{
  "abstract": "Background Kappa free light chain (KFLC) index has emerged as a diagnostic biomarker for multiple sclerosis (MS). This study aims to evaluate the diagnostic accuracy of the KFLC-index in Chinese patients with MS, and its capacity to discriminate MS from myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and neuromyelitis optica spectrum disorders with aquaporin-4 antibody (AQP4+NMOSD).Methods 428 patients tested for KFLC-index were enrolled in the study, including 130 patients with MS, 41 with MOGAD, 25 with AQP4+NMOSD, 123 with other inflammatory or infectious neurological disorders (OIND) and 109 with non-inflammatory neurological disorders (NIND). Their oligoclonal band (OCB) results and clinical data were reviewed.Results KFLC-index was significantly higher in MS (20.1 (0.9–388.9)) compared with MOGAD (4.8 (0.8–56.1), p=0.003), AQP4+NMOSD (4.5 (1.5–46.4), p=0.011), OIND (2.9 (0.6–238.7), p<0.001) and NIND (1.8 (0.6–110.7), p<0.001). The optimal cut-off value for the KFLC-index to identify MS from the non-selective controls was 8.3, with an accuracy comparable to that of OCB (area under the curve 0.84 vs 0.81, p=0.249). The optimal cut-off values for differentiating MS from MOGAD and AQP4+NMOSD were 18.5 and 12.1, with performance similar to OCB (p=0.756 and 0.064). Combination of KFLC-index and OCB outperformed OCB alone in differentiating MS from non-selective controls and MOGAD (p<0.001 and p=0.044). Female (p=0.009) and higher cerebrospinal fluid leucocyte count (p<0.001) were associated with higher KFLC-index in MS.Conclusion KFLC-index is a valuable diagnostic tool for differentiating MS from other inflammatory demyelinating diseases.",
  "authors": [
    {
      "affiliations": [
        "Department of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China",
        "National Center for Neurological Disorders, Shanghai, People's Republic of China",
        "Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Hongmei Tan"
    },
    {
      "affiliations": [
        "Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Xuan Deng"
    },
    {
      "affiliations": [
        "Department of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China",
        "National Center for Neurological Disorders, Shanghai, People's Republic of China",
        "Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Jingzi ZhangBao"
    },
    {
      "affiliations": [
        "Department of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China",
        "National Center for Neurological Disorders, Shanghai, People's Republic of China",
        "Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Lei Zhou"
    },
    {
      "affiliations": [
        "Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Wenqing Wu"
    },
    {
      "affiliations": [
        "Department of Radiology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China",
        "Institute of Functional and Molecular Medical Imaging, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Haiqing Li"
    },
    {
      "affiliations": [
        "Department of Radiology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China",
        "Institute of Functional and Molecular Medical Imaging, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Yuxin Li"
    },
    {
      "affiliations": [
        "Department of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China",
        "National Center for Neurological Disorders, Shanghai, People's Republic of China",
        "Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Yuxin Fan"
    },
    {
      "affiliations": [
        "Department of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China",
        "National Center for Neurological Disorders, Shanghai, People's Republic of China",
        "Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Zhouzhou Wang"
    },
    {
      "affiliations": [
        "Department of Ophthalmology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Yiqin Xiao"
    },
    {
      "affiliations": [
        "Department of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China",
        "National Center for Neurological Disorders, Shanghai, People's Republic of China",
        "Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Chongbo Zhao"
    },
    {
      "affiliations": [
        "Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Ming Guan"
    },
    {
      "affiliations": [
        "Department of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China",
        "National Center for Neurological Disorders, Shanghai, People's Republic of China",
        "Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Chao Quan"
    },
    {
      "affiliations": [
        "Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China"
      ],
      "name": "Haoqin Jiang"
    }
  ],
  "title": "KFLC-index distinguishes multiple sclerosis from anti-myelin oligodendrocyte glycoprotein and aquaporin 4 diseases in a Chinese cohort",
  "uid": "181fe130-5953-58d5-aebe-ec372176ad81"
}