The American Association for Thoracic Surgery (AATS) 2022 Expert Consensus Document: The use of mechanical circulatory support in lung transplantation.

OBJECTIVE: The use of mechanical circulatory support (MCS) in lung transplantation has been steadily increasing over the prior decade, with evolving strategies for incorporating support in the preoperative, intraoperative, and postoperative settings. There is significant practice variability in the use of these techniques, however, and relatively limited data to help establish institutional protocols. The objective of the AATS Clinical Practice Standards Committee (CPSC) expert panel was to review the existing literature and establish recommendations about the use of MCS before, during, and after lung transplantation. METHODS: The AATS CPSC assembled an expert panel of 16 lung transplantation physicians who developed a consensus document of recommendations. The panel was broken into subgroups focused on preoperative, intraoperative, and postoperative support, and each subgroup performed a focused literature review. These subgroups formulated recommendation statements for each subtopic, which were evaluated by the entire group. The statements were then developed via discussion among the panel and refined until consensus was achieved on each statement. RESULTS: The expert panel achieved consensus on 36 recommendations for how and when to use MCS in lung transplantation. These recommendations included the use of veno-venous extracorporeal membrane oxygenation (ECMO) as a bridging strategy in the preoperative setting, a preference for central veno-arterial ECMO over traditional cardiopulmonary bypass during the transplantation procedure, and the benefit of supporting selected patients with MCS postoperatively. CONCLUSIONS: Achieving optimal results in lung transplantation requires the use of a wide range of strategies. MCS provides an important mechanism for helping these critically ill patients through the peritransplantation period. Despite the complex nature of the decision making process in the treatment of these patients, the expert panel was able to achieve consensus on 36 recommendations. These recommendations should provide guidance for professionals involved in the care of end-stage lung disease patients considered for transplantation.

A case report of a prolonged decrease in tacrolimus clearance due to co-administration of nirmatrelvir/ritonavir in a lung transplant recipient receiving itraconazole prophylaxis.

BACKGROUND: Drug-drug interaction management is complex. Nirmatrelvir/ritonavir is a potent cytochrome P450 (CYP) 3A inhibitor and influences pharmacokinetics of co-administered drugs. Although there are several reports about drug-drug interactions of nirmatrelvir/ritonavir, an influence of a concomitant use of nirmatrelvir/ritonavir and another potent CYP3A inhibitor on tacrolimus remains unclear. Here, we experienced a lung transplant patient with the novel coronavirus disease 2019 (COVID-19). In this patient, nirmatrelvir/ritonavir was administered, and the inhibitory effect of itraconazole on CYP3A was prolonged. CASE PRESENTATION: We present a case in forties who had undergone lung transplantation. He was administered itraconazole and tacrolimus 1.0 mg/d, with a trough value of 8-12 ng/mL. The patient contracted the COVID-19, and a nirmatrelvir/ritonavir treatment was initiated. During the antiviral treatment, tacrolimus administration was discontinued for 5 d. Tacrolimus was resumed at 1.0 mg/d after completion of the nirmatrelvir/ritonavir treatment, but the trough value after 7 d was high at 31.6 ng/mL. Subsequently, the patient was placed on another 36-h tacrolimus discontinuation, but the trough value decreased to only 16.0 ng/mL. CONCLUSIONS: Co-administration of ritonavir caused a prolonged decrease in tacrolimus clearance through its inhibitory effects on CYP3A in a patient taking itraconazole. Management of drug-drug interaction by pharmacists can be important for patients with multiple medications.

Efficacy and safety of the SARS-CoV-2 mRNA vaccine in lung transplant recipients: a possible trigger of rejection.

