Eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as allergic granulomatosis,[3]^[4] is an extremely rare autoimmune condition that causes inflammation of small and medium-sized blood vessels (vasculitis) in persons with a history of airway allergic hypersensitivity (atopy).^[5]

It usually manifests in three stages. The early (

Effective treatment of EGPA requires suppression of the immune system with medication. This is typically glucocorticoids, followed by other agents such as cyclophosphamide or azathioprine.^{[citation needed]}

Signs and symptoms

Eosinophilic granulomatosis with polyangiitis consists of three stages, but not all patients develop all three stages or progress from one stage to the next in the same order;

The prodromal stage is characterized by allergy. Almost all patients experience asthma and/or allergic rhinitis,[9] with more than 90% having a history of asthma that is either a new development, or the worsening of pre-existing asthma,^[10] which may require systemic corticosteroid treatment.^[7] On average, asthma develops from three to nine years before the other signs and symptoms.^[7]

The allergic rhinitis may produce symptoms such as

The third and final stage, and hallmark of EGPA, is inflammation of the blood vessels, and the consequent reduction of blood flow to various organs and tissues.^[7] The damage done to the blood vessels can be explained by the overabundance of eosinophils that are produced and flowing throughout the vasculature of the body; eosinophil production, while essential for assisting inflammatory responses to infections and diseases, can lead to tissue damage when it is done in excess.^[15] Local and systemic symptoms become more widespread and are compounded by new symptoms from the vasculitis.^[14]

Severe complications may arise. Blood clots may develop within the damaged arteries in severe cases, particularly in arteries of the abdominal region, which is followed by infarction and cell death, or slow atrophy.^[14] Many patients experience severe abdominal complaints; these are most often due to peritonitis and/or ulcerations and perforations of the gastrointestinal tract, but occasionally due to acalculous cholecystitis or granulomatous appendicitis.^[14]

The most serious complication of the vasculitic stage is

The American College of Rheumatology 1990 criteria for diagnosis of Churg–Strauss syndrome lists these criteria:^{[needs update]}

• Asthma
• hypereosinophilia
  , i.e. eosinophil blood count greater than 1,500/microliter
• Presence of
  mononeuropathy or polyneuropathy
• Unfixed pulmonary infiltrates
• Presence of paranasal sinus abnormalities
• Histological evidence of extravascular eosinophils

For classification purposes, a patient shall be said to have EGPA if at least four of these six criteria are positive. The presence of any four or more of the six criteria yields a sensitivity of 85% and a specificity of 99.7%.^{[2][needs update]}

Risk stratification

The French Vasculitis Study Group has developed a five-point system ("five-factor score") that predicts the risk of death in Churg–Strauss syndrome using clinical presentations. These factors are:^[19]

• Reduced
  renal function
  (creatinine >1.58 mg/dl or 140 μmol/L)
• Proteinuria (>1 g/24h)
• Gastrointestinal hemorrhage, infarction, or pancreatitis
• Involvement of the central nervous system
• Cardiomyopathy

Having none of these factors indicates milder case, with a five-year mortality rate of 11.9%. The presence of one factor indicates severe disease, with a five-year mortality rate of 26%, and three or more indicate very severe disease: 46% five-year mortality rate.[20]

Imaging

On CT scan of the lungs, peripheral

Treatment for eosinophilic granulomatosis with polyangiitis includes glucocorticoids (such as prednisolone) and other immunosuppressive drugs (such as azathioprine and cyclophosphamide). In many cases, the disease can be put into a type of chemical remission through drug therapy, but the disease is chronic and lifelong.^{[citation needed]}

A systematic review conducted in 2007 indicated all patients should be treated with high-dose steroids, but in patients with a five-factor score of one or higher, cyclophosphamide pulse therapy should be commenced, with 12 pulses leading to fewer relapses than six. Remission can be maintained with a less toxic drug, such as azathioprine or methotrexate.^[22]

On 12 December 2017, the

In addition to mepolizumab, a number of emerging targeted biotherapies—including the anti-IgE monoclonal antibody omalizumab, immunomodulation with Interferon-α, and B cell therapy with rituximab—may lead to increasingly personalized treatment regimens for future EGPA patients. A review of EGPA treatments conducted in 2020 proposes integrating targeted biotherapies into EGPA management plans following failure of treatment with corticosteroids.[25]

History

Eosinophilic granulomatosis with polyangiitis was first described by

The memoir Patient, by musician Ben Watt (of Everything but the Girl fame), deals with his experience with EGPA in 1992, and his recovery.^[29] Watt's case was unusual in that it mainly affected his gastrointestinal tract, leaving his lungs largely unaffected; this unusual presentation contributed to a delay in proper diagnosis. His treatment required the removal of 5 m (15 ft) of necrotized small intestine (about 75%), leaving him on a permanently restricted diet.^[29]

Umaru Musa Yar'Adua, the president of Nigeria from 2007 to 2010, reportedly had EGPA and died in office of complications of the disease.^[30]

DJ and author Charlie Gillett was diagnosed with EGPA in 2006; he died four years later.^[31]

Japanese ski jumper Taku Takeuchi, who won the bronze medal in the team competition in 2014, has the disease and competed at the Sochi Olympics less than a month after being released from hospital treatment.^[32]

New Zealand reporter and television presenter Toni Street was diagnosed with the condition in 2015.^[33][34] Street has had health problems for several years, including removal of her gallbladder four months prior.^[35]

American professional basketball player Willie Naulls died on 22 November 2018 in Laguna Niguel, California, from respiratory failure due to EGPA,^[36] which he had been battling for eight years.^[37]

Canadian stand-up comic Candy Palmater died on December 25, 2021, shortly after being diagnosed with EGPA.^[38]

Filipino actress Kris Aquino, sister of former Philippine President Benigno Aquino III, revealed on 16 May 2022 that she was diagnosed with EGPA.^[39]

References