Elevated Serum Immunoglobulin G4 Research Articles

CORONARY ARTERY ANEURYSM IN IGG4–RELATED DISEASE

Abstract Introduction Coronary artery ectasia is a rare disease defined as a local or diffuse dilatation of the coronary artery more than 1.5 times the diameter of the adiacent normal segment. The etiology is diverse and can be rarely associated with immunoglobulin G4 (IgG4)–related disease. The high levels of serum IgG4 may promote the development of low–density plaques, intimal thickening due to pericoronitis and subsequent coronary ectasia. Case Report We present the case of a 72–year–old male patient with arterial hypertension, dyslipidemia, chronic renal insufficiency, and a family history of cardiovascular diseases. In the previous year, he suffered a cerebral hemorrhage attributed to an unspecified cerebral vascular malformation, which was managed with an endovascular approach. The patient was admitted for Non–ST–segment Elevation Myocardial Infarction (NSTEMI). Coronary angiography revealed widespread ectasia of the coronary vessels, a chronically occluded marginal branch, and an aneurysmatic proximal right coronary artery with the presence of a thrombus on the aneurysmal segment, dissolved following administration of intracoronaric heparin. Furthermore a critical stenosis at the crux involving the posterior interventricular branch was detected and angioplasty with drug–eluting stent implantation was performed on the affected vessel. Given the coronary artery ectasia, aortic ectasia revealed by echocardiography, renal insufficiency and persistently elevated amylase and lipase levels, further diagnostic investigation was conducted suspecting IgG4–related disease. Hematological tests revealed elevated IgG and IgG4 subclass levels (882 mg/dL and 1438 mg/L, respectively), C3 117 mg/dL, C4 30 mg/dL, and total IgE 130 KU/L. The diagnosis of IgG4–related disease was confirmed and the patient was advised to continue cardiological and rheumatological follow–up. Conclusion When the coronary arteries are involved in the IgG4–related disease, risk of acute events such as heart attack may increase and the prognosis is poor. Coronary thickening and ectasia, typical imaging features, other aortic involvement and inflammation indicators, like elevated serum IgG4, should be considered as red flags for an early investigation and subsequent early intervention.

18F-FDG PET/CT in Pediatric Immunoglobulin G4-Related Disease.

A 14-year-old boy presented with severe, nonintentional weight loss, fatigue, and cough. Investigations were notable for raised inflammatory markers and significantly elevated serum immunoglobulin G4 (IgG4). 18F-FDG PET/CT was obtained for assessment of disease involvement and extent, to exclude differential diagnoses and to guide biopsy. The study demonstrated extensive FDG-avid nodal disease and multisystem organ involvement. Excisional biopsy of a right inguinal lymph node demonstrated reactive changes with numerous IgG4-positive plasma cells consistent with IgG4-related disease. He was commenced on immunosuppressive therapy with consequent weight restoration and symptom resolution.

Autoimmune pancreatitis: Cornerstones and future perspectives.

Autoimmune pancreatitis (AIP) is an autoimmune subtype of chronic pancreatitis resulting from the aberrant immune response against the pancreas, leading to inflammation and fibrosis. Although AIP is rare, its incidence is increasing and is often misdiagnosed as other pancreatic diseases. AIP is commonly classified into two types. Type 1 AIP (AIP-1) is typically associated with elevated serum immunoglobulin G4 (IgG4) levels and systemic manifestations, while type 2 AIP is typically a more localized form of the disease, and may coexist with other autoimmune disorders, especially inflammatory bowel diseases. Additionally, there is emerging recognition of a third type (type 3 AIP), which refers to immunotherapy-triggered AIP, although this classification is still gaining acceptance in medical literature. The clinical manifestations of AIP mainly include painless jaundice and weight loss. Elevated serum IgG4 levels are particularly characteristic of AIP-1. Diagnosis relies on a combination of clinical, laboratory, radiological, and histological findings, given the similarity of AIP symptoms to other pancreatic disorders. The mainstay of treatment for AIP is steroid therapy, which is effective in most cases. Severe cases might require additional imm-unosuppressive agents. This review aims to summarize the current knowledge of AIP, encompassing its epidemiology, etiology, clinical presentation, diagnosis, and treatment options. We also address the challenges and controversies in diagnosing and treating AIP, such as distinguishing it from pancreatic cancer and managing long-term treatment, highlighting the need for increased awareness and knowledge of this complex disease.

