Idiopathic multicentric Castleman disease | |
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Other names | Giant lymph node hyperplasia, lymphoid hamartoma, angiofollicular lymph node hyperplasia |
Micrograph of lymph node biopsy demonstrating hyaline vascular features consistent with Castleman disease | |
Specialty | Hematology, immunology, rheumatology, pathology |
Diagnostic method | Based on patient history, physical exam, laboratory testing, medical imaging, histopathology |
Frequency | approximately 1500-1800 new cases per year in the United States |
Idiopathic multicentric Castleman disease (iMCD) is a subtype of Castleman disease (also known as giant lymph node hyperplasia, lymphoid hamartoma, or angiofollicular lymph node hyperplasia), a group of lymphoproliferative disorders characterized by lymph node enlargement, characteristic features on microscopic analysis of enlarged lymph node tissue, and a range of symptoms and clinical findings.
People with iMCD have enlarged lymph nodes in multiple regions and often have flu-like symptoms, abnormal findings on blood tests, and dysfunction of vital organs, such as the liver, kidneys, and bone marrow.
iMCD has features often found in autoimmune diseases and cancers, but the underlying disease mechanism is unknown. Treatment for iMCD may involve the use of a variety of medications, including immunosuppressants and chemotherapy.
Castleman disease was named after Dr. Benjamin Castleman, who first described the disease in 1956. The Castleman Disease Collaborative Network is the largest organization focused on the disease and is involved in research, awareness, and patient support.
Patients with iMCD may experience enlarged lymph nodes in multiple lymph node regions; systemic symptoms (fever, night sweats, unintended weight loss, fatigue); enlargement of the liver and/or spleen; extravascular fluid accumulation in the extremities (edema), abdomen (ascites), or lining of the lungs (pleural effusion); lung symptoms such as cough and shortness of breath; and skin findings such as cherry hemangiomas. [1]
The cause of iMCD is not known and no risk factors have been identified. [2] Genetic variants have been observed in cases of Castleman disease; [3] however, no genetic variant has been validated as disease causing.
Unlike HHV-8-associated MCD, iMCD is not caused by uncontrolled HHV-8 infection. [2]
The disease mechanism of iMCD has not been fully described. It is known that interleukin-6 (IL-6), a molecule that stimulates immune cells, plays a role in some cases of iMCD. IL-6 levels measured in some patients with iMCD increase and decrease with corresponding changes in disease activity, mice treated with IL-6 develop features of iMCD, and blockade of the IL-6 pathway using the medications siltuximab and tocilizumab effectively treats some patients with iMCD. However, many patients with iMCD do not demonstrate elevated levels of IL-6 and IL-6 levels are not strongly correlated with response to treatment with anti-IL-6 medications. [1] In cases where IL-6 does play a role, the underlying cause of elevated IL-6 levels and the cells responsible for producing IL-6 remain unknown. [2]
Several theoretical mechanisms for iMCD have been proposed based on existing research and observed similarities between iMCD and other diseases that present with similar clinical findings and lymph node histology: [2]
There have been no reported cases of UCD transforming into iMCD.[ citation needed ]
iMCD is diagnosed according to evidence-based consensus diagnostic criteria, which require a thorough evaluation including patient history, physical exam, laboratory testing, radiologic imaging, and microscopic analysis (histology) of biopsied tissue from an enlarged lymph node.[ citation needed ] Diagnosis of iMCD requires clinical abnormalities, exclusion of other diseases, and a lymph node biopsy showing features consistent with Castleman disease. A lymph node biopsy alone is not sufficient to make the diagnosis.[ citation needed ]
Laboratory testing may demonstrate elevated C-reactive protein, decreased hemoglobin levels (anemia), low albumin levels, elevated creatinine, increased immunoglobulin levels, and abnormal (elevated or decreased) platelet counts. [1] Patients may also have elevations of molecules involved in inflammation (cytokines), such as Interleukin 6 (IL-6) and vascular endothelial growth factor (VEGF). [4]
Radiologic imaging will demonstrate enlarged lymph nodes in multiple regions, which are typically 18F-fluorodoxyglucose (FDG) avid on positron-emission tomography (PET). [5]
iMCD is commonly seen in patients with POEMS syndrome, but it is unclear if iMCD occurs as an independent disease process or a manifestation of POEMS syndrome in these patients. [5] Patients with iMCD have increased risk for solid tumors and cancers of the blood. [1] Occasionally, patients with iMCD present with lymphocytic interstitial pneumonitis. [5]
