Association between preexisting lung involvements and the risk of diffuse alveolar hemorrhage in patients with microscopic polyangiitis: A multi-center retrospective cohort study

Abstract

Objectives: To identify the factors associated with the risk of diffuse alveolar hemorrhage (DAH) in patients with microscopic polyangiitis (MPA), focusing on other preexisting lung involvements such as interstitial lung disease (ILD) and airway disease.

Methods: In this retrospective cohort study, we analyzed consecutive patients with myeloperoxidase-antineutrophil cytoplasmic antibody-positive MPA who had undergone chest computed tomography (CT) before starting treatment between 2006 and 2016. Patients who already had DAH at initial CT imaging were excluded. CT images were evaluated for the presence of ILD and airway disease. The association between preexisting lung involvements and the development of DAH was assessed using logistic regression models adjusted for various clinical characteristics.

Results: We identified 113 patients (median age 72 years; median follow-up duration 39 months), and 27 (24%) of them developed DAH during the follow-up. Airway disease was identified in 41 (36%) patients and was independently associated with the development of DAH (adjusted odds ratio 6.86, 95% confidence interval 1.85–25.4). However, ILD identified in 45 (40%) patients was not associated with DAH.

Conclusion: Our findings suggest that DAH in MPA occurs frequently in patients with airway disease. Attention to preexisting airway disease may help predict the development of DAH.

Keywords:

• Anti-neutrophil cytoplasmic antibody-associated vasculitis
• airway disease
• bronchiolitis
• bronchiectasis
• MPO-ANCA

Acknowledgements

The authors thank Shunya Kaneshita, Takahiro Seno, Kiyokazu Yoshinoya, Shogen Boku, Yu Kasamatsu, and Yoshihiro Kasamatsu for their contribution to data management and study conception. The authors also thank Enago (www.enago.jp) for the English language proofreading.

Conflict of interest

Keiichi Tamagaki has received research grants from Asahi Kasei, Chugai, and Takeda. Yutaka Kawahito has received research grants from Asahi Kasei, Chugai, and Pfizer. The remaining authors declare that they have no conflicts of interest.