ANCA-associated vasculitis (AAV) with childhood onset often affects multiple organs, showing symptoms at diagnosis in the ear, nose, and throat, as well as pulmonary and renal complications, a single-center study shows.
Also, researchers found, rituximab appears to be effective at inducing and maintaining remission in pediatric AAV patients.
The findings were presented at the 2019 Paediatric and Adolescent Rheumatology Conference, Oct. 8–9, in Birmingham, England, in a poster titled “Childhood onset ANCA-associated vasculitis: retrospective experience in single tertiary centre.”
AAV is a rare autoimmune condition found mostly in adults, but affects some children, too. Because its incidence is rare, children with AVV are treated according to information collected from adult patients. However, because symptoms may be different, approaches that work for adults may not be adequate for pediatric patients.
Seeking to describe the clinical features of childhood onset AAV, researchers at the Royal Manchester Children’s Hospital examined data from 10 children diagnosed with the condition at its center from 2014 to 2019.
Like in adult patients, the most common form of vasculitis was granulomatosis with polyangiitis (GPA, seven patients), followed by microscopic polyangiitis (MPA, two patients), and eosinophilic granulomatosis with polyangiitis (EGPA, one patient).
The disease was more common in girls — for each boy affected, four girls also had the condition – and affected the lungs and kidneys in all patients, except for the EGPA patient who had only lung involvement.
MPA emerged earlier than any other subtype, at an average age of 5.9 years compared to 13.2 for GPA and 11.8 years for EGPA, and patients had significant kidney symptoms. These patients also were diagnosed in less time than other patients — one month, compared to 2.5 months for GPA, and 11 months for EGPA.
Looking at the kind of autoantibodies patients had, researchers found that GPA patients mostly had antibodies against the proteinase 3 protein, while MPA patients mostly carried antibodies against the myeloperoxidase protein. The EGPA patient was negative for ANCA testing.
Three GPA patients with signs of progressive kidney disease and lung symptoms received a procedure called plasmapheresis, which removes the damaging autoantibodies from the blood. However, one patient had sustained bleeding in the lungs.
The two MPA patients had signs of significant renal failure. One patient died 19 months after diagnosis and the other received a kidney transplant.
All children were treated with cyclophosphamide, an immunosuppressant, and required further immunosuppression with either disease-modifying anti-rheumatic drugs or biologic agents. Most patients received mycophenolate mofetil or rituximab as maintenance therapy, which has been successful so far in maintaining remission.
“Childhood onset AAV are severe diseases with significant morbidity and mortality” associated with “multi-system involvement at presentation,” researchers wrote.
“Clinicians should investigate thoroughly for [ear, nose, and throat symptoms, as well as] pulmonary and renal complications at diagnosis,” they concluded.