group of fibroinflammatory diseases that affect a variety of tissues, resulting in tumour-like effects and/or organ dysfunction. Monoclonal gammopathies (MGPs) are a group of disorders characterized by clonal proliferation of plasma cells or lymphoid cells resulting in the secretion of a monoclonal immunoglobulin. Cases of MGPs in IgG4-RDs coexisting with plasma cell dyscrasias and lymphoid neoplasms have been reported over the past few years. Therefore, the results of examinations of M protein in IgG4-RD patients should be interpreted with caution. Herein, we report the case of a 58-year-old male with a history of type 2 diabetes who presented with submandibular masses, anosmia, swollen lymph nodes, proteinuria, and renal impairment. Laboratory tests revealed hyperglobulinemia and elevated levels of IgG4 (124 g/L) and serum-free light chains (sFLCs). Serum protein electrophoresis (SPEP) revealed an M spike of 5.6 g/dL, and immunofixation electrophoresis (IPE) revealed biclonal IgG-κ and IgG-λ. The patient underwent bone marrow, lymph node, and kidney biopsy, which ruled out plasma cell disorders and lymphoma. He was finally diagnosed with an IgG4-RD comorbid with diabetic nephropathy. The findings in this case highlight that significant activation of B cells in IgG4-RD patients, especially those with multiorgan involvement can lead to significant hyperglobulinemia and high sFLC and IgG4 levels, which are more pronounced in the setting of renal impairment. Relatively high concentrations of polyclonal IgG4 can give rise to a focal band bridging the β and γ fractions, which may mimic the appearance of a monoclonal band on SPEP and monoclonal gammaglobulinemia in IFE. The patient experienced considerable improvement in his symptoms after rituximab combined with glucocorticoid therapy, and a monoclonal immunoglobulin was not detected.

Non-infectious hypertrophic pachymeningitis associated with orbital inflammatory disease: a pooled analysis

PURPOSE

To describe four cases of non-infectious hypertrophic pachymeningitis (HP)-associated with orbital inflammatory disease (OID). This study summarises the clinico-radiological features, outcomes, and management of HP-associated OID.

METHODS

Retrospective case-series of patients with radiological evidence of HP and OID. Comprehensive literature review of all published English-language non-infectious causes of HP-associated OID. Reference lists were screened for inclusion of relevant articles.

RESULTS

Thirty-seven cases of HP-associated OID (Mean age: 49.2 ± 17.4 years old; Male: 15) were identified, including four cases from our institution. Aetiologies included ANCA-associated vasculitis (12/37), non-specific/idiopathic (11/37), IgG4/multifocal fibrosclerosis (11/37), neurosarcoidosis (1/37), inflammatory myofibroblastic tumour (1/37), and giant cell arteritis (1/37). Orbital pain, headache, visual deterioration, and cranial nerve palsies were common clinical presentations. Both "focal" and "diffuse" HP were observed, with the most common sign of orbital involvement being an inflammatory orbital mass, typically with orbital apex involvement. Orbital myositis and dacryoadenitis were less common. The cavernous sinus was the most common site of extra-orbital inflammation. There was no single differentiating specific radiological feature between non-specific and specific forms of HP-associated OID.

CONCLUSION

The clinico-radiological manifestations of HP-associated OID differ from those described in isolated HP or OID. There is no single specific radiological marker differentiating non-specific/idiopathic disease from secondary causes; however, the co-existence of HP in OID should prompt suspicion of an underlying cause. The disease may be refractory or resistant to initial treatment, although guidelines surrounding its management and the long-term prognosis remain to be determined.

The "great imitator": IgG4-related disease of the oral cavity. Two case reports and scoping review

This study aimed to review the lesser-known intraoral manifestations of immunoglobulin G4-related disease (IgG4-RD). In this paper we report an unprecedented case of oral IgG4-RD mimicking angiolymphoid hyperplasia with eosinophilia (ALHE), and another case presenting as plasma cell gingivitis. We then performed a scoping review of published cases of IgG4-RD involving the oral cavity. The following data were collected for each case: age, sex, intraoral site(s) involved, clinical appearance, imaging features, serum IgG4 values, histopathology, treatment, and follow-up duration. Fifty-one cases of oral IgG4-RD were published in literature. The hard palate and jaw bones were the two main locations reported, while the histological identification of a IgG4/IgG plasma cells ratio ≥40% was fundamental for diagnosis. Conversely, the pathological features of storiform fibrosis and obliterative phlebitis were not common. Future reports regarding oral IgG4-RD should report clear adherence to the recognized international diagnostic criteria of the disease.

Probable IGG4 related ophthalmic disease presenting with uveitis

We present a case of an uncommon presentation of IgG4-related ophthalmic disease (ROD). A 58-year-old female presented with unilateral acute anterior uveitis of the right eye, which progressed to scleritis with the development of an associated orbital mass despite treatment with oral glucocorticoid. Initial histopathology of an orbital biopsy was non-diagnostic and continued progression of the disease lead to complete loss of vision in the right eye. The development of uveitis in the previously unaffected left eye led to the decision for enucleation of the right globe and further orbital biopsy. Histopathology revealed features supporting IgG4-related ophthalmic disease. Oral glucocorticoid therapy failed to induce remission, and rituximab therapy was initiated, leading to a rapid resolution in her symptoms. Other cases with a similar presentation report a poor visual prognosis, highlighting the need for prompt diagnosis and treatment of uveitis associated with signs of orbital or scleral involvement.

Dry Crusty Nose: Not Just Rhinosinusitis! Hidden IgG4-related Disease Without IgG4 Level Rise

IgG4-related disease (IgG4-RD) is a fibro-inflammatory condition that can affect various organs. Localized sinonasal IgG4-RD is a rare condition characterized by bone and soft-tissue invasion. In this report, we present a case of a patient initially diagnosed with chronic rhinosinusitis, who underwent endoscopic sinus surgery and was later found to have biopsy proven IgG4-related sinonasal disease despite having normal serum levels of IgG4, resulting in erosion of the right lamina papyracea.

Myelodysplastic syndrome with IgG4‑related disease: A case report

At present, to the best of our knowledge, there are only a few case reports of IgG4-related disease (IgG4-RD) involving myelodysplastic syndrome (MDS), yet the incidence of MDS and IgG4-RD is increasing in middle-aged and elderly people. The present study presents a case of MDS combined with IgG4-RD admitted to Zhejiang Provincial Hospital of Chinese Medicine in September 2022. The (66-year-old; male) patient was admitted to the hospital due to hematopenia with an elevated IgG4 index. The diagnosis of MDS combined with IgG4-RD was confirmed after various exams, including pathological examination. The condition of the patient improved after 3 weeks of hormone therapy, with a significant increase in complete blood count compared with the pre-treatment period. MDS is a malignant hematological disorder with a high risk of conversion to leukemia, and IgG4-RD is a systemic immune-mediated disease with a poor prognosis often associated with malignancy. The present study presents and reviews the literature to better understand the coexistence of these two diseases.

