Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China.
Department of Rheumatology, West China Hospital, Sichuan University, Chengdu, China.
Clin Rheumatol. 2018 Nov;37(11):3017-3023. doi: 10.1007/s10067-018-4197-9. Epub 2018 Jul 12.
To investigate the value of lone anti-Smith antibody (anti-Sm) using Euroimmun line immunoassay (LIA) in a Chinese population. One thousand two hundred eight of 39,766 patients who were analyzed for anti-Sm had positive anti-Sm, and were divided into true group (having both positive Sm and nRNP/Sm bands) and lone group (only having Sm band without nRNP/Sm band). The proportions of clinical diagnosis of autoimmune diseases (AIDs), non-autoimmune diseases (NAIDs), concentration of C3, C4, and rheumatoid factor (RF), positive rate of autoantibodies of antinuclear antibody (ANA) profile, and titer of anti-Sm and ANA in systemic lupus erythematosus (SLE) patients were analyzed. Lone anti-Sm was evident in 271/1208 (22.42%) of all positive cases. One hundred seventy-five of them had definitive diagnoses with AIDs being the most prominent (69.71%, 122/175). Compared to the true group, SLE patients in the lone group showed significantly lower ANA and anti-Sm titers (both P < 0.001). There was no difference in frequency of other autoantibodies or C3, C4, and RF levels of SLE patients between the two groups. In NAIDs patients, lone anti-Sm indicates less incidence of kidney injury than true anti-Sm (P = 0.05). Lone anti-Sm has great diagnostic value in AIDs, especially SLE. Lone anti-Sm has relationship with mild kidney impairment. Positive anti-Sm patients with no clinical findings or SLE diagnosis should be submitted to new testing to identify changes in anti-Sm, because turning of lone anti-Sm to true anti-Sm indicates evolving kidney injury.
为了探讨在中国人中应用 Euroimmun 线免疫分析法（LIA）检测抗 Smith 抗体（anti-Sm）的价值。对 39766 例抗 Sm 阳性患者进行分析，其中 1208 例为真阳性（同时存在 Sm 和 nRNP/Sm 条带）和 lone 阳性（仅存在 Sm 条带而无 nRNP/Sm 条带）。分析了自身免疫性疾病（AIDs）、非自身免疫性疾病（NAIDs）、C3、C4 和类风湿因子（RF）浓度、抗核抗体（ANA）谱自身抗体的阳性率、系统性红斑狼疮（SLE）患者的抗 Sm 和 ANA 滴度的临床诊断比例。在所有阳性病例中，271/1208（22.42%）存在 lone anti-Sm。其中 175 例有明确诊断，以 AIDs 最为突出（69.71%，122/175）。与真阳性组相比， lone 阳性组的 SLE 患者的 ANA 和抗 Sm 滴度显著降低（均 P < 0.001）。两组间 SLE 患者其他自身抗体的频率或 C3、C4 和 RF 水平无差异。在 NAIDs 患者中，与真阳性抗 Sm 相比， lone 抗 Sm 表明肾脏损伤的发生率较低（P = 0.05）。在 AIDs 中，尤其是在 SLE 中， lone anti-Sm 具有重要的诊断价值。 lone anti-Sm 与轻度肾脏损害有关。没有临床发现或 SLE 诊断的抗 Sm 阳性患者应进行新的检测以识别抗 Sm 的变化，因为 lone anti-Sm 转为真阳性抗 Sm 表明肾脏损伤的进展。
