Clinical features and long-term outcomes of interstitial lung disease with anti-neutrophil cytoplasmic antibody

• Published in: BMC pulmonary medicine Vol. 21; no. 1; pp. 88 - 10
• Main Authors: Sun, Xin, Peng, Min, Zhang, Ting, Li, Zongru, Song, Lan, Li, Mengtao, Shi, Juhong
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 16.03.2021; BioMed Central; BMC
• Subjects: Age; Anti-neutrophil cytoplasmic antibody; Antibodies; Antigens; Antineutrophil cytoplasmic antibodies; Autoantibodies; Bacterial pneumonia; Biopsy; C-reactive protein; Comparative analysis; Diagnosis; Erythrocyte sedimentation rate; Fever; Health aspects; Idiopathic interstitial pneumonia; Inflammation; Interstitial lung disease; Laboratories; Leukocytes (neutrophilic); Lung diseases; Lung diseases, Interstitial; Medical prognosis; Microscopic polyangiitis; Neutrophils; Patient outcomes; Patients; Pneumonia; Prognosis; Pulmonology; Risk factors; Statistical analysis; Survival analysis; Vasculitis; China; Microscopic polyangiitis; Anti-neutrophil cytoplasmic antibody; Idiopathic interstitial pneumonia; Interstitial lung disease
• DOI: 10.1186/s12890-021-01451-4
• ISSN: 1471-2466

Patients with interstitial lung disease (ILD) are occasionally positive for anti-neutrophil cytoplasmic antibodies (ANCAs). Differences between ILDs secondary to microscopic polyangiitis (MPA) and isolated ANCA-positive idiopathic interstitial pneumonia (IIP) remain unclear. The aim of this study was to explore the differences in clinical features and outcomes between MPA-associated ILDs and isolated ANCA-positive IIPs. We reviewed 1338 ILDs patients with available ANCA results and retrospectively analysed 80 patients who were ANCA-positive. MPA-associated ILDs (MPA-ILDs group) and isolated ANCA-positive IIPs (ANCA-IIPs group) were compared. Among 80 patients with ANCA-positive ILDs, 31 (38.75%) had MPA-ILDs, and 49 (61.25%) had isolated ANCA-positive IIPs. Compared with ANCA-IIPs group, patients in MPA-ILDs group had a higher proportion of fever (p = 0.006) and higher neutrophil count (p = 0.011), erythrocyte sedimentation rate (ESR) (p < 0.001) and C-reactive protein (CRP) (p = 0.005). Multivariable analysis showed that ESR level was an independent risk factor for mortality in all 80 ANCA-positive ILDs patients (HR 1.028, p = 0.001). Survival in MPA-ILDs group was lower than that in ANCA-IIPs group, and further stratified analysis revealed that ANCA-IIPs patients with elevated ESR or CRP had a worse prognosis than those with normal inflammation markers, with 5-year cumulative survival rates of 60.00%, 86.90% and 100.00% in MPA-ILDs and ANCA-IIPs with and without elevated inflammation markers, respectively. Among patients with ANCA-positive ILDs, the prognoses of ANCA-IIPs with normal inflammation markers, ANCA-IIPs with elevated inflammation markers and MPA-ILDs were sequentially poorer. Therefore, stratified treatment should be considered in the management of ILDs patients positive for ANCAs.