Insights into the lung microenvironment after severe COVID-19

The SARS-CoV-2 is the betacoronavirus responsible for the coronavirus disease 2019 (COVID-19) pandemic. Severe COVID-19 affects approximately 10-15% of patients and results in prolonged morbidity and mortality. Little is known about the immunophenotypic changes of the lung parenchyma driven by the viral infection in patients who die of severe COVID-19. Ultrasound-guided lung biopsies (LB) were collected (IRB approval#1561/21) within few hours from death in 15 severe COVID-19 patients between November 2020 and January 2021, in two patients who underwent lung transplantation after COVID-19 and in one patient who had surgery for bacterial superinfection during COVID-19 disease. All samples underwent histologic and immunohistochemistry evaluation and molecular profiling using the nCounter Host Response and Coronavirus Panel plus. As controls, lungs from end-stage usual interstitial pneumonia (UIP;n=9) and from lobectomy for lung cancer (Norm;n=5) were used. Eleven lungs (61%) were positive for SARS-CoV-2 RNA. Signs of diffuse alveolar damage (DAD) were observed in 6 patients (30%). COVID-19 lungs showed a marked macrophage infiltration with M2 polarization compared with controls. Globally, COVID-19 lungs showed distinct molecular profiles from UIP or Norm lungs. Specifically, a marked upregulation of interferon-genes that was directly correlated with SARS-CoV-2 genes was seen in COVID-19 lungs. COVID-19-specific genes signatures (Log2FC >1.5;adj p<0.05) obtained using VENN diagram showed impairment of the STAT3-pathway accompanied by the upregulation of the NFkB signaling. Results herein provide new insights into lung alterations induced by severe COVID-19 and suggest novel potential targets for therapeutic intervention.

Telemonitoring: An Opportunity to Improve Multidisciplinary Care in Lung Transplanted Patients

Purpose: Telemedicine has been successfully employed in a wide range of specialties. We hereby present the results of a pivotal study we ran in our centre just before the COVID19 pandemic. Methods: This was a prospective study including all adult cystic fibrosis patients who underwent lung transplant (LuTx) from September 2017 to August 2019. Patients were randomized into two groups;patients assigned to the first arm (intervention) received a home medical assistant (HMA) system device, to which a pulse oximeter and a spirometer with reusable turbine were integrated;they were asked to perform a spirometry and register their SpO2 at rest and on effort on a twice-weekly basis. All the data were digitally transmitted to our centre, where physiotherapists and physicians were able to analyse them real-time. Both the groups received traditional hospital-based follow-up. Results: 32 patients were enrolled, 16 in each group. No statistically significant difference was found between the two groups (see Table 1).With reference to the telemonitoring group:- Adherence to telemonitoring significantly decreased during the 12months period of follow up (see figure 1).- Hospital reported data were consistent with the last being registered with the HMA device.- Of note, two patients were requested to anticipate their hospital routine visit because of a FEV1 decrease being reported on their HMA device, in order to rule out possible acute lung allograft dysfunction.- 13 out of 16 patients reported a high degree of satisfaction with the telemonitoring experience. Conclusion: The COVID19 pandemic highlighted the necessity to investigate alternative practices to treat chronically ill individuals. In our study, telemonitoring proved to be a valuable tool to improve quality health care to LuTx recipients, especially for those who live far from the transplant centre. We are now implementing this approach scheduling online video consultations. Further research should be focused on standardizing quality of telemedicine services.

Lung Allograft Dysfunction in a COVID-19 Transplanted Patient is Associated with a Peculiar Immunopathological Phenotype

Purpose Lung transplantation (LT) after severe SARS-CoV-2 infection is emerging as a life-saving medical procedure for selected patients who experience acute respiratory distress syndrome (ARDS). We present the first immunopathological evaluation of a lung allograft rejection in a patient who underwent LT because of irreversible ARDS related to COVID-19. Methods Two male patients with irreversible ARDS caused by COVID-19 underwent bilateral LT at our Institution. A surveillance transbronchial biopsy (TBB) was performed 2 months after LT in the first patient (Pt#1), while the second patient (Pt#2) died because of allograft rejection at day 62 post LT and explanted lungs were retrieved. CT imaging of the lungs was performed three days before death. Morphological examination was performed by H&E, whereas the immunophenotyping was performed by immunohistochemistry. Results Imaging and morphological examination of Pt#2 lungs indicated the presence of a graft dysfunction with features of a restrictive, widespread usual interstitial pneumonia-like syndrome (Fig. 1A, B). The immunophenotyping showed that B-lymphocytes (CD20-positive) were nearly absent, CD8-T-cells were not particularly expanded (mean positive cells within the lung stroma=13.8%;Fig. 1C), and the CD4/CD8 ratio was not decreased (Fig. 1D). The T-regs (Foxp3-positive) were 6% of the overall population (Fig. 1E). Analysis of the immune checkpoint molecules PD1, Tigit, CTLA4 and PDL1 showed that the expression of PD-L1 alone was highly increased in vases and in alveolar cells of rejected lungs, whereas it was nearly undetectable in the TBB from Pt#1 (Fig. 1F, G). Conclusion PDL1 expression in vases was previously documented as a sign of indirect ARDS. Together with our preliminary data, we can hypothesize that PDL1 may play a role in tissue effacement and graft failure, possibly indicating poor allograft prognosis.

Lung Transplantation for Acute Respiratory Distress Syndrome Related to COVID-19: The Lesson Learned from the First Two Cases

Purpose The respiratory system, and namely the lung, is undoubtedly the preferential target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The clinical pictures are extremely various, up to the intensive care unit (ICU) admission for acute respiratory distress syndrome (ARDS). Lung transplantation (LT) is a consolidate therapeutic option for end-stage chronic respiratory diseases. Its role in an acute setting is questionable, particularly due to lack of experiences, donor shortage, and the difficulty to fully evaluate the potential recipient. We report our preliminary experience with the first two cases of LT for SARS-CoV-2 related ARDS, trying to provide some food for thought. Methods We retrospectively analysed our first two cases of bilateral LT for ARDS after COVID-19. We recorded data on pre-transplantation clinical course, transplantation management and outcomes. Results The two patients had a similar clinical evolution of COVID-19. Transplantations were successful in both cases;the first patient is alive and in good condition 5 months after transplantation, while the second died 62 days after surgery. Table 1 shows clinical details and relevant time-points. Conclusion Our experience showed that LT for COVID-19 is feasible. Importantly, observing a dedicated protocol made the procedure safe for the healthcare staff involved. On the other hand, our second unsuccessful case poses relevant questions: first of all, lung transplantation should be reserved to highly selected patient, after careful clinical, infective as well as psychiatric evaluation. The ethical aspects should also be considered in this situation, with regard to the centre rate mortality on waiting list. Anyway, the potential role of LT in the acute and sub-acute/chronic settings suggests the need for maintaining LT centre active during pandemic. Finally, COVID-19, once more, imposes to share clinical experiences.