OBJECTIVE: Solid organ transplant recipients have an increased risk of developing severe coronavirus disease 2019 (COVID-19). Although SARS-CoV-2 mRNA vaccination has been strongly recommended for solid organ transplant recipients, its efficacy and safety have remained unknown. METHODS: We performed an observational prospective cohort study in 18 lung transplant recipients who received two doses of SARS-CoV-2 mRNA vaccine, including BNT162b2 (n = 17) or mRNA-1273 (n = 1), between June and October 2021. The titers of IgG antibodies against the SARS-CoV-2 spike protein (S-IgG) were measured in serum samples collected before the prime dose, three weeks after the prime dose, and four weeks after the booster dose. Reactogenicity and adverse events were evaluated after vaccination. RESULTS: There were no recipients with previous SARS-CoV-2 infection prior to vaccination. S-IgG levels were elevated in 2/18 (11.1%) recipients after the prime dose and in 5/18 recipients (27.8%) after the booster dose (31.7 ± 30.6 U/ml). The time from transplantation to vaccination tended to be longer in the seropositive group than the seronegative group [7.5 (3.9-10.2) vs 2.8 (1.9-4.0) years, p = 0.059]. Maintenance dose of mycophenolate mofetil tended to be lower in the seropositive group than in the seronegative group [500 (250-500) vs 1000 (1000-1000) mg/day, p = 0.088]. Regarding the adverse events after vaccination, the development of chronic lung allograft dysfunction (CLAD) or antibody-mediated rejection (AMR) were observed in two seropositive patients. CONCLUSIONS: The antibody response to the SARS-CoV-2 mRNA vaccine was quite poor in lung transplant recipients. We experienced cases that developed clinical CLAD or AMR that was likely related to SARS-CoV-2 vaccination.

SARS-CoV-2 disrupts respiratory vascular barriers by suppressing Claudin-5 expression.

In the initial process of coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects respiratory epithelial cells and then transfers to other organs the blood vessels. It is believed that SARS-CoV-2 can pass the vascular wall by altering the endothelial barrier using an unknown mechanism. In this study, we investigated the effect of SARS-CoV-2 on the endothelial barrier using an airway-on-a-chip that mimics respiratory organs and found that SARS-CoV-2 produced from infected epithelial cells disrupts the barrier by decreasing Claudin-5 (CLDN5), a tight junction protein, and disrupting vascular endothelial cadherin-mediated adherens junctions. Consistently, the gene and protein expression levels of CLDN5 in the lungs of a patient with COVID-19 were decreased. CLDN5 overexpression or Fluvastatin treatment rescued the SARS-CoV-2-induced respiratory endothelial barrier disruption. We concluded that the down-regulation of CLDN5 expression is a pivotal mechanism for SARS-CoV-2-induced endothelial barrier disruption in respiratory organs and that inducing CLDN5 expression is a therapeutic strategy against COVID-19.

Improved absorption of itraconazole tablet by co-administration with lemon beverages in a lung transplant recipient: A case report.

After lung transplantation, itraconazole (ITCZ) is used as a prophylaxis for aspergillosis. ITCZ is a weak base with high lipophilicity, and the dissolution and absorption of ITCZ tablets and capsules are pH dependent. Therefore, ITCZ may not achieve sufficient serum concentrations in patients with higher gastric pH because of its poor bioavailability. We report a case of a woman in fifties with post-COVID-19 respiratory failure who successfully underwent lung transplantation, followed by improved bioavailability of ITCZ tablets when given with acidic lemon beverages. The patient was initially administered ITCZ oral solution; this was discontinued because of its unpleasant taste, nausea, and vomiting. The ITCZ oral solution was replaced with ITCZ tablets 78 days after transplantation; however, serum concentrations of ITCZ and hydroxy-ITCZ were below the detection limit (100 ng/mL). We co-administered ITCZ tablets with commercially available lemon beverages. Subsequently, serum concentrations of ITCZ and hydroxy-ITCZ increased to 341 and 673 ng/mL, respectively, on the 125th day after transplantation. Infection with fungi, including Aspergillus spp., was not observed in this case. The patient had no adverse events such as gastric ulcer or hyperglycemia. These results suggest that the co-administration of lemon beverages and ITCZ tablets may help achieve better absorption of ITCZ in patients taking acid suppressants.

