Plasmapheresis in ANCA-Associated Vasculitis with Active Kidney Involvement in the United States (2016-2020): A Cross-Sectional Study.

KEY POINTS

Plasmapheresis is recommended for treating ANCA-associated vasculitis with severe renal and/or lung involvement. We established the cohort being admitted for ANCA-associated vasculitis with active kidney involvement from the 2016–2020 National Inpatient Sample. We described characteristics, inpatient procedures, lengths of stay, hospital costs, and disposition for patients treated with plasmapheresis.

BACKGROUND

Plasmapheresis is currently recommended when ANCA-associated vasculitis (AAV) presents with severe kidney and/or lung involvement. This cross-sectional study aimed at describing characteristics of hospitalized patients diagnosed with AAV with severe kidney involvement undergoing plasmapheresis in the United States.

METHODS

We defined the study population as adults hospitalized for active kidney involvement with a new diagnosis of AAV (by subtype or unspecified). We established the cohort from the 2016–2020 National Inpatient Sample by International Classification of Diseases, Tenth Revision, Clinical Modification codes. In this cross-sectional study, we described demographic and clinical characteristics, associated inpatient procedures, lengths of stay, hospital costs, and disposition at discharge comparing patients treated and not treated with plasmapheresis.

RESULTS

We identified a total of 975 patients with hospitalized AAV with acute kidney involvement in the United States treated by plasmapheresis over the 5-year period. Demographic characteristics of patients who received plasmapheresis were similar to those in patients who did not (=5670). There were no regional differences in the proportion of patients who received plasmapheresis; however, plasmapheresis was deployed more frequently among patients admitted to urban teaching hospitals relative to rural and non-teaching hospitals. Patients treated with plasmapheresis were more likely to have had AKI (96% versus 90%, = 0.0007), AKI requiring dialysis (52% versus 16%, < 0.001), hypoxia (40% versus 16%, < 0.0001), and respiratory failure requiring mechanical ventilation (13% versus 3%, = 0.0003).

CONCLUSIONS

During 2016–2020, plasmapheresis was deployed in approximately 20% of patients being admitted for AAV and acute kidney involvement in the United States. As standards of care and practice evolve, the role of plasmapheresis in the management of AAV with acute kidney involvement will require further study.