An 86-year-old woman is monitored for IgA λ-associated multiple myeloma, treated in second intention with dexamethasone, revlimid and daratumumab after a relapse. A control serum protein electrophoresis detects the presence of a new monoclonal spike, later confirmed by immunofixation as an IgG κ. Suspecting an interference due to the immunotherapy, a daratumumab specific immunofixation reflex assay (DIRA) is performed, with the addition of anti-daratumumab antibodies, confirming the interference. A second multiple myeloma case is presented, describing interference with daratumumab co-migrating with the original monoclonal immunoglobulin. Based on these cases, we propose an algorithm of action to confirm the interference and provide an accurate biological result consistent with the therapeutic and clinical context.

Keywords: analytical interference; daratumumab; electrophoresis; myeloma.

一位86岁的女性患者因IgA λ相关的多发性骨髓瘤接受监测，在病情复发后采用地塞米松、来那度胺和达拉莫单抗进行二线治疗。控制血清蛋白电泳检测到一个新的单克隆峰，随后通过免疫固定确认为IgG κ。怀疑是由于免疫疗法的干扰，进行了针对达拉莫单抗的特异性免疫固定反射试验（DIRA），加入抗达拉莫单抗抗体后证实了这一干扰。另一例多发性骨髓瘤病例中描述了达拉莫单抗与原始单克隆免疫球蛋白共迁移造成的干扰。基于这些案例，我们提出了一种确认干扰并提供符合治疗和临床背景的准确生物结果的操作算法。

关键词： 分析干扰；达拉莫单抗；电泳；骨髓瘤。