Perosa Federico, Favoino Elvira, Favia Isabella Eleonora, Vettori Serena, Prete Marcella, Corrado Addolorata, Cantatore Francesco Paolo, Valentini Gabriele
Department of Biomedical Sciences and Human Oncology (DIMO), Systemic Rheumatic and Autoimmune Diseases Unit, University of Bari Medical School, Bari Department of Clinical and Experimental Internal Medicine "F. Magrassi, A.Lanzara"-Rheumatology Section, Second University of Naples, Naples Department of Medical and Surgery Sciences, Rheumatology Unit, University of Foggia, Foggia, Italy.
Medicine (Baltimore). 2016 Jun;95(25):e3931. doi: 10.1097/MD.0000000000003931.
Patients with systemic sclerosis (SSc) who express autoantibodies to centromeric proteins (CENPs) are at risk of developing pulmonary vascular disease and pulmonary arterial hypertension without fibrosis. Currently no biomarkers are available to predict these complications. We previously characterized the fine specificity of anti-CENP-A antibodies in SSc by screening a phage display library (expressing random 12-mer peptides), and identified phage clones whose peptides were differentially recognized by patients' autoantibodies. Here, we examined if subgroups of SSc patients with different anti-CENP-A antibody subspecificities also differ clinically, and if serum reactivity to phage-displayed peptides can predict pulmonary vascular disease.Clinical data and serum samples were collected from 84 anti-CENP-A-positive SSc patients. Indirect ELISAs were used to test serum reactivity. Pulmonary vascular disease was defined as high systolic pulmonary arterial pressure (sPAP) and low diffusing lung capacity for carbon monoxide (DLCO; percent of predicted values).Sera were screened for reactivity to peptides expressed by phage clones pc4.2 and pc14.1, confirming our earlier observation of differential specificities. Linear regression showed that the levels of antibodies specific for the 2 phage clones were associated with clinical features of pulmonary vascular disease, but in opposite ways: anti-pc4.2 antibodies were positively associated with sPAP and inversely associated with DLCO, whereas anti-pc14.1 antibodies were inversely associated with sPAP and positively associated with DLCO. Anti-pc4.2 and anti-pc14.1 antibody levels predicted sPAP independently of DLCO. These associations were confirmed by logistic regression using antibodies as predictors and dichotomized sPAP (cutoff, 45 mm Hg) as outcome. The ratio of the 2 antibody levels was a useful marker in predicting high sPAP.This study demonstrates that some SSc clinical features associate with subspecificities of anti-CENP-A antibodies. Moreover, it shows that a simple, inexpensive phage-based assay can predict which SSc patients have high sPAP and low DLCO, hence who are at greater risk of developing pulmonary arterial hypertension. The ability to identify these at-risk patients can contribute to clinical efficiency and effectiveness. Further research into the peptides expressed by the phage clones may reveal the molecular mechanisms that put some anti-CENP-A-positive patients at greater risk than others for pulmonary vascular disease.
表达着丝粒蛋白（CENPs）自身抗体的系统性硬化症（SSc）患者有发生无纤维化的肺血管疾病和肺动脉高压的风险。目前尚无生物标志物可用于预测这些并发症。我们之前通过筛选噬菌体展示文库（表达随机12肽）来表征SSc中抗CENP-A抗体的精细特异性，并鉴定出其肽段被患者自身抗体差异性识别的噬菌体克隆。在此，我们研究了具有不同抗CENP-A抗体亚特异性的SSc患者亚组在临床上是否也存在差异，以及血清对噬菌体展示肽段的反应性是否可预测肺血管疾病。
收集了84例抗CENP-A阳性的SSc患者的临床数据和血清样本。采用间接酶联免疫吸附测定（ELISA）检测血清反应性。肺血管疾病定义为高收缩期肺动脉压（sPAP）和低一氧化碳弥散肺容量（DLCO；预测值百分比）。
检测血清对噬菌体克隆pc4.2和pc14.1所表达肽段的反应性，证实了我们之前关于差异性特异性的观察结果。线性回归显示，针对这2个噬菌体克隆的特异性抗体水平与肺血管疾病的临床特征相关，但方式相反：抗pc4.2抗体与sPAP呈正相关，与DLCO呈负相关，而抗pc14.1抗体与sPAP呈负相关，与DLCO呈正相关。抗pc4.2和抗pc14.1抗体水平独立于DLCO预测sPAP。以抗体作为预测指标、二分法sPAP（临界值，45 mmHg）作为结局的逻辑回归证实了这些相关性。这2种抗体水平的比值是预测高sPAP的有用标志物。
本研究表明，一些SSc临床特征与抗CENP-A抗体的亚特异性相关。此外，研究表明一种简单、廉价的基于噬菌体的检测方法可以预测哪些SSc患者具有高sPAP和低DLCO，从而确定哪些患者发生肺动脉高压的风险更大。识别这些高危患者的能力有助于提高临床效率和效果。对噬菌体克隆所表达肽段的进一步研究可能揭示使一些抗CENP-A阳性患者比其他患者发生肺血管疾病风险更高的分子机制。
