IgG4-related disease | |
---|---|
Other names | IgG4-related systemic disease |
Low power view of IgG4-related prostatitis. The prostatic stroma shows a dense inflammatory infiltrate and fibrosis (H&E, 100x) | |
Specialty | Immunology/Rheumatology |
IgG4-related disease (IgG4-RD), formerly known as IgG4-related systemic disease, is a chronic inflammatory condition characterized by tissue infiltration with lymphocytes and IgG4-secreting plasma cells, various degrees of fibrosis (scarring) and a usually prompt response to oral steroids. In approximately 51–70% of people with this disease, serum IgG4 concentrations are elevated during an acute phase. [1] [2] [3]
It is a relapsing-remitting disease associated with a tendency to mass forming, tissue-destructive lesions in multiple sites, with a characteristic histopathological appearance in whichever site is involved. Inflammation and the deposition of connective tissue in affected anatomical sites can lead to organ dysfunction, organ failure, or even death if not treated. [4]
Early detection is important to avoid organ damage and potentially serious complications. [5] Treatment is recommended in all symptomatic cases of IgG4-RD and also in asymptomatic IgG4-RD involving certain anatomical sites. [4] [6]
IgG4-related disease has been described as an indolent condition. Although possibly based on opinion rather than on objective assessments, symptoms, if any, are commonly described as mild in the medical literature. [7] This can be in spite of considerable underlying organ destruction. People are often described as being generally well at the time of diagnosis, although some may give a history of weight loss. Pain is generally not a feature of inflammation. However, it may occur as a secondary effect, for example, due to either obstruction or compression.
Laboratory levels of IgG4 greater than 135 mg/dL
Moreover, diagnosis is made due to the presence of painless swellings or mass lesions, or due to complications of masses, e.g. jaundice due to involvement of the pancreas, biliary tree or liver. Symptoms are commonly attributed to other conditions and other diagnoses may have been made years before diagnosis, e.g. urinary symptoms in men attributed to common prostate conditions. Lesions may also be detected incidentally on radiological images, but can be easily misdiagnosed as malignancies.[ citation needed ]
Reported cases do include some significant symptoms or findings however:
System | Uncommon symptoms and complications |
---|---|
Neurological | Seizures, [8] [9] paralysis or hemiparesis, [8] cranial nerve palsies, [8] sensorineural hearing loss, [10] pituitary hormone deficiencies [11] |
Eye | Loss of vision, [8] proptosis [12] |
Cardiovascular | Constrictive pericarditis, [13] heart block, [14] ruptured aortic aneurysm, [15] [16] aortic dissection, [17] carotid artery dissection, [18] intracranial aneurysm, [19] angina, [20] sudden cardiac death [21] [22] |
Respiratory | Airway obstruction, [23] pleural effusion [24] [25] |
Gastrointestinal | Esophageal obstruction, [26] [27] bowel obstruction [28] |
Urological | Renal failure, [29] hydronephrosis, [29] [30] testicular pain [31] |
IgG4-RD can involve one or multiple sites in the body. With multiorgan involvement, the sites involved can be affected at the same time (synchronously) or at different unrelated periods (metachronously).
