Clinical characteristics and outcomes of COVID-19 in kidney transplant recipients

Introduction. The pandemic caused by the SARS-CoV-2 coronavirus is characterized by significant morbidity and mortality. Kidney transplant recipients are at high risk of a more severe course of coronavirus infection due to ongoing immunosuppression, a high comorbidity index, and elder age.Aim. To investigate the features of the clinical course, the treatment applied and also the outcomes of the new coronavirus infection in patients after kidney transplantation.Material and methods. The retrospective study included 69 adult kidney transplant recipients continuously followed-up by our transplant nephrology service and who fell ill with COVID-19 from April 2020 till February 2021. The comparison study of the clinical pattern, laboratory and instrumental test results, treatment features and outcomes was made.Results. The most common clinical symptoms were hyperthermia (85.5%, n= 59), weakness (65.2%, n=45) and cough (52.2%, n=36), other symptoms were significantly less common. In 89.5% of cases (n=60), the virus ribonucleic acid was detected at least once by polymerase chain reaction; in 10.5% of cases (n=7), the polymerase chain reaction results were negative. According to CT, the extent of lung tissue lesion was identified as CT1 stage in 28 patients (46.7%), CT2 stage in 24 (40%); and only in 8 (13%) patients the lesion was assessed as CT3. Later on the number of patients with more than 50% lung damage increased to 16 (26.7%) and in 1 case the severity of lung tissue damage was consistent with CT4. Typical features for all patients were anemia and lymphopenia of varying severity, hypoproteinemia, increased serum creatinine and urea, C-reactive protein, ferritin, procalcitonin and D-dimer in the laboratory test results. The treatment included antiviral, antibacterial, anticoagulant therapy, corticosteroids, biological anti-cytokine drugs. In 95% of cases (n=66), the maintenance immunosuppressive therapy was changed up to complete withdrawal of the certain components. The patient survival rate with a functioning graft was 76.8% (n=53), the graft loss was observed in 4.3% of cases (n=3), and the lethal outcome was reported in 18.8% (n=13). The cause of death was a severe respiratory distress syndrome with multiple organ dysfunction complicated by sepsis and septic shock in 8 patients (61.5%). Invasive ventilation and hemodialysis were associated with 17.2 (p<0.00001) and 21.5 (p<0.0006) times higher risk of death, respectively.Conclusions. Severe lymphopenia is associated with a clinical worsening of the COVID-19 course. Predictors of fatal outcome were identified as follows: bacterial sepsis, invasive ventilation, the need for renal replacement therapy (p<0.00001). Immunosuppression adjustment should be personalized considering the severity of infection, age, comorbidities, post-transplant timeframe, and the risk of rejection.><0.00001). Immunosuppression adjustment should be personalized considering the severity of infection, age, comorbidities, post-transplant timeframe, and the risk of rejection.