Systemic Sclerosis (SSc) is a rare disease that causes the skin to thicken and form into scar tissue.
It can affect various parts of the body including the gastrointestinal track, kidneys, lungs, and heart. Two comorbidities often associated with the disease are Pulmonary Arterial Hypertension (PAH) and Interstitial Lung Disease (ILD). SSc patients may have PAH, ILD, or both, however a vast majority do have some level of fibrosis in the lungs, a symptom of ILD. Both PAH and ILD can unfortunately contribute to mortality in SSc.
There is a lot still unknown about these conditions. For instance, researchers aren’t sure if severe forms of ILD contribute to the development of PAH. It’s also not clear if PAH develops differently in individuals who don’t have SSc.
But, findings from a recent study show that we may be able to better evaluate the unique presence of these conditions in individuals. This means we will also be able diagnose these diseases earlier and patients, as a result, will receive the treatment they need much sooner. Additionally, understanding each individual patient’s unique molecular profile means clinicians can better recommend clinical trials and therapeutic targets.
In essence, the study indicated that PAH and ILD have a distinct pattern of active/silent genes. Some of these differences in genes are present early on in the disease, meaning the conditions may be identified soon after they unfold.
The Study
To examine the unique genomic profiles of PAH and ILD, researchers studied 69 different genes which had previously been associated with SSc-PAH. The expression of these 69 genes were evaluated within peripheral blood mononuclear cells, or PBMCs.
Participants included 39 patients who had SSc but no PAH, 21 with SSc and PAH, and 10 healthy controls. 11 of the participants also had ILD.
5 of the genes screened showed correlation to PAH. For instance, low levels of CD8B1 were correlated regardless of the presence of ILD. Additionally, high levels of THBS1 genes showed correlation with PAH, but only when individuals with ILD were not included in the analysis. Furthermore, S100P and CD8B1 genes in patients who were in early stages of PAH followed the patterns of expression shown in PAH patients as opposed to SSc patients without PAH (or the healthy controls).
Ultimately, this study indicates that specific genes may be activated early on in the course of PAH which means earlier detection of the disease may be possible. It also showed a clear distinction between the gene expression in PAH patients and the gene expression in those with ILD.
This study was published in the Journal of Scleroderma and Related Disorders.
You can read more about this study and what the findings could mean for those living with Systemic Sclerosis, PAH, or ILD here.