Several different diseases that have been known for many years are now considered to be manifestations of IgG4-RD. These include: type 1 autoimmune pancreatitis, interstitial nephritis, Riedel's thyroiditis, Mikulicz's disease, Küttner's tumor, inflammatory pseudotumors (in various sites of the body), mediastinal fibrosis and some cases of retroperitoneal fibrosis. [32] [33]
Organ or site | Preferred names | Previously used names |
---|---|---|
Head and neck | ||
Salivary gland | IgG4-related sialadenitis:
| Mikulicz's disease (salivary and lacrimal glands), [35] chronic sclerosing sialadenitis, Küttner's tumour (submandibular glands) |
Orbit | IgG4-related ophthalmic disease (IgG4-ROD) including:
| Mikulicz's disease (salivary and lacrimal glands), [35] Idiopathic orbital inflammatory disease, orbital pseudotumor |
Paranasal sinuses [36] | Chronic sinusitis, Eosinophilic angiocentric fibrosis (upper respiratory tract and orbit) [37] | |
Pharynx | IgG4-related pharyngitis [38] | |
Thyroid gland | IgG4-related thyroid disease | Riedel's thyroiditis, Riedel's struma |
Soft tissues of the head and neck | Idiopathic cervical fibrosis, [39] sclerosing cervicitis, cervical fibrosclerosis | |
Central Nervous System | ||
Pituitary gland | IgG4-related hypophysitis:
| Autoimmune hypophysitis |
Meninges | IgG4-related pachymeningitis (dura mater), IgG4-related leptomeningitis [40] [41] (arachnoid and pia mater) | Idiopathic hypertrophic pachymeningitis |
Chest and abdomen | ||
Pancreas | IgG4-related pancreatitis | Type 1 autoimmune pancreatitis, lymphoplasmacytic sclerosing pancreatitis, 'chronic pancreatitis with diffuse irregular narrowing of the main pancreatic duct' [42] |
Lung | IgG4-related lung disease | Pulmonary inflammatory pseudotumour |
Pleura | IgG4-related pleuritis | |
Liver | IgG4-related hepatopathy | |
Bile duct | IgG4-related sclerosing cholangitis | |
Gallbladder | IgG4-related cholecystitis | |
Aorta (especially the infrarenal portion) | IgG4-related aortitis, IgG4-related periaortitis [43] | Inflammatory aortic aneurysm, Chronic sclerosing aortitis, chronic periaortitis. |
Branches of the aorta (including coronary, [36] renal or iliac arteries) | IgG4-related periarteritis [43] | |
Pericardium | IgG4-related pericarditis | |
Mediastinum | IgG4-related mediastinitis | Fibrosing mediastinitis, chronic sclerosing mediastinitis |
Retroperitoneum | IgG4-related retroperitoneal fibrosis | Retroperitoneal fibrosis, Albarran-Ormond syndrome, Ormond's disease, perirenal fasciitis, Gerota's fasciitis/syndrome, periureteritis fibrosa, sclerosing lipogranuloma, sclerosing retroperitoneal granuloma, non-specific retroperitoneal inflammation, sclerosing retroperitonitis, retroperitoneal vasculitis with perivascular fibrosis. [44] |
Mesentery | IgG4-related mesenteritis (subtypes are: mesenteric panniculitis, mesenteric lipodystrophy and retractile mesenteritis) [44] | Sclerosing mesenteritis, systemic nodular panniculitis, liposclerosis mesenteritis, mesenteric Weber–Christian disease, mesenteric lipogranuloma, xanthogranulomatous mesenteritis. [44] |
Breast | IgG4-related mastitis | Sclerosing mastitis |
Genitourinary | ||
Kidney | IgG4-related kidney disease (IgG4-RKD):
| Idiopathic hypocomplementemic tubulointerstitial nephritis |
Prostate | IgG4-related prostatitis | |
Vas deferens | IgG4-related perivasal fibrosis [31] [45] | Chronic orchialgia |
Scrotum | IgG4-related paratesticular pseudotumor, [34] [46] IgG4-related epididymo-orchitis [34] | Paratesticular fibrous pseudotumor, inflammatory pseudotumor of the spermatic cord, pseudosarcomatous myofibroblastic proliferations of the spermatic cord, proliferative funiculitis, chronic proliferative periorchitis, fibromatous periorchitis, nodular periorchitis, reactive periorchitis, fibrous mesothelioma [47] |
Other | ||
Lymph nodes | IgG4-related lymphadenopathy | |
Skin | IgG4-related skin disease | Angiolymphoid hyperplasia with eosinophilia, [48] cutaneous pseudolymphoma [49] |
Nerve | IgG4-related perineural disease [34] [50] |
This is not a complete list, as IgG4-RD can involve any site in the body.
Other affected sites, confirmed on histology to be manifestations of IgG4-RD, include: heart; [14] hard palate, [51] esophagus, [26] [27] stomach, [52] small intestine, [53] rectum, [54] adrenal gland, [55] ovary, [56] uterus, [24] ureter, [57] bladder, [58] urachus, [59] and synovium. [60] Approximately 1/3 of cases exhibit increases in blood eosinophil counts, either eosinophilia or hypereosinophilia.[ citation needed ]
Radiologic evidence suggestive of involvement of the superior vena cava [14] and seminal vesicle [61] has been reported in confirmed cases of IgG4-RD.
Whatever area of the body is involved, the hallmark histopathological features of IgG4-RD are: [3] [32] [33]
Other histopathological features associated with IgG4-RD are:
In an article from 1977, histological research into 349 cases of Küttner's tumor (now known as 'IgG4-related sialadenitis') identified four distinct stages of the fibroinflammatory process: [62]
This may reflect the inflammatory process and development of fibrosis that occurs in other organs involved in IgG4-RD.