Spontaneous regression of immunoglobulin G4-related dacryoadenitis and multiple organ involvement: A case report

Immunoglobulin G4 (IgG4)-related dacryoadenitis is rarely resolved spontaneously without steroids. Here, we report a case of IgG4-related dacryoadenitis and extra-ophthalmic lesions with spontaneous regression. This is a clinical case report. A 56-years-old man had a 1-year and 7-month-old histories of neck and eyelid swelling, respectively. On the first examination, the lacrimal and submandibular glands were palpable bilaterally. Computed tomographic images showed enlargement of the lacrimal gland on both sides, right pulmonary hilar lymph node, and pancreas, and thickening of the abdominal aortic wall. Blood tests demonstrated elevated serum IgG4 level and positive hepatitis B surface antibody. Pathological examination of the biopsied lacrimal gland specimens revealed marked IgG4-positive plasma cell infiltration. The patient was monitored carefully without steroid administration. Serum IgG4 level had gradually decreased during follow-up period and reached the normal range 3 years after the biopsy. At 4-year follow-up, the lacrimal and submandibular glands were not palpable on either side. Computed tomographic images demonstrated no enlargement of the lacrimal gland, submandibular gland, or lymph nodes, and improvement of the enlarged pancreas and thickened abdominal aortic wall. Our case indicates that careful observation can be an option in selected cases with risks of steroid treatment or silent clinical course.

The Significance of Serum IgG4/IgG and IgG4/IgG1 Ratio in the Diagnosis Value of IgG4-Related Diseases.

Elevated serum immunoglobulin G4 (IgG4) is one of the important features of patients with IgG4-related diseases (IgG4-RD). But diagnosing these diseases using IgG4 alone is tricky because the tests can sometimes give inaccurate results. Our research is focused on studying the ratio of IgG4 to two other substances, immunoglobulin G (IgG) and immunoglobulin G1 (IgG1), in the blood. We hope this approach will lead to more accurate diagnoses of IgG4-RD. We conducted a study on 68 patients diagnosed with IgG4-related diseases (IgG4-RD) and 160 individuals suffering from other autoimmune diseases (AID) at our hospital between June 2018 and June 2022. Eighty healthy people who underwent physical examination in our hospital at the same time were randomly selected as controls, and medical records were collected for all subjects. The serum IgG and IgG subclasses were detected, and the IgG4/IgG and IgG4/IgG1 ratios were calculated. We found that patients with IgG4-RD have significantly higher average levels of serum IgG4 and more elevated IgG4/IgG and IgG4/IgG1 ratios compared to individuals with other AID patients and those in good health (p < 0.001). The receiver operating characteristic (ROC) curve analysis showed that the diagnostic effectiveness area under the curve (AUC) of the serum IgG4/IgG ratio for IgG4-RD was 0.906 (95% confidence interval [CI], 0.865-0.947) and 0.921 (95% CI, 0.876-0.965) when comparing with other AID patients and healthy individuals, respectively. The optimal cut-off value for the IgG4/IgG ratio was 0.147 (with 72.1% sensitivity and 94.4% specificity) compared with AID patients and 0.129 (with 77.9% sensitivity and 96.2% specificity) compared with healthy individuals. Similarly, the AUC of the serum IgG4/IgG1 ratio for diagnosing IgG4-RD was 0.919 (95% CI, 0.882-0.956) and 0.916 (95% CI, 0.870-0.962) when compared with patients with other AID and healthy individuals, respectively. When we divided our study participants into a high IgG4/IgG ratio group (>0.129) and a normal IgG4/IgG ratio group (≤0.129) using a cut-off point of 0.129, we found through logistic regression analysis that those with a high IgG4/IgG ratio were more likely to be associated with IgG4-RD (odds ratio [OR], 31.25; 95% CI, 15.31-63.79; p < 0.001). Likewise, a high IgG4/IgG1 ratio was also significantly linked to an increased risk of IgG4-RD (OR, 36.39; 95% CI, 17.57-75.38; p < 0.001). The serum's IgG4/IgG and IgG4/IgG1 ratios are independently linked to IgG4-RD and are valuable in its diagnosis.