Clinical Performance of Immunonephelometric Assay and Chemiluminescent Immunoassay for Detection of IgG Subclasses in Chinese

BACKGROUND

Detection of IgG subclasses (IgGSc) is vital for the diagnosis and management of disease, especially IgG4-related diseases (IgG4-RD). This study aimed to evaluate the performances of the chemiluminescent immunoassay (CLIA) for detecting IgGSc and diagnosing IgG4-RD by IgGSc.

METHODS

A total of 40 individuals with IgG4-RD, 40 with primary Sjogren's syndrome (pSS), and 40 healthy controls (HCs) were enrolled. Serum samples were collected for the simultaneous detection of IgG1, IgG2, IgG3, and IgG4 by the Siemens immunonephelometric assay and the CLIA. The correlation analysis was performed, and diagnostic value was analyzed by the receiver operating characteristic (ROC) curve.

RESULTS

Patients with IgG4-RD had higher IgG4 (p < 0.001) and lower IgG1 (p < 0.001) than those with pSS, and HC. The results by the Siemens immunonephelometric assay and the CLIA showed a strong correlation in detecting IgG1, IgG2, IgG3, and IgG4 (r = 0.937, r = 0.847, r = 0.871, r = 0.990, all p < 0.001, respectively). The sum of IgG1, IgG2, IgG3, and IgG4 using two assays strongly correlated with total IgG by the IMMAGE 800 (r = 0.866, r = 0.811, both p < 0.001, respectively). For discriminating IgG4-RD from pSS and HC, no significant differences were observed in CLIA IgG4 and Siemens immunonephelometric assay IgG4 (z = 0.138, p = 0.891), which provided the area under the curves (AUCs) of 0.951 (p < 0.001) and 0.950 (p < 0.001), respectively. The AUCs of CLIA IgG1 and Siemens immunonephelometric assay IgG1 in distinguishing pSS from IgG4-RD and HC were 0.761 (p < 0.001) and 0.765 (p < 0.001), respectively, with no significant differences (z = 0.228, p = 0.820).

CONCLUSIONS

The CLIA and the Siemens immunonephelometric assay appeared to have good consistency with comparable diagnostic value in detecting IgGSc, especially IgG4, and IgG1 that can accurately identify IgG4-RD or pSS in clinical practice.

IgG4-related disease: an update on pathology and diagnostic criteria with a focus on salivary gland manifestations

Immunoglobulin G4-related disease (IgG4-RD) is a multi-organ disorder characterized by a highly variable clinical presentation depending on the affected organ/s, extent of tumefactive fibroinflammatory lesions, and associated functional impairment. The disease pursues a chronic, relapsing, often asymptomatic course and hence may pose a significant diagnostic challenge. Diagnostic delay can lead to progressive fibrosis and irreversible organ damage resulting into significant morbidity and even mortality. Given its broad clinical spectrum, physicians of all specialties may be the first clinicians facing this diagnostic challenge. Outside the pancreatobiliary system, the head and neck represents the major site of IgG4-RD with variable organ-specific diffuse or mass-forming lesions. In up to 75% of cases, elevated serum IgG4 levels are observed, but this figure possibly underestimates the fraction of seronegative cases, as the disease manifestations may present metachronously with significant intervals. Together with negative serology, this can lead to misdiagnosis of seronegative cases. A standardized nomenclature and diagnostic criteria for IgG4-RD were established in 2012 and revised in 2020 facilitating scientific research and expanding the range of diseases associated with IgG4 abnormalities. In addition to orbital pseudotumor, dacryoadenitis, Riedel thyroiditis, sinonasal manifestations, and rare miscellaneous conditions, IgG4-related sialadenitis is one of the most frequent presentations in the head and neck region. However, controversy still exists regarding the relationship between sialadenitis and IgG4-RD. This review focuses on the clinicopathological features of IgG4-related sialadenitis and its contemporary diagnostic criteria.

Utility of 18F-FDG PET/CT for differential diagnosis between IgG4-related lymphadenopathy and angioimmunoblastic T-cell lymphoma

AIM

To explore the utility of the 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG) positron-emission tomography (PET)/computed tomography (CT) in the differential diagnosis of IgG4-related lymphadenopathy (IgG4-RLAD) and angioimmunoblastic T-cell lymphoma (AITL).

MATERIALS AND METHODS

Retrospective analysis of 18F-FDG PET/CT imaging findings in clinically diagnosed IgG4-RLAD and AITL cases was undertaken to record the distribution, morphological characteristics, and imaging features of the affected lymph nodes, as well as FDG uptake of the spleen and bone marrow. Standardised uptake values normalised to lean body mass were evaluated for maximum (SULmax), average (SULavg), and peak values (SULpeak). Univariate and multivariate logistic regression was used to screen for statistically significant imaging findings to discriminate IgG4-RLAD from AITL.

RESULTS

Twenty-two cases of IgG4-RLAD (17 men, five women, median age 49.5 years) and 22 cases of AITL (16 men, six women, median age 55 years) were finally included in the analysis. There were no AITL patients with involvement of a single lymph node region. AITL patients had more involvement of the different nodal regions except cervical and pelvic nodal regions. A practical assessment method based on a combination of SULpeak-LN/SULavg-liver, SULpeak-spleen, and the number of involved nodal regions, improved the performance for differential diagnosis between both groups with an overall classification accuracy of 90.9%.

CONCLUSIONS

18F-FDG PET/CT is a useful tool for distinguishing AITL from IgG4-RLAD, and it can also help determine the optimal biopsy site for suspected cases of IgG4-RLAD or AITL, reduce the need for re-biopsy procedures, and enable physicians to develop timely treatment strategies.

Autoimmune hepatitis-primary biliary cholangitis overlap syndrome complicated by various autoimmune diseases: A case report

BACKGROUND

Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) are two common clinical autoimmune liver diseases, and some patients have both diseases; this feature is called AIH-PBC overlap syndrome. Autoimmune thyroid disease (AITD) is the most frequently overlapping extrahepatic autoimmune disease. Immunoglobulin (IgG) 4-related disease is an autoimmune disease recognized in recent years, characterized by elevated serum IgG4 levels and infiltration of IgG4-positive plasma cells in tissues.