Diagnosis requires tissue biopsy of an affected organ with characteristic histological findings, a comprehensive medical history and physical examination from a physician astute in new and evolving connective tissue diseases such as IgG4-RD.
Serum immunoglobulin G4 (IGG4) is often elevated, but this is not always the case. However, IgG4 blood lab levels greater than 135 are considered an evolving diagnostic criterion for disease suspicion [63]
The goal of treatment is the induction and maintenance of remission so as to prevent progression of fibrosis and organ destruction in affected organ(s).
An international panel of experts have developed recommendations for the management of IgG4-RD. [4] [6] They concluded that in all cases of symptomatic, active IgG4-RD that treatment is required. Some cases with asymptomatic IgG4-RD also require treatment, as some organs tend to not cause symptoms until the late stages of disease. Urgent treatment is advised with certain organ manifestations, such as aortitis, retroperitoneal fibrosis, proximal biliary strictures, tubulointerstitial nephritis, pachymeningitis, pancreatic enlargement and pericarditis.
In untreated patients with active disease, the recommended first-line agent for induction of remission is glucocorticoids unless contraindications exist. Glucocorticoids characteristically result in a rapid and often dramatic improvement in clinical features and often a resolution of radiographic features. However, where advanced fibrotic lesions have resulted in irreversible damage, the response to glucocorticoids and other current treatment options may be poor or even absent.
Although not validated yet in clinical trials, the common induction regime is prednisolone 30–40 mg per day for 2–4 weeks, then gradually tapered over 3 to 6 months. Recurrences during or after tapering of glucocorticoids are frequent, however. Steroid-sparing immunosuppressive agents might be considered, depending on local availability of these drugs, for use in combination with glucocorticoids from the start of treatment in order to reduce the side-effects of prolonged glucocorticoid usage. Steroid-sparing agents that have been used include rituximab, azathioprine, methotrexate, and cyclophosphamide, although trials are needed to ascertain the effectiveness of each drug in IgG4-RD.
Following a successful induction of remission, maintenance therapy might be given in some cases, for example when there is a high risk of relapse or in patients with organ-threatening manifestations. Common maintenance therapy is prednisolone 2.5–5 mg per day, or use of a steroid-sparing agent instead.
Relapses are common, and a previous history of relapse appears to be a strong predictor of future relapse. When relapse occurs while off therapy and there has been a prolonged disease remission following initial glucocorticoid induction, then the relapse can usually be managed successfully with a re-induction strategy using glucocorticoids. Introducing a steroid-sparing agent might also need to be considered for relapses; however, none has been tested in prospective, controlled studies, and evidence for their efficacy beyond that offered by concomitant glucocorticoid therapy is scarce. [5]
In one retrospective cohort study, baseline concentrations of serum IgG4, IgE and blood eosinophils were found to be independently predictive of relapse risk following treatment with rituximab with or without glucocorticoids; the higher the baseline values, the greater the relapse risk and the shorter the time to relapse. [64]
When organ involvement causes local mechanical problems, further organ-specific interventions may be necessary. For example, when a tumefactive lesion causes obstruction of the bile duct, it may be necessary to insert a biliary stent to allow the bile to drain freely.
Similarly, ureteral or vascular stents, surgical resection or radiotherapy may be considered for various different presenting problems.
Research is also underway to evaluate the effect and safety of plasmablast-directed therapy with a monoclonal antibody (XmAb5871, obexelimab) which inhibits B-cell function without depleting these immune cells. [65]
As recognition of IgG4-RD is relatively recent, there are limited studies on its epidemiology. It is therefore difficult to make an accurate estimation of prevalence. Furthermore, age of onset is almost impossible to estimate; age at diagnosis is frequently misused as the age of onset.
