A new Australian study has examined how patient characteristics and treatment approaches in idiopathic pulmonary fibrosis patients has changed over the past decade.
The use of immunosuppressive therapy in idiopathic pulmonary fibrosis remains higher than expected despite the decline, Australasian experts say.
Idiopathic pulmonary fibrosis, a leading type of interstitial lung disease is becoming increasingly common.
The way in which data on IPF patients has been collected for clinical and research purposes across Australia and New Zealand has changed over time. But has the type of patient who develops IPF – and how they are treated – also changed?
These are the questions posed by a team of Australasian researchers behind a recent study published in the Internal Medicine Journal.
“There are limited real-world observational demographic and treatment data available for IPF,” the researchers wrote.
“Our findings provide in-depth contemporary insights into demographic and treatment data in Australian and New Zealand patients with IPF recruited from a wide range of geographical locations and clinical settings.”
To understand if and how the clinical characteristics and treatment profile of patients with IPF had changed over time, researchers compared data for 647 patients from the Australian Idiopathic Pulmonary Fibrosis Registry (AIPFR; enrolled between 2012 and 2016) and 852 patients with IPF from the Australasian Interstitial Lung Disease Registry (AILDR; enrolled between May 2016 and December 2023).
All patients were aged 18 years and older and had a diagnosis of IPF as per criteria outlined by the American Thoracic Society, the European Respiratory Society, the Japanese Respiratory Society, and the Latin American Thoracic Association (ATS/ERS/JRS/ALAT).
Both cohorts contained more men than women (67.7% in the AIPFR and 72.0% in the AILDR). Patients in the AIPFR were slightly younger than patients in the AILDR (average age 70.9 years versus 74.3 years) but a greater proportion had a current or previous history of smoking (71.7% versus 62.8%). The average BMI was similar between cohorts (28.7kg/m2 in the AIPFR, 29.2kg/m2 in the AILDR).
From a physiological perspective, the two cohorts had a similar level the predicted percentage of forced vital capacity (81.0% and 83.4% for the AIPFR and AILDR, respectively) but the predicted percentage of diffusing capacity of the lung for carbon monoxide was lower in patients from the AIPFR compared to those from the AILDR (48.4% versus 59.4%).
The most common comorbidities among patients enrolled in the AIPFR were gastro-oesophageal reflux disease (GORD; 41%), chronic obstructive pulmonary disease (36%), and coronary artery disease (28%). In contrast, the leading comorbidities among patients enrolled in the AILDR were cardiac disease (40.3%), previous surgery (27.3%), and GORD (23.0%).
The proportion of patients using antifibrotic therapy almost tripled between the AIPFR and AILDR cohorts (23% and 68%). When considering only the AILDR patients, 40.4% were on nintedanib and 35.6% were on pirfenidone.
The researchers felt the reported increase in antifibrotic therapy use between the two cohorts was consistent with clinical trial outcomes from 2014, which showed pirfenidone and nintedanib could reduce disease progression and all-cause mortality among patients with IPF, which subsequently lead to changes in clinical practice guidelines.
“Availability of subsidised nintedanib and pirfenidone for IPF in Australia and New Zealand has supported broad access to evidence-based therapy,” they noted.
“The increased use of antifibrotic therapy is also consistent with recommendations included in the 2017 IPF treatment position statement by the Thoracic Society of Australia and New Zealand and Lung Foundation Australia.”
There was also a corresponding decrease in the proportion of patients receiving immunosuppressants: 46% of the AIPFR cohort were taking prednisone (and 7% were taking azathioprine) compared to the 12% of patients enrolled in the AILDR who were on prednisone and the 1% on azathioprine.
The characteristics of AILDR patients who were and were not using immunosuppressants were largely similar, apart from a greater proportion of immunosuppressant-using patients having comorbidities such as obstructive sleep apnoea (28.0% versus 13.2%) and pulmonary hypertension (23.0% versus 11.7%).
“This raises several unanswered questions, including whether IPF was the correct diagnostic label for these patients, as well as whether the use of short-burst corticosteroids for acute exacerbations was a relevant factor,” the researchers wrote.
Related
“The observation is a prompt for future studies, as concurrent autoimmune features in other ILD subtypes, notably hypersensitivity pneumonitis, have been shown to exhibit different disease behaviours.”
The researchers concluded that “the baseline demographics from these two IPF cohorts recruited during a period of dramatic evolution in disease management are largely comparable”.
They also highlighted the benefits that registries such as the AILDR could bring.
“Our results demonstrate the importance of AILDR as a platform to enable benchmarking and quality assurance in IPF disease and its management,” they concluded.
“As more pharmacological and nonpharmacological interventions become available for IPF, registry data will help to provide insights into real-world therapeutic practices and implementation of consensus guideline recommendations.”
