オオツキ　ミチオ   Ootsuki Michio   大月　道夫    所属   医学部 医学科（東京女子医科大学病院）    職種   教授・基幹分野長
論文種別	症例報告
言語種別	英語
査読の有無	査読あり
表題	A case of monoclonal gammopathy of undetermined significance with abnormal low levels of plasma glycated albumin by M protein.
掲載誌名	正式名：Clinica chimica acta; international journal of clinical chemistry 略　 称：Clin Chim Acta ISSNコード：18733492/00098981
掲載区分	国外
巻・号・頁	487,pp.337-340
著者・共著者	Kuramoto Noriko, Wakahara Tatsuya, Tamagawa Yuichi, Uchino Takahiro, Koseto Masahiro, Kawakami Manabu, Otsuki Michio, Aoki Yoshimasa, Ishibashi Midori, Kasayama Soji, Sumitani Satoru, Koga Masafumi
発行年月	2018/12
概要	BACKGROUND:It is known that an immunoglobulin abnormality affects various clinical laboratory measurements and leads to abnormal values. We experienced a case of monoclonal gammopathy of undetermined significance (MGUS) showing a falsely low plasma glycated albumin (GA) level.CASE REPORT:The patient was a 75-y-old male who visited our hospital for thrombocytosis identified during a medical checkup. Based on further examinations, he was diagnosed with MGUS (IgM-κ type). Laboratory examinations revealed that the plasma GA level was significantly low at -1.3% but the serum GA level was reasonable at 15.5%. We investigated the cause of the falsely low plasma GA level.RESULTS:The patient's plasma became turbid after mixing with the first reagent for GA measurement. The plasma GA level was increased by dilution of the plasma. The plasma GA level was falsely decreased only at the time of measurement on a sample collected using a blood-collecting tube with heparin sodium. The GA level was decreased by adding heparin sodium to the patient's serum, whereas the GA level was increased by neutralization of the patient's plasma with protamine sulfate. The GA level was increased after adding polyethylene glycol to the patient's plasma. Serum GA levels in healthy controls were decreased by adding purified M protein from the patient's serum.CONCLUSIONS:We report a patient with MGUS whose plasma GA concentration was falsely decreased by M protein when blood was drawn in a heparin sodium-containing tube.
DOI	10.1016/j.cca.2018.10.018
PMID	30317021