Detecting immunoglobulin G4-related intracranial arteriopathy with magnetic resonance vessel wall imaging: a preliminary experience in two cases

BackgroundDetecting immunoglobulin G4 (IgG4)-related intracranial arteriopathy, a rare neurovascular complication of IgG4-related disease, is challenging. While magnetic resonance (MR) vessel wall imaging (VWI) can visualize various neurovascular pathologies, its application to this arteriopathy has not been reported as of this writing.Case presentationA 74-year-old male and a 65-year-old female manifested multiple cranial nerve palsy and neck pain, respectively. Both cases exhibited multiorgan masses with markedly elevated serum IgG4 levels and were clinically diagnosed with IgG4-related disease. Three-dimensional T1-weighted black blood VWI with and without contrast agent identified intracranial vascular lesions characterized as nearly-circumferential mural thickening with homogeneous contrast enhancement in the internal carotid and vertebral arteries; some of the lesions had been unrecognized with screening MR angiography due to expansive remodeling. The former patient underwent corticosteroid therapy, and VWI after treatment revealed decreased mural thickening and enhancement.ConclusionFurther studies to elucidate characteristic findings of VWI might contribute to early detection of this treatable pathology.

It Melts Like Snow: Steroid Responsiveness of Immunoglobulin G4-Related Disease

Dear Editor, A 35-year-old male presented with insidious onset gradually progressive bilateral painless submandibular swelling, followed by periorbital swelling [Figure 1] for the past 7 years. He had no constitutional or sicca symptoms. He had no history of addiction or autoimmunity in the family. Systemic examination was unremarkable. On evaluation, he had raised inflammatory markers with a negative autoimmune panel. Magnetic resonance imaging orbit showed bilateral orbital extraconal soft-tissue masses with contrast enhancement. Incisional biopsy from the extraconal mass was suggestive of fibrocollagenous stroma with aggregation of lymphocytes, plasma cells, and histiocytes without any necrosis or granuloma. On further evaluation, submandibular gland biopsy showed chronic sialadenitis with immunoglobulin G4 (IgG4)-positive plasma cell >10/hpf and IgG4: IgG ratio >40% [Figure 2] without any major organ involvement on imaging. The diagnosis of IgG4-related disease was kept. He was started on oral steroid 0.5 mg/kg/day and observed a rapid clinical response within 15 days of steroid therapy. Later, he was started on azathioprine and continued with tapering dose of steroid. He was followed up every month for first 3 months and then every 3 monthly upto 16 months without any signs of recurrence. For a long-standing indolent disease of 7 years, drastic steroid response with resolution of clinical symptoms was quite evident in our case.Figure 1: (a) Pretreatment bilateral upper eyelid swelling, (b) pretreatment bilateral submandibular swelling, (c and d) during glucocorticoid therapy (day 15) resolution of orbital and submandibular swelling, respectivelyFigure 2: Salivary gland with seromucinous acini and ducts embedded in mildly fibrotic stroma with numerous lymphoid follicles with germinal centers (a and b: H and E). Clusters of plasma cells are highlighted with CD138 immunohistochemical stain (c). IgG4 positive cells, >10/hpf (d)IgG4-related disease (IgG4-RD) is a chronic, systemic, fibroinflammatory condition with variable organ manifestation. CD4+ T-cells and B-cells are central to the pathogenesis causing organ damage and fibrosis. Marked expansion of IgG4-secreting plasmablast in the blood is usually seen in active and untreated cases.[1] Key to diagnosis is the classical histopathological hallmarks of lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis. IgG4 RD usually has a good response to steroids but a variable relapse rate. Factors associated with lesser treatment response and relapse were well analyzed in a Japanese multicenter study. Multivariate analysis from the study revealed that intermediate steroid initial dose (0.4–0.69 mg/day), slow tapering regimen (<0.4 mg/day), and shorter disease duration were associated with a significantly lower rate of disease relapse.[2] The study of isolated IgG4 ophthalmic disease also echoed similar results regarding steroid response and relapse, with more relapse in those with elevated serum IgG4 levels and a shorter duration of initial steroid treatment (<5 months). Low-dose steroid maintenance should be considered to avoid recurrence in patients with elevated serum IgG4 levels.[3] Later on, rituximab therapy showed promising results in inducing remission[4] and steroid-free long-term maintenance.[5] Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

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.

