Melcion C, Mougenot B, Baudouin B, Ronco P, Moulonguet-Doleris L, Vanhille P, Beaufils M, Morel-Maroger L, Verroust P, Richet G
Clin Nephrol. 1984 Sep;22(3):138-43.
Renal failure is a frequent but inconstant complication of myeloma related to light chain excretion. Since it has been suggested that cationic light chains (lc) are most likely to induce renal damage, we have studied the isoelectric point (pI) of light chains produced by 17 patients with myeloma and related the results to the type and severity of renal damage assessed clinically and pathologically. In order to do so, we have applied immunoenzymatic techniques which allow identification of light chain types as well as measurement of pI without prior purification. Ten of fifteen patients with renal failure produced lambda light chains. There was no simple relationship between the isoelectric point and nephrotoxicity. However, light chains with the lowest pI observed in this series were associated with normal renal function in two cases and with acute reversible but severe renal failure requiring dialysis in five cases. By contrast, pI values above 6.0 observed in the remaining patients were associated with moderate renal failure in six patients with recently diagnosed myeloma and with irreversible renal failure, and in two patients in whom myeloma had been evolutive for several years. We thus suggest that further pI measurements may help to identify light chains with different nephrotoxic potentials.
肾衰竭是骨髓瘤常见但不恒定的并发症，与轻链排泄有关。由于有人提出阳离子轻链（lc）最有可能导致肾损伤，我们研究了17例骨髓瘤患者产生的轻链的等电点（pI），并将结果与临床和病理评估的肾损伤类型及严重程度相关联。为了做到这一点，我们应用了免疫酶技术，该技术无需事先纯化就能鉴定轻链类型并测量pI。15例肾衰竭患者中有10例产生λ轻链。等电点与肾毒性之间没有简单的关系。然而，本系列中观察到的最低pI的轻链，在2例中与正常肾功能相关，在5例中与需要透析的急性可逆但严重的肾衰竭相关。相比之下，其余患者中观察到的pI值高于6.0，在6例近期诊断为骨髓瘤的患者中与中度肾衰竭相关，在2例骨髓瘤已发展数年的患者中与不可逆肾衰竭相关。因此，我们认为进一步测量pI可能有助于识别具有不同肾毒性潜力的轻链。