CASE SUMMARY

A 68-year-old female patient was admitted with a history of right upper quadrant pain, anorexia, and jaundice on physical examination. Laboratory examination revealed elevated liver enzymes, multiple positive autoantibodies associated with liver and thyroid disease, and imaging and biopsy suggestive of pancreatitis, hepatitis, and PBC. A diagnosis was made of a rare and complex overlap syndrome of AIH, PBC, AITD, and IgG4-related disease. Laboratory features improved on treatment with ursodeoxycholic acid, methylprednisolone, and azathioprine.

CONCLUSION

This case highlights the importance of screening patients with autoimmune diseases for related conditions.

Mass spectrometry in IgG4-related disease diagnosis

We compared liquid chromatography tandem mass spectrometry (LC-MS/MS) against Binding Site immunonephelometry (BSIN) with regards to these methods' abilities to diagnose IgG4-related disease (IgG4-RD). IgG subclasses were gathered from laboratory from December 2011 to December 2020. The IgG4-RD positive and negative patients were diagnosed according to the ACR/EULAR classification criteria by extensive chart review. Both methods' results were compared in terms of test characteristics. For BSIN, there were 43 IgG4-RD positive cases and 174 disease negative cases, while for LC-MS/MS, there were 102 IgG4-RD positive cases and 562 disease negative cases. The majority of IgG4-RD patients by BSIN and LC-MS/MS had an elevated IgG4 level, 81% and 86%, respectively. For BSIN, the ROC curve, cut-off value of 1.25 g/L, had a sensitivity of 81% and a specificity of 84%. For LC-MS/MS, the ROC curve, cut-off value of 1.25 g/L, had a sensitivity of 86% and a specificity of 84%. The responder index score to IgG4 level r-correlation value for BSIN and LC-MS/MS was 0.5 and 0.6, respectively. In our center, LC-MS/MS and BSIN are equivalent test methods in IgG4-RD diagnosis. IgG4 level does correlate with disease activity by the responder index. LC-MS/MS is a valid and equally reliable alternative to BSIN in the diagnosis of IgG4-related disease.

Magnetic resonance imaging in paediatric ocular and orbital lesions: A pictorial review

Paediatric orbital lesions encompass a wide spectrum of benign and malignant entities that can arise from different components of the orbit. Clinical symptoms and signs are often nonspecific, and imaging plays a crucial role in the diagnosis and management. Ultrasonography has a limited role and radiation is a major concern with CT especially in the paediatric population. MRI is the modality of choice that avoids the radiation hazard and provides superior soft tissue contrast. The lesions can be localized using the 'compartment' approach which helps to narrow the list of differentials. MRI also provides critical information for management such as presence of perineural spread and intracranial extension. This article depicts the spectrum of Magnetic Resonance imaging findings encountered in paediatric ocular and orbital lesions.

Activation of fibroblasts by plasma cells via PDGF/PDGFR signaling in IgG4-related sialadenitis

IgG4-related sialadenitis (IgG4-SA) is one of the IgG4-related disease. The histological features of IgG4-SA include dense lymphoplasmacytic infiltrates and fibrosis. This study aimed to reveal the involvement of plasma cells in the development of fibrosis and the mechanism underlying fibrosis in IgG4-SA. Hematoxylin-eosin staining, Azan staining, silver staining, and immunohistochemistry (IHC) were performed on IgG4-SA and chronic sialadenitis specimens, and theses samples were analyzed by image analysis software. Histological spatial analysis was used to analyze the localization of IHC-positive cells and the distances between these cells. In the IgG4-SA group, many secondary lymphoid follicles with germinal centers were found, and many collagen fibers developed around these germinal centers. Collagen fibers composed mainly of type I collagen was abundant at sites away from secondary lymphoid follicles, and reticular fibers composed of type III collagen was abundant near secondary lymphoid follicles. Many FAP+ fibroblasts and MUM1+ plasma cells were localized near secondary lymphoid follicles. Histological spatial analysis demonstrated that 90.4% of MUM1+ plasma cells accumulated within 20 µm of FAP+ fibroblasts. Multiple immunofluorescence assays revealed that MUM1+ plasma cells expressed platelet-derived growth factor (PDGF) β, and FAP+ fibroblasts expressed PDGF receptor (PDGFR) β and pSTAT3 in IgG4-SA. We have shown that fibrosis is localized around secondary lymphoid follicles and that fibroblasts are activated by plasma cells via PDGF/PDGFR signaling in IgG4-SA.

Significant CA 19-9 elevation in IgG4-related autoimmune pancreatitis - A diagnostic dilemma

IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder characterized by dense infiltration of IgG4-positive plasma cells in the affected tissue along with characteristic storiform fibrosis that can lead to the development of tumefactive lesions in any organ. CA19-9 is a marker for pancreato-biliary malignancy, however mild to moderate elevation of CA 19-9 can also be observed in IgG4-RD autoimmune pancreatitis (AIP) and sclerosing cholangitis (IgG4-SC). Therefore, it becomes difficult to differentiate between these entities. We describe the case of a 65-year-old male with history of IgG4-RD, presenting with jaundice and abdominal pain. He was found to have a pancreatic mass with significantly elevated IgG4 162 (2-96 mg/dL and CA19-9 levels 2830 (0-35 U/ml). Patient underwent ERCP and biopsy, which ruled out pancreatic cancer and cholangiocarcinoma. He was diagnosed with IgG4-RD autoimmune pancreatitis (AIP) and sclerosing cholangitis. Treatment with steroids and rituximab resulted in significant improvement in the bilirubin and a dramatic decrease in CA19-9 levels.

Cardiac Masses and Pseudomasses: An Overview about Diagnostic Imaging and Clinical Background

A cardiac lesion detected at ultrasonography might turn out to be a normal structure, a benign tumor or rarely a malignancy, and lesion characterization is very important to appropriately manage the lesion itself. The exact relationship of the mass with coronary arteries and the knowledge of possible concomitant coronary artery disease are necessary preoperative information. Moreover, the increasingly performed coronary CT angiography to evaluate non-invasively coronary artery disease leads to a rising number of incidental findings. Therefore, CT and MRI are frequently performed imaging modalities when echocardiography is deemed insufficient to evaluate a lesion. A brief comprehensive overview about diagnostic radiological imaging and the clinical background of cardiac masses and pseudomasses is reported.

