Owing to its complex and heterogeneous nature, and the need to differentiate it from other diseases with similar symptoms and radiological and histopathological features, idiopathic pulmonary fibrosis (IPF) is challenging to diagnose. During an evening symposium, organised by F. Hoffmann-La Roche and chaired by Athol Wells (London, United Kingdom), a group of experts discussed the early diagnosis and treatment of IPF.
High-resolution CT (HRCT) is an essential part of the diagnostic algorithm in patients with suspected IPF, so the consultant radiologist is a core member of the multidiciplinary team (MDT). The observed patterns are categorised as usual interstitial pneumonia (UIP), possible UIP or inconsistent with UIP. The presence of a UIP pattern on HRCT supports a diagnosis of IPF and, in accordance with the ATS/ERS diagnostic criteria, requires four features:
• subpleural, basal predominance;
• reticular abnormality; and
• honeycombing with or without traction bronchiectasis.
Honeycombing is manifested on HRCT as clustered cystic airspaces and is critical for making a diagnosis of IPF it is the distinguishing feature between a UIP and a possible UIP pattern on HRCT. The extent of honeycombing and the severity of traction bronchiectasis on HRCT are factors predictive of survival in IPF.
In patients with suspected IPF without a definite UIP pattern on HRCT, current guidelines recommend a histopathological analysis of a surgical lung biopsy, if clinically feasible, in order to determine a diagnosis of IPF. No histopathological pattern is diagnostic for IPF when considered in isolation. Rather, a diagnosis of IPF is made based upon specific combinations of radiological and histopathological patterns. According to the ATS/ERS diagnostic criteria for IPF, the UIP pattern on histopathology requires four features:
• evidence of marked fibrosis or architectural distortion with or without honeycombing in a predominantly subpleural or paraseptal distribution;
• presence of patchy involvement of lung parenchyma by fibrosis; and
• presence of fibroblastic foci.
In patients with IPF, the presence of fibroblastic foci on histopathology is probably a predictor of survival.
Cellular analysis of bronchoalveolar lavage (BAL) may assist in the diagnosis of certain forms of interstitial lung disease (ILD). For patients with suspected IPF, BAL is important to rule out a diagnosis of chronic hypersensitivity pneumonitis. However, it remains unclear if BAL adds significant diagnostic specificity compared with clinical evaluation and exposure history.
Following diagnosis of IPF, an important consideration is the timing of treatment initiation, especially in patients with well-preserved lung function, such as a FVC of ≥80%. The timely and accurate diagnosis of IPF is critically important for ensuring that patients gain access to appropriate clinical services and medical treatment. The therapeutic landscape for IPF is evolving, with two antifibrotic drugs, pirfenidone and nintedanib, having received regulatory approval from the European Medicines Agency (EMA).
Role of MDT
A MDT discussion should be the standard of care for patients with (suspected) IPF. The MDT comprises consultant pulmonologists, radiologists and histopathologists, as well as ILD clinical nurse specialists and other experts in ILDs. Following a diagnosis of IPF, discussion among MDT continues to be important throughout the patient journey. The role of a MDT following the diagnosis of IPF consists of supporting treatment decision-making, monitoring for disease progression and considering referral for lung transplantation and/or palliative care.
Clinical nurse specialist
The role of the ILD clinical nurse specialist (CNS) within the MDT is largely centered on the health needs of patients and their families, Anne-Marie Russell (London, United Kingdom) stated during this session. Patients need information, education and support that is tailored to their individual context at all stages along the pathway of care. The ILD CNS is often the first point of contact for patients with IPF. The nurse has a particular role in helping patients to manage treatment-related adverse events. Furthermore, the ILD CNS contributes a unique perspective on psychosocial aspects of health that influence patient management. The nurse plays a key role in transitions in care and palliation of symptoms.
Source: Session 275, Industry Evening Symposium, F. Hoffmann-La Roche. Early diagnosis of IPF: a patient journey. September 4th, 17:15-19:15, Platinum Room 1+2.