Elevation of N-(Carboxymethyl)valine Residue in Hemoglobin of Diabetic Patients

• Published in: Diabetes care Vol. 24; no. 5; pp. 891 - 896
• Main Authors: Uchimura, Tomonori, Nakano, Kazushi, Hashiguchi, Teruto, Iwamoto, Hisahiko, Miura, Keisuke, Yoshimura, Yoshimichi, Hanyu, Naohiro, Hirata, Koichiro, Imakuma, Misturu, Motomiya, Yoshihiro, Maruyama, Ikuro
• Format: Journal Article
• Language: English
• Published: American Diabetes Association 01.05.2001
• ISSN: 0149-5992; 1935-5548
• DOI: 10.2337/diacare.24.5.891

Elevation of N -(Carboxymethyl)valine Residue in Hemoglobin of Diabetic Patients Its role in the development of diabetic nephropathy Tomonori Uchimura , MD 1 , Kazushi Nakano , MD 1 , Teruto Hashiguchi , MD 1 , Hisahiko Iwamoto , MSc 2 , Keisuke Miura , MSc 2 , Yoshimichi Yoshimura , PhD 2 , Naohiro Hanyu , MSc 3 , Koichiro Hirata , MSc 3 , Misturu Imakuma , MD 4 , Yoshihiro Motomiya , MD 5 and Ikuro Maruyama , MD, PhD 1 1 Department of Laboratory and Molecular Medicine, Kagoshima University School of Medicine, Kagoshima 2 Department of Research and Development for Diagnostics, A&T Corp., Hasaki, Ibaraki 3 Tsukuba Research Laboratories, Tokuyama Corp., Tsukuba, Ibaraki 4 Kimotsuki-gun Ishikai Hospital, Onejime, Kagoshima 5 Suiyukai Clinic, Kashihara, Nara, Japan Abstract OBJECTIVE —Advanced glycation end products (AGEs) are a risk factor for diabetic complications. We have developed an assay method for N -(carboxymethyl)valine (CMV) of the hemoglobin (CMV-Hb), which is an AGE generated from HbA 1c . Herein, we describe the clinical utility of CMV-Hb measurement for the diagnosis of diabetic nephropathy. RESEARCH DESIGN AND METHODS —BALB/c mice were immunized with carboxymethylated Hb and monoclonal antibody raised against CMV-Hb. This antibody was characterized by a surface plasmon resonance. We developed a latex immunoassay using the antibody and measured CMV-Hb from erythrocytes in type 2 diabetic patients and healthy control subjects (age 64.6 ± 12.0 vs. 61.1 ± 13.2 years, NS; HbA 1c 6.9 ± 1.5 vs. 5.2 ± 0.4%, P < 0.0001). RESULTS —A monoclonal antibody against CMV-Hb β-chain NH 2 -terminal and an assay method for measurement for CMV-Hb were both developed in our laboratory. CMV-Hb levels were significantly greater in the diabetic patients than in the control subjects (18.2 ± 6.9 vs. 12.7 ± 6.9 pmol CMV/mg Hb, P < 0.0001). No correlation was found between CMV-Hb and HbA 1c or CMV-Hb and glycated albumin. Levels of CMV-Hb increased as the diabetic nephropathy progressed. CONCLUSIONS —We established an assay method for CMV-Hb and confirmed the presence of CMV-Hb in circulating erythrocytes. CMV-Hb was more prevalent in diabetic patients than in healthy subjects. Furthermore, it was significantly higher in patients with diabetic nephropathy, suggesting that the presence of CMV-Hb may be a valuable marker for the progression of diabetic nephropathy. CM-Hb, carboxymethylated Hb CML, carboxymethyl lysine CMV, N-(carboxymethyl)valine CMV-Hb, N-(carboxymethyl)valine of Hb HPLC, high-performance liquid chromatography HAS, human serum albumin RAGE, receptor for AGE RU, resonance unit SPR, surface plasmon resonance TEA, triethylamine Footnotes Address correspondence and reprint requests to Ikuro Maruyama, Department of Laboratory and Molecular Medicine, Kagoshima University School of Medicine, 8-35-1 Sakuragaoka, Kagoshima City, 890-8520, Japan. E-mail: ucchii{at}khosp2.kufm.kagoshima-u.ac.jp . Received for publication 28 September 2000 and accepted in revised form 23 January 2001. A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.