P31 Childhood onset ANCA-associated vasculitis: retrospective experience in single tertiary centre
Authors: Khan Zahoor Elahi , Chieng Alice , Willis Emily , Riley Phil , McDonagh Janet 
Published: October 2019

Abstract

Background
Anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) are rare small and medium vessel vasculitides that include granulomatosis polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA). This retrospective review summarises the clinical features of a cohort of patients with childhood onset AAV at a single tertiary centre in the North West of England.

Methods
Identification of all patients with diagnosis of ANCA-associated vasculitis diagnosed from 2014 to 2019, using department database and PEDVAS data. Clinical information was collected retrospectively using electronic patient record and case notes.

Results
10 patients with AAV were identified, with GPA being the most common diagnosis (7 patients). 2 patients had MPA and 1 had EGPA. All patients with GPA fulfilled consensus EULAR/PRES criteria. The EGPA patient fulfilled ACR classification criteria.1 MPA patient fulfilled Chapel Hill Consensus Conference criteria. MPA presented in a younger age group compared to EGPA. AAV was more common in females, 8:2 female to male ratio, Table 1 .
All patients had pulmonary and renal involvement, with the exception of one EGPA patient having pulmonary disease with no evidence of glomerulonephritis (GN). MPA patients had significant renal disease and presented early, within 1 month of clinical symptoms. GPA patients had an average duration of symptoms of 2.5 months before presentation. GPA patients were mainly cANCA PR3 positive and MPA patients were MPO positive. The EGPA patient was not ANCA positive but had histological diagnosis of granulomatous vasculitis.
3 patients with GPA underwent plasmapheresis, with evidence of proliferative GN and pulmonary disease at presentation. One of these patients sustained pulmonary haemorrhage. The 2 patients with MPA presented with significant renal failure; one patient died 19 months after diagnosis, the other had renal transplant.
All patients received cyclophosphamide and required further immunosuppression with either DMARD or biologic. Most patients remain on MMF or rituximab as maintenance therapy which appears successful in maintaining remission so far.
P31 Table 1: Demographics and clinical features of patients with AAV GPA, n = 7 MPA, n = 2 EGPA, n = 1 Gender F:M 6:1 2:0 0:1 Mean age at onset 13.2 (8.7- 15) 5.9 (2.3- 9.6) 11.8 (years) Mean duration of follow-up (months) 23.2 (5- 36) 28.5 (19- 38) 53 Mean duration of symptoms 2.5 (1-6) 1 (1) 11 pre-presentation (months) ENT 4 1 1 Pulmonary 7 2 1 Renal 7 2 0 Asthma 0 0 1 Eosinophilia 0 0 1 ANCA PR3 +ve 6 0 0 ANCA MPO +ve 1 2 0 ESRF 0 2 0 Death 0 1 0 Plasmapheresis 3 2 0 Cyclophosphamide 7 2 1 Azathioprine 3 1 1 MMF 3 2 1 Rituximab 4 1 1

Conclusion
Childhood onset AAV are severe diseases with significant morbidity and mortality. Rituximab was found to be effective in induction as well as maintenance therapy in our patients. In our cohort, children had multi-system involvement at presentation. Clinicians should investigate thoroughly for ENT, pulmonary and renal complications at diagnosis.

Conflicts of Interest
The authors declare no conflicts of interest.