iMCD patients with thrombocytopenia, anasarca, myelofibrosis, renal dysfunction, and organomegaly syndrome (TAFRO syndrome) are considered to have a distinct clinical subtype of iMCD. Patients often have rapid progression of symptoms and frequently develop severe organ dysfunction. Compared to iMCD patients without TAFRO syndrome, iMCD patients with TAFRO syndrome are more likely to present with severe abdominal pain, low platelet levels, progressive renal dysfunction, and normal to mildly elevated immunoglobulin levels. [6] While iMCD with TAFRO syndrome was first described in Japanese patients in 2010, cases of iMCD with TAFRO syndrome have since been reported in non-Japanese patients in many other countries. [5]
Castleman disease describes a group of at least 3 distinct disorders—Unicentric Castleman disease (UCD), human herpesvirus 8 associated multicentric Castleman disease (HHV-8-associated MCD), and idiopathic multicentric Castleman disease (iMCD). Identifying the correct subtype of the disease is important, as the three disorders vary significantly in symptoms, clinical findings, disease mechanism, treatment approach, and prognosis. [5]
iMCD may be further differentiated by the presence of associated diseases, such as polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes syndrome (POEMS syndrome), or by distinct clinical features, such as thrombocytopenia, anasarca, myelofibrosis, renal dysfunction, and organomegaly syndrome (TAFRO syndrome). [5]
Diagnosis of iMCD requires: the presence of both major criteria, multiple regions of enlarged lymph nodes as demonstrated by medical imaging; the presence of at least two minor criteria, at least one of which must be an abnormal laboratory test; and exclusion of diseases that can mimic iMCD.[ citation needed ]
Radiologic imaging must demonstrate enlarged lymph nodes in multiple regions. [5]
The microscopic appearance (histology) of biopsied tissue from an enlarged lymph node must demonstrate a constellation of features consistent with Castleman disease. There are three patterns of characteristic histologic features associated with iMCD: [5]
iMCD most commonly demonstrates plasmacytic features; however, hypervascular features or a mixture of both hypervascular and plasmacytic features may also be seen in iMCD lymph nodes. The clinical utility of subtyping iMCD by histologic features is uncertain, as histologic subtypes do not consistently predict disease severity or treatment response.[ citation needed ]
Staining with latency-associated nuclear antigen (LANA-1), a marker of HHV-8 infection, must be negative to diagnose iMCD. [5]
Patients must experience at least two of the following 11 minor criteria with at least one being an abnormal laboratory test. [5]
Laboratory tests:
Clinical features:
Diagnosis requires exclusion of diseases that can present with similar clinical findings and similar appearance on microscopic analysis of tissue from an enlarged lymph node. Diseases that must be excluded in the diagnosis of iMCD include infectious diseases, such as HHV-8-associated MCD, Epstein-Barr virus mononucleosis, and reactive lymphadenopathy; autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis; and cancers, including lymphoma, multiple myeloma, and primary lymph node plasmacytoma. [5]
Due to the rarity of iMCD, data regarding treatment is limited and based on a combination of observational case series, case reports, and a single randomized clinical trial. Unlike UCD, for which surgery is the treatment of choice and curative for most patients, surgery is not effective in iMCD. [7] Instead of surgical treatment, a variety of medications are used based on disease severity and a patient's response to prior treatments. Siltuximab, a monoclonal antibody targeting IL-6, is the only medication approved by the United States Food and Drug Administration (FDA) for the treatment of iMCD; however, successful use of other medications has been reported in the literature. [8]
In 2018, the first evidence-based consensus treatment guidelines for iMCD were published by an international group of experts in the field. [9] In addition to creating a treatment algorithm for iMCD, these treatment guidelines established common definitions for disease severity and response to treatment.[ citation needed ]
Patients with iMCD are classified as having severe or non-severe disease based on the 5 criteria listed below. Patient with 2 or more of the below criteria are classified as having severe disease while patients with 0-1 of the criteria are classified as having non-severe disease.[ citation needed ]
Patients with iMCD are evaluated for treatment response based on changes in symptoms, sizes of involved lymph nodes, and laboratory testing. Each category is graded as a complete response, partial response, stable disease, or progressive disease. Overall treatment response is determined by the lowest category grade. For example, a patient with a complete laboratory response, a partial symptom response, and complete lymph node response would be given an overall treatment response of partial response. See below for descriptions of the criteria and grading of responses.[ citation needed ]
Laboratory tests include all of the following: C-reactive protein, Hemoglobin, Albumin, and eGFR.