Navigating the Spectrum: Atypical Pulmonary Involvement in Immunoglobulin G4-Related Disease

Immunoglobulin G4-related disease (IgG4-RD) is a systemic condition known to affect multiple organ systems. While its manifestations are diverse, pulmonary involvement, especially of the pleura, remains less common. We report the case of a 99-year-old Saudi male with a medical history of diabetes mellitus, chronic kidney disease, and hypertension. He presented with dyspnea and syncope, with radiological findings revealing pleural effusion and a mass in the right hemidiaphragm. Laboratory investigations highlighted elevated serum IgG4 levels, and histopathological evaluation confirmed the diagnosis of IgG4-RD. Notably, the patient's thoracic histopathology differed from typical IgG4-RD presentations, emphasizing the variability of the disease. This case underscores the significance of recognizing IgG4-RD as a potential cause of unexplained pleural effusion. It also highlights the need for a comprehensive diagnostic approach, integrating laboratory values, histopathological findings, and clinical context. Given the potential variability in thoracic IgG4-RD histopathology, clinicians should maintain a heightened awareness of this condition to avoid missed diagnoses.

Defective LAT signalosome pathology in mice mimics human IgG4-related disease at single-cell level

Mice with a loss-of-function mutation in the LAT adaptor (LatY136F) develop an autoimmune and type 2 inflammatory disorder called defective LAT signalosome pathology (DLSP). We analyzed via single-cell omics the trajectory leading to LatY136F DLSP and the underlying CD4+ T cell diversification. T follicular helper cells, CD4+ cytotoxic T cells, activated B cells, and plasma cells were found in LatY136F spleen and lung. Such cell constellation entailed all the cell types causative of human IgG4-related disease (IgG4-RD), an autoimmune and inflammatory condition with LatY136F DLSP-like histopathological manifestations. Most previously described T cell-mediated autoimmune manifestations require persistent TCR input. In contrast, following their first engagement by self-antigens, the autoreactive TCR expressed by LatY136F CD4+ T cells hand over their central role in T cell activation to CD28 costimulatory molecules. As a result, all subsequent LatY136F DLSP manifestations, including the production of autoantibodies, solely rely on CD28 engagement. Our findings elucidate the etiology of the LatY136F DLSP and qualify it as a model of IgG4-RD.

Fibrosis and bone marrow: understanding causation and pathobiology

Bone marrow fibrosis represents an important structural change in the marrow that interferes with some of its normal functions. The aetiopathogenesis of fibrosis is not well established except in its primary form. The present review consolidates current understanding of marrow fibrosis. We searched PubMed without time restriction using key words: bone marrow and fibrosis as the main stem against the terms: growth factors, cytokines and chemokines, morphology, megakaryocytes and platelets, myeloproliferative disorders, myelodysplastic syndrome, collagen biosynthesis, mesenchymal stem cells, vitamins and minerals and hormones, and mechanism of tissue fibrosis. Tissue marrow fibrosis-related papers were short listed and analysed for the review. It emerged that bone marrow fibrosis is the outcome of complex interactions between growth factors, cytokines, chemokines and hormones together with their facilitators and inhibitors. Fibrogenesis is initiated by mobilisation of special immunophenotypic subsets of mesenchymal stem cells in the marrow that transform into fibroblasts. Fibrogenic stimuli may arise from neoplastic haemopoietic or non-hematopoietic cells, as well as immune cells involved in infections and inflammatory conditions. Autoimmunity is involved in a small subset of patients with marrow fibrosis. Megakaryocytes and platelets are either directly involved or are important intermediaries in stimulating mesenchymal stem cells. MMPs, TIMPs, TGF-β, PDGRF, and basic FGF and CRCXL4 chemokines are involved in these processes. Genetic and epigenetic changes underlie many of these conditions.

Immunoglobulin G4-Related Lesions in Autoimmune Diseases: Unusual Presentations at Atypical Sites-A Tale of 2 Cases with Literature Review

Immunoglobulin G4-related disease (IgG4-RD) coexisting with clinically apparent autoimmune diseases, such as rheumatoid arthritis (RA) or antiphospholipid syndrome (APS), is a rarely documented combination in the scientific literature. In this case-based review, we present 2 intriguing cases with preexisting autoimmune diseases, namely, RA and primary APS, who exhibited coexistent IgG4- related lesions at unusual sites. The first case pertains to a patient with known RA who presented with an encasing mass in the esophagus leading to stricture, with histopathological diagnosis of IgG4-RD.The second patient, diagnosed with primary APS, experienced breathlessness, and imaging revealed a right atrial mass. Histopathological examination of the mass confirmed IgG4-RD. Notably, both patients demonstrated significant clinical improvement upon initiation of steroid therapy. Rheumatoid arthritis patients commonly exhibit elevated levels of IgG4 in their sera; however, RA with coexisting IgG4-RD is rarely reported in the literature. Similarly, APS with IgG4-related lesions is exceedingly rare. Although there are few case reports and series on esophageal and cardiac IgG4-RD, the occurrence of such unusual location of IgG4-related lesions in the context of known autoimmunity is presented here for the first time.

Clinical significance of the detection of serum IgG4 and IgG4/IgG ratio in patients with thyroid-associated ophthalmopathy

To evaluate the clinical significance of detecting serum IgG4 and the IgG4/IgG ratio in patients with thyroid-associated ophthalmopathy (TAO) and to explore whether high serum IgG4 levels and the IgG4/IgG ratio are associated with the severity and activity of TAO, we retrospectively assessed the records of 78 TAO patients and 32 controls collected in our hospital from July 2020 to July 2022. The TAO patients were divided into TAO inactive and TAO active phase groups according to the clinical activity score (CAS), and we evaluated the association between the serum IgG4 levels, the IgG4/IgG ratio, and the clinical data of the participants. The levels of IgG4 significantly increased in the TAO active group compared to those in the inactive and control groups (P < 0.05). Additionally, the number of patients with increased IgG4 levels (≥135 mg/dL) in the TAO active group was markedly higher than that in the inactive and control groups (P < 0.05). The IgG4/IgG ratio was also significantly enhanced in the TAO active group compared to the inactive and control groups (P < 0.05). CAS was identified as an independent factor influencing IgG4 levels in patients with TAO. The levels of serum IgG4, as well as the IgG4/IgG ratio, were significantly increased in some patients with active TAO, and they were related to the CAS, suggesting that the pathogenesis of TAO may be heterogeneous.

