Metal Profile and Apolipoprotein E in Parkinson’s Disease: Biomarkers of Neurodegenerative Diseases

Abstract

Background: Iron plays a key role in the pathogenesis of Parkinson’s disease (PD), which is the second most frequent neurodegenerative disease. Disturbances in the iron homeostasis can lead to cellular damage through hydroxyl radical production, leading to decreased myelin production and the synthesis and production of neurotransmitters in the central nervous system (CNS).

Aim and Objectives: The aim of the study was to compare the serum levels of iron, copper, ferritin, ceruloplasmin, transferrin, and TIBC levels in PD cases and controls and identify biomarker pool including demographic & genetic variants and blood biochemical markers. Further the association of APOE ε4 allele with PD was also studied.

Materials and Methods: A case-control study was undertaken in 100 PD and non-PD subjects each. Serum iron, copper, ferritin, transferrin, TIBC, ceruloplasmin, and APOE genotyping were measured. Biochemical assessments were performed in Biochemistry autoanalyzers, and APOE genotype was conducted by ARMS-PCR.

Result: In PD subjects serum iron, copper, ferritin, transferrin saturation, and ceruloplasmin levels were significantly low as compared to controls (p<0.001) whereas transferrin and TIBC levels were higher as compared to non-diseased subjects (p<0.01). The most common APOE genotype observed was ε3ε3 (62%) followed by ε3ε4 (25%) in PD subjects as compared to non-diseased subjects (ε3ε3 89%, ε3ε4 11% respectively). APOE ε4 allele was present in 32.0% PD subjects, as compared to 11% in non-diseased subjects.

Conclusion: In the present study raised iron, copper and APOE ε4 allele are associated with PD, suggesting their potential role as biomarkers in disease risk and progression.