Research and Development Division, Japan Blood Products Organization, Kobe, Hyogo, Japan.
Pharmacovigilance Division, Japan Blood Products Organization, Minato-ku, Tokyo, Japan.
Vox Sang. 2024 Oct;119(10):1106-1110. doi: 10.1111/vox.13710. Epub 2024 Jul 2.
Intravenous immunoglobulins (IVIgs) contain various autoantibodies, including those against glutamic acid decarboxylase (GADAb), a valuable biomarker of type 1 diabetes mellitus. Passive transfer of GADAb from IVIgs to patients poses a risk of misdiagnosis, and information on the specific titres of GADAb and their impact on diagnostic accuracy remains limited. This study aimed to provide further insights into the origin of GADAb detected in patient serum following IVIg infusion.
GADAb titres in IVIg products from Japan and the United States were measured using enzyme-linked immunosorbent assay-based assays. For reliable quantification, GADAb titres in pooled plasma were quantified and compared with those in the IVIg products. The determined titres were used to estimate the likelihood of passively detecting acquired GADAb in individuals receiving IVIgs.
GADAbs were prevalent in IVIg products; however, the titres varied significantly among different lots and products. Importantly, IVIg-derived GADAb was estimated to remain detectable in patient serum for up to 100 days following a dosage of 2000 mg/kg.
Clinicians should consider that IVIg preparations may contain GADAb, which can lead to false-positive results in serological assays. Careful interpretation of the assay results is key to the definitive diagnosis of type 1 diabetes mellitus.
静脉注射免疫球蛋白（IVIg）含有各种自身抗体，包括针对谷氨酸脱羧酶（GADAb）的抗体，GADAb 是 1 型糖尿病的有价值的生物标志物。GADAb 从 IVIg 被动转移到患者中会带来误诊的风险，关于 GADAb 的具体滴度及其对诊断准确性的影响的信息仍然有限。本研究旨在进一步了解静脉注射免疫球蛋白输注后患者血清中检测到的 GADAb 的来源。
使用基于酶联免疫吸附试验的测定法测量来自日本和美国的 IVIg 产品中的 GADAb 滴度。为了进行可靠的定量，定量了混合血浆中的 GADAb 滴度，并将其与 IVIg 产品进行了比较。使用确定的滴度来估计在接受 IVIg 的个体中被动检测获得性 GADAb 的可能性。
GADAb 在 IVIg 产品中很常见；然而，不同批次和产品之间的滴度差异很大。重要的是，估计在接受 2000mg/kg 剂量后，IVIg 衍生的 GADAb 可在患者血清中检测到长达 100 天。
临床医生应考虑到 IVIg 制剂可能含有 GADAb，这可能导致血清学检测出现假阳性结果。仔细解释检测结果是明确诊断 1 型糖尿病的关键。
