{
  "abstract": "Aims and methods Idiopathic multicentric Castleman disease (iMCD) is currently considered to be classified into three clinical subtypes, including idiopathic plasmacytic lymphadenopathy (IPL), thrombocytopaenia, anasarca, fever, reticulin fibrosis/renal dysfunction, organomegaly (TAFRO) and not otherwise specified (NOS). Among the three, iMCD-IPL closely mimics IgG4-related disease (IgG4-RD). In diagnosing IgG4-RD, it is sometimes challenging to distinguish iMCD-IPL patients that also meet the histological diagnostic criteria for IgG4-RD. In this study, we focused on the number of IgG4-positive cells in the lymph nodes and analysed the relationship with laboratory findings to distinguish iMCD-IPL from IgG4-RD. Thirty-nine patients with iMCD-IPL and 22 patients with IgG4-RD were included.Results Among the cases considered to be iMCD-IPL, 33.3% (13/39) cases also met the histological diagnostic criteria for IgG4-RD and serum IgG4 levels were not different between the two groups. However, the serum IgG4/IgG ratio was significantly higher in IgG4-RD, with a cut-off value of 19.0%. Additionally, a significant positive correlation between serum IgG levels and the number of IgG4-positive cells was observed in iMCD-IPL (p=0.001). The serum IgG cut-off value for distinguishing iMCD-IPL meeting histological criteria for IgG4-RD from other iMCD-IPL was 5381 mg/dL.Conclusions iMCD-IPL cases with high serum IgG levels (>5000 mg/dL) were likely to meet the diagnostic criteria for IgG4-RD because of the numerous IgG4-positive cells observed. A combination of clinical presentations, laboratory values including the serum IgG4/IgG ratios and histological analysis is crucial for diagnosis of IgG4-RD and iMCD-IPL.",
  "authors": [
    {
      "affiliations": [
        "Department of Molecular Hematopathology, Okayama University Graduate School of Health Sciences, Okayama, Japan",
        "Research Program for Intractable Disease by Ministry of Health, Tokyo, Japan"
      ],
      "name": "Asami Nishikori"
    },
    {
      "affiliations": [
        "Department of Molecular Hematopathology, Okayama University Graduate School of Health Sciences, Okayama, Japan",
        "Research Program for Intractable Disease by Ministry of Health, Tokyo, Japan"
      ],
      "name": "Midori Filiz Nishimura"
    },
    {
      "affiliations": [
        "Department of Medicine, Center for Cytokine Storm Treatment & Laboratory, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA",
        "Castleman Disease Collaborative Network, Philadelphia, Pennsylvania, USA"
      ],
      "name": "David C Fajgenbaum"
    },
    {
      "affiliations": [
        "Department of General Medicine, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama, Japan",
        "Department of Medicine, University of Hawai’i, Honolulu, Hawaiʻi, USA"
      ],
      "name": "Yoshito Nishimura"
    },
    {
      "affiliations": [
        "Department of Molecular Hematopathology, Okayama University Graduate School of Health Sciences, Okayama, Japan"
      ],
      "name": "Kanna Maehama"
    },
    {
      "affiliations": [
        "Department of Molecular Hematopathology, Okayama University Graduate School of Health Sciences, Okayama, Japan"
      ],
      "name": "Tomoka Haratake"
    },
    {
      "affiliations": [
        "Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama, Japan"
      ],
      "name": "Tetsuya Tabata"
    },
    {
      "affiliations": [
        "Research Program for Intractable Disease by Ministry of Health, Tokyo, Japan",
        "Department of Rheumatology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan"
      ],
      "name": "Mitsuhiro Kawano"
    },
    {
      "affiliations": [
        "Department of Pathology, Tokai University School of Medicine, Isehara, Japan"
      ],
      "name": "Naoya Nakamura"
    },
    {
      "affiliations": [
        "Department of Pathology, Saitama Medical University, Saitama, Japan"
      ],
      "name": "Shuji Momose"
    },
    {
      "affiliations": [
        "Research Program for Intractable Disease by Ministry of Health, Tokyo, Japan",
        "Department of Immunology and Rheumatology, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan"
      ],
      "name": "Remi Sumiyoshi"
    },
    {
      "affiliations": [
        "Research Program for Intractable Disease by Ministry of Health, Tokyo, Japan",
        "Department of Immunology and Rheumatology, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan"
      ],
      "name": "Tomohiro Koga"
    },
    {
      "affiliations": [
        "Department of Pathology and Oncology, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama, Japan"
      ],
      "name": "Hidetaka Yamamoto"
    },
    {
      "affiliations": [
        "University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA"
      ],
      "name": "Frits van Rhee"
    },
    {
      "affiliations": [
        "Research Program for Intractable Disease by Ministry of Health, Tokyo, Japan",
        "Department of Immunology and Rheumatology, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan"
      ],
      "name": "Atsushi Kawakami"
    },
    {
      "affiliations": [
        "Department of Molecular Hematopathology, Okayama University Graduate School of Health Sciences, Okayama, Japan",
        "Research Program for Intractable Disease by Ministry of Health, Tokyo, Japan"
      ],
      "name": "Yasuharu Sato"
    }
  ],
  "title": "Diagnostic challenges of the idiopathic plasmacytic lymphadenopathy (IPL) subtype of idiopathic multicentric Castleman disease (iMCD): Factors to differentiate from IgG4-related disease",
  "uid": "6c255c13-5eb2-5baf-9e51-8378f9ff8cd8"
}