Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity response to the fungus Aspergillus fumigatus, the spores of which are ubiquitous in soil and are commonly found in the sputum of healthy individuals. A.Fumigatus is responsible for a spectrum of lung diseases commonly grouped under the heading of aspergilloses. Aspergillus fumigatus is a fungus of the genus Aspergillus, and it is one of the most common Aspergillus species to cause disease in humans with a weakened immune response. ... Aspergillus fumigatus is a fungus of the genus Aspergillus, and it is one of the most common Aspergillus species to cause disease in humans with a weakened immune response. ... Aspergillosis is an infection or an allergic response caused by a fungus of the Aspergillus type. ...

Epidemiology

Estimating the prevalence of ABPA has been made difficult by lack of uniform diagnostic criteria and standardised tests. It usually occurs as a complication of other chronic lung disease, in particular asthma or cystic fibrosis. It is estimated that in the US ABPA may be present in between 0.5 and 2% of all asthma patients.

Immunology and pathophysiology

There is both a type I (atopic) and type III hypersensitivity response. Precipitating antibodies incite a type I acute hypersensitivity reaction with release of immunoglobulin E (IgE) and immunoglobulin G (IgG), resulting in mast cell degranulation with bronchoconstriction and increased capillary permeability. Immune complexes and inflammatory cells are then deposited within the bronchial mucosa leading to tissue necrosis and eosinophilic infiltrate, a type III reaction. The subsequent damage to the bronchial wall causes (proximal) bronchiectasis. Repeated acute episodes left untreated can result in progressive pulmonary fibrosis that is often seen in the upper zones and can give rise to a similar radiological appearance to that produced by tuberculosis. This article needs cleanup. ... Atopy (Greek ατοπία - placelessness, not allocatable) or atopic syndrome is the clustering of eczema (atopic dermatitis), allergic conjunctivitis, allergic rhinitis and asthma in certain individuals. ... A mast cell (or mastocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. ... Bronchoconstriction is the constriction of the airways in the lungs due to the tighting of surrounding smooth muscle, with consequent coughing, wheezing, and shortness of breath. ... Fibrosis is the formation or development of excess fibrous connective tissue in an organ or tissue as a reparative or reactive process, as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue. ... Tuberculosis (commonly shortened to TB) is an infection caused by the bacterium Mycobacterium tuberculosis, which most commonly affects the lungs (pulmonary TB) but can also affect the central nervous system (meningitis), lymphatic system, circulatory system (Miliary tuberculosis), genitourinary system, bones and joints. ...

The main features are therefore:

• bronchospasm
• increased mucus production and plugging of distal airways, leading to their collapse
• bronchiectasis

Clinical picture

Symptoms

• wheeze
• cough
• fever
• malaise
• recurrent pneumonia (eosinophilic, therefore not responding to antibiotics)
• expectoration of mucoid plugs (containing the fungal hyphae)
• unexplained worsening of asthma or cystic fibrosis

A wheeze is a continuous, coarse, whistling sound produced in the respiratory airways during breathing. ... See Fever for the Kylie Minogue album; Fever is also a song by Otis Blackwell. ... Malaise is a term used to refer to a general state of discomfort, tiredness, or illness. ... Pneumonia is an illness of the lungs and respiratory system in which the microscopic, air-filled sacs (alveoli) responsible for absorbing oxygen from the atmosphere become inflamed and flooded with fluid. ...

Investigations

A full blood count usually reveals eosinophilia and there is a raised serum IgE. Chest radiography shows various transient abnormalities: Eosinophilia is the state of having high eosinophil granulocytes in the blood. ...

• consolidation or collapse
• thickened bronchial wall markings
• peripheral shadows
• signs of proximal bronchiectasis

Aspergillus specific tests:

• precipitating antibodies to aspergillus species in >90% of cases
• aspergillus-specific IgE RAST test
• skin-prick test is almost always positive to Aspergillus fumigatus

A RAST test (short for radioallergosorbent test) is a blood test used to determine what a person is allergic to. ...

Management

The aim of treatment is to suppress the immune reaction to the fungus and to control bronchospasm.

The immune reaction is suppressed using oral corticosteroids: In physiology, corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. ...

• a high dose of prednisolone or prednisone (30 to 45 mg per day) in acute attacks
• a lower maintenance dose (5-10 mg per day)

Mucus plugs may be removed by bronchoscopic aspiration. It is almost impossible to eradicate the fungus but sometimes itraconazole (an anti-fungal) is used in combination with steroid therapy. Regular monitoring of the condition includes chest x-rays, pulmonary function tests, and serum IgE. The antibody levels usually fall as the disease is controlled, but they may rise again as an early sign of flare-ups. Prednisolone is a synthetic corticosteroid drug which is usually taken orally and can be used for a large number of different conditions. ... Prednisone is a synthetic corticosteroid drug which is usually taken orally and can be used for a large number of different conditions. ... Itraconazole (marketed as Sporanox® by Janssen Pharmaceutica) is an antifungal agent that is prescribed to patients with fungal infections. ... Spirometry (meaning the measuring of breath) is the most common of the Pulmonary Function Tests (PFTs), measuring lung function, specifically the measurement of the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. ...

See also

• Aspergillosis
• Asthma
• Cystic fibrosis
• Bronchiectasis

References

• P.Kumar and M.Clark, eds. Clinical Medicine, 4th Edition 1998
• M.Longmore, I.B.Wilkinson and S.Rajagopalan, eds. Oxford Handbook of Clinical Medicine, 6th Edition 2004
• P.A.Greenberger and R.Patterson. Allergic bronchopulmonary aspergillosis and the evaluation of the patients with asthma. J Allergy Clin Immunol 1988;81:646-650
• V.P.Kurup, B.Banerjee, P.A.Greenberger, J.N.Fink. Allergic Bronchopulmonary Aspergillosis: Challenges in Diagnosis. From Medscape General Medicine. full text

External links

• Medscape. ABPA: Challenges in Diagnosis (free registration required)
• GP notebook. ABPA
• Emedicine. Aspegillosis, thoracic (free registration required)
• Merck. APBA
• Medpix. ABPA radiology pictures