IgG4-Related Membranous Nephropathy with Acute Nephrotic Syndrome During Successful Steroid Maintenance Treatment for Type 1 Autoimmune Pancreatitis

BACKGROUND Immunoglobulin G4 (IgG4)-related diseases (IgG4-RD) are systemic fibroinflammatory diseases that can develop asynchronously in multiple organs. IgG4-related kidney disease (IgG4-RKD) is generally characterized by tubulointerstitial nephritis but can also manifest as membranous nephropathy without tubulointerstitial nephritis. IgG4-related membranous nephropathy can present as a phenotype of systemic disorders, including autoimmune pancreatitis-associated diabetes mellitus; however, its clinical features remain unclear. CASE REPORT A 56-year-old Japanese man presented to our university hospital with bilateral edema of his lower legs. He had received a diagnosis of type 1 autoimmune pancreatitis and associated diabetes mellitus 16 months prior. He was successfully treated with oral glucocorticoids 25 mg/day of prednisolone as an initial dose, followed by titration down to a maintenance dose (5 mg/day), without recurrence of autoimmune pancreatitis. The pancreas showed atrophy and required basal-bolus insulin therapy owing to insulin insufficiency. Massive proteinuria and hypoalbuminemia with nephrotic syndrome on examination led to a renal biopsy to investigate the etiology and diagnosis of IgG4-RKD. Methylprednisolone and cyclosporine A were successfully administered to ameliorate the proteinuria and control systemic IgG4-RD with IgG4-related membranous nephropathy. CONCLUSIONS Ig4-RKD occurred despite maintenance treatment with prednisolone monotherapy and was controlled with methylprednisolone and cyclosporine A. Measurement of clinical parameters, including proteinuria, was important, and a renal biopsy finally established the diagnosis of IgG4-RKD. IgG4-RKD can present with progressive glomerular lesions and can be latent in cases diagnosed with diabetic kidney disease, particularly in patients with insulin insufficiency.

'Spikeopathy': COVID-19 Spike Protein Is Pathogenic, from Both Virus and Vaccine mRNA

The COVID-19 pandemic caused much illness, many deaths, and profound disruption to society. The production of 'safe and effective' vaccines was a key public health target. Sadly, unprecedented high rates of adverse events have overshadowed the benefits. This two-part narrative review presents evidence for the widespread harms of novel product COVID-19 mRNA and adenovectorDNA vaccines and is novel in attempting to provide a thorough overview of harms arising from the new technology in vaccines that relied on human cells producing a foreign antigen that has evidence of pathogenicity. This first paper explores peer-reviewed data counter to the 'safe and effective' narrative attached to these new technologies. Spike protein pathogenicity, termed 'spikeopathy', whether from the SARS-CoV-2 virus or produced by vaccine gene codes, akin to a 'synthetic virus', is increasingly understood in terms of molecular biology and pathophysiology. Pharmacokinetic transfection through body tissues distant from the injection site by lipid-nanoparticles or viral-vector carriers means that 'spikeopathy' can affect many organs. The inflammatory properties of the nanoparticles used to ferry mRNA; N1-methylpseudouridine employed to prolong synthetic mRNA function; the widespread biodistribution of the mRNA and DNA codes and translated spike proteins, and autoimmunity via human production of foreign proteins, contribute to harmful effects. This paper reviews autoimmune, cardiovascular, neurological, potential oncological effects, and autopsy evidence for spikeopathy. With many gene-based therapeutic technologies planned, a re-evaluation is necessary and timely.

[AL amyloidosis mimicking IgG4-related disease: case report]

The article describes a unique clinical case of AL amyloidosis mimicking IgG4-related disease. Plasma cell dyscrasias can mimic clinical and laboratory manifestations of rheumatic diseases, which can lead to a delay in diagnosis and inappropriate therapy.

IgG4 plasma cell neoplasm in liver transplant biopsy masquerading as rejection

IgG4 plasma cell neoplasm and myeloma are rare disease entities, not associated with systemic fibroinflammatory IgG4 related disease. We herein present a case of IgG4 plasma cell neoplasm in a liver transplant biopsy. A 55 year old female was treated with living donor transplant and had a complicated post-operative course. Three months post-transplant, she presented with small for size syndrome, biliary stricture, and inferior vena cava stenosis. Concomitant liver biopsy revealed mild acute cellular rejection with central perivenulitis pattern, and mild centrilobular fibrosis. She was treated with steroids which resulted in improvement of liver enzymes. Seven months post-transplant, she presented with subtherapeutic prograf levels and cholestatic pattern of elevated liver tests. ERCP revealed a stone which was removed. Hematological evaluation revealed an abnormal serum protein electrophoresis (SPEP). Monoclonal IgG kappa was elevated along with mildly elevated free Kappa/Lambda ratio. She was followed up and readmitted two months later for worsening liver function tests. The liver biopsy showed monotypic Kappa-and IgG4-restricted plasma cell infiltrates in portal, periportal, sinusoidal and centrilobular regions, compatible with plasma cell neoplasm. In the clinical context of positivity for a serum M-spike, the monoclonal hepatic infiltrates were deemed consistent with a Kappa-and IgG4-restricted plasma cell neoplasm. Patient was treated with pulsed steroids, and liver function tests subsequently downtrended. She was followed up by Hemoncology, and the treatment plan included carfilzomib-based induction therapy and dexamethasone to prevent end-organ damage from evolving myeloma. In the meanwhile, she developed acute appendicitis, underwent appendectomy, and passed away in the post-operative period.

IgG4 Autoimmune Disease Masquerading As Oroantral Fistula

IgG4-related disease (IgG4-RD) is an immune-mediated disorder that involves multiple organs and is characterized by the infiltration of lymphoplasmacytic cells, including IgG4-positive plasma cells, along with storiform fibrosis and obliterative phlebitis in the inflamed organs. The primary sites affected by this condition include the pancreas, bile ducts, salivary glands, aorta, lungs, kidneys, meninges, lacrimal glands, mediastinal lymph nodes, and retroperitoneum. The pathogenesis is linked to a type 2 T-helper-cell cytokine profile and the involvement of regulatory T cells. However, the exact mechanism is still unknown. Patients with IgG4-related disease are frequently misdiagnosed as having malignancies due to the resemblance of the lesions to infections or other immune-mediated diseases and certain tumors, such as pancreatic cancer and pseudo-renal pelvis tumor. Prompt identification of IgG4-related disease is essential as a delayed diagnosis until advanced stages can result in severe organ damage and potentially fatal outcomes, despite the disease being highly responsive to treatment. This report presents a highly unusual case of IgG4-related disease (IgG4-RD) with an atypical presentation in a 38-year-old female patient. The patient sought medical attention in the emergency department due to nasal septal erosions and an oral-antral fistula. Nasal cultures were conducted and indicated the presence of Klebsiella ozaena. Subsequent investigations, including a nasal biopsy, confirmed the diagnosis of IgG4-related autoimmune disease.

Clinical presentation and organ-based outcomes of Multifocal fibrosclerosis: A systematic review

Objectives

Multifocal fibrosclerosis is a rare disorder causing progressive fibrosis of multiple organ systems. Existing data on the disease show that there are multiple manifestations of the disease, with different outcomes. However, quantitative data are scarce, prompting the need for our investigation.

