Abstract
We thank Meredith and Hull for the interest in our article about orbital Wegener's granulomatosis in a 9-year-old child as the initial presentation. 1 As stated in the article it is important for these patients to be managed by specialist centres which deal with paediatric immunological disease.
The child after obtaining the diagnosis was referred to a specialist centre in which she was enrolled onto the European Vasculitis Study Group (EUVAS) Trial. She was randomized in receiving mycophenolate 750 mg b.d. together with prednisolone 1 mg/kg/day orally which was tapered over the course of weeks as per protocol.
Mycophenolate mofetil (MMF) is a prodrug that is hydrolysed to mycophenolic acid. The active metabolite mycophenolic acid reversibly inhibits inosin-monophosphate-dehydrogenase (IMDH), a key enzyme of de novo purine synthesis. Lymphocytes are key effector cells in ANCA-associated systemic vasculitis (AASV), whose proliferation and function relies almost exclusively on de novo purine synthesis whereas most other cells use the salvage pathway.
MMF appears to be an excellent alternative to cyclophosphamide for induction of remission in AASV because it has strong immunosuppressive potency combined with low toxicity profile. After 6 months she was commenced on azathioprine 75 mg a day together with prednisolone of a maintenance dose of 7.5 mg as per the protocol. She is currently in remission. The trial is ongoing and results are yet to be published.
In summary we agree with Meredith and Hull's observation that corticosteroids alone are inadequate for both the induction and continual remission of Wegener's granulomatosis.
Footnotes
Competing interests
None declared