Four symptoms are assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4): Fatigue, anorexia, fever, and body weight[ citation needed ]
Treatment response for lymph nodes is evaluated using radiologic imaging and graded as complete response, partial response, stable disease, and progressive disease based on modified Cheson criteria. [10]
The treatment algorithm for iMCD is based primarily on disease severity and response to treatment. Because of the high rate of relapse with withdrawal of treatment, most patients with iMCD are treated with medications indefinitely.[ citation needed ]
Siltuximab, an IL-6 blocker, is the recommended treatment for all patients with non-severe iMCD regardless of measured IL-6 levels. Tocilizumab, a drug that also targets the IL-6 pathway, is commonly used as an alternative to siltuximab when siltuximab is unavailable. Corticosteroids may be added to anti-IL-6 therapy depending on clinical presentation. Rituximab, a drug targeting B-cells, is primarily recommended as a second line therapy for patients who do not respond to siltuximab or tocilizumab, but may be used as a first line agent in appropriate patients.[ citation needed ]
For patients with non-severe disease who fail to respond to siltuximab, tocilizumab, and rituximab, treatment recommendations are not well defined. Cytotoxic chemotherapies have been reported to induce remission in patients with non-severe iMCD; however, the use of cytotoxic chemotherapies is not currently recommended for non-severe iMCD due to high likelihood of relapse and severe side effect profiles. As an alternative, immunomodulators such as thalidomide, cyclosporine A, sirolimus, bortezomib, and anakinra are recommended due to their similar response rates and more favorable long term side effect profiles.[ citation needed ]
Recommended initial treatment for all patients with severe iMCD is high dose steroids combined with an anti-IL-6 agent such as siltuximab or tocilizumab, regardless of measured IL-6 levels. For patients who immediately improve with this regimen, steroids may be slowly tapered, but the anti-IL-6 agent should be continued indefinitely due to the high relapse rate with withdrawal of treatment. Due to the high risk of complications associated with severe iMCD, if patients worsen or fail to improve with high dose steroids and anti-IL-6 therapies, cytotoxic chemotherapy regimens are recommended. Patients with life-threatening disease, particularly those with TAFRO Syndrome, may require advanced measures such as breathing support with a mechanical ventilator or treatment with dialysis for kidney failure.[ citation needed ]
Following improvement in disease status, maintenance therapy with an anti-IL-6 agent or an immunosuppressant medication is typically continued indefinitely, as withdrawal of such medications can lead to relapse.[ citation needed ]
Patients with iMCD require routine assessment of treatment response and disease progression. It is recommended that follow-up visits include evaluation of symptoms, physical examination, laboratory testing, and radiologic imaging. [11]
iMCD can present as an acute life-threatening disease in some patients or a chronic disease in others. Some patients have longstanding stable disease while others experience flares of severe disease that may improve with treatment. [1] Successful treatment controls symptoms and organ dysfunction associated with iMCD, improves symptoms and organ dysfunction during disease flares, and prevents future disease flares.[ citation needed ]
Observed survival in a recent study of iMCD patients was 92% at 2 years, 76% at 5 years, and 59% at 10 years. [12]
There are approximately 1500-1800 new cases of iMCD diagnosed per year in the United States. iMCD can occur at any age, but the median age at presentation is approximately 50 years old. There is a slightly increased incidence of iMCD in women. [13]
There have been no published epidemiologic studies of Castleman disease outside of the United States; however, there has been no published data demonstrating increased or decreased incidence of Castleman disease in specific regions or ethnicities.[ citation needed ]
Castleman disease was first described by Dr. Benjamin Castleman in 1956. [14] World Castleman Disease Day was established in 2018 and is held every year on July 23.
