Hospitalization because of relapse or disease complications may be a major concern for patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) during follow-up, according to an article published in Annals of the Rheumatic Diseases.

In the study, researchers reviewed the hospitalization records of patients with AAV from 13 Italian hospitals. They examined the hospitalization dates, features, length of stay, primary discharge diagnoses, and patient data.

They employed an indirect method of calculating age- and sex-standardized hospitalization rates, per year and for the study period, using the 2007 to 2018 hospitalization data provided by the Italian Ministry of Health. Multivariable and survival models were used to investigate associations between these outcomes, clinical parameters at diagnosis, and preexisting comorbidities.

According to the results, there were 610 hospitalizations per 635 patients with AAV (19.4% microscopic polyangiitis, 34.6% granulomatosis with polyangiitis, 46.0% eosinophilic granulomatosis with polyangiitis) during a 12-year observation. In 19.8% of the cases, patients were hospitalized for life-threatening conditions that led to death in 2.3% of patients.

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Moreover, the median time to the first hospitalization was 504 days and the median hospitalization length was 8 days.

“The 2018 standardized hospitalization rate was 1.14 (0.91, 1.43) for all AAV combined, 1.13 (0.68, 1.76) for microscopic polyangiitis, 1.48 (1.02, 2.08) for granulomatosis with polyangiitis, and 0.90 (0.60, 1.31) for eosinophilic granulomatosis with polyangiitis. These rates tended to a gradual increase from 2007 to 2018 in the whole AAV cohort of patients and in every disease subset,” Berti and colleagues wrote.

Most patients were hospitalized for infectious diseases (18.7%), major AAV relapse and diagnostic re-evaluation (17.2% each), and cardiovascular diseases (10.8%). The most common infectious diseases included infections of the respiratory system (44.6%), followed by urinary tract (9.6%), and sepsis (6.3%).

On a similar note, the majority of patients with AAV hospitalized during follow-up had only 1 hospitalization (55.5%), followed by 2 (18.7%) and 3 or more hospitalizations (25.6%).

The researchers also identified a risk profile associated with high hospitalization rates: those with a diagnosis of granulomatosis with polyangiitis or microscopic polyangiitis (versus eosinophilic granulomatosis with polyangiitis), higher vasculitis activity (assessed by Birmingham Vasculitis Activity Score), ANCA positivity at diagnosis, as well as hospitalization at diagnosis, more preexisting comorbidities, and older age.


Berti A, Ottone M, Sartorelli S, et al. Hospitalization rates, features, and discharge diagnoses of a large nationwide cohort of ANCA-associated vasculitis. Ann Rheum Dis. Published online May 30, 2023.