<\/span><\/h2>\nIgG4 is a subclass of IgG, which is the most common form of immunoglobulin<\/span>. IgG represents the 75% of antibodies<\/span> circulating in the blood, which are an essential part of the immune response secondary to infection<\/span> and toxins<\/span>. IgG is made by plasma<\/span> cells, a specific type of B lymphocyte<\/span>.<\/p>\nThere are four IgG subclasses. The IgG4 subclass is the least common of these, representing approximately 4% of IgG in serum<\/span>. IgG4 has a unique structure. Its specific biological role is uncertain. However, IgG4 is known to play a role in protection against type 1 hypersensitivity<\/span> reactions, for example to bee venom, and in the Pathogenesis<\/span> of autoimmune<\/span> blistering diseases such as pemphigus vulgaris, helminth<\/span> infections and malignancy<\/span> even melanoma<\/span>.<\/p>\n<\/span>What is IgG4 related disease?<\/span><\/h2>\nIgG4-related disease is a recently described rare disease syndrome<\/span> consisting of many disease entities previously thought to be unrelated. These conditions have the pathological characteristics of:<\/p>\n\n- \nInflammatory<\/span> pseudotumors, that is, organomegaly<\/span> or nodules<\/span> inside an organ<\/li>\n
- Lymphoplasmacytic infiltration<\/span> from tissues with many IgG4-positive plasma cells<\/li>\n
- Storiform fibrosis<\/span> (scarring involving cells arranged like a cartwheel in histology<\/span>)<\/li>\n<\/ul>\n\n
<\/span>IgG4-related disease: inflammatory cutaneous pseudotumor<\/span><\/h5>\n<\/section>\n\n\n
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IgG4-related disease: inflammatory cutaneous pseudotumor<\/p>\n
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IgG4-related disease: inflammatory cutaneous pseudotumor<\/p>\n<\/p><\/div>\n<\/section>\n
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Elevated serum IgG4 is present in 60 to 70% of patients.<\/p>\n
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<\/span>What is the cause of IgG4 related disease?<\/span><\/h2>\nThe cause of IgG4-related disease is unknown.<\/p>\n
\n- It can be an autoimmune disorder: antinuclear antibodies and autoantibodies<\/span> to pancreatic antigens<\/span> have been found in autoimmune pancreatitis<\/span>.<\/li>\n
- Has characteristics of an allergic disorder: abnormally high Th2 cytokines<\/span> in tissues, increased IgE and increased T-reg lymphocytes<\/span> in the blood, and raised eosinophils<\/span> counts in the 40% of the patients. IL-10 cytokines (interleukin<\/span> 10) and TGF-\u03b2 (transforming growth factor<\/span> Beta) are known to support IgG4 production and are at elevated levels in IgG4-related disease.<\/li>\n<\/ul>\n
<\/span>Who gets IgG4-related disease?<\/span><\/h2>\nMost of the patients described with IgG4-related disease are middle-aged or older men.<\/span><\/p>\n<\/span>What are the clinical features of IgG4-related disease?<\/span><\/h2>\nIgG4-related disease occurs in several ways.<\/p>\n
\n- Most people with IgG4-related disease are constitutionally well. <\/li>\n
- IgG4-related disease can be diagnosed as an incidental finding when someone undergoes a routine radiological<\/span> or surgical research.<\/li>\n
- 60-90% of people with IgG4-related disease have multiple organ involvement.<\/li>\n
- IgG4-related disease often occurs as swelling or within an organ (such as skin, orbit, and lung); This is known as an inflammatory pseudotumor.<\/li>\n
- IgG-related autoimmune pancreatitis is more likely than other forms of IgG-related disease to be associated with the disease elsewhere, such as the hilum lymphadenopathy<\/span>, bile duct injuries, lacrimal<\/span> and compromise of the salivary glands, hypothyroidism<\/span>and retroperitoneal fibrosis.<\/li>\n
- Lacrimal, parotid or submandibular salivary disease related to IgG4, pneumonitis<\/span>and kidney disease are associated with pancreatitis in <20% de los casos.<\/li>\n
- Patients with IgG4-related disease may have symptoms of allergy<\/span> like asthma<\/li>\n
- Up to 40-80% of patients with IgG4-related disease have lymphadenopathy.<\/li>\n
- \nCutaneous<\/span> Manifestations of IgG4-related disease include erythematous<\/span> plates<\/span>, papules<\/span>and subcutaneous<\/span> nodules, often itchy, and usually on the face or forearm. Most patients with IgG4-related skin disease report an inflammatory enlargement of the lacrimal or salivary glands at some point.<\/li>\n<\/ul>\n
\n\nOrgan-specific IgG4-related disease<\/caption>\n<\/tbody>\n\n\n| Organ<\/th>\n | Disease<\/th>\n<\/tr>\n |
\n| Gastrointestinal disease<\/td>\n | \n\n- Pancreatitis (autoimmune pancreatitis type 1)<\/li>\n
- \nIdiopathic<\/span> retroperitoneal fibrosis (Ormond's disease)<\/li>\n
- Sclerosing cholangitis<\/li>\n
- Gastritis<\/li>\n
- Hepatitis<\/span><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n| \nLymph node<\/span> intervention<\/td>\n | \n\n- \nGeneralized<\/span> lymphadenopathy<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n| Salivary and lacrimal disease<\/td>\n | \n\n- Mikulicz disease of the lacrimal glands (dacryoadenitis) and the salivary glands (sialoadenitis)<\/li>\n
- Sclerosing sialoadenitis (K\u00fcttner tumor<\/span> of the submandibular salivary gland)<\/li>\n
