Often misdiagnosed, patients face a complicated journey with autoimmune pulmonary alveolar proteinosis

Swaminathan Perinkulam Sathyanarayanan, MBBS, a second-year fellow in pulmonary and critical care medicine at the University of Florida in Gainesville, discussed an analysis presented at the 2024 CHEST Annual Meeting that highlighted the patient journey with autoimmune pulmonary alveolar proteinosis (aPAP).

Question:

Can you talk about the complicated journey patients with autoimmune pulmonary alveolar proteinosis face in terms of diagnosis and treatment?

Swaminathan  Perinkulam Sathyanarayanan:

aPAP stands for autoimmune pulmonary alveolar proteinosis. It’s a rare lung disease. It’s caused by accumulation of these proteinaceous substances, because one of the factors involved in clearing these substances is eliminated by antibodies produced by our body. Any pulmonary condition, the common symptoms are coughing, shortness of breath, which is what aPAP presents with. When they go to the community doctors, they may end up doing CAT scans or X-rays, which can mimic the presentation of some of the common diseases that we see like pneumonia, for example. Oftentimes, there’s always a delay in diagnosis or misdiagnosis, which I think is the biggest challenge faced by some of these patients. Eventually, by the time they come to pulmonologists who are well versed with this condition, they’ve had multiple misdiagnoses, multiple mismanagements that ends to a delay in diagnosis, which often causes a lot of anxiety and fear among patients.

Question:

What are some of the treatment options and unmet needs for this patient population?

Swaminathan  Perinkulam Sathyanarayanan:

It’s kind of a unique treatment that is commonly practiced, I would say across the country. It’s something called a whole lung lavage. Essentially what we’re doing is we’re filling the lungs with salt water or normal saline, and we’re cleansing out of these proteinaceous substances which accumulate in the lung. That’s one of the more commonly practiced treatments everywhere. But with new research, we’ve found that there are some medications that replace the factor that gets lost in this condition, which is called GMCSF.

We have some studies, something called an IMPALA study, which came out in 2020 showing that an inhaled version of this GM-CSF has the ability to prevent the occurrence of this accumulation of proteinaceous substance and it delays the need for this whole lung lavage condition. There’s also some research going on in terms of looking at other treatment modalities like statins and a diabetic medication called pioglitazone. But they’re all kind of in the early phases of research.

As to kind of the other struggles that patient deal with is a lot of these treatment modalities are, especially the inhaled version of the GM-CSF, is not something that is always covered by the insurance. We may end up seeing patients who are … They could benefit from this medication, but they may end up having some financial struggles, or these medications are sometimes only available in advanced centers. Oftentimes, we may see patients who have either financial issues getting these medications, or pulmonologists, they may not end up giving these medications.

Whole lung lavage, the process itself, it takes the hospital admission. They have to be in the hospital. You lavage 1 lung at a certain … in a day. It may require 2 to 3 days being in the hospital. They may end up with a breathing tube. As you can imagine, this causes a lot of anxiety amongst patients when we discuss the treatment modalities for these patients.

Question:

You presented a poster at the 2024 CHEST Annual Meeting titled “A Patient Journey Map For People Living With Autoimmune Pulmonary Alveolar Proteinosis.” Can you discuss the goals of the analysis and how that was conducted?

Swaminathan  Perinkulam Sathyanarayanan, MD:

[At the] University of Florida, we have a big patient population where we take care of patients with aPAP, so in coordination with pharmaceutical company and other patients who’ve undergone these experiences, we developed a patient journey map where we did a lot of questionnaires with either online, or with patient advisory board meeting, and sometimes even 1-to-1 patient interviews where we sat with patients and discussed with them kind of their journey with aPAP from how it started, what are the symptoms that they faced, how they ended up with the diagnosis, and what kind of treatments they’ve been and how it’s going. It was nice to hear their perspective on how their journey was and navigating through this disease. That’s what I’m going to present in my poster.

