Bridge to transplant using a flow-adaptive extracorporeal total artificial lung system following bilateral pneumonectomy for septic ARDS

Acute respiratory distress syndrome (ARDS), when complicated by secondary pneumonias caused by nosocomial antibiotic-resistant pathogens and septic shock, can carry mortality rates exceeding 80%. We performed single-cell RNA sequencing and Visium HD spatial transcriptomics on an explanted lung from a 33-year-old patient with influenza-associated ARDS complicated by carbapenem-resistant Pseudomonas aeruginosa pneumonia and refractory septic shock. Our results demonstrated diffuse and uniform tissue destruction in the affected lung, with dense infiltration by neutrophils, monocyte-derived alveolar macrophages, and activated T cells. We also observed marked expansion of aberrant basaloid epithelial cells and CTHRC1-positive myofibroblasts coexisting with widespread inflammation, accompanied by near-complete loss of normal alveolar architecture. The resulting molecular signatures recapitulated those seen in end-stage fibrotic lung disease and were consistent with irreversible injury rather than a recoverable ARDS phenotype. Overall design: Snap-frozen lung samples were obtained for single-cell RNA sequencing (scRNA-seq) using the 10X Genomics Chromium Single Cell Flex Gene Expression Assay and sequenced on a HiSeq 4000. A total seven samples from different regions were collected for sequencing. Raw scRNA-seq reads were demultiplexed with CellRanger (v7.1.0) and mapped to the human genome (HG38). FFPE samples were used for spatial transcriptomic analysis, and the sequencing reads were mapped to human genome (HG38).