肾功能不全为首发临床表现多发性骨髓瘤的临床特征

Clinical features of multiple myeloma patients with renal insufficiency as the initial clinical manifestation

目的 探讨仅以肾功能不全为首发临床表现的多发性骨髓瘤（MM）的临床特征。方法 回顾性分析140例确诊为MM患者的临床资料，以患者首次就诊时血肌酐〉177 μmol/L为标准分为肾功能不全组和肾功能正常组。采用非条件Logistic回归分析MM患者肾功能不全的独立影响因素。结果 肾功能不全组患者的免疫球蛋白以三系（IgG、IgA和IgM）减少为主，占55.7%；而肾功能正常组患者以IgG型为主，占54.3%，差异有统计学意义（P〈0.001）。肾功能不全组和肾功能正常组患者的低IgM水平（〈0.4 g/L）、血红蛋白、白细胞、血沉、尿酸、校正血钙、总蛋白、球蛋白、蛋白尿和血尿差异均有统计学意义（均P〈0.05）。非条件Logistic回归分析结果显示，低IgM水平、血沉、血红蛋白、总蛋白、蛋白尿、血尿和尿酸为影响MM患者肾功能不全的独立因素（均P〈0.05）。结论 低IgM水平（〈0.4 g/L）是仅以肾功能不全为首发症状MM患者的重要临床特征。对于肾功能不全伴免疫球蛋白三系减少或低IgM水平的中老年患者，应早期排除MM，减少误诊。

Objective To analyze the clinical features of multiple myeloma （MM） with renal insufficiency as the initial manifestation, and to improve the level of clinical diagnosis of MM, and reducing misdiagnosis of this disease. Methods To retrospectively analyze the clinical data of 140 patients with MM, who were admitted in our Department of Nephrology and Hematology. They were diagnosed as MM by bone marrow aspiration biopsy. The patients were divided into renal insufficiency group and normal renal function group, based on the criterion of serum creatinine 〉 177 μmol/L. The two groups were statistically analyzed by t test, rank sum test, χ^2 test and binary logistic regression analysis. Results 55.7% of the patients in the renal insufficiency group presented low level of three immunoglobulin classes （ IgG, IgA, IgM） , while in the normal-renal function group, 54. 3% of patients mainly presented IgG subtype, showing statistically significant differences between the two groups （P〈0.001）. Univariate analysis showed that IgM level （〈0.4 g/L）, hemoglobin, white blood cells, erythrocyte sedimentation rate （ESR）, total protein, globulin, uric acid, corrected serum calcium, proteinuria and hematuria were statistically significantly different between the two groups （P〈0.05 for all）. Unconditional logistic regression analysis showed that lower level of IgM （ OR = 19.992, 95% CI： 1.327-301.202）, hemoglobin, uric acid, ESR, serum total protein, proteinuria and hematuria are independent risk factors for the development of renal insufficiency in MM patients （P〈0.05 for all）. Conclusions Low level of IgM （ 〈0.4 g/L） is an important clinical characteristics of MM patients with renal insufficiency as the initial clinical manifestation. For middle-aged and elderly patients, who present as low levels of three IgG classes （ IgG, IgA, IgM） or low level of IgM, multiple myeloma should be excluded, so as to reduce the misdiagnosis.