Metraiah El Hakem Abdelkarim, Regan Helen, Louw Johanna, Kidder Dana
Renal Unit, Aberdeen Royal Infirmary, Aberdeen, UK.
NHS Grampian, Aberdeen, Aberdeen, UK.
BMJ Case Rep. 2017 Jan 23;2017:bcr2016217946. doi: 10.1136/bcr-2016-217946.
Estimation of kidney function by measuring serum creatinine is one the commonest laboratory tests conducted in clinical practice. Enzymatic methods are often used to measure serum creatinine. Clinicians should be aware of the limitations of these methods, such as test interference with paraproteins.We present a case of falsely elevated serum creatinine in a patient referred for renal biopsy. The combination of fluctuating creatinine and normal blood urea level was unusual. Serum protein electrophoresis revealed the presence of an IgM paraprotein. Further investigations confirmed an underlying diagnosis of lymphoplasmacytoid lymphoma. This case highlights how IgM paraprotein can interfere with creatinine estimation by enzymatic assay and the utility of alternative methods of estimating serum creatinine.
通过测量血清肌酐来评估肾功能是临床实践中最常用的实验室检查之一。酶法常被用于测量血清肌酐。临床医生应了解这些方法的局限性，例如检测会受到副蛋白的干扰。我们报告一例因肾活检转诊患者血清肌酐假性升高的病例。肌酐波动与血尿素水平正常的组合情况并不常见。血清蛋白电泳显示存在IgM副蛋白。进一步检查确诊为淋巴浆细胞样淋巴瘤。该病例凸显了IgM副蛋白如何干扰酶法测定肌酐，以及血清肌酐替代评估方法的实用性。