Method

A comprehensive systematic review was performed from inception to November 16, 2022, with the restriction of English language, not including review articles. Article screening and extraction was performed independently, and shortlisted articles were assessed for bias. Analysis was performed using SPSS Version 25 (IBM® SPSS® Statistics; Chicago, IL, USA). Data were presented as frequencies and percentages, with a confidence interval of 95%.

Result

This review included 134 patients, with 78 (58.2%) males. Mean age was 53.6 years and included two pediatric patients. The most common comorbidity was diabetes (9.7%). Prevalent presenting symptoms included pain (47.8%) and swelling (35.1%). A mean of 2.51 organs or anatomical sites was affected, retroperitoneum (64.2%) being most affected. The pancreas (30.0%) and digestive system (47.0%) were the organs/organ systems most affected. Patients had favorable outcomes in 79.1% of cases, 87.3% had no relapse, and 91.8% of patients survived the condition.

Conclusion

The findings in this study provide a quantitative measurement of the demographics, presentations, organ manifestations, and outcomes of multifocal fibrosclerosis. We found the disease to be prevalent in males in Japan or the United States, with the abdomen and its organs being commonly involved.

The multidisciplinary approach to eosinophilia

Eosinophilic granulocytes are normally present in low numbers in the bloodstream. Patients with an increased number of eosinophilic granulocytes in the differential count (eosinophilia) are common and can pose a clinical challenge because conditions with eosinophilia occur in all medical specialties. The diagnostic approach must be guided by a thorough medical history, supported by specific tests to guide individualized treatment. Neoplastic (primary) eosinophilia is identified by one of several unique acquired genetic causes. In contrast, reactive (secondary) eosinophilia is associated with a cytokine stimulus in a specific disease, while idiopathic eosinophilia is a diagnosis by exclusion. Rational treatment is disease-directed in secondary cases and has paved the way for targeted treatment against the driver in primary eosinophilia, whereas idiopathic cases are treated as needed by principles in eosinophilia originating from clonal drivers. The vast majority of patients are diagnosed with secondary eosinophilia and are managed by the relevant specialty-e.g., rheumatology, allergy, dermatology, gastroenterology, pulmonary medicine, hematology, or infectious disease. The overlap in symptoms and the risk of irreversible organ involvement in eosinophilia, irrespective of the cause, warrants that patients without a diagnostic clarification or who do not respond to adequate treatment should be referred to a multidisciplinary function anchored in a hematology department for evaluation. This review presents the pathophysiology, manifestations, differential diagnosis, diagnostic workup, and management of (adult) patients with eosinophilia. The purpose is to place eosinophilia in a clinical context, and therefore justify and inspire the establishment of a multidisciplinary team of experts from diagnostic and clinical specialties at the regional level to support the second opinion. The target patient population requires highly specialized laboratory analysis and therapy and occasionally has severe eosinophil-induced organ dysfunction. An added value of a centralized, clinical function is to serve as a platform for education and research to further improve the management of patients with eosinophilia. Primary and idiopathic eosinophilia are key topics in the review, which also address current research and discusses outstanding issues in the field.

Characteristics of patients with incidental eosinophilia admitted to a tertiary hospital in southern China

Background

The characteristics of patients with eosinophilia are heterogeneous and the outcomes can vary from asymptomatic to severe.

Objective

To describe the feature of patients with eosinophilia in a single center.

Design

Based on the electronic medical records from Yangjiang People's Hospital in China, the inpatients admitted between June 2018 and February 2021 with measured blood eosinophil counts were evaluated.

Methods

Eosinophilia was defined as a peripheral blood eosinophil count of ≥0.5 × 10⁹/L. Differences were compared by eosinophilia severity. The medical records of patients with moderate to severe eosinophilia were reviewed and summarized in terms of examination, diagnoses and management. And these patients were matched with patients without incidental eosinophilia by propensity score and the differences were compared.

Results

A total of 7,835 patients with eosinophilia were identified out of 131,566 total inpatients. All types of eosinophilia were most common in males (8.2%; 5,351/65,615), and in patients aged 0-6 years (11.6%; 1,760/15,204), and in the pediatric (10.8%; 1,764/16,336) department, followed by dermatology (10.6%; 123/1,162), Oncology (7.5%; 394/5,239) and Intensive care unit (ICU) (7.4%; 119/1,608). Patients with moderate to severe eosinophilia were more likely to admit to ICU (moderate: 1.3%; severe: 0.50%). In patients with moderate to severe eosinophilia, only 205/621 (33%) had eosinophilia mentioned in their records, and only 63/621 (10.1%) underwent investigations for eosinophilia. The majority of patients with moderate to severe eosinophilia (372/621, 59.9%) had an infectious disease, and little examination (7.4%; 46/621) was taken to identify the cause of eosinophilia, and only 39/621 (6.3%) of patients had a discrete cause of eosinophilia identified. Patients with moderate to severe eosinophilia (24.3%; 151/621) exhibited certain chance to have organ dysfunction.

Conclusion

Incidental eosinophilia in inpatients was frequently neglected and less investigated. Multidisciplinary consultation may improve outcomes of inpatients with moderate to severe eosinophilia.

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.

Immunoglobulin G4-Related Disease, Lymphadenopathy, and Lymphoma

Lymphadenopathy occurring in patients with immunoglobulin G4 (IgG4)-related disease, termed IgG4-related lymphadenopathy, shows morphologic heterogeneity and overlap with other nonspecific causes of lymphadenopathy including infections, immune-related disorders, and neoplasms. This review describes the characteristic histopathologic features and diagnostic approach to IgG4-related disease and IgG4-related lymphadenopathy, with comparison to nonspecific causes of increased IgG4-positive plasma cells in lymph nodes, and with emphasis on distinction from IgG4-expressing lymphoproliferative disorders.

Diagnostic spectrum of hypereosinophilia based on bone marrow pathology: 10 years' experience at a tertiary care hospital

BACKGROUND

Hypereosinophilia (HE) is defined as peripheral blood (PB) eosinophil count exceeding 1.5 × 10⁹ /L. As the causes of HE can be diverse, the work-up of patients was complicated. In this study, we aimed to categorize the underlying diseases associated with HE and demonstrate minimum diagnostic approach.

METHODS

Cases presenting with HE within 7 days of bone marrow (BM) examination conducted between 2008 and 2019 were selected. Cases were classified by the revised 2022 WHO and ICC classification. We also assessed morphologic features of unclassified persisting HE (>4 weeks) patients according to the morphologic criteria suggested a previous study by Wang et al. RESULTS: A total of 364 patients were included. The work-up confirmed primary HE in 38.7%, secondary HE in 48.9%, HE patients with insufficient evaluation in 13.7%. When conducted a slide review of HE patients with sustained HE more than 4 weeks among HE patients with insufficient evaluation, the morphological features showed abnormal eosinophils in PB/BM (69.0%/81.0%), hypercellularity (26.2%), myelofibrosis (7.1%), increased M:E ratio (5.3%), and dysmegakaryopoiesis (4.8%). Of these patients, 14 patients who met all morphologic criteria were suspected of CEL.

