Особенности патологической анатомии легких при COVID-19

Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) resulting from an immune-mediated response in susceptible and sensitized individuals to a large variety of inhaled antigens. Chronic HP with a fibrotic phenotype is characterized by disease progression and a dismal prognosis. The aim of this study was to identify predictors of progression and mortality in patients with chronic HP in real clinical practice. Materials and methods: This retrospective, multicenter, observational study used data from a registry of 1355 patients with fibrosing ILDs. The study included 292 patients diagnosed with chronic HP based on the conclusion of a multidisciplinary discussion (MDD). Results: The patients were divided into groups with progressive (92 (30.3%) patients) and nonprogressive pulmonary fibrosis (200 (69.7%) patients). The most significant predictors of adverse outcomes were a DLco < 50% predicted, an SpO2 at the end of a six-minute walk test (6-MWT) < 85%, and a GAP score ≥ 4 points. Conclusion: Pulmonary fibrosis and a progressive fibrotic phenotype are common in patients with chronic HP. Early detection of the predictors of an adverse prognosis of chronic HP is necessary for the timely initiation of antifibrotic therapy.

Background: Until recently, Russia did not utilize noninvasive fractional flow reserve (FFR) assessment. We developed an automated algorithm for noninvasive assessment of FFR based on a one-dimensional (1D) mathematical modeling.Objective: The research aims to evaluate the diagnostic accuracy of this algorithm.Methods: The study enrolled 80 patients: 16 of them underwent 64-slice computed tomography – included retrospectively, 64 – prospectively, with a 640-slice CT scan. Specialists processed CT images and evaluated noninvasive FFR. Ischemia was confirmed if FFR < 0.80 and disproved if FFR ≥ 0.80. The prospective group of patients was hospitalized for invasive FFR assessment as a reference standard. If ischemic, patients underwent stent implantation. In the retrospective group, patients already had invasive FFR values.Statistical analysis was performed using GraphPad Prism 8. We compared two methods using a Bland–Altman plot and per-vessel ROC curve analysis. Considering the abnormality of distribution by the Kolmogorov-Smirnov test, we have used Spearman’s rank correlation coefficient.Results: During data processing, three patients of the retrospective and 46 patients of the prospective group were excluded. The sensitivity of our method was 66.67% (95% CI: 46.71–82.03); the specificity was 78.95% (95% CI: 56.67–91.49), p = 0.0052, in the per-vessel analysis. In per-patient analysis, the sensitivity was 69.57% (95% CI: 49.13–84.40); the specificity was 87.50% (95% CI: 52.91–99.36), p = 0.0109. The area under the ROC curve in the per-vessel analysis was 77.52% (95% CI: 66.97–88.08), p < 0.0001.Conclusion: The obtained indices of sensitivity, specificity, PPV, and NPV are, in general, comparable to those in other studies. Moreover, the noninvasive values of FFR yielded a high correlation coefficient with the invasive values. However, the AUC was not high enough, 77.52 (95% CI: 66.97–88.08), p < 0.0001. The discrepancy is probably attributed to the initial data heterogeneity and low statistical power.

Aim.To evaluate the diagnostic accuracy of a noninvasive method of fractional flow reserve (FFR) assessment based on a one-dimensional hemodynamic model build on data obtained from the coronary computed tomography angiography (CCTA).Material and methods.The study enrolled 57 patients: 16 of them underwent 64-slice computed tomography — included retrospectively, 34 — prospectively, with a 640-slice CT scan. Specialists from the Laboratory of Mathematical Modeling processed CT images and evaluated noninvasive FFR. Ischemia was confirmed if FFR <0,80 and disproved if FFR ≥0,80. After that the prospective group of patients was hospitalized for invasive FFR assessment as a reference standard; if ischemia was proved, patients underwent stent implantation. In the retrospective group, patients already had invasive FFR values estimated. Statistical analysis was performed using R programming language packages (cran-r.project.com). Continuous variables are presented as mean values ± standard deviations, order variables are presented as medians with interquartile ranges in parentheses. We used the D’Agostino-Pearson omnibus test for the assessment of normality of distribution; a Q-Q Plot was also constructed. We performed the Bland-Altman analysis and ROC-analysis for comparison of these two methods, and the Pearson’s chi-squared to assess the degree of correlation.Results.During data processing, 3 patients of the retrospective and 34 patients of the prospective group were excluded from the study. The sensitivity of our method was 90,91% (95% CI; 58,72-99,77), specificity — 86,67% (95% CI; 59,54-98,34), P<0,05, accuracy — 88,46 (95% CI; 69,85-97,55) — in per-vessel analysis. In perpatient analysis, the sensitivity was 91,67% (95% CI; 61,52-99,79), specificity — 80% (95% CI; 28,36-99,49), (P<0,05); accuracy 88,24 (95% CI; 63,56-98,54).Conclusion.Our method has quite a high accuracy and can be successfully used in clinical practice in order to enhance the diagnostic efficiency of the CCTA.

Хронические фиброзирующие интерстициальные заболевания легких с прогрессирующим фенотипом

Aim. Compare radiological patterns of COVID-19 pneumonia with pulmonary histology in deceased patients. Materials and methods. The analysis of recent lifetime CT studies of deceased patients was performed with the identification of all existing and leading CT symptoms, including “ground glass”, “crazy paving”, consolidation, as well as the symptom complex (pattern) of organizing pneumonia. Based on the CT symptoms, we selected the target points for taking the specimens by 3-D reconstructions. At the autopsy the lungs were entirely fixed into the front and then marked on CT sections cut from 1 to 3 pieces that were placed in paraffin and processed according to the standard technique, stained with hematoxylin and eosin and fuchsin-facelina. The specimens were analyzed by identifying all available histology changes and selecting the leading one. Results. 45 targeted pieces of lung tissue were obtained from 14 deceased COVID-19 patients (7 men/ 7 women), with an average age of 77.1 ± 12.9 (49–90 years). In deceased patients with the presence of the "ground glass" symptom, in most cases (57.1%) revealed an increase in intra-alveolar cellularity, hyaline membranes, desquamation of the alveolar epithelium and infiltration of the interalveolar septum by lymphocytes, which corresponds to the exudative phase of diffuse alveolar damage (DAP). Mosaic histological changes with alternation of filled alveoli (intraalveolar edema, clusters of red blood cells, macrophages, lymphocytes) and air alveoli were detected from the areas of “crazy paving” zones. Several cases demonstrated interstitial edema and lymphoid infiltration of interalveolar partitions of different severity without their thickening. Areas of consolidation were histologically represented by extensive intraalveolar hemorrhages and / or typical zones of hemorrhagic infarcts in 45.5% of cases. Perilobular consolidation, subpleural cords, symptoms of “halo” and “reverse halo”, which we considered as part of the symptom complex of organizing pneumonia in 43% of cases, morphologically corresponded to organizing pneumonia (the proliferative phase of DAP), as well as to distelectases. Conclusion. Comparison of CT patters and post-mortem pulmonary histology in COVID-19 deceased patients demonstrated that CT symptoms and patterns correspond to certain morphological changes of different phases of DAP.