Churg-Strauss syndrome

Content

Introduction

Introduction

Eosinophilic Granulomatosis with Polyangiitis EGPA, formerly known as Churg-Strauss syndrome, is an inflammation of the small and medium-sized blood vessels (vasculitis).

In general, inflammation is a natural response of the body's defense system (immune system) to injury or infection and helps fight invading microorganisms. However, in some cases, for reasons not always defined, inflammation occurs against one's own healthy tissues (auto-inflammatory or autoimmune response). In particular, in vasculitis the immune system attacks the blood vessels causing swelling and obstruction of the same.

In EGPA, the most commonly affected organs are the lungs and skin, but the heart, kidneys, nerves and intestines may also be involved.

In this type of vasculitis, both in the blood and in the affected tissues, there are very high levels of a type of white blood cell, eosinophils, which in addition to being correlated with allergies, fight infections caused by parasites.

EGPA affects men and women equally, with a frequency of about 11-13 people per million. The average age at which it is discovered is around 40; it is very rare in children over 65 years of age.

Symptoms

Symptoms

People with eosinophilic granulomatosis with polyangiitis (EGPA) often have nonspecific disorders (symptoms) such as fever, malaise, anemia, and weight loss. A frequent disorder is a severe form of asthma that appears in adulthood. Sinusitis and a host of other ailments such as skin rashes, pins and needles or numbness, intestinal problems, anemia, heart problems, muscle and joint pain and fatigue are often present.

An important indicator to ascertain (diagnose) EGPA is represented by the evolution over time of the disorders which often develop in 3 phases:

  • first "prodromal" phase, people often suffer from allergies: allergic asthma, which usually appears in adulthood, sinusitis since adolescence, allergic rhinitis and nasal polyposis which tends to recur after surgical removal. The prodromal phase can persist for many years
  • second "eosinophilic" phase, high levels of eosinophils are found in the blood and, often, also infiltrated in the tissues of the affected organs such as the respiratory system, the gastrointestinal tract (abdominal pain, nausea, vomiting, diarrhea and more rarely bleeding) and the heart
  • third and last "vasculitic" phase, begins the inflammation of the small and medium vessels (vasculitis), often between the ages of twenty and thirty. Tiredness, weight loss and fever often precede this phase. In the third and last phase the disorders caused by the involvement of the present vessels predominate. in the various organs and systems. This phase is essentially characterized by:
    • peripheral neuropathy, (multiple mononeuritis in 65-75% of cases)
    • lesions on the skin, most frequently in relief, appear in about 51% of people
    • kidney problems, (in about 25% of people they consist of focal or segmental necrotizing glomerulonephritis and, more rarely, interstitial nephritis or mesangial glomerulonephritis)
    • damage to the heart, (cardiomyopathy, vasculitis, heart failure and pericarditis)

The sequence of phases is not always so well defined, they can overlap and some disturbances may not occur at all.

Causes

Causes

Although the exact cause of eosinophilic granulomatosis with polyangiitis (EGPA) is not known, the importance of allergic manifestations suggests an autoimmune process associated with a combination of as yet unidentified factors.

In autoimmune diseases, the body's defense system (immune system) instead of merely reacting against invading organisms, such as bacteria and viruses, attacks healthy tissues, causing inflammation. About 40% of people with EGPA have antibodies directed to antigens present in the neutrophil cytoplasm (ANCA) which are typical markers of autoimmune vasculitis.

Diagnosis

Diagnosis

The most recent rules for ascertaining eosinophilic granulomatosis with polyangiitis (EGPA), written by the European Respiratory Society (ERS), state that a person with EGPA should have:

  • asthma
  • high levels of eosinophils in the blood (> 10%)
  • damage from vasculitis to skin, nerves, kidneys, lungs, heart
  • blood tests suggesting vasculitis

The ERS also suggested a subtype of EGPA called hypereosinophilic asthma with systemic manifestations (HASM), in which there is no vasculitis but damage caused by eosinophilic white blood cells to the organs.

