Parenchymal lung abnormalities following hospitalisation for COVID-19 and viral pneumonitis: a systematic review and meta-analysis

Abstract

IntroductionPersisting respiratory symptoms in COVID-19 survivors may be related to development of pulmonary fibrosis. We assessed the proportion of chest CT scans and pulmonary function tests consistent with parenchymal lung disease in the follow-up of people hospitalised with COVID-19 and viral pneumonitis.MethodsSystematic review and random effects meta-analysis of proportions using studies of adults hospitalised with SARS-CoV-2, SARS-CoV, MERS-CoV or influenza pneumonia and followed up within 12 months. Searches performed in MEDLINE and Embase. Primary outcomes were proportion of radiological sequelae on CT scans; restrictive impairment; impaired gas transfer. Heterogeneity was explored in meta-regression.ResultsNinety-five studies (98.9% observational) were included in qualitative synthesis, 70 were suitable for meta-analysis including 60 SARS-CoV-2 studies with a median follow-up of 3 months. In SARS-CoV-2, the overall estimated proportion of inflammatory sequelae was 50% during follow-up (0.50; 95% CI 0.41 to 0.58; I2=95%), fibrotic sequelae were estimated in 29% (0.29; 95% CI 0.22 to 0.37; I2=94.1%). Follow-up time was significantly associated with estimates of inflammatory sequelae (−0.036; 95% CI −0.068 to –0.004; p=0.029), associations with fibrotic sequelae did not reach significance (−0.021; 95% CI −0.051 to 0.009; p=0.176). Impaired gas transfer was estimated at 38% of lung function tests (0.38 95% CI 0.32 to 0.44; I2=92.1%), which was greater than restrictive impairment (0.17; 95% CI 0.13 to 0.23; I2=92.5%), neither were associated with follow-up time (p=0.207; p=0.864).DiscussionSequelae consistent with parenchymal lung disease were observed following COVID-19 and other viral pneumonitis. Estimates should be interpreted with caution due to high heterogeneity, differences in study casemix and initial severity.PROSPERO registration numberCRD42020183139.

Lung function and radiological findings 1 year after COVID-19: a prospective follow-up

“…Although functional recovery from severe COVID-19 pneumonia occurs within 1 year after discharge, approximately one third of patients (39.8%) still have decreased DLCO. These findings are in line with the results from a Chinese cohort [ 15 ], albeit excluding patients requiring invasive mechanical ventilation, and are consistent with a recently published meta-analysis [ 34 ]. Among our key findings is that although more severe patients showed higher diffusion impairment 2 months after discharge, this difference lost significance at 6 and 12 months.…”

Evidence of Continued CD4+ and CD8+ T Cell Activity After SARS-COV-2 Clearance in a Late COVID-19 Pneumonia Heart Transplant Patient

“…Data from a recently published review show that approximately 20% of COVID-19 patients progress to fibrotic sequelae that persist until the one-year follow-up [ 19 ].…”

Current Understanding of Post-COVID Pulmonary Fibrosis: Where Are We?

“…Although most patients improve over time, a systematic review and meta-analysis of studies within one year following hospitalization demonstrated the presence of opacities suggestive of lung fibrotic lesions in almost one third of the exams (0.29; 95% CI 0.22–0.37). 12 Techniques that employ automatic quantification of tomographic abnormalities can be used to assess the progression of the extent of pulmonary impairment over time in COVID-19. A Brazilian study found pulmonary abnormalities in 80% of patients evaluated 90 days after hospital discharge, with ground-glass opacities and parenchymal bands as the predominant lesions.…”