【摘要】 目的 比较免疫球蛋白(Ig)及轻链的指数方法与合成曲线方法在评估鞘内合成方面的一致性及诊断效能，并探讨其在多种神经系统疾病中的应用价值。方法 回顾性收集2012年1月至2023年12月北京大学第一医院神经内科住院的神经系统疾病患者488例，包括多发性硬化(MS)、视神经脊髓炎谱系疾病(NMOSD)、急性播散性脑脊髓炎(ADEM)、病毒性脑炎(VE)、自身免疫性脑炎(AE)、吉兰-巴雷综合征(GBS)、慢性炎性脱髓鞘性多发性神经根神经病(CIDP);另收集非炎症性神经系统疾病211例作为对照组。检测入组患者的脑脊液与血清白蛋白、IgG/A/M及总κ、λ轻链水平，计算各指标商及指数。基于对照组数据建立Ig及总轻链的鞘内合成参考曲线。采用κ系数和McNemar检验比较指数方法与合成曲线方法判断鞘内合成的一致性及异常检出率差异。结果 各疾病组间，指数方法与合成曲线方法判断鞘内合成的一致性因指标而异，总κ轻链一致性最低(κ=0,一致率69.24%),总λ轻链最高(一致率86.39%)。在绝大部分疾病亚组白蛋白商正常的患者中，合成曲线方法判断各Ig及总κ轻链的鞘内异常合成检出率均低于指数方法(P<0.05)。结论 在血脑屏障正常情况下，指数方法与合成曲线方法在判断鞘内Ig及总轻链合成时一致性较低，合成曲线方法更为严格。建议临床实验室同时报告两种方法的结果。在白蛋白商正常时，应优先参考更为严格的合成曲线法结果，以避免高估鞘内合成；当血脑屏障受损时，两种方法的结果可互为参照，并需谨慎解读，且须密切结合寡克隆区带结果。IgA、M及总λ轻链的鞘内合成在不同疾病中具有潜在诊断意义。更多还原

【Abstract】 Objective To compare the consistency and diagnostic performance of the index method and the synthesis curve method in evaluating intrathecal synthesis of immunoglobulins(Ig) and light chains, and to explore their application value in various neurological diseases. Methods A retrospective analysis was conducted on 488 patients with neurological diseases hospitalized in the Department of Neurology, Peking University First Hospital from January 2012 to December 2023, including multiple sclerosis(MS), neuromyelitis optica spectrum disorders(NMOSD), acute disseminated encephalomyelitis(ADEM), viral encephalitis(VE), autoimmune encephalitis(AE), Guillain-Barré syndrome(GBS), and chronic inflammatory demyelinating polyradiculoneuropathy(CIDP). Another 211 patients with non-inflammatory neurological diseases were enrolled as controls. Albumin, IgG, IgA, IgM, and total κ and λ light chain levels were measured in paired cerebrospinal fluid(CSF) and serum samples, and corresponding quotients and indices were calculated. Reference curves for intrathecal synthesis of Ig and total light chains were established based on control data. The κ coefficient and McNemar test were used to compare the consistency and differences in abnormal detection rates between the index method and the synthesis curve method for determining intrathecal synthesis.Results The consistency between the two methods varied across different analyses, with the lowest consistency for total κ light chains(κ=0, agreement rate 69.24%) and the highest for total λ light chains(agreement rate 86.39%). In most disease subgroups with a normal albumin quotient, the synthesis curve method yielded significantly lower detection rates of abnormal intrathecal synthesis for all Ig and total κ light chains compared to the index method(P<0.05).Conclusions Under intact blood-brain barrier conditions, the consistency between the index method and the synthesis curve method in assessing intrathecal Ig and total light chain synthesis is low, with the synthesis curve method being more stringent. It is recommended that clinical laboratories report results from both methods. When the albumin quotient is normal, priority should be given to the stricter synthesis curve results to avoid overestimating intrathecal synthesis. When the blood-brain barrier is impaired, the results of the two methods could be cross-referenced and interpreted with caution, and must be closely combined with oligoclonal band findings. Intrathecal synthesis of IgA, IgM, and total λ light chains shows potential diagnostic significance across different neurological diseases.更多还原