Clinical characteristics of a concurrent condition of IgG4-RD and Castleman's disease

Clinical and Radiologic Differences in Lung Involvement Between IgG4-Related Disease and Plasma Cell-Type Idiopathic Multicentric Castleman Disease

PURPOSES

Immunoglobulin G4-related disease (IgG4-RD) and plasma cell-type idiopathic multicentric Castleman disease (PC-iMCD) have many overlapping features. Their differential diagnosis is challenging and crucial for clinical management due to their different prognoses and treatments. However, reports that compare these conditions are scarce, especially for patients with lung involvement. In this study, we attempted to clarify the clinical and radiologic differences in lung involvement between IgG4-RD and PC-iMCD.

METHODS

Patients with IgG4-RD or PC-iMCD who exhibited lung involvement were enrolled. Clinical and chest CT findings at baseline were compared.

RESULTS

A total of 178 patients with IgG4-RD and 61 patients with PC-iMCD exhibited lung involvement. The IgG4-RD group consisted of older patients (P < 0.001) and had a higher male‒female ratio (P = 0.004). Patients with PC-iMCD were more inclined to present constitutional and respiratory symptoms, anemia, thrombocytosis and hypoalbuminemia (all P < 0.001). Although IgG4 levels were commonly elevated in both diseases, they were significantly greater in the IgG4-RD (median: 16,100 mg/L) than in the PC-iMCD (median: 3130 mg/L) (P < 0.001). Patients with IgG4-RD showed significantly lower levels of IgG, IgA, IgM (median: 21.59 g/L, 1.70 g/L, and 0.68 g/L, respectively) than in the PC-iMCD (median: 34.42 g/L, 4.85 g/L, and 2.11 g/L, respectively) (all P < 0.001). The levels of CRP, ESR and IL-6 were significantly greater in the PC-iMCD (median: 72.15 mg/L, 103 mm/h, and 18.30 pg/mL, respectively) than that in the IgG4-RD (median: 1.54 mg/L, 22 mm/h, and 2.85 pg/mL, respectively) (all P < 0.001). Although both nodular lesions and thickened bronchovascular bundles were common in these two diseases, PC-iMCD patients presented more extensive nodular lesions (P < 0.001), and IgG4-RD patients presented more diffuse thickened bronchovascular bundles (P < 0.001). Cysts were almost exclusively observed in PC-iMCD patients.

CONCLUSIONS

Compared with IgG4-RD, PC-iMCD is a more aggressive condition, associated with more common symptoms and more severe inflammation. Radiologically, extensive nodular lesions or cysts suggest a diagnosis of PC-iMCD, whereas diffuse thickened bronchovascular bundles indicate a diagnosis of IgG4-RD.

Malignant transformation of biliary adenofibroma combined with benign lymphadenopathy mimicking advanced liver carcinoma: A case report

BACKGROUND

Biliary adenofibromas (BAFs) are rare primary hepatic neoplasms, some of which can potentially undergo malignant transformation. Here, we describe a rare case of malignant transformation of BAF.

CASE SUMMARY

A 51-year-old female was referred to our hospital with epigastric pain. Computed tomography showed a solitary liver mass combined with the enlargement of multiple mediastinal and cervical lymph nodes, clinically mimicking a liver carcinoma with extensive lymph node metastasis. However, core needle biopsy suggested BAF with malignant transformation. Finally, the patient underwent curative resection of the neoplasm and was recurrence-free for 12 mo.

CONCLUSION

Our case serves as an example of a rare manifestation of BAF. Our report and the previously published experience, reinforce that curative resection should be considered the primary treatment for BAFs with malignant transformation, leading to a favorable prognosis.

Immunohistochemical analysis of pyroptosis-related protein expression in IgG4-related sialadenitis

Background

NLRP3 (NOD‐, LRR‐ and pyrin domain‐containing protein 3)‐induced pyroptosis is involved in the development of a variety of autoimmune diseases, but its role in IgG4‐related sialadenitis (IgG4‐RS) is unclear.