- \nChronic<\/span> sclerosing dacryoadenitis of the lacrimal glands<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n| Eye disease<\/td>\n | \n\n- Inflammatory pseudotumor of the orbit.<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n| Heart disease<\/td>\n | \n\n- Chronic sclerosing aortitis and periaortitis<\/li>\n
- Constrictive periaortitis<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n| Thyroid disease<\/td>\n | \n\n- Riedel's thyroiditis<\/li>\n
- \nFibrosing<\/span> Hashimoto's thyroiditis<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n| Lung disease<\/td>\n | \n\n- Inflammatory pseudotumor<\/li>\n
- \nInterstitial<\/span> pneumonitis<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n| Nephropathy<\/td>\n | \n\n- Tubulointerstitial nephritis<\/span>\n<\/li>\n
- Membranous glomerulonephritis<\/li>\n
- Inflammatory pseudotumor<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n| Skin illness<\/td>\n | \n\n- Inflammatory pseudotumor<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
\n| Other<\/td>\n | \n\n- Prostatitis<\/li>\n
- Hypophysitis<\/span><\/li>\n
- Pachymeningitis<\/span><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n \n \n \n<\/div><\/div><\/div><\/div>\n <\/span>How is IgG4-related disease diagnosed?<\/span><\/h2>\nDiagnosis of IgG4-related disease can be difficult, since multiple organs may be involved simultaneously. The diagnostic criteria have not been fully developed.<\/p>\n Investigation into suspected IgG4-related disease requires a combination of clinical, endoscopic<\/span>radiological and serological<\/span> Tests for organ involvement and terminal organ damage (eg, hormonal abnormalities).<\/p>\nTissue diagnosis requires a biopsy<\/span> of affected organic tissues, including skin biopsy. See IgG4-related skin disease pathology<\/span>. Features include:<\/p>\n\n- Lymphoplasmacytic infiltrate<\/span>\n<\/li>\n
- Stormy fibrosis pattern<\/li>\n
- Plasma cells positive for IgG4 (the number of positive cells to confirm the diagnosis depends on the tissue type; most> 30-50 per high-power field, some, such as kidney, 10 per high-power field).<\/li>\n<\/ul>\n
Blood tests are not diagnostic, but can show:<\/p>\n \n- \nPeripheral<\/span> eosinophilia<\/span>\n<\/li>\n
- IgG4 raised serum.<\/li>\n<\/ul>\n
There are specific criteria for the diagnosis of some specific tissue disorders, such as autoimmune pancreatitis.<\/p>\n <\/span>How is IgG4-related disease treated?<\/span><\/h2>\nIgG4-related disease is usually treated with systemic<\/span> steroids, often prednisone 40 mg per day for 2 to 4 weeks followed by a gradual decrease in dose.<\/p>\nIn patients who cannot withdraw from prednisone, a steroid sparing agent such as azathioprine or mycophenolate can be used. Rituximab, a Cell B<\/span>exhausting monoclonal<\/span> antibody<\/span>, has been used with some success.<\/p>\nSpecific organ replacement therapy may be required:<\/p>\n \n- Thyroxine for thyroiditis (thyroid disease) causing hypothyroidism<\/li>\n
- Pancreatic enzyme<\/span> replacement for pancreatic insufficiency<\/li>\n
- \nInsulin<\/span> for diabetes mellitus<\/li>\n
- Hormone replacement for hypopituitarism: hydrocortisone, thyroxine, growth hormone, desmopressin, and sex<\/span> hormonestestosterone<\/span> for men; estrogen<\/span> and progesterone<\/span> for women).<\/li>\n<\/ul>\n
<\/span>Which is the forecast<\/span> of IgG4-related disease?<\/span><\/h2>\nThe prognosis of IgG4-related disease is variable. It can resolve or persist spontaneously, with recurring and remitting symptoms.<\/p>\n Main causes of morbidity<\/span> and mortality are significant implications of organs such as:<\/p>\n\n- Liver cirrhosis<\/span>\n<\/li>\n
- Portal hypertension<\/span>\n<\/li>\n
- Biliary obstruction<\/li>\n
- Retroperitoneal fibrosis<\/li>\n
- \nAortic<\/span> dissection of an aneurysm<\/li>\n
- Mellitus diabetes<\/li>\n
- Pancreatic insufficiency<\/li>\n<\/ul>\n
IgG4-related disease may be associated with a possible increased risk of non-Hodgkin lymphoma<\/span>. It is not known whether IgG4-related disease leads to an increased risk of other forms of Cancer<\/span>.<\/p>\n<\/section>","protected":false},"excerpt":{"rendered":"\u00bfQu\u00e9 es la IgG4? IgG4 es una subclase de IgG, que es la forma m\u00e1s com\u00fan de inmunoglobulina. IgG representa el 75% de anticuerpos circulando en la sangre, que son…<\/p>","protected":false},"author":8,"featured_media":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-16465","wiki","type-wiki","status-publish","format-standard"],"_links":{"self":[{"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/wiki\/16465","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/types\/wiki"}],"author":[{"embeddable":true,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/comments?post=16465"}],"version-history":[{"count":0,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/wiki\/16465\/revisions"}],"wp:attachment":[{"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/media?parent=16465"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/categories?post=16465"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/doctorhoogstra.com\/en\/wp-json\/wp\/v2\/tags?post=16465"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}} | | | | | | | | | |