Diagnosis of Idiopathic Pulmonary Fibrosis

Fernando J. Martinez, MD, MS: The guidelines for the diagnostic process for idiopathic pulmonary fibrosis [IPF] for all of the interstitial lung diseases in general have revised over the years, and in large part have been driven by the American Thoracic Society (ATS), European Respiratory Society (ERS), Japanese Respiratory Society (JRS), and the Latin American Society (LAS)—those groups that have identified experts to come up with recommendations. The most recent iteration of this was in 2018 where we modified the approach, which includes suspicion of the disorder—cough, breathlessness, the predominant symptoms—and evaluation for potential alternate causes of the interstitial lung disease.

It has not been idiopathic. That includes identifying connected tissue disease, exposures that could be associated with chronic hypersensitivity pneumonitis, for example. A very prominent role for chest imaging, particularly high-resolution CT [computerized tomography] where there’s been a tremendous amount of advance in understanding the patterns of abnormality that would be most likely to be associated with a final diagnosis of idiopathic pulmonary fibrosis.

The pattern is the pattern of usual interstitial pneumonia. And there’s a very explicit description within the guidelines regarding reticulation, honeycomb, the pattern of those abnormalities, their distribution, their severity. That’s now standardized. The most recent significant change has been to really codify the importance of a multidisciplinary discussion, what’s called an MDD, as a format for ensuring in each step that we’re doing the right thing by the patient and their caregivers as we go through the diagnostic process.

So that includes a rigorous discussion regarding the clinical history, the potential etiologies for interstitial lung disorder, whether it’s idiopathic or not, and the imaging components and direct discussions with the radiologists regarding the role of imaging. And then pathologists if biopsy is entertained or completed. That MDD is now at several levels during the diagnostic guideline as recommended by those 4 societies.

Steven D. Nathan, MD, FCCP: IPF can be diagnosed early, or it can be diagnosed late. The patients who tend to have a diagnosis earlier are those who are more robust or more active. You notice their symptoms earlier in the disease course and come to clinical attention earlier in their disease course versus those patients who are more sedentary and don’t stress their bodies at all will only notice the onset of symptoms late in the disease course.

Now, sometimes patients can go misdiagnosed. They might be diagnosed as COPD[chronic obstructive pulmonary disease] or something else and it can be a year or 2 before a diagnosis of IPF is attained. Some patients can present for the first time with an acute exacerbation of their underlying IPF, and some patients will only come to attention once they have an IPF acute exacerbation, which would then automatically put them late in their disease course because the prognosis of acute exacerbations tends to be rather poor.

This does impact how we manage them. Sometimes if I see a patient for the first time and they’re very advanced, requiring a lot of oxygen, or tachypneic at rest and can’t do much of anything, then the discussion might be about palliative care and hospice management. If I see them early, then I’m going to talk about the early implementation of therapy such as the antifibrotics, and possibly, if they are lung transplant candidates, talking about the role of lung transplantation at some point in their future. Some of the patients who present late might still be transplant candidates, but it’s always better to work them up for transplant earlier in their disease course rather than trying to work them up later in their disease course where they might have limited rehab potential or might have comorbidities that take a longer period of time to address, such as obesity.

Some of the patients might present early on and we have identified potential comorbidities or contraindications to lung transplant that we can address over time. But, if they present late with these contraindications, then it’s less likely that we can turn those around and make them a viable transplant candidate. So we always encourage the earl referral for transplantation, actually even at the time that the diagnosis is made. A lot of times I’ll say to patients let’s hope for the best but prepare for the worst at the same time. Preparing for the worst is putting that safety net of having a lung transplant evaluation should the need arise at some point in the future.

Fernando J. Martinez, MD, MS: The multidisciplinary team, the MDD, this discussion process has evolved since our original definition about 20 years ago when we developed this process at University of Michigan. Initially, it was only the clinician, the respiratory clinician for short, the thoracic radiologist, and then a pathologist. And that interactive in-person discussion now in the post-COVID era, a lot of this is done virtually and works actually quite well. I think that the most recent evolution of this MDD of this discussion has expanded to understand that oftentimes more individuals are needed as part of that discussion.

Rheumatologists are now routinely involved in our MDDs given the prevalence of interstitial lung disease and the broad advances in therapeutic approaches to patients with those disorders. They’re now part of this. But we also have frequently primary care clinicians who join these, particularly virtually. We have respiratory specialists, nurse specialists that are often a component.

I don’t think we now are in a situation where we know exactly who should be there. It’s the individuals that are most likely to be able to provide the needed input to ensure that we have the most accurate diagnosis for a patient and their family. At the very least it’s a pulmonologist, a radiologist, and now likely a rheumatologist.

Transcript Edited for Clarity