Interstitial Lung Fibrosis Following COVID-19 Pneumonia

Abstract

Background and Objectives: Pulmonary fibrosis represents a stage of normal physiologic response to inflammatory aggression, mostly self-limiting and reversible; however, numerous patients treated for SARS-CoV-2 pneumonia present after release from hospital residual lung fibrosis. In this article, we aim to present an optimization method for evaluating pulmonary fibrosis by quantitative analysis, to identify the risk factors/predictors for pulmonary fibrosis in patients with SARS-CoV-2 infection, and to characterize the impact of pulmonary fibrosis on the symptomatology of patients after release from the hospital. Materials and Methods: We performed a prospective observational study on 100 patients with severe forms of pneumonia, with a control group of 61 non-COVID normal patients. Results: We found persistent interstitial changes consistent with fibrotic changes in 69% of patients. The risk of fibrosis was proportional to the values of erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and lactate dehydrogenase (LDH), and to the duration of hospitalization. The imaging parameters correlated with increased risk for interstitial fibrosis were the number of affected pulmonary lobes and the percent of interstitial pulmonary fibrosis. Conclusions: The main risk factors for pulmonary fibrosis post-COVID-19 identified in our study are increased ESR, CRP, LDH, duration of hospitalization and the severity of pneumonia.

Lactate dehydrogenase contribution to symptom persistence in long COVID: A pooled analysis

“…Finally, 46 studies with 8289 participants (3338 PASC and 4951 controls) were included in our pooled analysis (Table 1). 24–69 These included studies were all peer‐reviewed, published between 2020 and 2023; had data from 28 studies in Resp‐PASC, 10 studies in Neuro‐PASC, 5 studies in Cardio‐PASC, 2 studies in gastrointestinal‐PASC and as only 1 study was in Reno‐PASC. Thirty‐four studies were of cohort design, 11 were case control and 1 cross‐sectional.…”

Chronic Pulmonary Manifestations of COVID-19 Infection: Imaging Evaluation

“…Irregular bronchial dilatation is common in DAD due to fibroblastic activity, but frequently resolves in convalescence, arguing against the use of the term “traction bronchiectasis” until long-term follow up shows irreversibility. Honeycombing, the most certain sign of fibrosis, is uncommonly reported at CT in COVID-19, in most series reported as 0-5% ( 18 ) ( 36 ). Parenchymal bands and residual perilobular opacities seen in many patients may represent previous organizing lung injury, and do not always represent fibrosis.…”

“…Long-term parenchymal findings Chronic lung abnormalities of COVID-19 likely represent a complex mixture of sequelae of direct viral damage, acute lung injury with diffuse alveolar damage, ventilator-associated lung injury, and immune-mediated processes. The likelihood and magnitude of chronic findings increase with severity of infection, ARDS, duration of hospitalization and mechanical ventilation, older age ( 18 ) ( 19 ) ( 20 ) and inflammatory markers such as C-reactive protein and D-dimer ( 20 ).…”

“…Many studies show correlations between late imaging findings, symptoms, and pulmonary function tests. In a quantitative analysis of lung parenchymal findings 3 months after discharge for severe COVID-19 pneumonia, extent of involvement showed statistically significant correlations with fatigue, shortness of breath, cough, memory loss, and dizziness ( 18 ). Among pulmonary function tests, a decreased DLCO has been the most frequently reported abnormality ( 36 ), found in 35% in a recent meta-analysis ( 42 ), and correlates with residual ground-glass opacity, reticulation, and air trapping ( 27 ).…”

Immune-mediated lung diseases: A narrative review

“…Coronavirus disease 2019 (COVID-19) has been the leading cause of morbidity and mortality since the identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019 ( 197 , 198 ).…”