Impact of Immunosuppressive Therapy on Pulmonary Perfusion in Kidney Transplant Recipients after COVID-19 illness. Authors' Names

Barbara Infante¹Dario Troise^1,2*Matteo Gravina³Bruno Minopoli³Marcella Gambacorta³Carmen Montanile³Luca Macarini³Silvia Mercuri¹Annalisa Cappiello¹Maddalena Panico¹Elena Ranieri⁴Giuseppe Stefano Netti⁴Carlo Alfieri⁵Giuseppe Castellano⁵Giovanni Stallone¹

• ¹Division of Nephrology, Dialysis and Transplantation, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Apulia, Italy
• ²Karolinska Institutet (KI), Solna, Stockholm, Sweden
• ³Department of Radiology, University of Foggia, Foggia, Apulia, Italy
• ⁴Department of Medical and Surgical Sciences, University of Foggia, Foggia, Apulia, Italy
• ⁵Department of Clinical and Community Sciences, Faculty of Medicine and Surgery, University of Milan, Milan, Lombardy, Italy

Introduction: Patients who have received kidney transplants (KTR) are considered to be more susceptible to the severity of COVID-19-related illness. The transplanted patient's respiratory outcome worsened because of the ventilation-perfusion mismatch that occurs during the infection, which has been linked to endothelial damage. In this context, a reduction in immunosuppressive therapy is advisable to improve patient outcomes. However, the prognosis and suggested treatment for these types of patients are still debated. Methods: We retrospectively analyzed 48 KTRs with stable graft function on calcineurin inhibitor therapy who underwent transient modification of the maintenance immunosuppressive regimen with withdrawal of mycophenolic acid/mycophenolate mofetil or mTOR inhibitor (mTORi) during COVID-19 infection and their reintroduction after healing. Pulmonary functional tests (EGA and spirometry) and DECT (Dual-energy CT) scans were performed 1 month following the negative nasopharyngeal swab (T0) and then after six months (T6).The presence an mTOR inhibitor in immunosuppressive therapy was associated with a significant increase in lung perfusion for the entire lung parenchyma of the mTORi-treated group, both in each lung segment considered separately and all of them together. Conclusion: Our findings are consistent with the observation that the use of mTORi could play a potentially beneficial role in improving pulmonary perfusion.