A 2011 study estimated the incidence of IgG4-RD in Japan at 2.8–10.8/million population, with a median age of onset of 58 years. [66] Another study based on United States healthcare administrative claims data estimated the prevalence of IgG4-RD at 5.3/100,000 (about 1/20,000). [67]
Names previously used for IgG4-RD: |
---|
IgG4-related systemic disease (IgG4-RSD) IgG4-related sclerosing disease IgG4-related systemic sclerosing disease IgG4-related autoimmune disease IgG4-associated multifocal systemic fibrosis IgG4-associated disease IgG4 syndrome Hyper-IgG4 disease Systemic IgG4-related plasmacytic syndrome IgG4-positive multiorgan lymphoproliferative syndrome |
Prior to 2011, IgG4-RD used to get mentioned in the medical literature under various different names. [2] [66] In addition, there are a number of historical reports in the literature of disease associations, which, in retrospect are likely to have been different manifestations of IgG4 disease. For example, Banerjee et al[1989] reported two patients with autoimmune hepatitis and febrile panniculitis. On each occasion the panniculitis responded to increasing the doses ofprednisolone. [68]
At the International Symposium on IgG4-Related Diseases, the consensus name of IgG4-related disease was endorsed for the condition. [2] This name had already been agreed upon as a consensus name among Japanese investigators, [2] [3] notably choosing not to use the term 'systemic' as that might lead to malignant tumours in other organs getting incorrectly diagnosed as being just another manifestation of the IgG4-related condition. [66]
However, some experts at the international symposium did express reservations about naming the disease after IgG4, as its role in pathogenesis is questionable and the use of serum IgG4 concentrations as a biomarker is unreliable. [2]
An expanded term, 'Immunoglobulin G4-related disease', has sometimes been used also. [69] However, this term was never referenced in the 2012 recommendations for nomenclature, [2] and its use would appear to be erroneous.
Henoch–Schönlein purpura (HSP), also known as IgA vasculitis, is a disease of the skin, mucous membranes, and sometimes other organs that most commonly affects children. In the skin, the disease causes palpable purpura, often with joint pain and abdominal pain. With kidney involvement, there may be a loss of small amounts of blood and protein in the urine, but this usually goes unnoticed; in a small proportion of cases, the kidney involvement proceeds to chronic kidney disease. HSP is often preceded by an infection, such as a throat infection.
Parotitis is an inflammation of one or both parotid glands, the major salivary glands located on either side of the face, in humans. The parotid gland is the salivary gland most commonly affected by inflammation.
Relapsing polychondritis is a systemic disease characterized by repeated episodes of inflammation and in some cases deterioration of cartilage. The disease can be life-threatening if the respiratory tract, heart valves, or blood vessels are affected. The exact mechanism is poorly understood.
Retroperitoneal fibrosis or Ormond's disease is a disease featuring the proliferation of fibrous tissue (fibrosis) in the retroperitoneum, the compartment of the body containing the kidneys, aorta, renal tract, and various other structures. It may present with lower back pain, kidney failure, hypertension, deep vein thrombosis, and other obstructive symptoms. It is named after John Kelso Ormond, who rediscovered the condition in 1948.
Benign lymphoepithelial lesion or Mikulicz' disease is a type of benign enlargement of the parotid and/or lacrimal glands. This pathologic state is sometimes, but not always, associated with Sjögren's syndrome.
Pemphigoid is a group of rare autoimmune blistering diseases of the skin and mucous membranes. As its name indicates, pemphigoid is similar in general appearance to pemphigus, however unlike pemphigus, pemphigoid does not feature acantholysis, a loss of connections between skin cells.
Autoimmune Pancreatitis (AIP) is an increasingly recognized type of chronic pancreatitis that can be difficult to distinguish from pancreatic carcinoma but which responds to treatment with corticosteroids, particularly prednisone. Although autoimmune pancreatitis is quite rare, it constitutes an important clinical problem for both patients and their clinicians: the disease commonly presents itself as a tumorous mass which is diagnostically indistinguishable from pancreatic cancer, a disease that is much more common in addition to being very dangerous. Hence, some patients undergo pancreatic surgery, which is associated to substantial mortality and morbidity, out of the fear by patients and clinicians to undertreat a malignancy. However, surgery is not a good treatment for this condition as AIP responds well to immunosuppressive treatment. There are two categories of AIP: Type 1 and Type 2, each with distinct clinical profiles.
Riedel's thyroiditis, is a chronic form of thyroiditis. It is now believed that Riedel's thyroiditis is one manifestation of a systemic disease that can affect many organ systems called IgG4-related disease. It is often a multi-organ disease affecting pancreas, liver, kidney, salivary and orbital tissues and retroperitoneal space. The hallmarks of the disease are fibrosis and infiltration by IgG4 secreting plasma cells.
Aortitis is the inflammation of the aortic wall. The disorder is potentially life-threatening and rare. It is reported that there are only 1–3 new cases of aortitis per year per million people in the United States and Europe. Aortitis is most common in people 10 to 40 years of age.
