Determining the prognosis of patients with pulmonary fibrosis

Sometimes it’s the simplest things that can make all the difference. Unfortunately, when it comes to informing patients with a new diagnosis of pulmonary fibrosis what to expect, things are anything but simple.

For years, pulmonologists have dreaded the moment when we inform patients of a diagnosis of pulmonary fibrosis. The discussion invariably involves informing them that this disease (which they have probably never heard of) may either kill them or have minimal effect on their lives, or have a moderate effect. Alternatively, it may have very little effect at first, but then suddenly become much worse. How can we tell which of these courses the person can expect? Well, we’re not really sure, we’ll just have to wait and see what happens.

To this day, I remain amazed at the stoicism and strength that the person who is sitting across from me accepts this information. For these people there exists neither a good prognostic tool nor an effective treatment. One would think that for such a stark disease there would be 10k runs, gala fundraising dinners, and a powerful Washington lobby.

But there isn’t.

There is no nationwide clamor for research dollars. No push for the cure, or even for any effective treatment. No distinctive ribbon clad awareness week (ok there is, but I bet you’ve never heard of it).

So it is with a great sense of excitement that we greet any new research which hints at the possibility that we can more accurately tell our patients with this disease what they might expect in terms of prognosis. Such was the case as I read through the recent issue of Chest.

Researchers at Inova Fairfax Hospital in Falls Church, Virginia looked at the possibility of using the red cell distribution width (RDW) as a prognostic measure in patients with pulmonary fibrosis. The RDW is a blood test which measures variability in sizes of circulating red cells. The test is inexpensive, and usually drawn (and often ignored) as part of a complete blood count. Physicians who order a CBC usually pay attention to the hemoglobin, white blood cell and platelet counts, and hardly ever give the RDW a second glance.

But perhaps we should.

As variability in the size of red blood cells as measured by the RDW can tell us about pathological inflammation. The RDW has already found some use in helping with prognosis in people with pulmonary hypertension and congestive heart failure, so why not pulmonary fibrosis?

In this study, they found that people who had a RDW of less than 15 had a median survival of 43 months, whereas those who had a RDW of greater than 15 had a median survival of only 16 months. Survival appeared to be worse in those with even higher levels of RDW, and also appeared better in those with much lower levels. They also found that survival worsened in those individuals in whom the RDW increased by more than 0.01 per month on average.

The idea of using a simple method to help determine the prognosis of patients with pulmonary fibrosis is exciting. Now if only we could find an equally simple method of improving that prognosis.

Deep Ramachandran is a pulmonary and critical care physician who blogs at CaduceusBlog.  He can be reached on Twitter @Caduceusblogger.

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