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.
Autoimmune Diseases/drug therapy* ; Biomarkers ; Glucocorticoids/therapeutic use* ; Humans ; Immunoglobulin G ; Immunoglobulin G4-Related Disease/drug therapy*

IgG4-related disease (IgG4-RD) is a rare autoimmune fibrosis disease characterized by elevated serum IgG4 and tissues as well as organs infiltrated with IgG4-positive cells, resulting in swelling and damage.It is currently treated as first-line treatment with glucocorticoids. Autoimmune hemolytic anemia (AIHA) is also a relatively rare disease that caused by autoreactive erythrocyte antibodies. Although both are autoimmune-related diseases, they rarely overlap. The relationship between them is not clear. A case of IgG4-RD combined with AIHA is reported. The patient has shortness of breath, cough, and sputum after physical activity. Physical examination showed appearance of anemia, yellow staining of skin and sclera, palpable neck and multiple swollen lymph nodes. Laboratory examination, bone marrow biopsy, and lymph node biopsy confirmed the diagnosis. Therefore, clinicians should develop ideas and raise awareness of such diseases.
Anemia, Hemolytic, Autoimmune ; diagnosis ; drug therapy ; Autoimmune Diseases ; complications ; Biopsy ; Humans ; Immunoglobulin G ; Immunoglobulin G4-Related Disease ; complications ; diagnosis

A case of IgG4-related disease presented with a duodenal ulcer to improve the understan-ding of IgG4-related diseases was reported. A 70-year-old male presented with cutaneous pruritus and abdominal pain for four years and blackened stools for two months. Four years ago, the patient went to hospital for cutaneous pruritus and abdominal pain. Serum IgG4 was 3.09 g/L (reference value 0-1.35 g/L), alanine aminotransferase 554 U/L (reference value 9-40 U/L), aspartate aminotransferase 288 U/L (reference value 5-40 U/L), total bilirubin 54.16 μmol/L (reference value 2-21 μmol/L), and direct bilirubin 29.64 μmol/L (reference value 1.7-8.1 μmol/L) were all elevated. The abdominal CT scan and magnetic resonance cholangiopancreatography indicated pancreatic swelling, common bile duct stenosis, and secondary obstructive dilation of the biliary system. The patient was diagnosed with IgG4-related disease and treated with prednisone at 40 mg daily. As jaundice and abdominal pain improved, prednisone was gradually reduced to medication discontinuation. Two months ago, the patient developed melena, whose blood routine test showed severe anemia, and gastrointestinal bleeding was diagnosed. The patient came to the emergency department of Beijing Hospital with no improvement after treatment in other hospitals. Gastroscopy revealed a 1.5 cm firm duodenal bulb ulcer. After treatment with omeprazole, the fecal occult blood was still positive. The PET-CT examination was performed, and it revealed no abnormality in the metabolic activity of the duodenal wall, and no neoplastic lesions were found. IgG4-related disease was considered, and the patient was admitted to the Department of Rheumatology and Immunology of Beijing Hospital for further diagnosis and treatment. The patient had a right submandibular gland mass resection history and diabetes mellitus. After the patient was admitted to the hospital, the blood test was reevaluated. The serum IgG4 was elevated at 5.44 g/L (reference value 0.03-2.01 g/L). Enhanced CT of the abdomen showed that the pancreas was mild swelling and was abnormally strengthened, with intrahepatic and extrahepatic bile duct dilation and soft tissue around the superior mesenteric vessels. We pathologically reevaluated and stained biopsy specimens of duodenal bulbs for IgG and IgG4. Immunohistochemical staining revealed remarkable infiltration of IgG4-positive plasma cells into duodenal tissue, the number of IgG4-positive cells was 20-30 cells per high-powered field, and the ratio of IgG4/IgG-positive plasma cells was more than 40%. The patient was treated with intravenous methylprednisolone at 40 mg daily dosage and cyclophosphamide, and then the duodenal ulcer was healed. IgG4 related disease is an immune-medicated rare disease characterized by chronic inflammation and fibrosis. It is a systemic disease that affects nearly every anatomic site of the body, usually involving multiple organs and diverse clinical manifestations. The digestive system manifestations of IgG4-related disease are mostly acute pancreatitis and cholangitis and rarely manifest as gastrointestinal ulcers. This case confirms that IgG4-related disease can present as a duodenal ulcer and is one of the rare causes of duodenal ulcers.
Aged ; Humans ; Male ; Abdominal Pain/drug therapy* ; Acute Disease ; Bilirubin ; Duodenal Ulcer/etiology* ; Immunoglobulin G ; Immunoglobulin G4-Related Disease/diagnosis* ; Pancreatitis/drug therapy* ; Positron Emission Tomography Computed Tomography ; Prednisone/therapeutic use* ; Pruritus/drug therapy*