Non-invasive ventilation using a novel ventilator and non-vented full-face mask for patients with respiratory failure during the COVID-19 pandemic: Report of three cases.

The Japanese government's latest manual on COVID-19 management mentions non-invasive ventilation (NIV). Before this version, we experienced three cases in which COVID-19 was a concern. Each case had one of the following conditions: obesity hypoventilation syndrome, amyotrophic lateral sclerosis, acute heart failure with acute kidney injury with hypercapnia. The guidelines indicate that patients with these diseases are good candidates for NIV. NIV was used in a negative pressure room with staff in personal protective equipment. We describe the use of NIV instruments with anti-viral filters and a non-vented mask, including a new NIV machine for COVID-19 respiratory care.

Living-Donor Lung Transplantation for Post-COVID-19 Respiratory Failure.

This report describes a case of coronavirus disease 2019 (COVID-19)-associated respiratory failure requiring urgent living-donor lobar lung transplantation (LDLLTx). Severe hypoxia requiring extracorporeal membrane oxygenation (ECMO) developed in a 57-year-old woman with positive viral status. Her respiratory function deteriorated, with almost totally collapsed lungs. All of her other organs functioned well. After 104 days of ECMO support, she underwent urgent LDLLTx using cardiopulmonary bypass. The grafts worked well, and she was weaned from cardiopulmonary bypass after reperfusion. LDLLTx is an option for selected patients with post-COVID-19 end-stage respiratory failure.

Successful treatment of COVID-19-related acute respiratory distress syndrome with a rare blood type: A case report.

Extracorporeal membrane oxygenation is indispensable for critically severe COVID-19 patients. However, it would be inapplicable to patients with a rare blood type or blood transfusion refusal. In that case, severely conservative fluid management with the sacrifice of renal functions and hydrocortisone therapy should be considered for better oxygenation.

Mammalian enteral ventilation ameliorates respiratory failure.

BACKGROUND: Several aquatic organisms such as loaches have evolved unique intestinal breathing mechanisms to survive under extensive hypoxia. To date, it is highly controversial whether such capability can be adapted in mammalian species as another site for gas exchange. Here, we report the advent of the intestinal breathing phenomenon in mammalians by exploiting EVA (enteral ventilation via anus). METHODS: Two different modes of EVA were investigated in an experimental model of respiratory failure: intra-rectal oxygen O2 gas ventilation (g-EVA) or liquid ventilation (l-EVA) with oxygenated perfluorocarbon. After induction of type 1 respiratory failure, we analyzed the effectiveness of g-EVA and I-EVA in mouse and pig, followed by preclinical safety analysis in rat. FINDINGS: Both intra-rectal O2 gas and oxygenated liquid delivery were shown to provide vital rescue of experimental models of respiratory failure, improving survival, behavior, and systemic O2 level. A rodent and porcine model study confirmed the tolerable and repeatable features of an enema-like l-EVA procedure with no major signs of complications. CONCLUSIONS: EVA has proven effective in mammalians such that it oxygenated systemic circulation and ameliorated respiratory failure. Due to the proven safety of perfluorochemicals in clinics, EVA potentially provides an adjunctive means of oxygenation for patients under respiratory distress conditions. FUNDING: This work is funded by the Research Program on Emerging and Re-emerging Infectious Diseases, Research Projects on COVID-19 (JP20fk0108278, 20fk0108506h0001), from the Japan Agency for Medical Research and Development (AMED), to T.T.; Strategic Promotion for Practical Application of Innovative Medical Technology, Seeds A (A145), to T.T.; and KAKENHI 19K22657, to T.C.-Y. This research is partially supported by the AMED Translational Research Program; Strategic Promotion for Practical Application of Innovative Medical Technology (TR-SPRINT), to T.C.-Y.; and AMED JP18bm0704025h0001 (Program for Technological Innovation of Regenerative Medicine), to T.T.