More severe lung disease tied to worse outcomes in AAV-ILD
Study: Risk higher for disease progression, respiratory failure, death
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Among people with ANCA-associated vasculitis (AAV) and interstitial lung disease (ILD), severe lung scarring and poorer lung function at the time of ILD diagnosis are tied to a higher risk of lung disease progression, respiratory failure, and death, a European study shows.
ILD is a condition marked by inflammation and progressive scarring of lung tissue, and a common lung manifestation of AAV.
Data also showed that treatment with rituximab (sold as Rituxan, with biosimilars available) was associated with the greatest improvements in lung function, especially in patients with more severe lung scarring.
This study highlights “the need for early identification and individualized treatment in ILD associated with AAV,” and “identified meaningful clinical, radiologic, and prognostic features,” researchers wrote.
The study, “Interstitial Lung Disease in Antineutrophil Cytoplasmic Antibody–Associated Vasculitis: A European Multicenter Study,” was published in Arthritis & Rheumatology.
Cough, shortness of breath most common symptoms at ILD diagnosis
AAV is a group of diseases typically caused by self-reactive antibodies, called ANCAs, that overly activate neutrophils, a type of immune cell. This results in inflammation and damage to small blood vessels in several organs, most frequently the lungs and kidneys.
ILD is a serious lung disease that can occur in association with AAV (AAV-ILD), or as an isolated condition with the presence of ANCAs, but no vasculitis, or blood vessel inflammation (ANCA-ILD).
To learn more about the features and outcomes of AAV-ILD and ANCA-ILD, a team of researchers retrospectively analyzed data from 123 people with AAV-ILD and 39 people with ANCA-ILD who were seen at six centers across four European countries.
More than half of the participants (57%) were men and they were followed for a median of 4.2 years. AAV patients had a median age of 72 years at diagnosis, and in terms of AAV type, most had microscopic polyangiitis (61%).
In both groups, ANCAs targeting the myeloperoxidase protein were detected in about 85% of patients, while the remaining patients had ANCAs against the proteinase 3 protein. Median levels of both types of ANCAs at diagnosis were significantly higher among those with AAV.
Among all participants, the most common symptoms at ILD diagnosis included cough (85%) and shortness of breath (75%). On chest CT scans, usual interstitial pneumonia (UIP) was the most common radiological pattern (56%), followed by nonspecific interstitial pneumonia (NSIP, 17%). UIP is marked by more permanent lung scarring, or fibrosis, and tends to have a worse prognosis, while NSIP often has more inflammation than scarring.
ANCA-ILD patients were significantly more likely to have cough (81% vs. 57%), shortness of breath (81% vs. 48%), UIP (69% vs. 51%), and more severe fibrosis than those with AAV-ILD. In contrast, diffuse alveolar hemorrhage, a form of lung bleeding, was present exclusively in the AAV-ILD group (18%).
ANCA-ILD patients also had poorer lung function, with significantly lower total lung capacity, or the maximum volume of air the lungs can hold after a deep breath (63% vs. 90%).
53% of patients experienced lung fibrosis progression during follow-up
During follow-up, participants with UIP and those with NSIP showed a significantly greater annual decline in forced vital capacity (FVC) percentage compared with those with other disease patterns. FVC percentage is a lung function measure that indicates how much air a person forcefully exhales after a deep breath relative to the predicted average for someone with the same age, sex, and other factors.
Overall, 96% of patients received immunosuppressive treatment, most commonly glucocorticoids, but rates of use, including glucocorticoids and rituximab, were significantly higher in the AAV-ILD group.
Treatment with rituximab led to the greatest annual FVC percentage gain during follow-up, particularly in participants with UIP. The therapy was associated with a trend toward improved FVC percentage in both AAV-ILD and ANCA-ILD groups.
These findings highlight the urgent need for early diagnosis, standardized radiologic evaluation, and a multidisciplinary strategy to optimize care and improve prognosis in this underrecognized, high-risk patient population.
Over follow-up, 53% of the patients experienced lung fibrosis progression on CT scans (radiologic progression), while 48% died, and 19% developed respiratory failure, which occurred significantly earlier in ANCA-ILD patients.
“Survival did not differ between the AAV-ILD and ANCA-ILD groups,” the researchers wrote. The most common cause of death was lung disease progression caused by an infection or ILD worsening.
Statistical analyses adjusted for potential influencing factors showed that younger age and more severe lung fibrosis at ILD diagnosis were significantly associated with a higher risk of radiologic progression.
Also, lower FVC% at ILD diagnosis and more severe fibrosis were independent risk factors of respiratory failure, while older age and lower FVC% at ILD diagnosis were significantly associated with a higher risk of death.
“These findings highlight the urgent need for early diagnosis, standardized radiologic evaluation, and a multidisciplinary strategy to optimize care and improve prognosis in this underrecognized, high-risk patient population,” the researchers wrote.