Pulmonary Adenosquamous Cell Carcinoma With Systemic Lymphadenopathy due to Immunoglobulin G4-Related Disease: A Case Report

A 75-year-old man with diabetes mellitus showed elevated C-reactive protein (CRP) level at his regular visit. Computed tomography scan showed a lung tumor in his left lower lobe and systemic lymphadenopathy including abdominal lymph nodes. The patient was diagnosed as primary pulmonary squamous cell carcinoma with systemic lymph node metastasis. Thereafter, unexpected steroid pulse therapy for accidental acute exacerbation of interstitial pneumonia rapidly shrank lymphadenopathy. At this time, we also found elevated serum immunoglobulin G4 (IgG4) level (385 mg/dL). Considering these findings, we doubted the lymph nodes metastases at the initial staging, and then corrected cancer-staging (C-staging) from inferior vena cava (IVC) to inferior abdomen (IA). In addition, during the steroid tapering, sudden onset and uncontrollable left pneumothorax required surgical approach. Curative-intent left lower lobectomy with lymphadenectomy was performed for the lung cancer. Pathological findings revealed coexistence of adenosquamous carcinoma and infiltration of IgG4-positive plasma cells in the resected mediastinal lymph node. We detected 384 IgG4-positive cells per high power field. IgG4/IgG-positive cell ratio was 54%. Based on these findings, the diagnosis of IgG4-related disease with primary adenosquamous carcinoma (p-stage IIIA) was confirmed. The patient died 24 days after surgery because of another acute exacerbation of interstitial pneumonia. Our case alerts oncologists to IgG4-related disease as a possible underlying comorbidity which may confuse pretreatment clinical stage. J Med Cases. 2021;12(4):164-171 doi: https://doi.org/10.14740/jmc3649

Visual impairment in immunoglobulin G4-related disease: A case report.

The present study reports on the case of a 50-year-old male with sinusitis, diplopia, secretory otitis media and skin eczema for >14 years. The patient presented with visual impairment in both eyes and subxiphoid pain on admission to the First Affiliated Hospital of China Medical University (Shenyang, China). Orbital CT revealed a slightly thickened left inferior rectus muscle. Due to a periocular mass, enlarged lymph nodes, elevated serum immunoglobulin G4 (IgG4) levels and enriched IgG4-positive plasma cells in the lymph nodes, the diagnosis of IgG4-related disease (IgG4-RD), possibly involving at least 10 organs, was established. Following treatment with methylprednisolone, the serum IgG4 levels decreased to normal and binocular vision returned to normal. Unlike previously reported cases, the present case exhibited no swollen masses around the optic nerve. The purpose of the present case report was to improve the understanding of IgG4-RD.

Immunoglobulin G-4-Related Retroperitoneal Fibrosis.

Retroperitoneal fibrosis is caused by the replacement of normal retroperitoneal tissue with fibrosis. The majority of the cases are idiopathic, but some secondary causes include malignancy, infection, drugs, and radiotherapy. Immunoglobulin G-4 (IgG-4) related disease is a relatively newer disease and one of the rarer causes of retroperitoneal fibrosis. It usually involves the pancreas, lungs, kidneys, aorta lacrimal and salivary glands, or extrapancreatic bile duct. Elevated serum IgG-4 is the biomarker of the disease and its levels correlate with disease activity. High-dose glucocorticoid is the treatment of choice.

Abstract 13337: Increased Serum Immunoglobulin G4 Level is a Novel Predictor of Cardiovascular Events Independent of Established Risk Factors: Results From the Real-cad Study

