NEW DIAGNOSTIC POSSIBILITIES FOR DETERMINING THE NATURE OF RESPIRATORY SYMPTOMS IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE
As of today, it is not completely known why there is a large number of eosinophils in the peripheral blood of some patients with chronic obstructive pulmonary disease (COPD) in the stable phase of the pathological process: it possibly evidences of the mistaken diagnosis of COPD instead of bronchial asthma (BA); possible respiratory symptoms in these patients due not only to the action of air pollutants, and hypersensitivity to household, epidermal, mold allergens; perhaps these are the cases of overlap syndrome. Recently, in order to address some of the issues mentioned above, new diagnostic possibilities have appeared, among them − the method of molecular allergy diagnosis Phadiatop, which allows to determine the molecular structure of allergenic proteins, “guilty” of the body’s sensitization to certain allergens. If the Phadiatop test sample results are positive, it is necessary to define a group of inhaled allergens, and then − the specific allergens in groups with the positive result. The negative Phadiatop test result means that the allergic-like symptoms are not caused by respiratory allergies, therefore, it is necessary to carry out studies of other organs and systems (digestive, immune, endocrine, etc.). We conducted a pilot study in 12 patients (average age − 65.0 ± 3.8 years, 7 men, and 5 women) with a long verified diagnosis (more than 5 years ago) of COPD stage III. Determining the level of eosinophil and total IgE in the blood, as well as the study of the Phadiatop test were conducted in the dynamics on the background of the planned treatment of patients − at their inclusion in the study, after 6 and 12 months. The results showed that the presence of signs of respiratory allergosis in COPD patient (according to Phadiatop test) are most often accompanied by increased levels of eosinophils and / or total IgE level in blood. However, in a certain proportion of patients with laboratory evidence of respiratory allergosis these indicators can be normal. Increased total IgE levels in the blood of COPD patient without the confirmed presence of signs of respiratory allergosis (according to the Phadiatop test) narrows the scope for further diagnostic search in the direction of another (non-respiratory) disease. Taking into account the data that the Phadiatop test results may change in the dynamics of patients’ follow-up, it can be assumed that the manifestations of respiratory allergosis may change over time. Since the Phadiatop test is more sensitive and specific for the detection of symptoms of respiratory allergosis, it should be more widely used at the stages of screening and follow-up of patients with COPD (instead of determining the level of blood eosinophils and / or total IgE).
2. Fattahi, F. Atopy is a risk factor for respiratory symptoms in COPD patients: results from the EUROSCOP study / Fattahi F. et al. // Resp. Res. – 2013. – Vol. 14. – P. 10.
3. Global initiative for chronic obstructive lung disease (GOLD). Global strategy for diagnosis, management, and prevention of chronic obstructive pulmonary disease. Update 2016. [E-source] – Mode of access: http://www.goldcopd.org/uploads/users/files/WatermarkedGlobal%20Strategy%202016(1).pdf.
4. Jones, P.W. Development and first validation of the COPD Assessment Test. / Jones P.W. et al. // Eur. Respir. J. – 2009. – Vol. 34. – P. 648–654.
5. Raherison, C. IgE level and Phadiatop® in an elderly population from the PAQUID cohort: relationship to respiratory symptoms and smoking / Raherison C. et al. // Allergy. – 2004. – Vol. 59 (9). – P. 940–945.
Vidal, C. Evaluation of the phadiatop test in the diagnosis of allergic sensitization in a general adult population / Vidal C. et al. // J. Investig. Allergol. Clin. Immunol. – 2005. – Vol. 15 (2). – P. 124–130.