Most AAV patients in North America affected by lung complications
Study: Pulmonary manifestations associated with permanent damage
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Lung complications are common among adults with ANCA-associated vasculitis (AAV), affecting four in five individuals throughout their disease course, with some developing lasting damage, a study found.
According to the new analysis of more than 1,000 patients in the U.S. and Canada, patterns of lung involvement differed between those with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), the two most common types of AAV.
“Pulmonary manifestations are common in AAV and are associated with permanent damage,” researchers wrote. “Systematic assessments of individuals with AAV for pulmonary involvement will likely improve detection of these manifestations.”
The study, “Pulmonary manifestations of granulomatosis with polyangiitis and microscopic polyangiitis,” was published in Seminars in Arthritis and Rheumatism.
Learning how lungs are affected in AAV helps assess disease severity
AAV is a group of autoimmune diseases marked by inflammatory damage to small blood vessels driven by self-reactive antibodies called ANCAs. While the disease can affect nearly any part of the body, it often involves the kidneys, nerves, and skin.
AAV also affects the lungs, causing symptoms such as shortness of breath, chest pain, coughing, wheezing, or even coughing up blood. Some people with AAV develop interstitial lung disease (ILD), a serious condition characterized by inflammation and fibrosis (scarring) that can lead to life-threatening lung failure.
Understanding how the lungs are affected in AAV is important for assessing disease severity, determining treatment, and guiding disease monitoring. Yet, there is limited information on how common these lung manifestations are in AAV.
Therefore, researchers collected data from 1,026 adults with AAV (55.1% women) enrolled in the Vasculitis Clinical Research Consortium Longitudinal Study at 11 centers across Canada and the U.S. The median age of participants was 51.3 years, and they were followed for a median of 4.4 years.
Among the 860 people with GPA, most (82.7%) experienced lung involvement at some point. At diagnosis, 64% already had lung problems. During follow-up, 46.2% had lung issues, and about 1 in 6 (16.5%) developed lung symptoms for the first time after diagnosis.
More than half (52.3%) of GPA patients with lung involvement had multiple lung problems. The most common findings at diagnosis were lung nodules or cavities, bleeding in the lungs (diffuse alveolar hemorrhage or DAH), and inflammatory infiltrates. During follow-up, nodules and inflammatory infiltrates remained the most frequent problems.
Smoking didn’t appear to affect likelihood of lung symptoms at diagnosis
Lung involvement was also common in MPA. Of 166 people with MPA, 74.1% had lung manifestations during their disease course. At diagnosis, 56.5% had lung symptoms. During follow-up, 35.5% experienced lung problems, and 1 in 6 (15.7%) developed lung involvement for the first time.
About half (50.4%) had multiple types of lung complications at diagnosis, including DAH, inflammatory infiltrates, and respiratory failure. Manifestations at follow-up matched those with GPA.
Across all patients, 456 people had lung problems during follow-up. Of these, 63.2% experienced recurrent episodes of the same issue, while 36.8% developed new lung manifestations. Overall, 519 disease relapses occurred, with less than half (41.4%) involving the lungs.
Lung involvement rates were similar whether patients tested positive or negative for ANCAs (78.4% vs. 81.2%). Smoking also did not appear to affect the likelihood of lung symptoms at diagnosis (62.4% of smokers vs. 62.9% of non-smokers).
These findings highlight the need for thorough assessment of all individuals with AAV for pulmonary manifestations, as well as a better understanding of the natural history and optimal treatment strategies for each manifestation.
Ear, nose, and throat (ENT) problems were more common in GPA than in MPA. In both conditions, ENT symptoms were more common among patients with lung nodules, cavities, or airway inflammation. In contrast, ENT issues were less likely among people with DAH. In GPA specifically, ENT symptoms were associated wtih airway inflammation. In MPA, ENT symptoms were linked to lung nodules or cavities, and were less likely to occur in those with DAH.
Serious long-term lung damage developed in 179 patients (17.4%). This included persistent breathlessness, permanent loss of lung function, and ILD. Pulmonary fibrosis, or lung scarring, developed in 44 people. Among the 19 patients diagnosed with ILD, the median age was higher than the overall population (66.6 years), and 68.4% tested positive for the MPO type of ANCA.
“These findings highlight the need for thorough assessment of all individuals with AAV for pulmonary manifestations, as well as a better understanding of the natural history and optimal treatment strategies for each manifestation,” the researchers wrote.
