Abstract
We explored effective therapeutic targets for systemic sclerosis (SSc) patients with high risk for pulmonary arterial hypertension (PAH) by plasma proteomics analysis. A total of fifty-seven patients with SSc were enrolled in the study and the prevalence of PAH was 19.3%. On the other hand, 75.4% of SSc patients showed the ratio of forced vital capacity percentage/diffusing capacity of the lungs for carbon monoxide percentage> 1.6 and met criteria for high risk of PAH. Identification of elevated plasma proteins in SSc patients with high risk of PAH, followed by upstream regulator analysis, predicted interleukin (IL)-17A as a major upstream molecule. Furthermore, we performed in vitro neutralization study using MT-6194, a bispecific antibody targeting both IL-17A and IL-6 receptor. We found that MT-6194 broadly suppressed the increased expression of downstream molecules of IL-17A including IL-17A-related cytokines/chemokines, IL-17A-driven NFκB pathway and IL-6-driven JAK/STAT pathway which were shown to be increased in SSc patients with high risk of PAH by the proteomics. Consequently, it is revealed that IL-17A is a promising target for early intervention in SSc patients with high risk for PAH.