On Demand Medical Testing

Homocysteine may be ordered as part of a screen for people at high risk for heart attack or stroke. It may be useful in someone who has a family history of coronary artery disease but no other known risk factors. Its utility for this purpose, however, continues to be questioned because the role, if any, that homocysteine plays in the progression of cardiovascular disease (CVD) has not been established. Routine screening, such as that done for total cholesterol, is not yet recommended.

Elevations in serum lactate dehydrogenase occur from myocardial infarction, liver disease, pernicious and megaloblastic anemia, pulmonary emboli, malignancies, and muscular dystrophy. 

This test measures the amount of lead in the blood.

Leptin is an adipocyte-derived hormone that is essential for normal body weight regulation. Leptin production is under neuroendocrine control so that serum concentrations vary directly with the amount of triglycerides stored in adipose tissue depots.

A lipase test measures the amount of this enzyme in a blood sample. High amounts of lipase may be found in the blood when the pancreas is damaged or when the tube leading from the pancreas (pancreatic duct) to the beginning of the small intestine is blocked.

A lipid panel is a blood test that measures lipids—fats and fatty substances used as a source of energy by your body. Lipids include cholesterol, triglycerides, high-

Elevated concentrations of Lp(a) are associated with increased risk of coronary artery disease.

Lyme disease is caused by a bacterium borrelia burgdorferi and is transmitted by ticks. EIA is the screening test with high sensitivity for antibody detection. Western blot testing qualitatively examines with high specificity antibodies in a patient's specimen. Western blot testing is appropriate for confirming a detected EIA test result.