Diffuse infiltrative lymphocytosis syndrome (DILS) is a rare multi-system complication of HIV believed to occur secondary to an abnormal persistence of the initial CD8+ T cell expansion that regularly occurs in an HIV infection. This persistent CD8+ T cell expansion occurs in the setting of a low CD4+/CD8+ T cell ratio and ultimately invades and destroys tissues and organs resulting in the various complications of DILS. DILS classically presents with bilateral salivary gland enlargement (parotitis), cervical lymphadenopathy, and sicca symptoms such as xerophthalmia and xerostomia, but it may also involve the lungs, nervous system, kidneys, liver, digestive tract, and muscles. Once suspected, current diagnostic workups include (1) confirming HIV infection, (2) confirming six or greater months of characteristic signs and symptoms, (3) confirming organ infiltration by CD8+ T cells, and (4) exclusion of other autoimmune conditions. Once the diagnosis of DILS is confirmed, management includes highly active antiretroviral therapy (HAART) and as-needed steroids. With proper treatment, the overall prognosis of DILS is favorable.
Necrotizing vasculitis, also called systemic necrotizing vasculitis, is a general term for the inflammation of veins and arteries that develops into necrosis and narrows the vessels.
Cryoglobulinemic vasculitis is a form of inflammation affecting the blood vessels (vasculitis) caused by the deposition of abnormal proteins called cryoglobulins. These immunoglobulin proteins are soluble at normal body temperatures, but become insoluble below 37 °C (98.6 °F) and subsequently may aggregate within smaller blood vessels. Inflammation within these obstructed blood vessels is due to the deposition of complement proteins which activate inflammatory pathways.
Multifocal fibrosclerosis and idiopathic fibrosclerosis are disorders of unknown aetiology, characterised by fibrous lesions (co-)occurring at a variety of sites. Known manifestations include retroperitoneal fibrosis, mediastinal fibrosis and Riedel's thyroiditis.
Salivary gland diseases (SGDs) are multiple and varied in cause. There are three paired major salivary glands in humans: the parotid glands, the submandibular glands, and the sublingual glands. There are also about 800–1,000 minor salivary glands in the mucosa of the mouth. The parotid glands are in front of the ears, one on side, and secrete mostly serous saliva, via the parotid ducts, into the mouth, usually opening roughly opposite the second upper molars. The submandibular gland is medial to the angle of the mandible, and it drains its mixture of serous and mucous saliva via the submandibular duct into the mouth, usually opening in a punctum in the floor of mouth. The sublingual gland is below the tongue, on the floor of the mouth; it drains its mostly mucous saliva into the mouth via about 8–20 ducts, which open along the plica sublingualis, a fold of tissue under the tongue.
Chronic sclerosing sialadenitis is a chronic (long-lasting) inflammatory condition affecting the salivary gland. Relatively rare in occurrence, this condition is benign, but presents as hard, indurated and enlarged masses that are clinically indistinguishable from salivary gland neoplasms or tumors. It is now regarded as a manifestation of IgG4-related disease.
IgG4-related prostatitis is prostate involvement in men with IgG4-related disease (IgG4-RD), which is an emerging fibroinflammatory disease entity which is characterised (i) by a tendency to mass forming lesions in multiple sites of the body and (ii) by usually a prompt response to steroid therapy.
IgG4-related ophthalmic disease (IgG4-ROD) is the recommended term to describe orbital manifestations of the systemic condition IgG4-related disease, which is characterised by infiltration of lymphocytes and plasma cells and subsequent fibrosis in involved structures. It can involve one or more of the orbital structures.
IgG4-related skin disease is the recommended name for skin manifestations in IgG4-related disease (IgG4-RD). Multiple different skin manifestations have been described.
A woven or storiform pattern is a histopathologic architectural pattern. The name "storiform" originates from Latin storea 'woven', as storiform tissue tends to resemble woven fabric on microscopy.
Obexelimab is an experimental drug developed to treat IgG4-related disease and lupus. It works as a "bifunctional, non-cytolytic, humanised monoclonal antibody that binds CD19 and Fc gamma receptor IIb to inhibit B cells, plasmablasts, and CD19-expressing plasma cells."
{{cite journal}}
: CS1 maint: numeric names: authors list (link){{cite journal}}
: CS1 maint: numeric names: authors list (link)