Multidisciplinary discussions, CTD screening and bronchoalveolar lavage pivotal points of new IPF guidelines
Multidisciplinary discussions, connective tissue disease (CTD) screening and the performance of bronchoalveolar lavage (BAL) are among the pivotal points recommended by new guidelines for the diagnosis of idiopathic pulmonary fibrosis (IPF) reported at the recent European Respiratory Society (ERS) International Congress 2018.
“IPF is a chronic progressive form of fibrosing interstitial pneumonia common among male smokers >60 years old. Diagnosis requires exclusion of other causes of interstitial lung disease [ILD] and the presence of high-resolution CT [HRCT] pattern consistent with usual interstitial pneumonia [UIP],” explained Professor Ganesh Raghu, chair of ATS-ERS-JRS-ALAT evidence-based guideline for the diagnosis of IPF. [Am J Respir Care Med 2018;198:e44-e68]
The new guidelines recommend that for patients with newly detected ILD, taking detailed history of both medication use and environmental exposures and serological testing for CTDs are highly recommended. Anti-nuclear antibody (ANA) testing should be done by immunofluorescence method along with erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor and myositis panel.
For patients who have an HRCT pattern of probable UIP, indeterminate for UIP or alternative diagnosis, analysis of BAL fluid is recommended. Another diagnostic test that can be used for this group of patients is surgical lung biopsy.
However, the panel made no recommendations for or against transbronchial lung biopsy and cryobiopsy due to limitation of evidence, lack of standardized approach, and undesirable consequences associated with these procedures.
Multidisciplinary discussions are of utmost benefit if patients are categorized as probable UIP or indeterminate for UIP or if an alternate diagnosis is considered. Pulmonologists, radiologists, pathologists and rheumatologists are recommended to take part in the diagnostic process.
The panel also discouraged the use of serum biomarkers such as MMP-7, SPD, CCL-18 or KL-6 to diagnose IPF because of high false positive and false negative rates associated with these tests.
“For patients who show a UIP pattern on HRCT, hence diagnostic of IPF, BAL, surgical lung biopsy, transbronchial lung biopsy and cryobiopsy would not be necessary,” Raghu said.
“The future directions of these guidelines would involve revisiting HRCT patterns, and the utility of BAL and transbronchial biopsy. The use of cryobiopsy must also be standardized, as is the use of empiric therapy, genetic markers and genetic counselling for IPF,” he added.
“IPF is most likely if there is moderate-to-severe traction bronchiectasis/bronchiolectasis in a man >50 years or a woman >60 years of age, extensive [>30 percent] reticulation on HRCT in an individual aged >70 years, increased neutrophils, and/or the absence of lymphocytosis in BAL with a multidisciplinary discussion reaching a confident diagnosis of IPF,” he suggested.
“IPF is indeterminate if an adequate biopsy can reclassified it into a more specific diagnosis after multidisciplinary discussion,” he noted.
The recently published Fleischner white paper consensus statement has a number of overlaps with the new guidelines discussed. Notable differences included biopsy recommendations by the guidelines but not by the consensus statement. [Eur Respir J 2018, doi: 10.1183/13993003.01485-2018]