Assessment of long-term radiological signs of COVID-19 viral-associated pneumonia in patients with sarcoidosis of the respiratory system

Relevance. It is known that both sarcoidosis of the respiratory organs (SRO) and COVID-19-associated pneumonia involve connective tissue structures in the lungs in pathological processes, which may have similar clinical and radiological manifestations. Computed tomography (CT) of high resolution of the chest is the main method for diagnosing various pathologies of the respiratory system with a morphological substrate.Aim: the objective is to evaluate long-term outcomes of various CT signs of sarcoidoses and COVID-19 pneumonia.Materials and methods. The study was cohort-based and retrospective. 37 patients with sarcoidosis of the respiratory organs who had suffered from COVID-19associated pneumonia for more than one year prior to admission to the Central Research Institute were examined. The X-ray semiotics of patients with SRO after COVID-19 were analyzed to develop a differentiated approach and dynamic monitoring of these patients. The prevalence of lung lesions associated with COVID-19 was estimated according to 4 degrees of severity, based on the adopted methodological recommendations from the Moscow Medical Center in 2020.Results. Signs of interstitial densification characteristic of SRS were found in 50% of cases (χ2 = 35.18, p = 0.00001), whereas for COVID-19, changes in the peripheral interstitium were more characteristic and were detected in 65% of cases (χ2 =52.46, p=0.00). The extent of the changes was limited in SRS in 46% of cases and in COVID-10 in 69% (χ²=10.8, p= 0.1). By localization, changes were subpleural in 7% of SRS cases and 81% of COVID-1 cases.The predominant topic of change in SRS was basal (77%), with caudal changes in COVID (80%).Pleural involvement was characteristic of granuloma-level SRS in 97% and COVID in 16%. Vascular involvement was 96% in SRS and 39% in COVID.Conclusion. The CT data did not reveal a significant effect of COVID-19 on the course or change of the X-ray pattern, the stage of sarcoidosis of IHL and the lungs. Probably, granulomatous lung inflammation is a more dominant process than viral lesions associated with COVID-19. Changes in the lungs on CT scans do not always correlate with clinical manifestations of COVID-19 or SRS, so further study of their interaction is required in clinical practice.