Clinical significance of isolated v lesions in paediatric renal transplant biopsies: muscular arteries required to refute the diagnosis of acute rejection

Summary Intimal vascular lesions are considered features of acute T‐cell‐mediated rejection yet can occur in the absence of tubulointerstitial inflammation, termed isolated ‘v’ lesions. The clinical significance of these lesions is unclear. The diagnosis requires a biopsy with the presence of arteries. The frequency of adequate biopsies was analysed in 89 renal transplant biopsies from 57 paediatric renal allograft recipients, and the incidence of isolated endarteritis was determined. 60 (67%) biopsies contained an artery and of these, isolated ‘v’ lesions occurred in 6 (10%). 5 (83%) biopsies with isolated ‘v’ lesions were associated with positive DSA, suggesting that these lesions may represent acute antibody‐mediated rejection. Patients with vessel‐negative biopsies had an increased decline in eGFR (median −20.5, IQR −24.4 to 1.2 ml/min/1.73 m2 vs. −9.6, IQR −78.7 to −6.8 ml/min/1.73 m2; P = 0.01). Patients with vessel‐negative biopsies were more likely to have repeat biopsy for ongoing allograft dysfunction, (25.0% vs. 2.4%; P