Optimizing the management of AQP4 antibody-positive NMOSD: A Canadian consensus

Aquaporin-4-IgG-positive (AQP4+) neuromyelitis optica spectrum disease (NMOSD) is a rare demyelinating disorder/astrocytopathy with an estimated prevalence of 1 per 100,000 population in Canada. An expert panel of Canadian clinicians developed consensus recommendations for the diagnosis and treatment of AQP4+ NMOSD to optimize patient outcomes. Panel co-chairs (DLR, MSF) developed recommendations for voting by the 18 consensus group members using a modified e-Delphi method. Statements with an average >4.25 on a 5-point Likert-type scale were adopted. Consensus was achieved for 25 of 27 recommendations on the first round of voting; two recommendations achieved consensus after revision with a second round of voting. There was consensus on the application of current international criteria for the diagnosis of AQP4+ NMOSD in pediatric and adult patients; use of a live or fixed cell-based assay to detect AQP4 antibodies; urgent early use of intravenous methylprednisolone and plasma exchange for acute attacks; use of a prednisone taper until dosing of a maintenance therapy is optimized; and initiation of long-term maintenance therapy with a monoclonal antibody therapy. It was recommended that vaccination status be checked and vaccinations updated, including administration of any missing non-live vaccinations in patients on prednisone following a relapse. There was consensus that treatment should be maintained long-term since discontinuation is associated with considerable risk of potentially disabling relapses regardless of age and/or disease stability. It is hoped that this expert consensus will help guide the management of AQP4+ NMOSD patients and improve long-term outcomes.