Galván Raquel, Fernández-Riejos Patricia, Sánchez Martínez Pilar María, Rodríguez-Chacón Carmen, Sánchez Mora Catalina, León-Justel Antonio
Laboratory Medicine Department, Virgen Macarena University Hospital, Av. Dr. Fedriani, 3, 41009, Seville, Andalusia, Spain.
Pract Lab Med. 2023 Jun 19;36:e00320. doi: 10.1016/j.plabm.2023.e00320. eCollection 2023 Aug.
The definition of Insulin autoimmune syndrome includes the presence of high levels of blood insulin and insulin autoantibodies. We encountered a 45-years-old white man with a high insulin serum value that do not fit with the C-peptide result. To discard or to confirm an analytical interference and diagnose a possible Insulin Autoimmune Syndrome we performed the following investigations: dilution linearity test, heterophilic antibody blocking, polyethylene glycol precipitation, measurements with alternative assays, and gel filtration chromatography by size exclusion. The latter technique confirmed that most of the insulin was complexed with a 150-kDa protein, corresponding to immunoglobulin G, identified as insulin autoantibodies. These antibodies were responsible for hypoglycemia attacks in the patient, who had a previous autoimmune disease. This case highlights the importance of carefully analyzing the results and ruling out possible interferences, as well as considering all kinds of pathologies, even if they are infrequent.
胰岛素自身免疫综合征的定义包括血液中高水平的胰岛素和胰岛素自身抗体。我们遇到一名45岁的白人男性，其血清胰岛素值很高，但与C肽结果不相符。为了排除或确认分析干扰并诊断可能的胰岛素自身免疫综合征，我们进行了以下检查：稀释线性试验、嗜异性抗体阻断、聚乙二醇沉淀、用替代方法测量以及尺寸排阻凝胶过滤色谱法。后一种技术证实，大部分胰岛素与一种150 kDa的蛋白质结合，该蛋白质对应于免疫球蛋白G，被鉴定为胰岛素自身抗体。这些抗体导致了该患者的低血糖发作，该患者曾患自身免疫性疾病。这个病例强调了仔细分析结果并排除可能干扰以及考虑各种病理情况的重要性，即使这些情况并不常见。
