ABSTRACT
BACKGROUND AND AIMS: Graft artery stenosis can have a significant shortand long-term negative impact on kidney graft function. We previously reported an unusual number of graft-arterial anomalies following kidney transplantation (KTx) in children during the first coronavirus disease (COVID-19) pandemic wave (Berteloot et al.) [1]. We report herein the 1-year follow-up of these patients. METHOD: In this retrospective study, we included all children who received a KTx at our centre from February to July 2020. We compared their outcome to that of paediatric recipients who were transplanted at our centre from 2015 to 2019 and presented an allograft vascular complication ('Historic' group) by querying our local data warehouse. RESULTS: Among the 9 children who received a KTx at our centre between February and July 2020 [8 boys, median age 10 years (3-17)], 8 presented Doppler features suggesting arterial stenosis, with an unusual extensive pattern (Figure 1) after a median delay of 13 days (8-113). For comparison, persistent spectral Doppler arterial anomalies were observed in only 5% of children following KTx at our centre over the previous 5-year period and were all focal anastomotic stenoses. In addition, five children had lymphoceles, which required surgical management as compared to only one patient in the 5 previous years (1%). We retrospectively diagnosed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-20 infection in 6/8 children with arterial stenosis on serologies performed at D0, including one boy with a history of positive real time reverse transcription-polymerase chain reaction (RT-PCR) 120 days before KTx. None of the patients had reported any symptom suggestive of COVID-19. The remaining two patients had received a graft from an asymptomatic deceased adolescent donor with a positive serology at D0. These data led us to suspect immune post-viral graft vasculitis, triggered by SARS-CoV-2. At 1-year post-transplantation, the outcome was favourable in the 8 isolated KTx recipients. A total of 4/8 children had normal blood pressure and 4 had controlled high blood pressure on mono or bi-therapy. Doppler anomalies had resolved in 5/8 and persisted in 3/8 with a trend for improvement of peak systolic velocities and no severe consequences on kidney function and histology. Indeed, the median glomerular filtration rate (GFR) was 91 mL/min/1.73 m2 (65-129), with unspecific and mild lesions on 4/8 protocol kidney biopsies (IFTA 1 or Cpt 1). One liver-kidney graft recipient had persistent hypertension and diffuse irregular inflammatory parietal thickening of the whole vascular graft associated with a parietal thrombus upstream of the birth of the two hepatic arteries (Figure 2);treated with anti-aggregation and prednisone 10 mg/d. CONCLUSION: Our case series suggests a risk of post-viral kidney graft vasculitis in children with recent SARS-CoV-2 infection in the recipient or donor. Pre-transplant vaccination against COVID-19 is mandatory in children > 5 years and their kidney donor candidates at our centre. We also strongly recommend vaccination of all people aged > 5 years in the household. (Figure Presented).