Background: Inflammation is a mediator of atherosclerosis progression. However, it remains unclear whether immunoglobulin G4 (IgG4)-related immuno-inflammation may play a specific role in cardiovascular disease. Methods: We used a case-cohort design to analyze the association of serum IgG4 levels with future cardiovascular events. The sample included 561 cases of the primary end point, defined as cardiovascular death, myocardial infarction, ischemic stroke, or unstable angina, and a random subcohort of 1688 (1409 males; mean age, 68.1 ± 8.4 years), of whom 73 were also cases, selected from 12413 eligible participants with stable coronary artery disease in the Randomized Evaluation of Aggressive or Moderate Lipid Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) study. Results: This case-cohort study had a median follow-up of 3.9 years (interquartile range [IR] 2.9-4.6). Serum IgG4 levels at baseline were 45.3 mg/dL (IR 37.9-58.9), and 845 (50%) took high-dose statins in the subcohort sample. In Cox regression using age, gender, statin dose, high-sensitivity C-reactive protein (hsCRP), body mass index, estimated glomerular filtration rate (eGFR), hypertension, diabetes, and serum lipid profiles, including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides, as covariates, the highest IgG4 quartile was predictive of the primary end point at 4 years (hazard ratio [HR] 1.44, 95% confidence interval [CI] 1.03-2.00, P=0.031), compared with the lowest quartile. Similar results were observed for the secondary end point, a composite of the primary end point plus coronary revascularization (HR 1.60, 95% CI 1.16-2.20, P=0.004). Conclusions: Elevated serum IgG4 level at baseline predicted long-term cardiovascular outcomes independent of established risk factors and high-dose statin therapy in patients with stable CAD. Serum IgG4 may reflect residual cardiovascular risk.

IGG4-related diseases in endocrinology

Immunoglobulin-G4-related disease (IgG4-RD) is a chronic immunomediated pathology of different organs of local or systemic nature, which has been established as a separate clinical entity in the early 2000s and is characterized by storiform fibroid inflammation of the affected tissues, their increase, and elevated serum immunoglobulin-G4 (IgG4) levels. The most common manifestations of the disease are major salivary and lacrimal gland enlargement, lymphadenopathy and type 1 autoimmune pancreatitis (AIP1), however, other organs may be also involved (the thyroid, eyes, meninges, heart, lungs, kidneys, aorta, upper airways, mesentery, etc.). The effectiveness of treatment of IgG4-RD, as well as other pathological conditions, is also determined by the timely diagnosis. However, the latter is complicated due to the variety of clinical manifestations and rather variable diagnostic criteria. It is necessary to constantly update the evidence-based knowledge and diagnostic algorithms within this pathology in order to overcome the difficulties, and involve immunologists, endocrinologists, pathologists and specialists in other spheres. This review provides information about the etiology, pathogenesis, and current methods of diagnosis and treatment of IgG4-related diseases, as well as examples of some manifestations of IgG4-RD that an endocrinologist may face in practice.

Evaluate the Differences in CT Features and Serum IgG4 Levels between Lymphoma and Immunoglobulin G4-Related Disease of the Orbit.

Background: Benign immunoglobulin G4 (IgG4)-related orbital disease (IgG4-ROD)—characterized as tumors mimicking malignant orbital lymphoma (OL)—responds well to steroids, instead of chemotherapy, radiotherapy and/or surgery of OL. The objective of this study was to report the differences in computed tomography (CT) features and- serum IgG4 levels of IgG4-ROD and OL. Methods: This study retrieved records for patients with OL and IgG4-ROD from a pathology database during an eight-year-and-five-month period. We assessed the differences between 16 OL patients with 27 lesions and nine IgG4-ROD patients with 20 lesions according to prebiopsy CT features of lesions and prebiopsy serum IgG4 levels and immunoglobulin G (IgG) levels This study also established the receiver-operating curves (ROC) of precontrast and postcontrast CT Hounsfield unit scales (CTHU), serum IgG4 levels, serum IgG levels and their ratios. Results: Significantly related to IgG4-ROD (all p < 0.05) were the presence of lesions with regular borders, presence of multiple lesions—involving both lacrimal glands on CT scans—higher median values of postcontrast CTHU, postcontrast CTHU/precontrast CTHU ratios, serum IgG4 levels and serum IgG4/IgG level ratios. Compared to postcontrast CTHU, serum IgG4 levels had a larger area under the ROC curve (0.847 [95% confidence interval (CI): 0.674–1.000, p = 0.005] vs. 0.766 [95% CI: 0.615–0.917, p = 0.002]), higher sensitivity (0.889 [95% CI: 0.518–0.997] vs. 0.75 [95% CI: 0.509–0.913]), higher specificity (0.813 [95% CI: 0.544–0.960] vs. 0.778 [95% CI: 0.578–0.914]) and a higher cutoff value (≥132.5 mg/dL [milligrams per deciliter] vs. ≥89.5). Conclusions: IgG4-ROD showed distinct CT features and elevated serum IgG4 (≥132.5 mg/dL), which could help distinguish IgG4-ROD from OL.

