Haptoglobin and Iron in Parkinson's Disease

A total of 342 participants, 100 PD patients and 242 age- and gender matched controls, were included in the study. All study participants were seen for one study visit in the morning at one of two Bastyr University Clinics in the Seattle area. Study participants were fasting at the time of the visit. During the study visit, participants donated a blood sample for the blood tests and complete an epidemiology questionnaire.

A subset of 51 of the study participant who were seen for the visit at Bastyr University, underwent brain scan and Magnetic Resonance Imaging (MRI), at the University of Washington Department of Radiology. The MRI part of the study aims at estimating brain iron levels.

Primary outcomes

• Iron metabolism differences between PD patients and controls [Up to 7 years]: Iron metabolism will be measured by testing for serum iron and iron-binding proteins, and by estimating brain iron by MRI. Serum iron parameters that will be measured include total serum iron, iron-binding proteins such as transferrin and ferritin, and tests related to iron metabolism: transferrin % saturation, unsaturated iron binding capacity, soluble transferrin receptor, complete blood count, hemoglobin, uric acid, haptoglobin, haptoglobin phenotype. Differences in serum iron parameters, and brain iron levels, between PD patients and controls will be calculated.

Secondary outcomes

• Environmental factors affecting PD risk and gene-environment interactions [recruitment until January 2016]: Questionnaire data will be analyzed to identify risk factors for PD by comparing lifestyle and dietary patterns from questionnaire between PD cases and controls. Interaction between haptoglobin phenotype and tobacco smoking on PD risk will be calculated, as well as interaction between haptoglobin phenotype and environmental factors such as tobacco smoking and diet on serum iron and brain iron levels.

Sex: All, ages: 35 Years to 92 Years, accepts healthy volunteers

Inclusion Criteria for the Controls, for the blood draw and epidemiology visit:

* Volunteers should be of age between 52 and 82 years of age, males of females.

Exclusion Criteria for the Controls:

* presence of a neurodegenerative disease,
* presence of active cancer under treatment,
* HIV sero-positivity, Hepatitis B, C, of A sero-positivity
* rheumatoid arthritis
* recent blood donation (less than three months before the visit).
* fever at the time of the visit

Inclusion Criteria for the Parkinson's disease patients:

Diagnosis of Parkinson's disease (UKBB clinical criteria).

Exclusion criteria for the Parkinson's disease patients, for the blood draw and epidemiology visit:

* Presence of other neurodegenerative diseases, apart for Parkinson's disease
* two or more family members with Parkinson's disease
* presence of active cancer under treatment
* HIV sero-positivity, Hepatitis B, C, of A sero-positivity
* rheumatoid arthritis
* recent blood donation (less than three months before the visit).
* fever at the time of the visit

Exclusion criteria for the Magnetic Resonance Imaging:

* presence in the body of a ferro-magnetic metallic foreign object such as, but not limited to:
* a cardiac pacemaker
* aneurism clip
* neuro-stimulator
* surgical clip
* artificial limb or joint
* orthopedic items, such as screws, nails, pins, rods,
* any metallic foreign body from a previous injury, bullets, shrapnels, metal slivers.
* exclusion criteria for MRI is also the presence of claustrophobia

• Costa-Mallen P, Checkoway H, Zabeti A, Edenfield MJ, Swanson PD, Longstreth WT Jr, Franklin GM, Smith-Weller T, Sadrzadeh SM. The functional polymorphism of the hemoglobin-binding protein haptoglobin influences susceptibility to idiopathic Parkinson's disease. Am J Med Genet B Neuropsychiatr Genet. 2008 Mar 5;147B(2):216-22. doi: 10.1002/ajmg.b.30593. PMID 17918239

• Paola Costa-Mallen, PhD, Principal investigator, Bastyr University