Uromodulin and microRNAs (miRNAs) have recently been investigated as potential biomarkers for kidney graft associated pathology and outcome, with a special focus on biomarkers indicating specific disease processes and kidney graft survival. The study’s aim was to determine whether expression of serum uromodulin concentration and selected miRNAs might be related to renal function in kidney transplant recipients (KTRs). The uromodulin concentration and expression of six selected miRNAs (miR-29c, miR-126, miR-146a, miR-150, miR-155, and miR-223) were determined in the serum of 100 KTRs with stable graft function and chronic kidney disease of all five stages. Kidney graft function was estimated with routine parameters (creatinine, urea, cystatin C, and Chronic Kidney Disease Epidemiology Collaboration study equations) and precisely measured using chromium-51 labelled ethylenediaminetetraacetic-acid clearance. The selected miRNAs were shown to be independent of kidney graft function, indicating their potential as biomarkers of associated kidney graft disease processes. In contrast, the serum uromodulin level depended entirely on kidney graft function and thus reflected functioning tubules rather than any specific kidney graft injury. However, decreased concentrations of serum uromodulin can be observed in the early course of tubulointerstitial injury, thereby suggesting its useful role as an accurate, noninvasive biomarker of early (subclinical) kidney graft injury.

Coronavirus disease 2019 (COVID-19) can lead to various multisystem disorders, including thrombotic microangiopathy (TMA). We present here eight patients with COVID-19-associated TMA who were treated at our center. Our aim was to summarize the demographic and clinical characteristics of the patients and discuss the possible role of COVID-19. One patient presented with thrombotic thrombocytopenic purpura (TTP) and seven with atypical hemolytic–uremic syndrome (aHUS.) Most patients had no obvious symptoms of COVID-19, and TMA occurred after viremia. Two patients had concomitant non-COVID-19-related triggers for TMA: exposure to tacrolimus and everolimus; first presentation of antiphospholipid syndrome. The patient with TTP was treated with therapeutic plasma exchange (TPE), steroids and caplacizumab, resulting in complete hematologic recovery. Six patients with aHUS were treated with TPE with or without steroids, four of whom received a C5 complement inhibitor and one an intravenous immunoglobulin. One patient with aHUS was treated with a C5 complement inhibitor and a steroid. We observed one partial and one complete recovery of renal function, while five patients experienced renal failure. There were no deaths. We believe that COVID-19 may act as a trigger for TMA in patients who have either pre-existing endothelial injury or an underlying predisposition to complement activation, and may also trigger autoimmune diseases. As a consequence of the different underlying pathophysiologies, the treatment of COVID-19-associated TMA requires a specific approach based on the subtype of the syndrome and possible concomitant triggers.

Tixagevimab/cilgavimab (TIXA/CILGA) was introduced in early 2022 as a promising new drug for pre-exposure prophylaxis against COVID-19 in immunocompromised patients. The aim of our study was to evaluate the efficacy and safety of TIXA/CILGA in a Slovenian national cohort of kidney transplant recipients as pre-exposure prophylaxis in the Omicron era. Demographic, clinical, laboratory, and therapeutic data were collected from electronic and paper medical rec-ords. Of the 106 patients who received TIXA/CILGA, 6 patients (5.7%) subsequently acquired SARS-CoV-2 breakthrough infection. The incidence of SARS-CoV-2 infection was only slightly lower compared with patients who did not receive TIXA/CILGA (7.0%). All patients who re-ceived TIXA/CILGA had a mild disease course, whereas 20% of patients who did not receive TIXA/CILGA required hospitalization and two patients died. Adverse effects most likely related to TIXA/CILGA occurred in 12% of patients, one of whom experienced deep vein thrombosis. None of the patients suffered acute myocardial infarction or cerebrovascular insult. Overall, the benefit of added protection for kidney transplant patients appears to outweigh the potential risk of adverse events and provide additional protection against severe COVID-19 protection.