The PIRCHE (Predicted Indirectly ReCognizable HLA Epitopes) score is an HLA epitope matching algorithm. PIRCHE algorithm estimates the level of presence of T-cell epitopes in mismatched HLA. The PIRCHE-II numbers associate with de novo donor-specific antibody (dnDSA) formation following liver transplantation and kidney allograft survival following renal transplantation. The aim of our study was to assess the PIRCHE-II score in calcineurin inhibitor (CNI)-free maintenance immunosuppression recipients.

This was a retrospective study of forty-one liver transplant recipients on CNI-free immunosuppression and with available liver allograft biopsies. Donors and recipients were HLA typed. The HLA-derived mismatched peptide epitopes that could be presented by the recipient's HLA-DRB1 molecules were calculated using PIRCHE-II algorithm. The associations between PIRCHE-II scores and graft immune-mediated events were assessed using receiver operating characteristics curves and subsequent univariate and multivariate analyses.

CNI-free patients with cellular rejection, humoral rejection, or severe portal inflammation had higher mean PIRCHE-II scores compared to patients with normal liver allografts. PIRCHE-II score and donor age were independent risk factors for liver graft survival in CNI-free patients (HR: 8.0, 95% CI: 1.3–49, p = .02; and HR: 0.88, 95% CI: 0.00–0.96, p = .007, respectively).

PIRCHE-II scores could be predictive of liver allograft survival in CNI-free patients following liver transplantation. Larger studies are needed to confirm these results.

PIRCHE（预测的间接可识别HLA表位）评分是一种HLA表位匹配算法。PIRCHE算法估计错配HLA中T细胞表位的存在水平。PIRCHE-II编号与肝移植后新生供体特异性抗体（dnDSA）的形成以及肾移植后肾脏同种异体移植物的存活有关。我们研究的目的是评估无钙调神经磷酸酶抑制剂（CNI）的维持免疫抑制接受者的PIRCHE-II评分。

这是对41位肝移植受者进行无CNI免疫抑制和可用肝同种异体移植活检的回顾性研究。捐赠者和接受者均采用HLA类型。使用PIRCHE-II算法计算了受体的HLA-DRB1分子可能呈现的HLA衍生的错配肽表位。PIRCHE-II评分与移植物免疫介导的事件之间的关联使用接收器操作特征曲线以及随后的单变量和多变量分析进行评估。

与正常肝同种异体移植患者相比，无细胞排斥，体液排斥或严重门静脉炎症的无CNI患者的PIRCHE-II平均得分更高。PIRCHE-II评分和供体年龄是无CNI患者肝移植存活的独立危险因素（HR：8.0，95％CI：1.3-49，p  = .02； HR：0.88，95％CI：0.00-0.96 ， 分别为p = .007）。

PIRCHE-II评分可以预测无肝移植后无CNI患者的肝移植存活率。需要更大的研究来证实这些结果。