Abstract：
BACKGROUND: Primary Sjögren syndrome (pSjS) is one of the most prevalent systemic autoimmune diseases and characterized with hyperactivation of B cell and the abundant presence of autoantibodies in sera. The salivary gland epithelial cells (SGECs) release autoantigens to evoke autoimmunity through releasing elevated apoptosis or secreting autoantigen-containing exosomes, thus identifying autoantibodies directly to SGECs might provide insights into disease related biomarkers as well as further elucidating pathogenesis mechanisms. The present study was undertaken to identify autoantibodies to SGECs and to evaluate its clinical values in Chinese pSjS.
METHODS: Cell-based indirect immunofluorescence and immunostaining, two-dimensional electrophoresis and liquid chromatograph-tandem mass spectrometry were conducted to identify the autoantibodies to human salivary gland cell line A253 in pSjS sera. Enzyme-linked immunosorbent assay (ELISA) was applied to identify autoantibody titer in pSjS cohort and healthy controls. The prevalence and clinical significance of the identified autoantibodies was further assessed in pSjS population.
RESULTS: Anti-calreticulin (CALR) antibody was identified as a new autoantibody directly to SGECs in sera from pSjS patients. Anti-CALR antibody were detected in 37 of 120 pSjS patients (30.83 %) and 1 of 54 healthy controls (1.85 %). It was found in 40.85 % pSjS with anti-SSA positive, 53.85 % with anti-SSB positive, and 14.7 % in sero-negative pSjS. Anti-CALR antibody was associated with clinical manifestations including weight loss(p = 0.045), vasculitis (p = 0.031), and laboratory parameters including erythrocyte sedimentation rate (ESR) (r = 0.056, p = 0.021), Krebs von den Lungen-6 (KL-6) (r = 0.121, p = 0.035), IgG (r = 0.097, p < 0.001), IgG2 (r = 0.142, p = 0.022), IgG3 (r = 0.287, p < 0.001), fibrinogen (r = 0.084, p = 0.016), D-Dimer (r = 0.086, p = 0.012) and fibrinogen degradation production (r = 0.150, p = 0.002). The expression of CALR in salivary glands was related to lymphocytes infiltration into salivary glands in pSjS patients (r = 0.7076, p = 0.0034).
CONCLUSIONS: To our knowledge, this was the first study to investigate the prevalence and clinical significance of anti-CALR antibody in Chinses pSjS patients. The present study identified an autoimmune antibody, anti-CALR antibody, as a good autoimmune biomarker for sero-negative pSjS.
METHODS: Cell-based indirect immunofluorescence and immunostaining, two-dimensional electrophoresis and liquid chromatograph-tandem mass spectrometry were conducted to identify the autoantibodies to human salivary gland cell line A253 in pSjS sera. Enzyme-linked immunosorbent assay (ELISA) was applied to identify autoantibody titer in pSjS cohort and healthy controls. The prevalence and clinical significance of the identified autoantibodies was further assessed in pSjS population.
RESULTS: Anti-calreticulin (CALR) antibody was identified as a new autoantibody directly to SGECs in sera from pSjS patients. Anti-CALR antibody were detected in 37 of 120 pSjS patients (30.83 %) and 1 of 54 healthy controls (1.85 %). It was found in 40.85 % pSjS with anti-SSA positive, 53.85 % with anti-SSB positive, and 14.7 % in sero-negative pSjS. Anti-CALR antibody was associated with clinical manifestations including weight loss(p = 0.045), vasculitis (p = 0.031), and laboratory parameters including erythrocyte sedimentation rate (ESR) (r = 0.056, p = 0.021), Krebs von den Lungen-6 (KL-6) (r = 0.121, p = 0.035), IgG (r = 0.097, p < 0.001), IgG2 (r = 0.142, p = 0.022), IgG3 (r = 0.287, p < 0.001), fibrinogen (r = 0.084, p = 0.016), D-Dimer (r = 0.086, p = 0.012) and fibrinogen degradation production (r = 0.150, p = 0.002). The expression of CALR in salivary glands was related to lymphocytes infiltration into salivary glands in pSjS patients (r = 0.7076, p = 0.0034).