Methods

Salivary gland tissues from 19 patients with IgG4‐RS were designated the experimental group, and peritumoral tissues from 20 patients with benign salivary gland tumours were designated the control group. The cell morphology and fibrosis in the IgG4‐RS samples were observed by haematoxylin‐eosin (H&E) and Masson trichrome (MT) staining. Immunohistochemical (IHC) staining was used to determine pyroptosis‐related proteins (NLRP3, ASC (apoptosis‐associated speck‐like protein containing a CARD), Caspase‐1, GSDMD (gasdermin family members, including digestive dermatin D), interleukin 1β (IL‐1β), and interleukin 18 (IL‐18)) expression levels.

Results

Increased lymphoid follicle proliferation, germinal centre plasma cell infiltration, and irregular fibrosis were observed in the experimental group compared with the control group. The NLRP3, ASC, Caspase‐1, GSDMD, IL‐1β, and IL‐18 levels were significantly higher in the experimental group than in the control group (p < 0.0001).

Conclusion

This study suggested that pyroptosis‐related proteins might be involved in IgG4‐RS pathogenesis. However, the specific cellular pathway involved and whether multiple cell death pathways contribute to the occurrence of IgG4‐RS still need to be further studied.

Update on classification, diagnosis, and management of immunoglobulin G4-related disease

Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized chronic fibro-inflammatory autoimmune disease, and its recognition has been constantly increasing worldwide over the last few years. A correct and timely recognition, as well as appropriate intervention, is crucial for the treatment of IgG4-RD. For certain subtypes of IgG4-RD, organ-specific criteria are formulated to make the diagnosis more accurate. New biomarkers have emerged in the recent years to aid the disease diagnosis, its prognosis prediction, as well as therapy response monitoring. Although recurrence is very common in IgG4-RD, glucocorticoid is still the first-line treatment for the majority of patients. The factors that affect the likelihood of disease relapse are multifaceted. The selection strategy of various steroid-sparing agents is still being explored. Besides, when patients have special sites involvement leading to severe clinical conditions, surgical operation or interventional therapy should also be considered. An update on classification, diagnosis, and management of IgG4-RD is provided in the current study to fully elucidate the recommended clinical practice of this mysterious disease.

IgG4-related disease. Clinical manifestation differential diagnosis and recent International Diagnostic Criteria for IgG4-related disease

Immunoglobulin G4- related disease (IgG4-RD) is a rare systemic fibro-inflammatory disorder. Autoimmune pancreatitis is the most frequent manifestation of IgG4-RD. However, IgG4-RD can affect any organ such as salivary glands, orbits, retroperitoneum, prostate and many others. Recent research enabled a clear clinical and histopathological description of IgG4-RD and in 2019 four Clinical phenotypes of IgG4-related disease were described. Diagnosis is based on morphological examination with typical findings of lymphoplasmocellular inflammation, storiform fibrosis and obliterative phlebitis in IgG4-RD biopsies and the tissue invading plasma cells largely produce IgG4. Elevated serum IgG4 levels are found in many but not all patients. New diagnostic criteria for IgG4-RD have been published recently in 2019 and 2021. This review summarizes current knowledge on pathophysiology, clinical manifestations, diagnosis and differential diagnosis of IgG4-RD from the point of view 2022 and in next article brings overview of the IgG4-RD therapy.

Immunoglobulin G4-related lymph node disease with an orbital mass mimicking Castleman disease: A case report

BACKGROUND

Immunoglobulin (Ig) G4-associated diseases are a group of systemic diseases involving multiple organs and are also known as IgG4-associated sclerosing diseases. IgG4-associated lymphadenopathy occurring in the lymph nodes is characterized by a lack of specificity due to its clinicopathological characteristics and must be differentiated from a variety of lesions, such as Castleman disease, lymphatic follicular reactive hyperplasia, and lymphoma.

