Pulmonary arterial hypertension (PAH) is associated with a diverse array of diseases that result in similar histologic and clinical phenotypes. The pathogenesis of PAH is complex, and it is likely that multiple modulating genes and environmental factors are involved. Such complexity lends itself to the use of microarray technology, which allows the efficient and accurate simultaneous expression measurement of thousands of genes.
Circulating blood cells may contain disease-specific information either because of inherent genomic alterations or because of local environmental changes. Furthermore, the gene expression of immune-modulating cells may provide disease-specific information due to inflammatory and autoimmune mechanisms that are putatively involved in the pathogenesis of PAH. We hypothesized that the analysis of gene expression profiles from peripheral blood mononuclear cells would distinguish patients with PAH from healthy volunteers. We also hypothesized that a subset of these genes would distinguish patients with idiopathic PAH (IPAH) from those with PAH due to secondary causes.