Categories


Blood Measures

Measures derived from blood samples

Subcategories

Inflammatory markers

Inflammatory markers are quantified by Endogen Searchlight technologies (Billerica, MA) using highly sensitive multiplexed sandwich enzyme-linked immunosorbent assay (ELISA) arrays. The multiplex ELISA arrays are tested for spotting consistency and specificity to rule out the presence of cross-reactivity or nonspecific binding resulting from multiple antibody combinations.

Measures of inflammatory markers are available for a subset of MAP participants with blood samples collected between April 2003 and May 2005 and MARS participants with blood samples collected between August 2004 and July 2007.

Not all MAP measures are derived from blood samples taken at baseline. MARS measures are derived from blood samples taken at baseline.

Note: Analysis after log transformation is recommended.

Age-related inflammation Age-related inflammation
Ratio of good to bad inflammation Ratio of good to bad inflammation
Vascular inflammation - 2 items Vascular inflammation based on 2 inflammatory markers
Vascular inflammation - 3 items Vascular inflammation based on 3 inflammatory markers
CRP level Log transformed level of C-reactive protein
IL-1beta level Log transformed level of interleukin-1beta
IL-1RA level Log transformed level of interleukin-1 receptor agonist
IL-10 level Log transformed level of interleukin-10
IL-6 level Log transformed level of interleukin-6
IL-6R level Log transformed level of interleukin-6 receptor
MMP9 level Log transformed level of matrix metallopeptidase 9
TNF-alpha level Log transformed level of tumor necrosis factor-alpha
VCAM level Log transformed level of vascular cell adhesion molecule

Pathogens

Antibody levels are measured from serum samples using solid-phase enzyme immunoassay at Stanley Laboratory of Developmental Neurovirology at the Johns Hopkins School of Medicine, blinded to participants’ clinical characteristics.

CMV serostatus Cytomegalovirus serostatus in serum
Gliadin serostatus Gliadin serostatus in serum
HSV-1 serostatus Herpes simplex virus type 1 serostatus in serum
Toxoplasma serostatus Toxoplasma serostatus in serum
Toxoplasma serostatus (IU) Toxoplasma serostatus in serum (international units)

Routine laboratory tests

A standard procedure is used to collect blood samples. Using sterile technique, phlebotomists and nurses skilled in venipuncture collect the blood specimen. Specimens are then transferred to Quest Diagnostics (www.questdiagnostics.com) for analysis. Tests include: basic metabolic panel, complete blood count, lipid panel, thyroid panel, and hemoglobin A1c test.

Anemia Anemia calculated from hemoglobin using WHO criteria
Blood urea nitrogen (BUN) Blood urea nitrogen in blood samples
Calcium level Calcium level in blood samples
Carbon dioxide level Carbon dioxide level in blood samples
Chloride level Chloride level in blood samples
Cholesterol/HDL ratio Ratio of total cholesterol to HDL in blood samples
Creatinine level Creatinine level in blood samples
Estimated glomerular filtration rate Glomerular filtration rate based on Modified Diet in Renal Disease study
Fasting status Fasting status at time of blood draw
Glucose level Glucose level in blood samples
Hematocrit Hematocrit in blood samples
Hemoglobin Hemoglobin in blood samples
Hemoglobin A1c level Hemoglobin A1c in blood samples
HDL cholesterol level HDL cholesterol level in blood samples
LDL cholesterol level LDL cholesterol level in blood samples
Mean corpuscular hemoglobin (MCH) Mean corpuscular hemoglobin in blood samples
Mean corpuscular hemoglobin concentration (MCHC) Mean corpuscular hemoglobin concentration in blood samples
Mean corpuscular volume (MCV) Mean corpuscular volume in blood samples
Platelet count Platelet count in blood samples
Potassium level Potassium level in blood samples
RBC count Red blood cell (RBC) count in blood samples
RBC distribution width Red blood cell distribution width in blood samples
Sodium level Sodium level in blood samples
TSH level Thyroid-stimulating hormone level in blood samples
Total cholesterol level Total cholesterol level in blood samples
Triglyceride level Triglyceride level in blood samples
WBC count White blood cell (WBC) count in blood samples