Intravenous immunoglobulin therapy in antineutrophil cytoplasmic antibody-associated vasculitis

Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) includes three heterogeneous and difficult to treat clinical entities. Intravenous immunoglobulins (IVIG) may constitute a good therapeutic option, although data hitherto are scarce. The aim of this study was to assess the effectiveness and safety of IVIG in AAV in a real-world setting.

Single center observational study of patients with AAV with at least one cycle of IVIG since January of 2000 to December of 2020. AAV diagnosis was based on a compatible clinical presentation and positive ANCA serology and/or compatible histology. Disease activity was assessed by the Birmingham Vasculitis Activity Score (BVAS). The effectiveness was evaluated by clinical and laboratory parameters (CRP, ESR) and its glucocorticoid-sparing effect. These variables were measured at one, six, twelve and twenty-four months of IVIG treatment. The doses of IVIG were 2g/kg in the following cycles of administration: 1 g/kg/day in 2 days (n=12); 0.5 g/kg/day in 4 days (n=11); 0.4 g/kg/day in 5 days (n=5). The clinical improvement was classified according to BVAS categories in remission, partial response and no response.

Twenty-eight patients (15 granulomatosis-polyangiitis, 10 microscopic polyangiitis and 3 eosinophilic granulomatosis with polyangiitis) were included. Reasons for using IVIG were relapse/refractory disease (n=25), active or suspected infection (n=3), and both (n=5). We observed a rapid and maintained BVAS score improvement, increasing from 34.6% at 1 month to 56.5% at 2 years of follow-up (p=0.12), and a reduction of glucocorticoids dose. Therapy was well tolerated and adverse events mild and scarce.

IVIG represents an effective and relative safe therapeutic alternative in relapsing/refractory AAV or in presence of a concomitant active infection.