The Castleman Disease Collaborative Network was founded in 2012 and is the largest organization focused on Castleman disease. It is a global collaborative network involved in research, awareness, and patient support. [15]
Non-Hodgkin lymphoma (NHL), also known as non-Hodgkin's lymphoma, is a group of blood cancers that includes all types of lymphomas except Hodgkin lymphomas. Symptoms include enlarged lymph nodes, fever, night sweats, weight loss, and tiredness. Other symptoms may include bone pain, chest pain, or itchiness. Some forms are slow-growing while others are fast-growing. Unlike Hodgkin lymphoma, which spreads contiguously, NHL is largely a systemic illness.
Kikuchi disease was described in 1972 in Japan. It is also known as histiocytic necrotizing lymphadenitis, Kikuchi necrotizing lymphadenitis, phagocytic necrotizing lymphadenitis, subacute necrotizing lymphadenitis, and necrotizing lymphadenitis. Kikuchi disease occurs sporadically in people with no family history of the condition.
Castlemandisease (CD) describes a group of rare lymphoproliferative disorders that involve enlarged lymph nodes, and a broad range of inflammatory symptoms and laboratory abnormalities. Whether Castleman disease should be considered an autoimmune disease, cancer, or infectious disease is currently unknown.
Juvenile idiopathic arthritis (JIA), formerly known as juvenile rheumatoid arthritis (JRA), is the most common chronic rheumatic disease of childhood, affecting approximately 3.8 to 400 out of 100,000 children. Juvenile, in this context, refers to disease onset before 16 years of age, while idiopathic refers to a condition with no defined cause, and arthritis is inflammation within the joint.
Lymphadenopathy or adenopathy is a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of an inflammatory type is lymphadenitis, producing swollen or enlarged lymph nodes. In clinical practice, the distinction between lymphadenopathy and lymphadenitis is rarely made and the words are usually treated as synonymous. Inflammation of the lymphatic vessels is known as lymphangitis. Infectious lymphadenitis affecting lymph nodes in the neck is often called scrofula.
POEMS syndrome is a rare paraneoplastic syndrome caused by a clone of aberrant plasma cells. The name POEMS is an acronym for some of the disease's major signs and symptoms, as is PEP.
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.
Minimal change disease(MCD), also known as lipoid nephrosis or nil disease, among others, is a disease affecting the kidneys which causes nephrotic syndrome. Nephrotic syndrome leads to the loss of significant amounts of protein in the urine, which causes the widespread edema (soft tissue swelling) and impaired kidney function commonly experienced by those affected by the disease. It is most common in children and has a peak incidence at 2 to 6 years of age. MCD is responsible for 10–25% of nephrotic syndrome cases in adults. It is also the most common cause of nephrotic syndrome of unclear cause (idiopathic) in children.
In hematology, hemophagocytic lymphohistiocytosis (HLH), also known as haemophagocytic lymphohistiocytosis, and hemophagocytic or haemophagocytic syndrome, is an uncommon hematologic disorder seen more often in children than in adults. It is a life-threatening disease of severe hyperinflammation caused by uncontrolled proliferation of benign lymphocytes and macrophages that secrete high amounts of inflammatory cytokines. It is classified as one of the cytokine storm syndromes. There are inherited and non-inherited (acquired) causes of HLH.
