[Frontiers in Bioscience 14, 3879-3883, January 1, 2009]

Identification of autoantibody against beta-amyloid peptide in the serum of elderly

Ji-Hoon Sohn1, Jung On So1, Hyun Joo Hong1, Jong Won Kim2, Duk Ryul Na2, Manho Kim3, Hee Kim4, Eunjoo Nam4, Hee Jin Ha4, Young Ho Kim4, Inhee Mook-Jung1

1Department of Biochemistry and Cancer Research Institute, Seoul National University College of Medicine, Seoul, 110-799, Korea, 2Department of Neurology, Samsung Medical Center, Seoul, 135-710, Korea, 3Department of Neurology, Seoul National University College of Medicine, Seoul, 110-799, Korea, 4Digital Biotech, Inc., Gyeongi, 425-838, Korea

TABLES OF CONTENTS

1. Abstract
2. Introduction
3. Materials and methods
3.1. Patients and Controls
3.2. Purification of human anti-A-beta antibody
3.3. Anti-A-beta antibody enzyme-linked immunosorbent assay (ELISA)
3.4. Animals and immunohistochemistry
3.5. Statistical analysis
4. Results and Discussion
5. Acknowledgments
6. References

1. ABSTRACT

Alzheimer's disease (AD) is characterized by two major neurological features: amyloid deposits and neurofibrillary tangles in the brain. According to the amyloid cascade hypothesis, accumulation of amyloid-beta peptide (A-beta) plays a central role in the pathogenesis of AD. Several lines of evidence suggest that antibodies against A-beta play a protective role in the neuropathology of AD. In this study, we describe the purification of an autoantibody against A-beta from human serum using affinity purification method. The purified autoantibody recognized A-beta deposits in the brain of aged Tg2676 mice, an animal model of AD. The serum levels of anti-A-beta autoantibody correlated inversely with age in both AD patients and control non-demented elderly subjects. Furthermore, the levels were significantly lower in AD patients compared with the age-matched control subjects. It is the first time to show the identification of endogenous anti-A-beta autoantibody in human serum and suggesting that serum levels of anti-A-beta autoantibody might be a good biomarker for AD patients.