Experts Collaborate to Develop New International Guidelines for IPF Diagnosis

Updated international guidelines to help clinicians diagnose idiopathic pulmonary fibrosis (IPF) were recently published in the American Journal of Respiratory and Critical Care Medicine.

These new 2018 clinical practice recommendations are the result of a collaborative effort between experts from four major respiratory societies — the American Thoracic Society, the European Respiratory Society, the Japanese Respiratory Society, and the Latin American Thoracic Society.

The guidelines were outlined in the article, “Diagnosis of Idiopathic Pulmonary Fibrosis: An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline.”

IPF is a severe respiratory disease characterized by shortness of breath, dry cough, and reduced respiratory function with low levels of oxygen.

“Diagnosing IPF is challenging because these symptoms are non-specific: they occur with all other interstitial lung diseases and with other respiratory problems,” Ganesh Raghu, MD, chair of the guideline committee, said in a press release.

“Because drugs may slow the progression of IPF, an early and accurate diagnosis is essential for prompt and appropriate treatment for this fatal disease,” said Raghu, who is also a professor and director of the Center for Interstitial Lung Disease at the University of Washington in Seattle.

These four organizations had previously collaborated in 2011 to establish the first clinical practice guidelines for the diagnosis and management of IPF.

The guidelines were developed based on clinical evidence, and provided recommendations on how to revise radiological and tissue analysis findings to confirm an IPF diagnosis. However, since then, it became clear that the defined diagnostic criteria had critical limitations that could prevent an accurate and rapid IPF diagnosis.

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Supported by new evidence collected from several observational studies and randomized clinical trials, a multidisciplinary committee has now updated the 2011 guidelines to help clinicians make a more accurate IPF diagnosis.

The committee was composed of 29 members, including international clinical and scientific experts, as well as an IPF patient. They discussed all available IPF-related evidence, and using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach, they assessed the evidence quality and made recommendations.

“We required 70% agreement on the direction of the recommendation to make a recommendation; if such agreement was not achieved, no recommendation was made,” the researchers wrote.

“This [approach] should provide the health care community with confidence that the recommendations are as unbiased and evidence-based as possible,” said Kevin C. Wilson, MD, lead methodologist and project manager, and a professor of medicine at the Boston University School of Medicine.

A major difference implemented in the 2018 guidelines is the classification of patients according to four diagnostic categories defined by high-resolution tomography (HRCT) of the lung. These include the presence of usual interstitial pneumonia (UIP) pattern — a hallmark feature of lung fibrosis — probable UIP pattern, indeterminate pattern, and alternative diagnosis.

The committee also recommended the use of the same HRCT classification terminology for the microscopic analysis of lung tissue biopsies.

With this consistent categorization, the committee expects it will become easier for multidisciplinary team members, such as pulmonologists, radiologists, and pathologists, to discuss among themselves a patient’s case and more easily determine a diagnosis.

For diagnosing IPF in adults with newly detected interstitial lung disease (ILD) of unknown cause, the new recommendations state:

• A detailed history should be collected for all patients regarding medication use and environmental exposures, and blood testing should be performed to rule out the existence of a connective tissue disease as a potential cause of ILD.
• For patients with an HRCT pattern of probable UIP, indeterminate, or an alternative diagnosis, clinicians can decide on performing a bronchoalveolar lavage or surgical lung biopsy for additional evaluation. Use of a transbronchial lung biopsy or lung cryobiopsy for additional diagnostic testing was not recommended due to a lack of evidence.
• Multidisciplinary discussions can also be conducted to assist with IPF diagnosis in patients with an HRCT pattern suggestive of probable UIP, indeterminate, or alternative diagnosis.
• In contrast, for patients with newly detected ILD who have an HRCT pattern of UIP, a surgical lung biopsy, transbronchial lung biopsy, or lung cryobiopsy should not be performed. The committee recommended that if more testing is still required in such cases, clinicians should select a bronchoalveolar lavage over these other methods.
• Evaluation of blood biomarkers for the sole purpose of distinguishing IPF from other ILDs is also not recommended.

“Our hope is that this new guideline will bridge the gap between the experienced IPF experts and general pulmonologists in making a prompt and accurate diagnosis of IPF for the individual unfortunately confronted with the disease,” Raghu said. “This will allow patients to make well-informed decisions about treatment options and participation in clinical trials.”