Tocilizumab, sold under the brand name Actemra among others, is an immunosuppressive drug, used for the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis, cytokine release syndrome, COVID‑19, and systemic sclerosis-associated interstitial lung disease (SSc-ILD). It is a humanized monoclonal antibody against the interleukin-6 receptor (IL-6R). Interleukin 6 (IL-6) is a cytokine that plays an important role in immune response and is implicated in the pathogenesis of many diseases, such as autoimmune diseases, multiple myeloma and prostate cancer. Tocilizumab was jointly developed by Osaka University and Chugai, and was licensed in 2003 by Hoffmann-La Roche.
Drug rash with eosinophilia and systemic symptoms or drug reaction with eosinophilia and systemic symptoms (DRESS), also termed drug-induced hypersensitivity syndrome (DIHS), is a rare reaction to certain medications. It involves primarily a widespread skin rash, fever, swollen lymph nodes, and characteristic blood abnormalities such as an abnormally high level of eosinophils, low number of platelets, and increased number of atypical white blood cells (lymphocytes). However, DRESS is often complicated by potentially life-threatening inflammation of internal organs and the syndrome has about a 10% mortality rate. Treatment consists of stopping the offending medication and providing supportive care. Systemic corticosteroids are commonly used as well but no controlled clinical trials have assessed the efficacy of this treatment.
Adult-onset Still's disease (AOSD) is a form of Still's disease, a rare systemic autoinflammatory disease characterized by the classic triad of fevers, joint pain, and a distinctive salmon-colored bumpy rash. The disease is considered a diagnosis of exclusion. Levels of the iron-binding protein ferritin may be extremely elevated with this disorder. AOSD may present in a similar manner to other inflammatory diseases and to autoimmune diseases, which must be ruled out before making the diagnosis.
Siltuximab (INN), sold under the brand name Sylvant, is used for the treatment of people with multicentric Castleman's disease. It is a chimeric monoclonal antibody that binds to interleukin-6. It is an interleukin-6 (IL-6) antagonist.
Anti-interleukin-6 agents are a class of therapeutics. Interleukin 6 is a cytokine relevant to many inflammatory diseases and many cancers. Hence, anti-IL6 agents have been sought. In rheumatoid arthritis they can help patients unresponsive to TNF inhibitors.
Systemic juvenile idiopathic arthritis is a type of juvenile idiopathic arthritis (JIA) with extra-articular manifestations like fever and rash apart from arthritis. It was originally called systemic-onset juvenile rheumatoid arthritis or Still's disease.
Follicular hyperplasia (FH) is a type of lymphoid hyperplasia and is classified as a lymphadenopathy, which means a disease of the lymph nodes. It is caused by a stimulation of the B cell compartment and by abnormal cell growth of secondary follicles. This typically occurs in the cortex without disrupting the lymph node capsule. The follicles are pathologically polymorphous, are often contrasting and varying in size and shape. Follicular hyperplasia is distinguished from follicular lymphoma in its polyclonality and lack of bcl-2 protein expression, whereas follicular lymphoma is monoclonal, and expresses bcl-2.
Large B-cell lymphoma arising in HHV8-associated multicentric Castleman's disease is a type of large B-cell lymphoma, recognized in the WHO 2008 classification. It is sometimes called the plasmablastic form of multicentric Castleman disease. It has sometimes been confused with plasmablastic lymphoma in the literature, although that is a dissimilar specific entity. It has variable CD20 expression and unmutated immunoglobulin variable region genes.
Human herpesvirus 8 associated multicentric Castleman disease is a subtype of Castleman disease, a group of rare lymphoproliferative disorders characterized by lymph node enlargement, characteristic features on microscopic analysis of enlarged lymph node tissue, and a range of symptoms and clinical findings.
Unicentric Castleman disease is a subtype of Castleman disease, a group of lymphoproliferative disorders characterized by lymph node enlargement, characteristic features on microscopic analysis of enlarged lymph node tissue, and a range of symptoms and clinical findings.
David C. Fajgenbaum is an American immunologist and author who is currently an assistant professor at the Perelman School of Medicine of the University of Pennsylvania. He is most well known for his research into Castleman disease.