The diagnosis of EGPA is suggested by the symptoms (symptoms) present and the results of laboratory tests but, generally, it must be confirmed with a biopsy of the lung or other affected tissue.

Diagnostic tests

Blood tests, blood tests show high levels of eosinophilic white blood cells in patients with active EGPA. Tests are ordered to assess inflammatory activity (IgE levels, C-reactive protein, and ESR) and the presence of a type of vasculitis-related antibody (ANCA).

Chest X-ray, people with active EGPA may have lung tissue damage (infiltrates) visible on a chest X-ray.

Spirometry, spirometry is the most common and widespread examination of respiratory function. In the case of asthma, which is always present in patients with EGPA, this test shows the inability to exhale rapidly as required.

Biopsy, is the best way to ascertain the disease. Biopsy (taking a small piece of tissue to be analyzed) can show an accumulation of eosinophils (known as eosinophilic granuloma) and damage to blood vessels (vasculitis). Biopsies can be taken from any affected tissue (lung, nerves, skin, kidneys, etc.).

Bronchial washing, the investigation is performed with an instrument, the bronchoscope, which is inserted through the nose or mouth to perform a bronchial wash. The collected liquid is examined in the laboratory. This test is very useful for ruling out other problems such as infections or tumors.

Heart tests, EGPA can damage the heart which must therefore be kept under control through the electrocardiogram (ECG) and / or echocardiogram.

Current and past health status, present ailments and laboratory test results must be evaluated together to ascertain the disease.

Therapy

Therapy

High-dose corticosteroid therapy generally yields good results. In some cases it may be necessary to combine an immunosuppressive drug to avoid the recurrence of the disorders following the reduction of cortisone doses or its suspension. In the absence of treatment, however, survival 5 years from the discovery of the disease is about 25%.

Corticosteroids, steroids, such as prednisolone, are the primary resource in the care of people with eosinophilic granulomatosis with polyangiitis (EGPA). The start of treatment involves rather high levels of steroids which should be gradually reduced over the years. Dose reduction must be performed very carefully because if it is too rapid it can lead to greater activation of EGPA. Steroids can have multiple side effects.

Nasal and inhalation steroids, in addition to tablets, people with EGPA often need steroid sprays to control asthma and sinusitis and to breathe more easily.

Cyclophosphamidecyclophosphamide can be used in people with severe EGPA or who do not respond well to steroid treatment. This drug can be given by mouth or by intravenous injection for a limited period of time.

Azathioprine, azathioprine (immunosuppressant) can be added to treatment to reduce the level of steroids needed to control the disease.

MethotrexateUsed in a similar way to azathioprine, methotrexate (an immunosuppressant) is sometimes used to help lower steroid doses.

Rituximab, rituximab (monoclonal antibody directed against the CD20 protein found on B lymphocytes) is occasionally used in people with severe EGPA who have not benefited from other treatments.

Mepolizumab, treatment with mepolizumab (monoclonal antibody directed against interleukin 5) appears to be associated with significant benefits in adults who do not respond to other treatments (Italian Medicines Agency, AIFA: "FDA approves the first drug for eosinophilic granulomatosis with polyangiitis ").

Alternative medicine, there is no scientific evidence that any type of alternative medicine is useful in the treatment of EGPA and such products should not replace traditional medical treatments.

Complications

Complications

Without treatment, eosinophilic granulomatosis with polyangiitis (EGPA) can be fatal but steroid treatments have improved the life expectancy of patients. People with heart, kidney, gut and brain involvement appear to be at higher risk and may require more intensive care to prevent complications of the disease.

Although most of the disorders (symptoms) of EGPA are reversible with therapy, the obstruction of the vessels that carry blood to the nerves can permanently damage them and cause disability. Involvement of the heart is the leading cause of death and causes 50% of all deaths.

Bibliography

Bibliography

Vasculitis UK. About Vasculitis (English)

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