CONCLUSIONS

This study demonstrates that HE is associated with variable conditions. BM morphological assessment based on a robust criterion can help to confirm a MN irrespective of the presence of clonal markers. The work-up of patients in whom ruled out the common secondary causes of HE requires a systematic but sufficient approach including at a minimum BM karyotyping, PDGFRA testing, lymphocyte immunophenotyping and TCR gene rearrangement.

Pancreaticobiliary versus head and neck presentation of immunoglobulin G4-related disease: different sides of the same coin?

BACKGROUND AND STUDY AIM

Immunoglobulin G4-related disease (IgG4-RD) is a rare immune mediated fibroinflammatory condition. Pancreaticobiliary (PB) and head and neck (HN) are two of the most commonly involved anatomical sites. It has been postulated that PB IgG4-RD and HN IgG4-RD have distinct clinical phenotypes. Whether the optimum treatment regimen or response to therapy differs between them is unknown. We aimed to assess differences between PB and HN IgG4-RD in a cohort of IgG4 disease managed by an IgG4-RD multispecialty team.

METHODS

We performed a retrospective study of a prospectively maintained multidisciplinary IgG4-RD database to identify patients diagnosed with PB and HN IgG4-RD (based on initial presentation) between 2005 and 2019. The electronic patient records were reviewed. Use of immunosuppressive agents and clinical course was analysed.

RESULTS

60 patients with PB IgG4-RD and 14 with HN IgG4-RD were included in the study. PB IgG4-RD was associated with older age at diagnosis 64 versus 51 years (p<0.001), higher serum IgG4 level as a multiple of upper limit of normal median (IQR) 2 (1-3.75) vs 1 (1-2), (p=0.04) and greater proportion with more than one organ involved 68% vs 33% (p=0.03). HN IgG4-RD was more likely to receive second-line therapy 71% versus 36% (p=0.03). Persistent elevation of serum IgG4 after therapy was more common in PB IgG4-RD 84% versus 43% (p=0.03).

CONCLUSION

These findings support the contention that PB IgG4-RD and HN IgG4-RD have different clinical profiles and represent distinct subtypes of IgG4-RD.

Eosinophilia attention, diagnosis, treatment, and awareness in physicians: a cross-sectional survey

Background

Patients with incidental eosinophilia is becoming increasingly common in clinical practice. But it remains challenging to diagnose and treat owing to its complex etiology. The awareness of physicians and the strategies of diagnosis and treatment toward eosinophilia are still unclear.

Objective

We aimed to evaluate attention, diagnosis, treatment, and awareness of eosinophilia among physicians, as well as factors influencing clinical practice, and to find ways to improve the efficacy of this disease.

Design

This is a cross-sectional survey.

Methods

A cross-sectional study was conducted from 1 to 4 June 2021 in a tertiary hospital. Self-administered and validated electronic questionnaire was used to investigate the attention toward eosinophilia, the strategies of diagnosis and treatment, and the awareness in physicians.

Results

A total of 607 valid questionnaires were collected, with a response rate of 84.5%. Among the responders, 65.4% of physicians claimed to be familiar with patients with eosinophilia but only 11.0% of them had read the relevant guidelines or expert consensus. Among 207 physicians who had ever diagnosed patients with eosinophilia, only 19.4% had performed detailed examinations. The accuracy of awareness questions was 1.6-53.5%, and only 26.5% of physicians had high levels of awareness. An increase in the awareness level of up to 2.82 folds was seen among physicians with factors such as job title, encountering patients with eosinophilia, linking patients' conditions to peripheral blood eosinophil count, and paying attention to guidelines.

Conclusion

This study highlighted the importance of raising awareness and knowledge of eosinophilia among physicians in China. More works on education about eosinophilia guideline are needed, which may help physicians make decision with more benefits to patients.

Development of IgG4-related pancreatitis and kidney disease 7 years after the onset of undiagnosed lymphadenopathy: A case report

This report describes a patient diagnosed with immunoglobulin G4 (IgG4)-related pancreatitis and kidney disease 7 years after the onset of undiagnosed lymphadenopathy. A 48-year-old Japanese woman presented with fatigue and leg oedema. Computed tomography showed perigastric lymphadenopathy, for which she underwent a laparoscopic biopsy of the perigastric lymph nodes. Although histopathological examination of the lymph nodes did not lead to a definitive diagnosis, serological tests revealed elevated serum IgG4 levels (558 mg/dl) and IgG4 immunostaining of the lymph nodes showed IgG4-positive plasma cell infiltration, leading to the suspicion of IgG4-related disease. Further workup revealed no organ lesion other than lymphadenopathy. At age 55 years, despite having no subjective symptoms, contrast-enhanced computed tomography showed low-density lesions in the tail of the pancreas and the left kidney. Histopathological examination showed lymphocyte infiltration, consisting of a mixture of plasma cells and eosinophils, in both organs and obliterative phlebitis in the pancreas. IgG4 immunostaining of the kidney specimens showed 160 IgG4-positive cells per high-powered field, with the IgG4+/IgG+ cell ratio being almost 100%, leading to a diagnosis of IgG4-related pancreatitis and kidney disease. Treatment with prednisolone for 2 months resulted in lesion improvement. Although the diagnosis of IgG4-related lymphadenopathy is often challenging in patients with lymphadenopathy alone, findings in the present patient emphasise the importance of long-term follow-up, as it may allow early detection of involvement of other organs by IgG4-related disease.

