Department of Internal Medicine II, Heinrich Braun Klinikum Zwickau, Zwickau, Germany.
Kidney Blood Press Res. 2012;35(2):120-8. doi: 10.1159/000330715. Epub 2011 Nov 1.
Renal involvement in the light chain-associated diseases multiple myeloma (MM), amyloidosis (AL) and monoclonal immune position disease (MIDD) is common and differential diagnosis usually requires renal biopsy. The aim of this study was to investigate if noninvasive methods are viable to identify and differentiate between the various types of kidney diseases.
All patients with a light chain-associated disease admitted to our center from 1996 to 2008 were retrospectively evaluated. Renal biopsy data were correlated with proteinuria findings.
Only the ratio of free κ/λ light chains showed a good sensitivity for myeloma cast nephropathy (MCN), AL and MIDD. The λ light chain was characteristic for AL, the κ light chain dominated in MIDD. Renal function at the time of diagnosis was worst in MIDD. MCN presented with a proteinuria of > 3.5 g/g creatinine. In contrast, a higher proteinuria was found in AL or MIDD. Whereas the κ/λ ratio in the urine was pathological for all three diseases, extremely high or low ratios indicated the presence of MCN. However, in AL or MIDD, the ratio was only moderately elevated.
A noninvasive differentiation between MCN and other forms of renal light chain disease is possible.
轻链相关性疾病多发性骨髓瘤（MM）、淀粉样变性（AL）和单克隆免疫球蛋白沉积病（MIDD）常累及肾脏，且通常需要肾活检进行鉴别诊断。本研究旨在探讨是否可采用非侵入性方法来识别和区分不同类型的肾脏疾病。
回顾性评估了 1996 年至 2008 年期间我院收治的所有轻链相关性疾病患者。将肾活检数据与蛋白尿检测结果进行了相关性分析。
仅游离κ/λ轻链比值对骨髓瘤管型肾病（MCN）、AL 和 MIDD 具有较好的灵敏度。λ轻链是 AL 的特征，κ轻链在 MIDD 中占主导地位。MIDD 患者在诊断时的肾功能最差。MCN 的蛋白尿>3.5g/g 肌酐。相比之下，AL 或 MIDD 患者的蛋白尿更高。虽然三种疾病的尿液κ/λ 比值均存在病理性升高，但极高或极低比值提示存在 MCN。然而，在 AL 或 MIDD 中，比值仅中度升高。
对于 MCN 和其他类型的肾脏轻链疾病，非侵入性鉴别是可行的。
