IgG4-related disease is a new type of disease that was only recognized and named in the 21st century. It is a complex disease that can present in a variety of ways and is often seen in different departments such as internal medicine, surgery, oral medicine, ophthalmology, and dermatology due to different organ manifestations. The authors have diagnosed three cases of IBD in recent years. The authors have diagnosed three cases of IgG4-associated diseases in recent years, all of which were seen in several tertiary hospitals and clinical departments in the province over a period of 1-2 years, but were not clearly diagnosed due to the inability of the receiving physicians to provide a name for the disease. In order to raise awareness of the disease, some basic knowledge of IgG4-associated disease is introduced today to draw the attention of clinicians in various departments.
IgG4-related disease is a chronic, progressive, autoimmune disease associated with lgG4 that involves multiple organs or tissues. The disease may affect only one organ or multiple organs simultaneously or sequentially. The organs involved include pancreas, lacrimal gland, glands, pituitary gland, thyroid, lung, aorta, coronary artery, liver and gallbladder, kidney, prostate, breast, skin and lymph nodes. .
The clinical manifestations are mainly the symptoms of local compression and the dysfunction of the corresponding involved organs and tissues. If the pancreas is involved, there may be mild abdominal pain, discomfort, weakness of the limbs, nausea, anorexia, and obstructive xanthogranuloma in some patients. The involvement of the pituitary gland leads to diffuse enlargement of pituitary tissue, mostly manifesting as lethargy, weakness, physical fatigue, weight loss, anorexia, and unexplained uremia, etc.; other organ involvement will show corresponding manifestations Other organs may be involved, such as interstitial nephritis, intrahepatic cholangitis, cholecystitis, aortitis, arachnoiditis, mediastinitis, prostatitis, thyroiditis, mastitis, orbital inflammatory pseudotumor, skin lesions, lymphadenitis, pleurisy, pericarditis, etc. Fever and arthralgia are uncommon. Blood IgG is elevated, globulin is elevated, sedimentation is increased, eosinophils, IgE and C-reactive protein are elevated in some patients, and antinuclear antibodies and rheumatoid factor are abnormal.
Imaging examinations such as CT, MRI and ultrasound can reveal signs of organ enlargement and compression at the involved site, which are helpful in diagnosing the disease.
The diagnosis of IgG4-related diseases is mainly based on.
1. clinical manifestations of diffuse/limited swelling or masses in one or more organs.
2. elevated serum IgG4 concentration of 135 mg/dl.
3, Histopathological examination: including a large number of lymphocytes, plasma cell infiltration and fibrosis; 40% of IgG4-positive/IgG-positive cells infiltrated in the tissue and 10 IgG4-positive cells/high magnification field.
The histopathological features were the main basis for the diagnosis, followed by the IgG4-positive cell count and IgG4-positive/IgG-positive cell ratio in the tissues. Diagnosis of the disease also excludes malignant tumors of various organs (e.g., cancer, malignant lymphoma) and clinically similar diseases (e.g., CSS, nodular disease, granulomatous polyangiitis, Castleman’s disease, secondary retroperitoneal fibrosis, primary sclerosing cholangitis, dry syndrome); treatment is mainly applied with glucocorticoids, which are more effective, and soon after treatment the organ swelling is reduced or disappears and IgG4 decreases; it can also be combined with immunosuppressive agents such as azathioprine, cyclophosphamide, methotrexate and mortification. In our daily practice, IgG4-associated disease should be suspected if we encounter a patient with the following manifestations.
1, enlargement of the lacrimal or parotid or submandibular glands.
2, autoimmune pancreatitis.
3, inflammatory pseudotumor.
4, retroperitoneal fibrosis.
5, ocular tumor-like lesions.
6, autoimmune hepatitis.
7, sclerosing cholangitis.
8, prostatitis.
9, interstitial pneumonia.
10, interstitial nephritis.
11, thyroiditis or hypothyroidism.
12, pituitary inflammation.
13, inflammatory aneurysm.
14, dural meningitis.
15, mediastinal fibrosis, etc.
IgG4 and histopathological examination should be performed promptly to clarify the diagnosis.