Study Explores Risk Factors in AAV-ILD Mortality

Antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) with interstitial lung disease (AAV-ILD) is the primary lung manifestation of AAV and is associated with a higher risk of poor outcomes in affected patients, including death.

A new study by researchers at Sichuan Provincial People’s Hospital in China, published in Clinical Rheumatology in February, looked to explore the risk factors associated with mortality in individuals diagnosed with AAV-ILD.

“Early intervention and management of risk factors related to AAV-ILD will provide benefits to improve the poor prognosis of patients,” wrote corresponding author Xixi Chen and colleagues.

To gather results, a comprehensive search was conducted for English-language studies on AAV and AAV-ILD. Hazard ratios (HR) and 95% confidence intervals (CI) for mortality-related risk factors in AAV-ILD were gathered, and subgroup analyses were performed based on various candidate risk factors.

To evaluate the heterogeneity of the included studies, Cochran's Q statistic and inconsistency values were applied. A sensitivity analysis was carried out using a one-by-one elimination method, while publication bias was assessed through Egger’s test and the trim-and-fill method.

A total of eight studies involving 654 patients with AAV-ILD were included in the meta-analysis. Among these, four studies were conducted in China, two in Japan, one in South Korea, and one across France and Belgium.

The results indicated that older age was significantly associated with a 6% increased risk of death among patients with AAV-ILD, while a history of smoking was linked to a 61% higher risk. Usual interstitial pneumonia (UIP), a prevalent subtype of AAV-ILD, and acute exacerbation episodes of worsening symptoms were each associated with a twofold increase in mortality risk. Additionally, myeloperoxidase-antineutrophil cytoplasmic antibodies (MPA) were significantly related to a fourfold elevated risk of death.

A major finding from the study was that the use of immunosuppressive medications to induce remission in AAV was identified as a strong protective factor, significantly associated with a 60% reduction in mortality risk among patients with AAV-ILD.

A second protective factor was a higher predicted forced vital capacity (FVC%), which indicates better lung function and was linked to a 3% lower risk of death. FVC% measures the volume of air a person can forcibly exhale after taking a deep breath.

“In summary, our pooled analyses showed that age, ever smoker, FVC%, UIP pattern, AE, MPA and IFI were associated with AAV-ILD mortality,” the authors concluded. “Early intervention and management of risk factors related to AAV-ILD will provide benefits to improve the poor prognosis of patients.”