Question:

What were your observations and common themes from the analysis?

Swaminathan  Perinkulam Sathyanarayanan:

First of all, we wanted to focus on what kind of symptoms patients had, and the most common symptoms that the patient presented was breathlessness or shortness of breath, and fatigue and some cough. Some patients also complained of coughing up some white coffee-like material, which is the proteinaceous material that’s accumulating in the lung. When they have these symptoms, they often go to their primary care providers, or urgent care, or an emergency room. Oftentimes, they would get, like I said, misdiagnosed as having a pneumonia, or a kind of inflammation in the lung. One thing they get misdiagnosed, and the other thing is they often get mistreated. Most commonly they get a course of antibiotics or steroids, and it takes about 2 to 3 healthcare providers and multiple misdiagnoses until they actually end up with pulmonologist who’s able to make this diagnosis of aPAP.

Then patients often talk about various treatments that they’ve been, and the most common treatment that patients say that they’ve undergone is this whole lung lavage, which is roughly 94% of patients who have undergone this treatment, and followed by this inhaled GM-CSF that I talked about. This is roughly about 66% or two-thirds of patients who get this inhaled GM-CSF. This is often after an episode of whole lung lavage. Usually patients get put on this inhaled GM-CSF after a whole lung lavage is done. We also ask them about how are things going after they’ve been started on this medication. A lot of them do feel better, but there’s always this ongoing financial worries and emotional challenges that they face, whether they’ll need another whole lung lavage, or whether they’ll end up with a transplantation and things like that. This was the patient roadmap that we noticed in this study.

Question:

How might the findings of your analysis be used to potentially improve research and outcomes for patients with aPAP?

Swaminathan  Perinkulam Sathyanarayanan:

I think it’s really crucial to know that people often have multiple misdiagnoses. This is a rare condition. We have to acknowledge that. When you find certain features that don’t make sense… like let’s say a patient comes in with symptoms of shortness of breath or cough and they find these new infiltrates in the chest. If they don’t respond to antibiotics that are steroids, I think this study gives us an opportunity to think about, “Okay, are we missing a different diagnosis?” Could this be something else?

Early referral to an expert who deals with some of these rare conditions is something that would kind of get to the diagnosis faster. That way patients don’t suffer this amount of anxiety when they also come to a pulmonologist who is well versed in the management of this, your options for treatment like inhaled GM-CSF, whole lung lavage, and lung transplantation, those opportunities can be explored. I think it’s crucial that early referral to an advanced center, especially with a condition like aPAP, that’s really crucial.

Question:

Are there any other areas of research you think are important for this condition?

Swaminathan  Perinkulam Sathyanarayanan:

As we speak, there is a study called IMPALA-2 that’s going on. It’s like IMPALA-1 where the focus is on this inhaled GM-CSF, and they kind of look at some of the different outcomes that IMPALA-1 study did not focus on. Our hope is that once the study is published… currently this is not FDA approved; this is an off-label treatment that we offer for some of our patients. Once this study is published, we’re hoping that we’ll be able to get approval so that more patients can be on this inhaled medication.

The other thing that I want to talk about is oftentimes these patients get diagnosed based on lung biopsies or a bronchoscopy, but we have a test that is a minimally invasive test. It’s just a simple blood test that looks for antibodies for this condition. That’s also something that’s crucial for people to know, that you don’t need an invasive procedure to come to this diagnosis.

Like I mentioned previously, there’s also a lot of research showing that there is a fault in the lipid processing that happens with this condition. Medications that we give for controlling the cholesterol levels and diabetes may have a roll in this. Like medications like Lipitor or Crestor, sometimes we put some of these patients on these medications because they seem to have a benefit. More research is going on with those medications as well. We’re hoping that in the next few years people wouldn’t necessarily need to undergo this whole lung lavage, and this is something that we can control with an inhaled medication or an oral pill. This would avoid progression to lung transplant or even requiring sessions of whole lung lavage.