Clinical Significance of Elevated Serum Immunoglobulin G4 Levels in Patients With Rheumatoid Arthritis

Clinical Significance of Elevated Serum Immunoglobulin G4 Levels in Patients With Rheumatoid Arthritis

IDIOPATHIC RETROPERITONEAL FIBROSIS: A RARE CAUSE OF ABDOMINAL PAIN AND OBSTRUCTIVE UROPATHY

SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Retroperitoneal fibrosis (RPF) is a rare disorder that presents with subtle symptoms. It may be idiopathic or secondary to other causes; with the idiopathic form being either immunoglobulin G4 (IgG4) or non-IgG4 related. The incidence of idiopathic RPF has been reported to be 0.1 per 100,000 person-years with a male-to-female ratio of 1.9:1. Our case aims at highlighting this rare disorder as a cause of abdominal pain in a middle-aged man. CASE PRESENTATION: A 48-year-old man presented with persistent lower abdominal pain, decreased appetite and weight loss for three months. Physical exam was remarkable for mild abdominal tenderness. Laboratory results were remarkable for creatinine 1.6 mg/dL, BUN 56 mg/dL, CRP 35.7 mg/L and ESR 95 mm/hr. CBC, infectious workup, autoimmune panel, serum protein electrophoresis and tumor markers were unremarkable. Serum IgG and immunoglobulin G4 (IgG4) were normal. CT abdomen and pelvis revealed a soft tissue mass surrounding the distal abdominal aorta and inferior mesenteric artery; entrapping the left ureter accounting for left-sided hydroureteronephrosis. The patient underwent left uterolysis and DJ stent placement. Histopathology (H/P) of the mass showed an abundance of fibro-adipose tissue and lympho-plasmacytic infiltration with rare IgG4 positive plasma cells; negative for infection or malignancy. The patient was started on high dose prednisone leading to resolution of clinical symptoms. Serum creatinine level, ESR and CRP also returned to normal. A follow up CT scan showed regression of the mass. DISCUSSION: RPF is a rare fibro-inflammatory disease with poorly understood pathogenesis. Idiopathic RPF accounts for more than 70% of cases, with secondary causes related to retroperitoneal injury, malignancy, infection, drug therapy or genetic factors. Interestingly, a recent study (Zen et al) found a positive correlation between immunoglobin G4 (IgG4) on H/P and idiopathic RPF in 10 cases out of 17 patients. These cases were hallmarked by a unique H/P pattern and elevated serum IgG4 concentration. Our case, however, was the non-IgG4 related type. Patients with IRF most frequently present with abdominal pain, weight loss and features of obstructive uropathy. Elevated inflammatory markers and imaging studies aid in the diagnosis but biopsy is the gold standard. Goals of treatment for RPF is relief of ureteral obstruction and disease regression with glucocorticoids with or without other immunosuppressants. Tamoxifen has been used with success in patients who cannot tolerate glucocorticoids. Biologic therapies such as rituximab and tocilizumab have shown promise in select patients with refractory disease but further research is warranted. CONCLUSIONS: Idiopathic retroperitoneal fibrosis should be kept in the differential diagnosis of a patient presenting with abdominal or flank pain, obstructive uropathy and elevated markers of inflammation. Reference #1: Idiopathic retroperitoneal fibrosis: clinicopathologic features and outcome analysis. Yachoui R, Sehgal R, Carmichael B. Clin Rheumatol. 2016 Feb;35(2):401-7. https://doi.org/10.1007/s10067-015-3022-y. Epub 2015 Jul 25. Reference #2: Idiopathic and secondary forms of retroperitoneal fibrosis: a diagnostic approach. Urban ML, Palmisano A, Nicastro M, Corradi D, Buzio C, Vaglio A. Rev Med Interne. 2015 Jan;36(1):15-21. https://doi.org/10.1016/j.revmed.2014.10.008. Epub 2014 Nov 18. Reference #3: Idiopathic retroperitoneal fibrosis and its overlap with IgG4-related disease. Rossi GM, Rocco R, Accorsi Buttini E, Marvisi C, Vaglio A. Intern Emerg Med. 2017 Apr;12(3):287-299. https://doi.org/10.1007/s11739-016-1599-z. Epub 2017 Jan 9. DISCLOSURES: No relevant relationships by Moses Bachan, source=Web Response No relevant relationships by Muneer Khan, source=Web Response No relevant relationships by Zinobia Khan, source=Web Response No relevant relationships by Mariam Saeed, source=Web Response

