Comprehensive characteristics of pulmonary antineutrophil cytoplasmic antibody-associated vasculitis and the development of a predictive nomogram for mortality

Objectives: Antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) is a rare and potential devastating disease with high mortality, frequently with pulmonary involvement. Our study aimed to explore the pulmonary features of AAV and identify predictors of long-term survival.

Methods: We retrospectively analyzed 538 AAV patients diagnosed between January 2013 and July 2019, with follow-up data extending to August 2020. The Least absolute shrinkage and selection operator (LASSO) regression analysis was employed to identify variables predictive of mortality. Subsequently, a nomogram was developed, with its predictive accuracy and discrimination assessed by the concordance index and calibration curves, respectively.

Results: A total of 460 (85.5 %) AAV patients presented with pulmonary involvement. The mortality was 36.8 %. Patients with pulmonary involvement more frequently exhibited respiratory symptoms, predominantly interstitial lung disease on radiographs, and were at higher risk for respiratory failure, diffuse alveolar hemorrhage, mechanic ventilation and death (All P < 0.05). The LASSO regression pinpointed 16 predictors of mortality, and the predictive model demonstrated an area under the curve of 0.810. The nomogram, based on these variables, achieved a concordance index of 0.825, with calibration curve indicating excellent predictive agreement.

Conclusion: The study establishes a predictive model for AAV mortality with high accuracy, offering insights crucial for patient care. Pulmonary involvement, prevalent and linked to higher mortality, underscores the need for precise predictive tools in AAV management.