Australian research has identified clinical and serological risk factors predictive of pulmonary arterial hypertension (PAH) in both sub-types of systemic sclerosis.

Lead researcher and rheumatologist Dr Mandana Nikpour, from the University of Melbourne and St Vincent’s Hospital, told the limbic the models might eventually help refine screening algorithms for what is the leading cause of death in systemic sclerosis.

“Pulmonary hypertension increases the risk of death six-fold in systemic sclerosis and reduces life expectancy by about 1.5 decades,” she said.

“At the moment, current practice is to screen annually through a combination of echocardiography, lung function tests and blood tests for specific biomarkers.”

“However we wanted to find which patients were most at risk by defining their clinical characteristics. In time, there might be preventive treatment from which these patients could benefit.”

Treatment with advanced therapies such as endothelin receptor antagonists is currently restricted to proven PAH managed by designated prescribing centres.

Published in BMC Pulmonary Medicine the new research found the prevalence of PAH in the cohort of 1579 adults was 8.4%.

Calcinosis, sicca symptoms, mild interstitial lung disease and digital ulcers were predictive of PAH in patients with the limited form of the condition (lcSSc).

Oesophageal stricture, mild interstitial lung disease and the presence of anti-centromere antibody were predictive of PAH in diffuse cutaneous scleroderma (dcSSc).

“Interstitial lung disease was a common risk factor for PAH in both disease sub-types suggesting a similar pathogenic mechanism and that both interstitial lung disease and PAH can co-exist.” Dr Nikpour said.

She added that micro-aspiration associated with poor tone of the lower oesophageal sphincter and oesophageal dysmotility could drive the development of interstitial lung disease and, indirectly, PAH.

“The majority of patients with systemic sclerosis are already on proton pump inhibitors because they have symptomatic gastro-oesophageal reflux however we certainly suspect there are more patients with subclinical reflux,” she said.