Antifibrotic therapy can be started in patients with a working diagnosis of idiopathic pulmonary fibrosis (IPF) without requiring surgical lung biopsy (SLB), respiratory physicians say.
Their recommendation is based on a review of outcomes of patients who had possible usual interstitial pneumonia (UIP) pattern on high-resolution CT imaging who received antifibrotics following consensus diagnosis by expert multidisciplinary teams without SLB. These patients achieved similar outcomes to patients receiving therapy after a definite IPF diagnosis, a study from Italy found.
The current gold standard approach to diagnosing IPF in patients clinically suspected of having the disease involves identification of either a usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography (HRCT) or a combination of HRCT and lung biopsy when imaging is uncertain. A multidisciplinary discussion plays a key role in determining who should undergo biopsy.
But researchers in Italy, who investigated mortality rate and disease progression in 249 IPF patients on antifibrotic therapy across multiple sites, say a substantial proportion of patients with suspected IPF either cannot or are not willing to undergo the invasive procedure, and may be denied access to newly available treatment options because they do not meet diagnostic criteria.
Dr Giacom Sgalla and colleagues retrospectively looked at two IPF diagnostic subgroups: patients with a definite UIP pattern on HRCT and patients with possible UIP on HRCT and no SLB who received ‘a working diagnosis’ of IPF following consensus through multidisciplinary discussion (MDD).
According to investigators, IPF patients with possible UIP pattern on HRCT and no SLB showed similar survival rates as compared to IPF patients with definite UIP pattern on HRCT or SLB – a finding that was maintained when patients were stratified by GAP (gender, age and physiology) stage.
Time to disease progression, defined as time to death, 10% absolute decline in FVC or 50 m reduction in 6MWD, was also not significantly different between the two groups.
Physicians tended to avoid invasive procedures to diagnose the condition, said investigators who reported that a ‘noticeable’ proportion of IPF patients in the cohort (16.5%) and more than half of the patients with a possible UIP on HRCT received IPF diagnosis and antifibrotic treatment without requiring SLB.
The findings add weight to mounting evidence supporting the idea that biopsy confirmation of UIP may not be necessary when cases are adjudicated by teams of experts, say the researchers.
The study has prompted some respiratory specialists in Australia to call for broader criteria for accessing anti-fibrotic medications allowing specialists to make a working IPF diagnosis prior to commencing anti-fibrotic therapy.
In a linked editorial Dr Laura Glenn and Associate Professor Tamera Corte from the Interstitial Lung Diseases Unit at the Royal Prince Alfred Hospital in Sydney said such a change to guidelines would improve the overall and progression free survival of patients who do not meet diagnostic criteria in the real-life setting and have contraindications to biopsy to access treatment.
“Clinicians should not refer every patient with probable or indeterminate UIP to undergo biopsy, but consider on a case-by-case basis whether a biopsy is likely to influence management,” they wrote.
However, while they applauded the ‘reassuring’ findings for patients in who an SLB cannot be performed, the authors said the role of lung biopsy in IPF is not yet completely removed – it remains a crucial diagnostic tool in the rule out or in of other fibrosing interstitial lung diseases.
“One major reason to perform a biopsy is to exclude alternative aetiologies, for example, fibrotic non-specific interstitial pneumonia or fibrosing organising pneumonia, which exhibit different disease behaviour and treatment responsiveness to IPF. In addition, in patients with truly unclassifiable disease, which constitutes at least 7–10% of patients presented at interstitial lung disease (ILD) MDD, histopathology provides important diagnostic information and increases diagnostic confidence,” they said.
The study is published in Respirology.