Diseases of the respiratory system are among the most common diseases and so present a significant medical and social problem as the fourth leading cause of mortality [1, 2]. Among chronic respiratory diseases, much attention is paid to chronic obstructive pulmonary disease (COPD) and chronic bronchitis (CB) [3–5]. From 4% to 15% of total adult population suffer from COPD. The frequency of chronic bronchitis in different countries varies in a wide range from 10% to 47% on an average . The views of the researchers on the relationship of CB and COPD have been gradually changing with better understanding of the pathogenesis of these diseases but still they remain obscure. Earlier, the symptoms and morphological changes characteristic of chronic bronchitis were considered as stage 0 or a developing increased risk of COPD . Later, chronic bronchitis was considered as an independent disease which causes no lung function decline . In recent years, the researchers have become convinced that chronic bronchitis may precede the development of COPD . Patients with COPD usually ask for medical help only in the late stages of the disease, when medical treatment cannot prevent the progression of the disease and the development of complications. According to this problem, the possibly early preclinical diagnosis of COPD is urgent [1, 2].
Respiratory diseases are accompanied by the development of the chronic inflammatory reaction that greatly aggravates the course and prognosis of the underlying disease . The development of the inflammation in the pulmonary diseases involves also participation of the inflammatory mediators (cytokines, histamine, neutral proteases, and eicosanoids) [9–16]. Particular attention is paid to the lipid mediators - eicosanoids (prostaglandins, leukotrienes, thromboxanes), which are the final products of the metabolism of polyunsaturated fatty acids (PUFAs) [11, 13, 17]. The violation of the membrane FA composition and FA metabolism is an important factor in the development of the pulmonary diseases [18, 19]. Polyunsaturated fatty acids are on one hand the structural components of biological membranes [20, 21] and on the other hand they are substrates for synthesis of eicosanoids . Changes in the FA profile of the lipid membranes may lead to violation of the aggregation, and diffusion transfer of membrane components, the activity of membrane-bound enzymes and the expression of receptors, the membrane permeability and transport properties [20, 21]. Many functions of immune cells, such as secretion, chemotaxis, and sensitivity to microorganisms depend also on the fluidity of the membrane . The literature does not sufficiently highlight the qualitative and quantitative composition of FAs of cell membranes in chronic pulmonary diseases. Moreover, the results of different authors differ significantly, which may be associated with a variety of biomaterials used for FA analysis (red blood cells, plasma) and the degree of clinical severity of the pulmonary disease [24, 25]. There are no available data about possibility of using FA composition as a prognostic test for the complications in the chronic respiratory diseases.
Objective: To assess the fatty acid composition of the membranes of the red blood cells in patients with chronic bronchitis and stable chronic obstructive pulmonary disease.