FIBROSING PULMONARY SARCOIDOSIS: COMPUTED TOMOGRAPHY-BASED CLINICAL CHARACTERISTICS AND PHENOTYPES

Abstract. Introduction. Sarcoidosis is the epithelioid cell granulomatosis, the exact cause of which is unknown. In 5-20% of cases, pulmonary fibrosis develops that can adversely affect the patient’s prognosis. Aim. Assessing the clinical manifestations of fibrosing pulmonary sarcoidosis and comparing patients relevant to its various phenotypes, according to computed tomography findings. Materials and Methods. Findings in 81 pulmonary fibrosis patients were analyzed using high-resolution computed tomography. All patients were examined by a pulmonologist. Along with the assessment of laboratory, functional, and radiology findings in all patients, four phenotypes of fibrosis manifestations were compared according to high-resolution computed tomography findings, which were accepted using the international Delphi consensus technique. Results and Discussion. Among the patients, there were 43 (53.1%) women and 38 (46.9%) men, and their average age was 51.81±11.5 years. The median fibrosis formation duration was 8.20 [3.0; 11.0] years from the detection date. The primary examination was conducted in multidisciplinary institutions (53.1%), in tuberculosis dispensaries (31.1%), in oncology dispensaries (11.1%), and 3 patients were initially examined in federal research institutes. Decreased forced vital lung capacity was found in 58% of patients, increased blood calcium levels were in 6.5%, and in 17.5% it was found increased in their daily urine, and the increased angiotensin-converting enzyme levels were found in 38.3% of the patients studied. When analyzing the therapy performed prior to the fibrosis development, all three prerequisites of the Federal Clinical Guidelines (observation for at least 3 months after diagnosis, an initial dose of systemic glucocorticosteroid of at least 20 mg, and duration of at least 10 months) were only met in 11 patients (17.5%). 55.4% of patients received the repeated courses of systemic glucocorticosteroid therapy for relapses and exacerbations. Phenotypes B and C, which are closest to idiopathic pulmonary fibrosis according to high- resolution computed tomography, were accompanied by the greatest decrease in forced vital lung capacity and DLco. With these phenotypes, systemic glucocorticosteroids were more often prescribed immediately after detection, while all the requirements of clinical guidelines were met less often, pentoxifylline and vitamin E were used the least often as starting therapy, and pulse therapy was only performed with these phenotypes. Conclusions. Possible reasons for the unfavorable course included late detection and late referral to a third-level specialist, as well as failure to comply with clinical recommendations at the initial stage of sarcoidosis treatment. Manifestations of pulmonary fibrosis in sarcoidosis are heterogeneous in laboratory and functional parameters. Phenotypes of fibrosing pulmonary sarcoidosis recently agreed upon by high-resolution computed tomography had differences in the degree of respiratory impairment and saturation, which indicates the practical significance of such division of patients by the radiographic picture.