Interference of IgM-<i>κ</i> Type M Protein on Coagulation Test: A Case Report and Analysis of Its Cause

目的：通过一例华氏巨球蛋白血症患者探讨M蛋白对凝血试验的干扰，提高检验者对M蛋白的认识，避免影响临床的诊治。方法：查看凝固曲线发现干扰因素，通过进一步实验室检查明确干扰物质并分析原因。结果：大量IgM-κ型M蛋白在溶液环境改变时易出现沉淀干扰凝血实验的检测。结论：M蛋白可通过溶液浊度的改变干扰凝血实验的检测，当发现患者凝血结果异常或与临床表现不符时，应及时与临床沟通，并查看凝固曲线，必要时手工法进行复查。Objective: To explore the interference of M protein on coagulation test through a case of Waldenstrom macroglobulinemia, so as to improve the understanding of M protein in the laboratory and avoid affecting clinical diagnosis and treatment. Methods: The interfering factors were found by checking the coagulation curve, and the interfering substances were identified by further laboratory tests and the reasons were analyzed. Results: A large amount of IgM-κ type M protein was easy to precipitate and interfere with the detection of coagulation test when the solution environment changed. Conclusions: M protein can interfere with the detection of coagulation test by changing the turbidity of the solution. When the patient’s coagulation results are found to be abnormal or inconsistent with the clinical manifestations, we should communicate with the clinic in time and check the coagulation curve, and manually recheck if necessary.