A case of eosinophilic granulomatosis with polyangiitis complicated with a similar condition to IgG4 related lung disease

BackgroundAtypical manifestations, such as elevated serum immunoglobulin-G4 (IgG4) and extra-pulmonary IgG4 positive plasmacyte infiltration, have been described in patients with eosinophilic granulomatosis with polyangiitis (EGPA), such complicated situation might not be readily differentiated from IgG4-related disease.Case presentationHere, we report an interesting and rare case of EGPA in a 41 year-old male with negative anti-neutrophil cytoplasmic antibodies (ANCAs), which showed abundant pulmonary IgG4-positive plasma cells infiltration and markedly elevated serum IgG4 levels without extra-pulmonary lesions of IgG4-related disease. The clinical characteristics hesitated us whether the diagnosis as EGPA overlapping with IgG4-related lung disease should be concluded because of the absence of storiform fibrosis and obliterative phlebitis with lymphoplasmacytic infiltration. The patient’s systemic symptoms, pulmonary lesions, blood eosinophils count / percentage, and serum IgG4 levels were significantly improved with immunosuppressive therapy.ConclusionsWe consider that the overlapping pathogenesis exists in the disease course of EGPA and IgG4-related disease, which may lead to interaction during the course of the diseases. And the utilization of diagnostic criteria for IgG4-related lung disease with the careful differentiation is needed in such cases.

Distribution characteristics of elevated serum immunoglobulin G4 (IgG4) and its relationship with IgG4-related disease

Objective: To elucidate the distribution characteristics of elevated serum immunoglobulin G4 (IgG4) and its relationship with immunoglobulin G4-related disease (IgG4-RD).Methods: In total, 14 522 unique patients who were tested for serum IgG4 over a 4.5 year period were enrolled. Demographic and serological characteristics of all patients, and the range of diseases and serological characteristics of patients with elevated serum IgG4, were retrospectively analysed. Organ involvement in IgG4-RD patients and the utility of serum immunoglobulin for distinguishing IgG4-RD from non-IgG4-RD were also investigated.Results: Elevated serum IgG4 (> 1.4 g/L) was observed in 1793/14 522 patients (12.3%) and primarily appeared in middle-aged and elderly men. Only 7.3% of patients with elevated serum IgG4 met the diagnostic criteria for IgG4-RD. Elevated serum IgG4 was also found in over 30 types of non-IgG4-RD. Serum IgG4 levels were higher in IgG4-RD patients with multiple-organ involvement and were positively correlated with the number of affected organs. The diagnostic utility of serum IgG4 for IgG4-RD was higher than that of the IgG4/IgG ratio and serum IgG. The optimal serum IgG4 cut-off value for diagnosing IgG4-RD was 2.06 g/L, with a sensitivity of 95.6% and specificity of 94.7%.Conclusions: Elevated serum IgG4 may be present in multiple non-IgG4-RD conditions. However, a high serum IgG4 concentration is of great value for IgG4-RD diagnosis, and there appears to be a positive relationship between serum IgG4 levels and organ involvement in patients with IgG4-RD. Examining the IgG4/IgG ratio and serum IgG does not improve the ability of IgG4-RD diagnosis.

Sa1831 – Elevated Serum Immunoglobulin G4 Fails to Prognosticate Inflammatory Bowel Disease Outcomes in Primary Sclerosing Cholangitis Patients

Sa1831 – Elevated Serum Immunoglobulin G4 Fails to Prognosticate Inflammatory Bowel Disease Outcomes in Primary Sclerosing Cholangitis Patients

Hypopituitarism associated with autoimmune pancreatitis: a case report

We herein report the case of a 64-year-old male patient with hypopituitarism associated with autoimmune pancreatitis (AIP). The patient was previously diagnosed with AIP based on the presence of a swollen pancreas, elevated serum immunoglobulin G4, and narrowing of the pancreatic duct by imaging. Magnetic resonance imaging revealed a pituitary stem tumor, and loading test showed a decrease in the function of the anterior lobe suggesting severe failure of growth hormone secretion. Treatment with steroids was effective in reducing the pituitary lesion and improving the function of the anterior lobe. The present case illustrates the importance of pituitary function evaluation before steroid treatment in patients with AIP.