CASE SUMMARY

A 65-year-old male patient, with Guillain-Barre syndrome for 5 years, presented to our hospital complaining of bilateral orbital mass for 2 years. After hospitalization, the results of the patient’s laboratory tests showed that immunoglobulin subgroup IgG4 was 33.90 g/L and IgG was 30.30 g/L, but serum interleukin-6 was normal. The pathological morphology of orbital mass and cervical lymph node were consistent, which showed that a large number of plasma cells and eosinophils were observed in the lymphatic follicles, and the interstitial fibrous tissue was proliferative. Immunohistochemistry showed that CD20 (B cells) (+), CD3 (T cells) (+), CD38 (+), IgG (+), IgG4 positive cells > 100/high powered field, and IgG4/IgG > 40%. Combined with clinical and immunohistochemical results, lymphadenopathy was consistent with Castleman disease-like IgG4-associated sclerosing disease. Prednisone acetate treatment was given at 40 mg/d. After 2 wk, the superficial lymph nodes and orbital masses shrank, and the IgG4 level decreased. As prednisone acetate was regularly used at a reduced dosage, no recurrence of the disease has been observed.

CONCLUSION

This case suggested that it is necessary to proceed cautiously in clinical practice with such patients, and immunoglobulin, complement, interleukin-6, C-reactive protein, and other examinations should be performed to confirm the diagnosis.

IgG4-related disease and idiopathic multicentric Castleman's disease: confusable immune-mediated disorders

IgG4-related disease (IgG4-RD) and idiopathic multicentric Castleman's disease (iMCD) are both rare systemic immune-mediated disorders. However, pathogenesis differs markedly between the two diseases, and differing therapeutic strategies are adopted: IgG4-RD is treated using a moderate dose of glucocorticoids or rituximab, while iMCD therapy involves an interleukin (IL)-6 targeted approach. Nonetheless, some clinical features of IgG4-RD and iMCD overlap, so differential diagnosis is sometimes difficult, even though the classification and diagnostic criteria of the diseases require careful exclusion of the other. The key findings in IgG4-RD are high IgG4/IgG ratio, allergic features, and germinal centre expansion involving T follicular helper cells, while iMCD involves polyclonal antibody production (high IgA and IgM levels), sheet-like mature plasma cell proliferation, and inflammatory features driven by IL-6. The distribution of organ involvement also provides important clues in both diseases. Particular attention should be given to differential diagnosis using combined clinical and/or pathological findings, because single features cannot distinguish IgG4-RD from iMCD. In the present review, we discuss the similarities and differences between IgG4-RD and iMCD, as well as how to distinguish the two diseases.

Steroid Therapy and Steroid Response in Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP), a unique subtype of pancreatitis, is often accompanied by systemic inflammatory disorders. AIP is classified into two distinct subtypes on the basis of the histological subtype: immunoglobulin G4 (IgG4)-related lymphoplasmacytic sclerosing pancreatitis (type 1) and idiopathic duct-centric pancreatitis (type 2). Type 1 AIP is often accompanied by systemic lesions, biliary strictures, hepatic inflammatory pseudotumors, interstitial pneumonia and nephritis, dacryoadenitis, and sialadenitis. Type 2 AIP is associated with inflammatory bowel diseases in approximately 30% of cases. Standard therapy for AIP is oral corticosteroid administration. Steroid treatment is generally indicated for symptomatic cases and is exceptionally applied for cases with diagnostic difficulty (diagnostic steroid trial) after a negative workup for malignancy. More than 90% of patients respond to steroid treatment within 1 month, and most within 2 weeks. The steroid response can be confirmed on clinical images (computed tomography, ultrasonography, endoscopic ultrasonography, magnetic resonance imaging, and 18F-fluorodeoxyglucose-positron emission tomography). Hence, the steroid response is included as an optional diagnostic item of AIP. Steroid treatment results in normalization of serological markers, including IgG4. Short- and long-term corticosteroid treatment may induce adverse events, including chronic glycometabolism, obesity, an immunocompromised status against infection, cataracts, glaucoma, osteoporosis, and myopathy. AIP is common in old age and is often associated with diabetes mellitus (33-78%). Thus, there is an argument for corticosteroid therapy in diabetes patients with no symptoms. With low-dose steroid treatment or treatment withdrawal, there is a high incidence of AIP recurrence (24-52%). Therefore, there is a need for long-term steroid maintenance therapy and/or steroid-sparing agents (immunomodulators and rituximab). Corticosteroids play a critical role in the diagnosis and treatment of AIP.