Plasma and Airway Levels of Surfactant Protein D Degradation Reflect Progression of ARDS in Ventilated Patients with SARS-CoV-2
American Journal of Respiratory and Critical Care Medicine
; 205(1), 2022.
Article
in English
| EMBASE | ID: covidwho-1927896
ABSTRACT
Background:
Patients with COVID-19 present severe respiratory symptoms progressing to acute respiratory distress syndrome (ARDS). Upon infection, SARS-CoV-2 destroys cells expressing the ACE2 receptor including alveolar type II cells (AT2). These cells are found in the alveolar-capillary barrier which normally secrete pulmonary surfactant, a complex of lipid and surfactant proteins (SPA, SP-B, SP-C, SP-D). Exogenous surfactant therapy (mainly composed of phospholipids, SP-B, and SP-C) has been successful in treating neonatal respiratory distress syndrome (nRDS) caused by surfactant deficiency in preterm babies.Plasma SP-D has been proposed as a marker of lung injury in COVID-19 but so far, no reports have evaluated sequential SP-D levels in both airway and plasma. As part of a clinical trial repurposing surfactant therapy to treat adult ventilated COVID-19 patients, we hypothesized that plasma SP-D levels may reflect decreased lung integrity and that SP-D degradation in plasma and airway samples from COVID-19 patients may reflect disease progression and severity.Methods:
Enzyme-linked immunosorbent assay (ELISA) was used to quantify SP-D concentration in patient plasma and tracheal aspirate samples. Western Blotting was used to identify any protein degradation. Sequential daily plasma and airway samples were analysed.Results:
SP-D concentration in serum was 10-20 times higher in patients ventilated for COVID-19 than in healthy volunteers. Additionally, the concentration of SP-D in plasma has shown to be 10-100-fold higher than in tracheal aspirates. Furthermore, degraded fragments of SP-D were detected at a higher ratio than intact SP-D in plasma of ventilated patients. This ratio decreased with administration of surfactant therapy (containing phospholipids and SP-B and SP-C but no SPA or SP-D).Conclusions:
Increased serum SP-D and decreased tracheal aspirate SP-D from ventilated COVID-19 patients suggested leakage of pulmonary surfactant into the bloodstream caused by damage to the alveolar-capillary barrier in diseased lungs. The ratio of degraded vs. intact SP-D found in the plasma was compared before and after therapeutic surfactant administration. The results indicated that levels of SP-D in plasma and tracheal aspirates together with the ratio of degraded and intact SP-D in the plasma may be useful indicators of the severity of COVID-19 lung disease progression.
endogenous compound; lung surfactant; phospholipid; surfactant; surfactant protein B; surfactant protein C; surfactant protein D; adult; adult respiratory distress syndrome; airway; artificial ventilation; clinical trial; conference abstract; controlled study; coronavirus disease 2019; drug therapy; enzyme linked immunosorbent assay; female; gene expression; human; human cell; human tissue; lung alveolus; lung disease; lung injury; male; neonatal respiratory distress syndrome; nonhuman; prematurity; protein blood level; protein degradation; protein expression; quantitative analysis; Severe acute respiratory syndrome coronavirus 2; tracheal aspiration procedure; ventilated patient; Western blotting
Full text:
Available
Collection:
Databases of international organizations
Database:
EMBASE
Language:
English
Journal:
American Journal of Respiratory and Critical Care Medicine
Year:
2022
Document Type:
Article
Similar
MEDLINE
...
LILACS
LIS