Daily Archive 07.11.2019

Exogenous Allergic Bronchioloalveolitis

Exogenous allergic bronchioloalveolitis (synonyms of the disease: hypersensitive pneumonitis) – diseases caused by inhalation of organic dust with a particle diameter of up to 5 μm, characterized by an inflammatory process (mainly in the alveoli and bronchioles) with interstitial infiltration and the formation of granulomas, which tend to fibrosis with repeated prolonged contact antigen. For the first time, a lung disease similar to exogenous allergic bronchioalveolitis was described in 1713 by Ramazzini, in more detail in 1932, Campbell (“farmer’s lung”). The name “exogenous allergic alveolitis”, proposed by Pepis in 1967 due to the frequent involvement of bronchioles in the process, is not entirely accurate, the term “exogenous allergic bronchioloalveolitis” is considered more correct . This is a relatively rare disease, but incidence can be high in certain areas. Outbreaks of it are most often observed in years with wet summers, usually a lot of snow falls.

Etiology of exogenous allergic bronchioloalveolitis

Organic substances that cause exogenous allergic bronchioloalveolitis are very diverse. The most common cause of the disease is thermophilic actinomycetes, bacteria with a morphological characteristic of fungi that are ubiquitous and are found in earth, compost, hay, straw dust, grain, sawdust and other wet organic materials that can mold and heat up to a temperature of 40-60 ° C optimal for mushroom growth. Actinomycetes also reproduce in the heating, cooling and air conditioning systems of the recirculating type. Many microorganisms have been identified in compressors and water from vacuum pumps that can cause the disease. The most important representative of thermophilic actinomycetes is Micropolyspora faeni, whose spores with a diameter of less than 5 microns can penetrate the periphery of the lung. Actinomycetes contain three antigens: A, B, C. Antigens A and B are proteins that cross-react with antigens of fungi of other species (Aspergillus, Mucor), C is a polysaccharide that is most specific. An important group of etiological factors of the disease is whey proteins and dust from the droppings of various birds (pigeons, parrots, chickens, ducks, turkeys). Bird droppings extract (a mixture of soluble proteins, glycoproteins and polysaccharides) is a species-specific antigen – serum g-globulin. Antigens of the gastrointestinal tract of birds, cross-react with serum proteins. The frequency of exogenous allergic bronchioloalveolitis due to bird proteins is low; more often, the disease is caused by the proteins of pigeons and parrots. Exogenous allergic bronchioloalveolitis can also provoke other animal proteins, in particular, inhalation of rat serum droplets is described as the cause of the disease in laboratory workers. The disease can cause plant dust (from cotton, hemp, hemp, cork) and some medications: pituitary powder in patients with diabetes insipidus, sometimes Intal.