Long-term outcome of renal transplantation in childhood-onset anti-neutrophil cytoplasmic antibody-associated vasculitis

Practice patterns and outcomes for pediatric ANCA vasculitis transplant recipients in a national cohort

BACKGROUND

Anti-neutrophil cytoplasmic autoantibody (ANCA) vasculitis is a rare condition in pediatric patients. Little is known about practice patterns and outcomes of pediatric transplant patients. The purpose of our study was to examine differences in patient characteristics, immunosuppression, and long-term graft outcomes between ANCA and non-ANCA vasculitis recipients.

METHODS

We used the Scientific Registry of Transplant Recipients to evaluate pediatric ANCA vasculitis recipients between the ages of 1 and 22 years old from 1991 to 2017 and compared them to non-ANCA vasculitis patients during the same time cohort in the USA.

RESULTS

A total of 26,431 transplant recipients were identified, of these, 337 with ANCA vasculitis. Mean 1-year eGFR was 62.46 and 64.92 ml/min/1.73 m² (p = 0.002), and mean 5-year eGFR was 57.95 and 59.38 ml/min/1.73 m² (p = 0.18) between the non-ANCA and ANCA groups, respectively. Five-year graft survival was similar in both groups (non-ANCA 75.5 vs. ANCA 78.6%; p = 0.19). Of those with graft loss within the ANCA group, only 0.6% was secondary to disease recurrence (p = 0.14).

CONCLUSIONS

Kidney transplant is a safe treatment modality for children with ANCA-related kidney failure. ANCA patients have comparable graft survival when compared to the general transplant population with a low risk of recurrence. Thymoglobulin was used in a higher proportion within the ANCA group compared to the non-ANCA group. Tacrolimus, mycophenolate mofetil/mycophenolic acid, and steroids were the predominant maintenance immunosuppression used in both groups. A higher resolution version of the Graphical abstract is available as Supplementary information.

Antineutrophilic cytoplasmic antibody-associated vasculitis and the kidney

PURPOSE OF REVIEW

The purpose of this review is to highlight recent studies that have emerged on the topic of ANCA-associated vasculitis with some historical context. The review also discusses how the adult data is relevant to pediatric patients.

RECENT FINDINGS

Pediatric studies on AAV are lacking. Therapies targeted to the inflammatory cascade specifically implicated in AAV, such as MPO inhibitors and complement mediators, are emerging. The PEXIVAS study recently called into question the routine use of plasma exchange (PLEX) in severe AAV, with no difference in ESKD or mortality found between patients who did or did not receive PLEX. Longer maintenance duration of nearly 48 months is preferred as compared with shorter duration in patients who are not on dialysis because of higher relapse rates in children with AAV.

SUMMARY

Current treatment in AAV includes corticosteroids, rituximab, and cyclophosphamide for induction. Maintenance therapy commonly consists of azathioprine or rituximab. Plasma exchange (PLEX) is no longer recommended for induction therapy for AAV but some experts still consider this as an option for patients who are not responding to therapy or have severe disease at presentation. However, emerging novel therapies may be on the horizon.

Kidney transplantation in pediatric patients with rheumatologic disorders

PURPOSE OF REVIEW

Providers caring for children with end-stage kidney disease from rheumatologic conditions face questions such as when to proceed with kidney transplantation, how common is disease recurrence posttransplant, how does recurrent disease impact patient and allograft outcomes, and what approaches are available to prevent and treat recurrent disease. We discuss recent developments and relevant literature that address these questions for the most common rheumatologic disorders that lead to end-stage kidney disease in childhood namely, systemic lupus erythematosus, IgA nephropathy, IgA Vasculitis/Henoch Schoenlein Purpura, and Anti-Neutrophil Cytoplasmic Antibody (ANCA)-associated vasculitis.

RECENT FINDINGS

Recent data suggest that children with IgA nephropathy, IgA vasculitis, and ANCA-associated vasculitis have similar patient and allograft survival to other conditions despite the risk of recurrent disease, yet those with lupus have worse posttransplant patient and allograft outcomes. A period of disease quiescence may be prudent prior to transplantation to decrease the risk of recurrence, which is associated with decreased allograft survival. Data on preventive strategies and treatment options are limited.

SUMMARY

It is recommended that patients with systemic rheumatologic conditions not be excluded from kidney transplantation but that patients be counseled on the risk of potential recurrent disease with its impact on transplant outcomes.

Cancer After Pediatric Kidney Transplantation: A Long-term Single-center Experience in Japan

Background

The cancer incidence, types, and risk factors after pediatric kidney transplantation (KT) have been reported in the United States, Canada, Europe, Australia, and New Zealand. However, no information is available about cancer in pediatric KT recipients in Asian countries.

Methods

Children aged <20 y who underwent initial KT from 1983 to 2016 were analyzed. We compared the cancer incidence with that in the general Japanese population using standardized incidence ratio and examined posttransplant cancer risk using Cox proportional hazards models.

Results

A total of 356 children (median age, 11.7 y; interquartile range, 5.0-17.6) received KT with a follow-up period of 4466 person-years. The median age of cancer onset was 18.5 y (interquartile range, 8.0-32.3), and 13 cancers occurred in 12 patients (3.4%). Two patients died from cancer. The most common cancers were posttransplant lymphoproliferative disorders (PTLDs) (38.5%). The median time to PTLD and non-PTLD diagnosis after KT was 0.6 and 16.4 y, respectively. There was no occurrence of skin cancer. The posttransplant cancer incidence was 9.9 times higher than that in the general age-matched population (standardized incidence ratio = 9.9; 95% confidence interval, 4.80-18.39). The cumulative cancer incidence was 5.3% in 20 y after KT, which is lower than that reported in previous studies. We could not identify any risk factors for all cancer after KT in all patients, whereas subgroup analysis in 264 patients with available data of recipient Epstein-Barr virus serological status showed that recipient Epstein-Barr virus-negative serology was an independent risk factor for cancer development.

Conclusions

The incidence of cancer is higher in Japanese pediatric KT recipients than in the general population. The cumulative incidence of cancer after KT was lower in our population than that previously reported. This may be because there was no skin cancer observed in the Japanese pediatric KT recipients in our study.