CONCLUSIONS: To our knowledge, this was the first study to investigate the prevalence and clinical significance of anti-CALR antibody in Chinses pSjS patients. The present study identified an autoimmune antibody, anti-CALR antibody, as a good autoimmune biomarker for sero-negative pSjS.
摘要：
背景：原发性干燥综合征（pSjS）是最普遍的全身性自身免疫性疾病之一，其特征是B细胞过度活化和血清中大量存在自身抗体。唾液腺上皮细胞（SGEC）通过释放升高的细胞凋亡或分泌含自身抗原的外泌体释放自身抗原以引起自身免疫，因此,直接鉴定针对SGECs的自身抗体可能提供对疾病相关生物标志物的见解,并进一步阐明发病机制.本研究旨在鉴定SGEC的自身抗体，并评估其在中国pSjS中的临床价值。
方法：基于细胞的间接免疫荧光和免疫染色，进行了双向电泳和液相色谱-串联质谱法，以鉴定pSjS血清中针对人唾液腺细胞系A253的自身抗体。应用酶联免疫吸附测定（ELISA）鉴定pSjS队列和健康对照中的自身抗体滴度。在pSjS人群中进一步评估所鉴定的自身抗体的患病率和临床意义。
结果：抗钙网蛋白（CALR）抗体被鉴定为一种新的直接抗pSjS患者血清中SGECs的自身抗体。在120例pSjS患者中的37例（30.83％）和54例健康对照中的1例（1.85％）中检测到了抗CALR抗体。在40.85%pSjS中发现抗SSA阳性，抗SSB阳性的53.85%，血清阴性pSjS为14.7%。抗CALR抗体与包括体重减轻在内的临床表现相关(p=0.045),血管炎（p=0.031），和实验室参数，包括红细胞沉降率（ESR）（r=0.056，p=0.021），KrebsvondenLungen-6（KL-6）（r=0.121，p=0.035），IgG（r=0.097，p<0.001），IgG2（r=0.142，p=0.022），IgG3（r=0.287，p<0.001），纤维蛋白原（r=0.084，p=0.016），D-二聚体(r=0.086,p=0.012)和纤维蛋白原降解产生(r=0.150,p=0.002)。pSjS患者唾液腺中CALR的表达与淋巴细胞浸润唾液腺有关（r=0.7076，p=0.0034）。
结论：据我们所知，这是首次调查抗CALR抗体在中国pSjS患者中的患病率和临床意义的研究。本研究发现了一种自身免疫抗体，抗CALR抗体，作为血清阴性pSjS的良好自身免疫生物标志物。
方法：基于细胞的间接免疫荧光和免疫染色，进行了双向电泳和液相色谱-串联质谱法，以鉴定pSjS血清中针对人唾液腺细胞系A253的自身抗体。应用酶联免疫吸附测定（ELISA）鉴定pSjS队列和健康对照中的自身抗体滴度。在pSjS人群中进一步评估所鉴定的自身抗体的患病率和临床意义。
结果：抗钙网蛋白（CALR）抗体被鉴定为一种新的直接抗pSjS患者血清中SGECs的自身抗体。在120例pSjS患者中的37例（30.83％）和54例健康对照中的1例（1.85％）中检测到了抗CALR抗体。在40.85%pSjS中发现抗SSA阳性，抗SSB阳性的53.85%，血清阴性pSjS为14.7%。抗CALR抗体与包括体重减轻在内的临床表现相关(p=0.045),血管炎（p=0.031），和实验室参数，包括红细胞沉降率（ESR）（r=0.056，p=0.021），KrebsvondenLungen-6（KL-6）（r=0.121，p=0.035），IgG（r=0.097，p<0.001），IgG2（r=0.142，p=0.022），IgG3（r=0.287，p<0.001），纤维蛋白原（r=0.084，p=0.016），D-二聚体(r=0.086,p=0.012)和纤维蛋白原降解产生(r=0.150,p=0.002)。pSjS患者唾液腺中CALR的表达与淋巴细胞浸润唾液腺有关（r=0.7076，p=0.0034）。
结论：据我们所知，这是首次调查抗CALR抗体在中国pSjS患者中的患病率和临床意义的研究。本研究发现了一种自身免疫抗体，抗CALR抗体，作为血清阴性pSjS的良好自身免疫生物标志物。
