ESTI previews updated ATS / ERS classification for IIPs

“This is breaking news, which just happens to coincide with the ESTI meeting,” said David Hansell MD, who will present a preview of the as-yet unpublished update to the ATS/ERS classification for idiopathic interstitial pneumonias (IIP).

“What is reassuring about this update is that the basic clinicopathological entities are intact and have not changed,” he said.Instead there is “a refinement of the 2002 ATS/ERS classification, with one or two new diseases included, and a notable addition being a novel way of categorizing patients based on their disease behavior.”

Also retained, and reinforced, in the updated edition is a multidisciplinary team approach to diagnosis between physicians, radiologists, and pathologists. “Diffuse lung disease is a diagnostically challenging area, even for those who are expert, and idiopathic interstitial pneumonias are especially difficult. We need all the information we can get. Even then we may not arrive at a bottom-line diagnosis,” said Hansell, a Professor of Thoracic Imaging at Imperial College London and a consultant radiologistwith Royal Brompton & Harefield NHS Foundation Trust.

A former President of the European Society of Thoracic Imaging, Hansell is a member of the writing committee that is now revising the 2002 IIP classification (a joint effort of the American Thoracic Society (ATS) and the European Respiratory Society (ERS)). “The original ATS/ERS classification of IIPs in 2002 was an important piece of work,” he said. “It sharpened up the language, made communications more precise, as everyone started to use the same terminology. Idiopathic pulmonary fibrosis in Japan and in California became the same disease.” “Non-specific interstitial pneumonia (NSIP) became recognized as a real entity,” he said, “and there was an appreciation that usual interstitial pneumonia (UIP) had a rather wider range of CT appearances than people had first thought.

“It was a very positive development, but there were loose ends, and over the next six years people began commenting that certain bits did not quite gel within the 2002 classification,” he said. “One issue that emerged was a paradox,” he said. “While classifications were based on pathology obtained from lung biopsy, very few patients with diffuse lung disease actually undergo a lung biopsy.”

“Without a bit of lung tissue to examine microscopically, we are in a position in which the diagnosis for 90% of patients is based on clinical and imaging findings,” said Hansell. “For 50 years or so, histopathology has been regarded as the gold standard, and now a good number of publications have highlighted that, contrary to what was assumed up to that point, histopathologic diagnosis didn’t consistently correlate with, nor predict, the outcome of the patient,” he said.

“I am not going to pretend that the update reclassification is going to solve all the problems, but it does go some way toward addressing them,” he said. “What is included in the update is a new way of classifying these diseases that is clinical and not histopathologic, what could be called ‘categorization by disease behavior’,” said Hansell.

It presents a pragmatic approach to patient management. A multidisciplinary team can take into account all available information and assign a patient to one of these five disease behaviors. The new method addresses the majority of patients who do not undergo a biopsy, or those cases, where even with a biopsy, there is not a final diagnosis. “This method is untried; and there is some excitement, because the approach will need to be tested in clinical practice,” he said. “These categories offer a useful way to codify interstitial pneumonias for those who are less experienced,” he said, adding that there are a lot of questions circling around just how easy it will be to apply the classification.

For your diary

ATS/ERS reclassification –

all change or no change?

Session ”Interstitial lung disease”

David Hansell, London, UK

Saturday June 23 at 14:45 – 15:15

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David Hansell was appointed Consultant Radiologist at the Royal Brompton Hospital in 1989 and Professor of Thoracic Imaging, National Heart and Lung Institute, Imperial College School of Medicine, London in 1998. His primary specialty is diagnostic imaging of the lungs, and he has a particular interest in high resolution computed tomography of diffuse lung diseases. He is a past President (2005) of the European Society of Thoracic Imaging and is President-Elect of the Fleischner Society.