title: [Case of pseudohypercreatininemia associated with monoclonal IgM gammopathy].
abstract: An 80-year-old man with well controlled hypertension for eight years and monoclonal IgM gammopathy was referred to our hospital in May 2010 due to persistent elevation of serum creatinine(s-Cr). At our hospital, urine and blood tests showed no abnormal findings as BUN and Cr were 15.0 mg/dL and 0.91 mg/dL, respectively. In contrast the referring hospital had obtained values of 10.4 mg/dL and 4.8 mg/dL, respectively. This discrepancy was replicated when s-Cr was measured in another sample from this patient using the enzyme assay kits employed by the referring hospital and our hospital. High-performance liquid chromatography (HPLC), which is the standard method for measuring s-Cr, gave a value in the normal range. After removing high molecular weight proteins (>3,000 D)from the serum sample, the s-Cr levels measured with the respective kits were similar. Since elevation of s-Cr was linked to that of IgM at the referring hospital, we diagnosed the patient as having pseudohypercreatininemia with monoclonal IgM gammopathy.
authors.affiliation: Department of Nephrology & Dialysis, Tazuke Kofukai Foundation, Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ikeda
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: Takafumi
authors.initials: T
authors.lastname: Miyake
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kakita
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Komiya
authors.forename: Satomi
authors.initials: S
authors.lastname: Yonemoto
authors.forename: Eri
authors.initials: E
authors.lastname: Muso
mesh_terms: D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001806:Blood Urea Nitrogen; D002851:Chromatography, High Pressure Liquid; D003401:Creatine / Q000097:blood*; D057075:Enzyme Assays / Q000379:methods; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D008297:Male; D010265:Paraproteinemias / Q000097:blood* / Q000175:diagnosis*; D011933:Reagent Kits, Diagnostic
chemical_list: D015415:Biomarkers; D007075:Immunoglobulin M; D011933:Reagent Kits, Diagnostic; D003401:Creatine