De novo myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-associated glomerulonephritis 31 years after living-donor kidney transplantation

Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis in Kidney Transplantation

Due to complex comorbidity, high infectious complication rates, an elevated risk of relapsing for primary renal disease, as well as inferior recipient and allograft survivals, individuals with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAVs) are often considered as poor transplant candidates. Although several aspects of recurrent and de novo AAVs remain unclear, recent evidence suggests that kidney transplantation (KT) represents the best option, which is also the case for this particular subgroup of patients. Special counselling and individualized approaches are strongly recommended at the time of enlistment and during the entire post-transplant follow-up. Current strategies include avoiding transplantation within one year of complete clinical remission and thoroughly assessing the recipient for early signs of renal or systemic vasculitis. The main clinical manifestations of allograft AAV are impaired kidney function, proteinuria, and hematuria with ANCA positivity in most cases. Mixed results have been obtained using high-dose steroids, mycophenolate mofetil, or cyclophosphamide. The aim of the present review was to summarize the available literature on AAVs in KT, particularly focusing on de novo pauci-immune glomerulonephritis.

Antibody-mediated rejection with the presence of glomerular crescents in a pediatric kidney transplant recipient: A case report

Glomerular crescents in kidney transplantation are indicative of severe glomerular injury and constitute a hallmark of RPGN. Their concurrence with ABMR has been rarely described only in adult patients. We report a case of 10-year-old boy with compound heterozygous Fin-major Finnish-type congenital nephrotic syndrome, who had received a deceased-donor kidney transplant 5 years before onset of acute kidney injury and nephrotic range proteinuria without hematuria. Kidney allograft biopsy illustrated 6 glomeruli with global sclerosis and 6 with remarkable circumferential or segmental cellular crescents. Negative glomerular immunofluorescence for immune-complex deposits and the absence of serum ANCA eliminated the presence of immune-mediated and ANCA-positive pauci-immune crescentic glomerulonephritis. Diagnosis of ABMR was based on the high levels of HLA class II DSA and the histological evidence of glomerulitis, peritubular capillaritis, and acute tubular injury with positive linear peritubular capillary C4d staining. The patient despite plasmapheresis and enhanced immunosuppressive treatment progressed to end-stage renal disease. We conclude that glomerular crescents may represent a finding of AMBR and possibly a marker of poor allograft prognosis in pediatric patients.

De novo pauci-immune glomerulonephritis in renal allografts

Pauci-immune glomerulonephritis in the native kidney presents with renal insufficiency, proteinuria, and hematuria, and is usually due to anti-neutrophil cytoplasmic antibodies. Rarely, kidney transplants can show this pattern as de novo disease. We performed a retrospective analysis in 10 cases of de novo pauci-immune glomerulonephritis. The mean time from transplant to diagnostic biopsy was 32 months (range, 4-96). All biopsies showed focal necrotizing or crescentic glomerulonephritis (mean 16% glomeruli, range 2-36%). Immunofluorescence and electron microscopy showed a pauci-immune pattern. No patients had evidence of systemic vasculitis. Anti-neutrophil cytoplasmic antibody results were available for 7 patients and were negative in all but one. Most patients had functioning grafts at one year after diagnosis. Two patients had repeat biopsies that showed continued active glomerulonephritis. We report the first clinicopathologic series of de novo pauci-immune glomerulonephritis which appears to be a unique pathologic entity that may occur early or late post-transplant and in our cohort is not associated with systemic vasculitis and usually not associated with anti-neutrophil cytoplasmic antibodies. The degree of crescent formation and renal impairment are milder than those of pauci-immune crescentic glomerulonephritis in the native kidney.

Recurrent and de novo Glomerulonephritis After Kidney Transplantation

The prevalence, pathogenesis, predictors, and natural course of patients with recurrent glomerulonephritis (GN) occurring after kidney transplantation remains incompletely understood, including whether there are differences in the outcomes and advances in the treatment options of specific GN subtypes, including those with de novo GN. Consequently, the treatment options and approaches to recurrent disease are largely extrapolated from the general population, with responses to these treatments in those with recurrent or de novo GN post-transplantation poorly described. Given a greater understanding of the pathogenesis of GN and the development of novel treatment options, it is conceivable that these advances will result in an improved structure in the future management of patients with recurrent or de novo GN. This review focuses on the incidence, genetics, characteristics, clinical course, and risk of allograft failure of patients with recurrent or de novo GN after kidney transplantation, ascertaining potential disparities between “high risk” disease subtypes of IgA nephropathy, idiopathic membranous glomerulonephritis, focal segmental glomerulosclerosis, and membranoproliferative glomerulonephritis. We will examine in detail the management of patients with high risk GN, including the pre-transplant assessment, post-transplant monitoring, and the available treatment options for disease recurrence. Given the relative paucity of data of patients with recurrent and de novo GN after kidney transplantation, a global effort in collecting comprehensive in-depth data of patients with recurrent and de novo GN as well as novel trial design to test the efficacy of specific treatment strategy in large scale multicenter randomized controlled trials are essential to address the knowledge deficiency in this disease.