The Role of Endothelial Barrier Function in the Fibrosis of Salivary Gland

In the salivary glands, fibrosis occurs in many pathological conditions. Endothelial tight junction (TJ)-based barrier function plays a vital role in maintaining the homeostasis of the salivary glands. However, whether endothelial barrier function is changed and involved in the pathogenesis of glandular fibrosis is unknown. Here, by using a mouse model in which the main excretory duct of the submandibular gland (SMG) was ligated to induce inflammation and fibrosis, endothelial barrier function and TJ protein expression and distribution were examined. Both 4-kDa and 70-kDa fluorescence-labeled dextrans permeated more in the 1-, 3-, and 7-d ligated SMGs. Meanwhile, the mRNA level of claudin-5 was increased with an obvious redistribution from apicolateral membranes to lateral membranes and cytoplasm in the fibrotic glands. Notably, the TJ sealer AT1001 significantly attenuated the disrupted endothelial barrier function and thereby ameliorated the glandular fibrosis. Cytokine array detection showed that monocyte chemoattractant protein-1 (MCP-1) was highly enriched in the 3-d ligated SMGs, and MCP-1 directly impaired barrier function, increased claudin-5 expression, induced the relocalization of claudin-5, and activated p-ERK1/2 in cultured human endothelial cells. Furthermore, the upregulation and disorganization of claudin-5 as well as the elevation of MCP-1 and p-ERK1/2 signaling were also confirmed in fibrotic SMGs from patients with chronic sialadenitis and immunoglobulin G4-related sialadenitis. Altogether, our findings revealed that disrupted endothelial barrier function contributed to the progression of glandular fibrosis, and targeting endothelial TJs might be a promising approach to alleviate salivary gland fibrosis-related diseases.

IgG4-related disease presenting with profound bilateral orbital and adnexal inflammation

Purpose

IgG4-related disease is an immune-mediated fibroinflammatory condition that can affect almost every major organ system. Orbital and adnexal involvement in IgG4-related disease though not uncommon can be varied depending on the site of the lymphoplasmacytic infiltration. This case of profound bilateral orbital inflammation is presented to demonstrate the significant clinical manifestations of IgG4-related ophthalmic disease.

Observations

A 52-year-old man with a remote and seemingly unrelated history of lymphadenopathy presented to the Oculoplastics clinic with massive bilateral upper and lower lid swelling and induration. Hematologic testing demonstrated an elevation in serum IgG4 - a non-specific finding seen in various infectious, inflammatory, and malignant processes. Imaging demonstrated diffuse enlargement of orbital structures, including the lacrimal glands and extraocular muscles, as well as inflammatory changes of the adnexal and retrobulbar soft tissue. Orbital biopsy was required to confirm the diagnosis of IgG4-related ophthalmic disease.

Conclusions and Importance

IgG4-related ophthalmic disease presents with various non-specific clinical signs and symptoms. The most common presentations include dacryoadenitis, enlarged orbital nerves, and orbital fat involvement; however, the extent of involvement both locally and systemically varies greatly. Clinical findings and imaging are helpful in narrowing the differential diagnosis; however, biopsy for histopathologic examination is essential to confirm IgG4-related disease. Physicians must maintain a high level of suspicion for the disease for proper management.

Proteomic characteristics of saliva in patients with different subgroups of IgG4-RD

Background

Immunoglobulin G4-related disease (IgG4-RD) is a newly defined disease entity, with great heterogeneity among IgG4-RD subgroups with different organ involvement patterns. Identification of the proteomic characteristics of IgG4-RD subgroups will be critical for the understanding of the pathogenic mechanisms of IgG4-RD.

Method

In this study, we performed proteomic analysis using Tandem Mass Tags (TMT) technology with "high field" mass analyzer with improved resolution and sequencing speed to investigate the proteomic profile of saliva and plasma samples from ten untreated IgG4-RD patients and five healthy controls (HCs). Differentially expressed proteins (DEPs) were identified by "t test" function in R package. Functional enrichment analysis was used to investigate pathways enriched in IgG4-RD samples.

Results

Most salivary DEPs identified in IgG4-RD patients compared with HCs were mainly enriched in neutrophil mediated GO bioprocess. Within the comparisons between four IgG4-RD subgroups, more DEPs were identified in the comparison of Mikulicz group and Head and neck group. Among four subgroups of IgG4-RD, Head and neck group showed the most distinctive proteomic expression pattern when compared with HCs. Moreover, "Neutrophil mediated process" related GO bioprocess was commonly identified between comparisons of Mikulicz group and Head and neck group, Head and neck group and Retroperitoneal aorta group, Head and neck group and HCs, IgG4-RD patients with saliva gland involvement and those without saliva gland involvement. Key DEPs that involved in this GO bioprocess were identified. Besides, we performed proteomic analysis for plasma samples between ten IgG4-RD and five HCs and there were several DEPs identified overlapped in saliva and plasma.

Conclusion

We identified multiple processes/factors and several signaling pathways in saliva that may be involved in the IgG4-RD pathogenesis.

Utility of renal biopsy in differentiating idiopathic multicentric Castleman disease from IgG4-related disease

Idiopathic multicentric Castleman disease (iMCD) is a subtype of human herpesvirus type 8 (HHV-8)-related Castleman disease that causes multi-organ damage, including kidney damage due to polyclonal lymphoproliferation and interleukin (IL)-6-induced cytokine storm. However, its renal pathological findings are unclear. We report the case of a woman in her 80 s who was diagnosed with iMCD based on renal pathological findings. Five years ago, hypergammaglobulinemia was detected, and her renal function declined. Renal biopsy revealed plasma cells infiltrating the stroma. Immunostaining revealed numerous IgG4-positive plasma cells. The serum IgG4 level was high, and she was initially diagnosed with IgG4-related disease (IgG4-RD) and treated with steroids. However, the therapeutic effect was poor. On re-examination, computed tomography revealed lymphadenopathy around the aorta and spleen. Renal histopathology showed numerous IL-6-positive plasma cells. Anemia and C-reactive protein (CRP) positivity persisted despite steroid administration. HHV-8 was negative, and polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes syndrome was not suspected. Thus, iMCD was diagnosed. Based on previous reports, there is no significant difference in IgG4 levels between iMCD and IgG4-RD, and IgG4-positive plasma cell infiltrates were observed in iMCD-affected organs. Therefore, it may be difficult to distinguish iMCD from IgG4-RD. In this case, high-serum IL-6 and CRP were observed, which are usually not seen in IgG4-RD but are common findings in iMCD, leading to the diagnosis. Patients with deep lymphadenopathy may be diagnosed with iMCD based on renal pathological findings. Renal biopsy is recommended for patients with suspected iMCD and decreased renal function.

Immunoglobulin G4-related disease with Marked Eosinophilia: A Case Report and Literature Review

We encountered a 78-year-old Japanese man with IgG4-related sialoadenitis complicated with marked eosinophilia. We diagnosed him with IgG4-RD (related disease) with a submandibular gland tumor, serum IgG4 elevation, IgG4-positive plasma cell infiltration, and storiform fibrosis. During follow-up after total incision of the submandibular gland, the peripheral eosinophil count was markedly elevated to 29,480/μL. The differential diagnosis of severe eosinophilia without IgG4-RD was excluded. The patient exhibited a prompt response to corticosteroid therapy. His peripheral blood eosinophil count was the highest ever reported among similar cases. We also review previous cases of IgG4-RD with severe eosinophilia.