Division of Rheumatology, Department of Internal Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
Rheumatol Int. 2019 Nov;39(11):1937-1944. doi: 10.1007/s00296-019-04445-y. Epub 2019 Sep 24.
Although anti-Smith (Sm) antibody is a highly specific antibody for systemic lupus erythematosus (SLE), the significance of anti-Sm antibody in patients with SLE is unclear. This study aimed to evaluate the association between anti-Sm antibodies and disease activity in patients with new-onset SLE. We included patients who were tested for anti-Sm antibodies at SLE diagnosis and within 12 months after diagnosis. SLE disease activity index (SLEDAI) was obtained at the time of the anti-Sm antibody test. The baseline disease activity was compared between patients with and without anti-Sm antibodies. The longitudinal association between disease activity and anti-Sm antibodies was also evaluated in total patients and in those with anti-Sm antibodies. Among 92 patients who were tested for anti-Sm antibodies at SLE diagnosis, 67 and another 67 patients were followed up for the presence of anti-Sm antibodies at 6 and 12 months, respectively. Although the baseline SLEDAI was comparable in patients with and without anti-Sm antibodies, the serum level of anti-Sm antibody was significantly correlated with SLEDAI (P = 0.003). At 12 months, anti-Sm antibody positivity was associated with higher SLEDAI and anti-dsDNA titer (P = 0.002, both). In addition, the changes in anti-Sm antibody titer over 12 months were correlated with the alterations in SLEDAI (P = 0.029).Anti-Sm antibody was associated with the baseline disease activity and the alteration of disease activity in patients with new-onset SLE. Monitoring of anti-Sm antibody titer may help assess the disease activity in SLE.
虽然抗 Smith（Sm）抗体是系统性红斑狼疮（SLE）的高度特异性抗体，但抗 Sm 抗体在 SLE 患者中的意义尚不清楚。本研究旨在评估新诊断的 SLE 患者中抗 Sm 抗体与疾病活动度的关系。我们纳入了在 SLE 诊断时和诊断后 12 个月内检测抗 Sm 抗体的患者。在检测抗 Sm 抗体时获得 SLE 疾病活动指数（SLEDAI）。比较有和无抗 Sm 抗体患者的基线疾病活动度。还评估了总患者和有抗 Sm 抗体患者中疾病活动度与抗 Sm 抗体之间的纵向关联。在 92 例在 SLE 诊断时检测抗 Sm 抗体的患者中，67 例和另外 67 例患者分别在 6 个月和 12 个月时随访抗 Sm 抗体的存在。尽管有和无抗 Sm 抗体患者的基线 SLEDAI 相似，但抗 Sm 抗体的血清水平与 SLEDAI 显著相关（P=0.003）。在 12 个月时，抗 Sm 抗体阳性与更高的 SLEDAI 和抗 dsDNA 滴度相关（P=0.002，均）。此外，12 个月内抗 Sm 抗体滴度的变化与 SLEDAI 的改变相关（P=0.029）。抗 Sm 抗体与新诊断的 SLE 患者的基线疾病活动度和疾病活动度的改变相关。监测抗 Sm 抗体滴度可能有助于评估 SLE 的疾病活动度。
