麻豆传媒

Pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD) are the leading causes of systemic sclerosis (SSc)-associated death, and there's increasing interest in patients with the combination of these conditions. A study presented at the American College of Rheumatology (ACR) annual meeting in Philadelphia aimed to describe the clinical phenotype and prognosis of people within the Australian Scleroderma Cohort Study (ASCS) with concurrent PAH and ILD.

In this exclusive 麻豆传媒 video, lead author Jessica Fairley, MD, a PhD candidate at St. Vincent's Hospital Melbourne in Australia, details the .

Following is a transcript of her remarks:

My name's Jessica Fairley. I'm a rheumatologist and PhD candidate at St. Vincent's Hospital in Melbourne. At St. Vincent's, we coordinate the Australian Scleroderma Cohort study, which is a multicenter Australian study of around 2,000 patients with scleroderma, which is particularly interesting looking at cardiopulmonary complications of scleroderma.

So, scleroderma or systemic sclerosis is a complex autoimmune disease, which is characterized by a triad of fibrosis or scarring, inflammation, and vasculopathy. And despite recent advances in rheumatology, scleroderma still has the sort of highest mortality of all the autoimmune rheumatic diseases. So, there's a lot of work to be done in scleroderma. And in particular, cardiopulmonary complications are a major cause of death and contribute to poor physical function in people with scleroderma.

We looked at people within the Australian Scleroderma Cohort study -- 1,500 people -- to compare people who met criteria for interstitial lung disease (or ILD), pulmonary arterial hypertension (or PAH) on a right heart catheter study, or both PAH and ILD together, or neither complications. So, we really looked between four groups in our cohort.

And we wanted to basically look at how common people getting both PAH and ILD together was, because we sort of historically thought that, PAH and ILD, they tended to be separate manifestations of scleroderma, whereas in recent times we've really identified that there are a significant cohort of patients who develop both complications. Which sort of makes sense, because in scleroderma up to 50% of people will get some interstitial lung disease on a high resolution CT scan of their chest. And the cumulative prevalence of PAH is sort of somewhere between 10 and 15%. So it sort of makes sense that there is a cohort that may develop both complications.

We looked at who got these complications, what their survival was like, and what it meant for patients -- so, what their health-related quality of life was like with one or both complications of systemic sclerosis.

We found that around 7% of our cohort developed PAH and ILD together, around 7% developed PAH alone, and around 24% developed ILD, and then the remaining 60% also developed neither complication over time. We found that people with PAH and ILD together were more likely to be older at the onset of their scleroderma, were more likely to be male, which is a common trend when we look at severe disease in multiple autoimmune diseases where men are less likely to get them, but if they do get them, they're more likely to be severe. We showed that people of Asian ethnicity were more likely to get PAH and ILD together. And we showed that people with raised inflammatory markers were more likely to get PAH and ILD together.

So, what did this mean for patients? Well, in terms of survival, we showed that the survival was significantly reduced in people with either PAH or PAH and ILD combined. And PAH or PAH and ILD conferred a significantly worse prognosis than those with interstitial lung disease or scleroderma alone. And that kind of fits with what we think about ILD in scleroderma where, in fact, there's a cohort of patients with ILD who probably have mild non-progressive disease and then there's a cohort with significantly worse survival.

So, we showed that the survival of PAH, whether with or without ILD, was significantly worse than with the scleroderma cohort in general. And in particular, we showed that PAH combined with severe or extensive ILD, that the prognosis of that group was significantly worse than the rest of the cohort.

In terms of health-related quality of life, we showed that physical function as measured by multiple patient reported outcomes was significantly worse in those with PAH and ILD combined. Those with PAH and ILD had around a 12-fold increase in patient-reported outcome measures of physical function below the median of our cohort. So, they were really much more likely to report poor physical function. And that compares to those with PAH who have quite poor physical function, being at around a seven-fold increased risk of kind of lower scores. So, we showed that physical function was really poor in that cohort. So, this was having a big impact on patient's quality of life.

And the other interesting question in all of this is pulmonary vasodilator treatment and who gets it. Now of course, this is an observational study and prescribing patterns over time have been difficult for PAH vasodilatory therapy in Australia, because we've only had combination therapy publicly funded since late 2020.

So, we showed that people with PAH-only were a little bit more likely to get vasodilatory therapy -- around 98% versus 90% in the PAH/ILD group, which fits with that concern about worsening V/Q [ventilation/perfusion] mismatching and worsening physical function with vasodilator therapy in those with PAH/ILD. But dual therapy was equally common between the groups. Triple therapy was more common in those with PAH-only but was relatively uncommon overall. But we did show that a lot of our patients were getting treated, but we weren't able to extrapolate any signal about mortality or impact in those patients.

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