ABSTRACT
BACKGROUND: Coronavirus Disease 2019 (COVID-19) can lead to the development of acute respiratory distress syndrome (ARDS). In some patients with non-resolvable (NR) COVID-19, lung injury can progress rapidly to the point that lung transplantation is the only viable option for survival. This fatal progression of lung injury involves a rapid fibroproliferative response and takes on average 15 weeks from initial symptom presentation. Little is known about the mechanisms that lead to this fulminant lung fibrosis (FLF) in NR-COVID-19. METHODS: Using a pre-designed unbiased PCR array for fibrotic markers, we analyzed the fibrotic signature in a subset of NR-COVID-19 lungs. We compared the expression profile against control lungs (donor lungs discarded for transplantation), and explanted tissue from patients with idiopathic pulmonary fibrosis (IPF). Subsequently, RT-qPCR, Western blots and immunohistochemistry were conducted to validate and localize selected pro-fibrotic targets. A total of 23 NR-COVID-19 lungs were used for RT-qPCR validation. FINDINGS: We revealed a unique fibrotic gene signature in NR-COVID-19 that is dominated by a hyper-expression of pro-fibrotic genes, including collagens and periostin. Our results also show a significantly increased expression of Collagen Triple Helix Repeat Containing 1(CTHRC1) which co-localized in areas rich in alpha smooth muscle expression, denoting myofibroblasts. We also show a significant increase in cytokeratin (KRT) 5 and 8 expressing cells adjacent to fibroblastic areas and in areas of apparent epithelial bronchiolization. INTERPRETATION: Our studies may provide insights into potential cellular mechanisms that lead to a fulminant presentation of lung fibrosis in NR-COVID-19. FUNDING: National Institute of Health (NIH) Grants R01HL154720, R01DK122796, R01DK109574, R01HL133900, and Department of Defense (DoD) Grant W81XWH2110032 to H.K.E. NIH Grants: R01HL138510 and R01HL157100, DoD Grant W81XWH-19-1-0007, and American Heart Association Grant: 18IPA34170220 to H.K.-Q. American Heart Association: 19CDA34660279, American Lung Association: CA-622265, Parker B. Francis Fellowship, 1UL1TR003167-01 and The Center for Clinical and Translational Sciences, McGovern Medical School to X.Y.
ABSTRACT
BACKGROUND: Aviptadil, a synthetic form of human vasoactive intestinal peptide, has entered clinical trials to treat critical coronavirus disease 2019 pneumonia with respiratory failure. Vasoactive intestinal peptide protects the lung against a broad array of injuries by binding to the vasoactive intestinal peptide receptor 1 receptor of alveolar type II cells, the cells that severe acute respiratory syndrome coronavirus 2 binds to. As the role of Aviptadil in treating pregnant patients with critical coronavirus disease 2019 pneumonia is unknown, the authors report successful treatment in such a patient who is ineligible for phase 3 trials of Aviptadil. CASE SUMMARY: Under an open-label Food and Drug Administration-approved Expanded Access Protocol NCT04453839, a 32-year-old female patient Gravida 6 Para 4 at 27-week gestation, body mass index 42.5 kg/m2, admitted to the ICU of a quaternary care hospital with critical coronavirus disease 2019 was treated in January 2021 and followed for 4 months post-ICU admission. Standard of care included remdesivir, methylprednisolone, enoxaparin, and inhaled epoprostenol. In addition, the patient received three successive 12-hour IV infusions of Aviptadil at 50/100/150 pmol/kg/hr escalating doses, per randomized clinical trial NCT04311697. Human subjects’ protection was overseen by the Institutional Review Board of the Houston Methodist Hospital. The patient was enrolled in the treatment and was given informed consent approved by the Food and Drug Administration and the Institutional Review Board. Data on the patient was incorporated based on her consent for de-identified data to be used in research given at the time of hospital admission in a manner approved by the Institutional Review Board (PRO00025607). Baseline inflammatory markers, arterial blood gases, radiologic imaging, oxygen requirements, Pao2/Fio2, continuous fetal monitoring at baseline, throughout the patient’s treatment with the investigational drug, and throughout the patient’s hospital course. CONCLUSION: The rapid clinical improvement seen in this patient treated with IV vasoactive intestinal peptide is consistent with the theory that vasoactive intestinal peptide protects the alveolar type II cell, ameliorates cytokine storm, and improves oxygenation in acute lung injury. This specific role of vasoactive intestinal peptide in the lung may be vital to combating the lethal effects of severe acute respiratory syndrome coronavirus 2 infection. In addition, the role of vasoactive intestinal peptide in the human maternal-fetal interface suggests that vasoactive intestinal peptide is a safe treatment of severe coronavirus disease 2019 respiratory failure during pregnancy.