Clinical practice guidelines of the Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis for the management of microscopic polyangiitis and granulomatosis with polyangiitis: The 2023 update

Objective To revise the 2017 clinical practice guidelines (CPG) for the management of microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) to reflect advancements in the field. Methods Similar to the 2017 CPG, the Grading of Recommendations, Assessment, Development, and Evaluation system was adopted for this revision. The intended users of this CPG include patients diagnosed with MPA or GPA in Japan and their families and healthcare professionals, including specialists and non-specialists. Based on a scoping review, four clinical questions (CQs) of the 2017 guidelines were modified, and six new CQs were added. Results We suggest a combination of glucocorticoid and cyclophosphamide or rituximab for remission induction therapy. In cases where cyclophosphamide or rituximab is used, we suggest the use of avacopan over high-dose glucocorticoid. Furthermore, we suggest against the use of plasma exchange in addition to the standard treatment in severe cases of MPA/GPA. Finally, we suggest the use of glucocorticoid and rituximab over glucocorticoid and azathioprine for remission maintenance therapy. Conclusions The recommendations have been updated based on patient preference, certainty of evidence, benefit and risk balance, and cost.