Department of Medicine, Hematology and Oncology, Ruhr-University of Bochum, Bochum, Germany.
Eur J Haematol. 2010 Sep;85(3):236-42. doi: 10.1111/j.1600-0609.2010.01475.x. Epub 2010 May 26.
Diagnosis of central nervous system (CNS) lymphoma depends on histopathology of brain biopsies, because no reliable disease marker in the cerebrospinal fluid (CSF) has been identified yet. B-cell lymphomas such as CNS lymphomas are clonally restricted and express either kappa or lambda immunoglobulin light chains. The aim of this study was to find out a potential diagnostic value of free immunoglobulin light chains released into the CSF of CNS lymphoma patients. Kappa (kappa) and lambda (lambda) free immunoglobulin light chains (FLC) were measured in CSF and serum samples collected from 21 patients with primary and secondary CNS lymphomas and 14 control patients with different neurologic disorders. FLC concentrations and ratios were compared between patient groups and were further analyzed in correlation with clinical, cytopathological, and radiological findings. FLC concentrations for all patients were lower in CSF when compared to serum. In patients with CNS lymphoma, the FLC ratios in CSF were higher (range 392-0.3) compared to control patients (range 3.0-0.3). Irrespective of cytopathological proven lymphomatous meningitis, in 11/21 lymphoma CSF samples the FLC ratios were markedly above 3.0 indicating a clonally restricted B-cell population. Increased FLC ratios in CSF were found in those patients showing subependymal lymphoma contact as detected in magnetic resonance imaging. In summary, this is the first report demonstrating that a significant proportion of patients with CNS lymphomas display a markedly increased FLC ratio in the CSF.
中枢神经系统（CNS）淋巴瘤的诊断依赖于脑活检的组织病理学，因为目前尚未发现脑脊液（CSF）中可靠的疾病标志物。B 细胞淋巴瘤，如 CNS 淋巴瘤，具有克隆限制性，表达κ或λ免疫球蛋白轻链。本研究旨在探讨脑脊液中游离免疫球蛋白轻链（FLC）释放对 CNS 淋巴瘤患者的潜在诊断价值。我们检测了 21 例原发性和继发性 CNS 淋巴瘤患者和 14 例具有不同神经系统疾病的对照组患者的 CSF 和血清样本中的κ（kappa）和λ（lambda）游离免疫球蛋白轻链（FLC）。比较了各组患者之间的 FLC 浓度和比值，并进一步分析了其与临床、细胞病理学和影像学发现的相关性。与血清相比，所有患者的 CSF 中的 FLC 浓度均较低。与对照组患者（范围 3.0-0.3）相比，CNS 淋巴瘤患者的 CSF 中 FLC 比值更高（范围 392-0.3）。无论细胞病理学是否证实存在淋巴瘤性脑膜，在 21 例淋巴瘤 CSF 样本中，11 例的 FLC 比值明显高于 3.0，表明存在克隆性 B 细胞群。在磁共振成像检测到的室管膜下淋巴瘤接触的患者中，发现 CSF 中的 FLC 比值增加。总之，这是第一个报告表明，相当一部分 CNS 淋巴瘤患者的 CSF 中存在明显升高的 FLC 比值。
