Systemic sclerosis (SSc) is a systemic disease characterized by vasculopathy, progressive fibrosis and autoimmune activation. Tryptophan (Trp) metabolism has been linked to altered immune cell function and to malignancy. We have investigated the role of Trp metabolic pathway in SSc measuring serum Trp, Kynurenine (Kyn) and Trp/Kyn ratio in a cohort of 97 SSc patients and 10 healthy controls. Association with disease characteristics was evaluated. We found that Trp levels in SSc patients were significantly lower compared to HCs. We also found that patients with diffuse cutaneous (dcSSc) had lower levels of Trp compared to limited cutaneous (lcSSc). These results were paralleled by higher levels of Kyn found in SSc patients compared to HCs and significantly lower levels in dcSSc compared to lcSSc. The autoantibody profile was also found to be significantly associated with Kyn and Trp levels as anti-RNA-polymerase III (ARA) positive patients were shown to have lower Trp levels and higher Kyn levels compared with anti-centromere and anti-topoisomerase I positive patients. Moreover, the highest Trp/Kyn was found in ARA+ patients with dcSSc, suggesting that an activation of the Kyn pathway, is more specifically associated with this subset of SSc patients. Stability over time makes these markers of Trp metabolism feasible for SSc stratification.

系统性硬化症（SSc）是一种以血管病，进行性纤维化和自身免疫激活为特征的系统性疾病。色氨酸（Trp）代谢与免疫细胞功能改变和恶性肿瘤有关。我们调查了97名SSc患者和10名健康对照者队列中Trp代谢途径在SSc测量血清Trp，Kynurenine（Kyn）和Trp / Kyn比值中的作用。与疾病特征的关联进行了评估。我们发现SSc患者的Trp水平明显低于HCs。我们还发现，与局限性皮肤（lcSSc）相比，弥漫性皮肤（dcSSc）患者的Trp水平较低。与HCs相比，SSc患者的Kyn含量较高，而lcSSc的dcSSc含量则明显较低。还发现自身抗体谱与Kyn和Trp水平显着相关，因为与抗着丝粒和抗拓扑异构酶I阳性的患者相比，抗RNA聚合酶III（ARA）阳性的患者具有较低的Trp水平和较高的Kyn水平。 。此外，在患有dcSSc的ARA +患者中发现了最高的Trp / Kyn，这表明Kyn途径的激活与SSc患者的这一亚型更特别相关。随着时间的推移，稳定性使Trp代谢的这些标记物可用于SSc分层。提示Kyn途径的激活更具体地与SSc患者的这一亚群相关。随着时间的推移，稳定性使Trp代谢的这些标记物可用于SSc分层。提示Kyn途径的激活与SSc患者的这一亚型更具体相关。随着时间的推移，稳定性使Trp代谢的这些标记物可用于SSc分层。