Bökenkamp A, Grabensee A, Stoffel-Wagner B, Hasan C, Henne T, Offner G, Lentze M J
Medical Center of Bonn University, The Children's Hospital, Bonn, Germany.
Clin Nephrol. 2002 Dec;58(6):417-22.
As a consequence of more intensified immunosuppression, post-transplant lymphoproliferative disease (PTLD) is increasingly observed in patients after solid-organ transplantation. Beta2-microglobulin, a low-molecular weight protein (MW 11.8 kDa), is produced by all nucleated cells as part of the HLA complex. Its serum concentration is directly correlated with prognosis in patients with lymphatic neoplasms. Like other low-molecular weight proteins, beta2-microglobulin is eliminated by glomerular filtration. This complicates its use as a tumor marker in renal insufficiency. Cystatin C, a low-molecular weight protein of 13.3 kDa, is a new marker of kidney function largely unaffected by extrarenal disease. We, therefore, sought to assess the potential of the beta2-microglobulin/cystatin C ratio (beta2M/Cys) as a marker of lymphoproliferation.
Beta2M/Cys was determined by particle-enhanced immunonephelometry in sera from 132 children with different degrees of renal insufficiency, 5 of whom had lymphoproliferative disease. Renal function was assessed using the Schwartz formula.
Beta2M/Cys was constant between 1.2 and 2.4 mg/mg for Schwartz GFR > or = 40 ml/min x 1.73 m2. With lower GFR, beta2M/Cys rose progressively, maximum values being found in the hemodialysis patients (4.85-11.73). Healthy renal transplant recipients had beta2M/Cys comparable to controls. With acute lymphoproliferative disease, all but one patient had significantly elevated beta2M/Cys between 2.68 and 3.68 mg/mg, which returned to normal in remission (1.67-2.35 mg/mg). The sensitivity of a beta2M/Cys ratio > 2.4 mg/mg for the detection of PTLD was 80%, the specificity 100%, positive predictive value 100%, negative predictive value 90%.
The beta2-microglobulin/cystatin C ratio is a promising parameter of lymphoproliferation in patients with normal or mildly impaired renal function.
由于免疫抑制的强化，实体器官移植患者中移植后淋巴细胞增生性疾病（PTLD）的发病率日益增加。β2微球蛋白是一种低分子量蛋白质（分子量11.8 kDa），由所有有核细胞作为HLA复合体的一部分产生。其血清浓度与淋巴瘤患者的预后直接相关。与其他低分子量蛋白质一样，β2微球蛋白通过肾小球滤过清除。这使得它在肾功能不全患者中作为肿瘤标志物的应用变得复杂。胱抑素C是一种分子量为13.3 kDa的低分子量蛋白质，是一种基本不受肾外疾病影响的新的肾功能标志物。因此，我们试图评估β2微球蛋白/胱抑素C比值（β2M/Cys）作为淋巴细胞增生标志物的潜力。
采用颗粒增强免疫比浊法测定132例不同程度肾功能不全儿童血清中的β2M/Cys，其中5例患有淋巴细胞增生性疾病。使用施瓦茨公式评估肾功能。
当施瓦茨肾小球滤过率（GFR）≥40 ml/min×1.73 m2时，β2M/Cys在1.2至2.4 mg/mg之间保持恒定。GFR较低时，β2M/Cys逐渐升高，在血液透析患者中达到最大值（4.85 - 11.73）。健康的肾移植受者的β2M/Cys与对照组相当。急性淋巴细胞增生性疾病患者中，除1例患者外，所有患者的β2M/Cys均显著升高，在2.68至3.68 mg/mg之间，缓解期恢复正常（1.67 - 2.35 mg/mg）。β2M/Cys比值>2.4 mg/mg检测PTLD的敏感性为80%，特异性为100%，阳性预测值为100%，阴性预测值为90%。
β2微球蛋白/胱抑素C比值是肾功能正常或轻度受损患者淋巴细胞增生的一个有前景的参数。
