Department of Immunology, Genetics and Pathology, Uppsala University, Rudbeck Laboratory C5, 751 85, Uppsala, Sweden.
Rheumatology Unit, Military Hospital, Omdurman, Sudan.
Sci Rep. 2020 Dec 3;10(1):21126. doi: 10.1038/s41598-020-78213-5.
The role of anti-nuclear autoantibody (ANA) specificities in immune complexes (IC) formation has been studied to a limited extent in SLE, and not at all in African SLE patients. We compared ANA in IC from Sudanese and Swedish SLE patients. We included 93 Sudanese and 332 Swedish SLE patients fulfilling the 1982 ACR criteria. IC were captured using C1q-coated beads. ANA specificities were quantified in sera and IC. Results were related to modified SLEDAI. Whereas serum levels of anti-Sm, anti-dsDNA and anti-ribosomal P were higher in Swedish patients, IC levels of most ANA specificities were higher among Sudanese patients. This difference was especially prominent for anti-chromatin antibodies, which remained after adjustment for age, disease duration and treatment. Total levels of C1q-binding IC correlated with levels of specific ANA in IC, with highest correlations for anti-chromatin antibodies among Sudanese patients. Whereas occurrence of anti- SSA/Ro60, anti-histone and anti-U1RNP in both serum and IC associated with high SLEDAI score, anti-dsDNA in IC but not in serum associated with high SLEDAI. ANA, especially antibodies targeting chromatin, accumulate more in IC from Sudanese SLE patients. If the autoantibody fraction forming IC is pathogenically important, this might explain the generally described severe SLE in black populations.
抗核抗体（ANA）特异性在免疫复合物（IC）形成中的作用在系统性红斑狼疮（SLE）中研究有限，在非洲 SLE 患者中根本没有研究。我们比较了苏丹和瑞典 SLE 患者的 IC 中的 ANA。我们纳入了 93 名苏丹和 332 名符合 1982 年 ACR 标准的瑞典 SLE 患者。使用 C1q 包被珠捕获 IC。在血清和 IC 中定量 ANA 特异性。结果与改良的 SLEDAI 相关。虽然瑞典患者血清中的抗 Sm、抗 dsDNA 和抗核糖体 P 水平较高，但苏丹患者的大多数 ANA 特异性 IC 水平较高。这种差异在抗染色质抗体中尤为明显，即使在调整年龄、疾病持续时间和治疗后，该差异仍然存在。C1q 结合 IC 的总水平与 IC 中特定 ANA 的水平相关，苏丹患者的抗染色质抗体相关性最高。苏丹患者血清和 IC 中存在抗 SSA/Ro60、抗组蛋白和抗 U1RNP 与高 SLEDAI 评分相关，而 IC 中存在抗 dsDNA 与高 SLEDAI 评分相关。ANA，特别是针对染色质的抗体，在苏丹 SLE 患者的 IC 中积累更多。如果形成 IC 的自身抗体部分具有致病性，这可能解释了黑人中普遍描述的严重 SLE。
