Department of Experimental, Preventive and Clinical Medicine, Center for Innovative Medicine.
Department of Rheumatology, Vilnius University Hospital Santaros Clinics, Vilnius, Lithuania.
Rheumatology (Oxford). 2022 Nov 28;61(12):4991-4996. doi: 10.1093/rheumatology/keac288.
Anti-TIF1-gamma autoantibodies can be detected with immunoprecipitation (IP), line blot (LB) and ELISA. We compared assay performance in patients with DM and the potential of these assays to detect anti-TIF1-gamma positive cancer-associated DM (CADM).
We included sera from 131 patients with DM followed at Karolinska University Hospital, Stockholm, Sweden and 82 healthy controls. Serum samples taken at DM diagnosis were tested for anti-TIF1-gamma autoantibodies with IP, two ELISAs (in-house and commercial) and LB. Cancer diagnosis and dates were obtained from the Swedish national cancer register. CADM was defined as a malignancy that developed within 3 years of DM diagnosis.
Anti-TIF1-gamma autoantibodies were detected in 19/101 (18.8%), 15/113 (13.2%), 34/131 (26%) and 45/131 (34.4%) of the patients with IP, LB, in-house and commercial ELISA, respectively. The anti-TIF1-gamma results from the in-house ELISA were confirmed with IP in 93 of 101 (92%) cases, κ = 0.76, with a commercial ELISA in 110 of 131 (84%) cases, κ = 0.63, and with LB in 101 of 113 (89.3%) cases, κ = 0.67. Anti-TIF1-gamma results with IP were confirmed with LB in 85 of 92 (92.4%) cases, κ = 0.73. For detecting CADM, the anti-TIF1-gamma in-house ELISA had a sensitivity of 58% and specificity of 86%, the commercial ELISA had a sensitivity of 63% and specificity of 82%, IP had a sensitivity of 52% and specificity of 92%, LB had a sensitivity of 40% and specificity of 96%.
The two anti-TIF1-gamma ELISA assays had advantages both for autoantibody detection and to identify anti-TIF1-gamma-positive CADM.
抗 TIF1-γ 自身抗体可用免疫沉淀（IP）、线印迹（LB）和 ELISA 检测。我们比较了 DM 患者的检测结果，并评估了这些检测方法对检测癌相关 DM（CADM）的抗 TIF1-γ 阳性的能力。
我们纳入了在瑞典斯德哥尔摩卡罗林斯卡大学医院就诊的 131 例 DM 患者和 82 例健康对照者的血清。在 DM 诊断时，使用 IP、两种 ELISA（内部和商业）和 LB 检测血清样本中的抗 TIF1-γ 自身抗体。从瑞典国家癌症登记处获取癌症诊断和日期。CADM 定义为在 DM 诊断后 3 年内发生的恶性肿瘤。
在 IP、LB、内部 ELISA 和商业 ELISA 检测中，分别有 19/101（18.8%）、15/113（13.2%）、34/131（26%）和 45/131（34.4%）例患者检测到抗 TIF1-γ 自身抗体。内部 ELISA 的抗 TIF1-γ 结果与 IP 在 101 例中的 93 例（92%）、κ=0.76，与商业 ELISA 在 131 例中的 110 例（84%）、κ=0.63，与 LB 在 113 例中的 101 例（89.3%）、κ=0.67相匹配。在 92 例中的 85 例（92.4%）中，IP 与 LB 确认了抗 TIF1-γ 结果，κ=0.73。对于检测 CADM，内部 ELISA 的抗 TIF1-γ 敏感性为 58%，特异性为 86%，商业 ELISA 的敏感性为 63%，特异性为 82%，IP 的敏感性为 52%，特异性为 92%，LB 的敏感性为 40%，特异性为 96%。
两种抗 TIF1-γ ELISA 检测方法在自身抗体检测和识别抗 TIF1-γ 阳性 CADM 方面均具有优势。
