This test is used as an aid in the diagnosis of certain autoimmune thrombotic disorders, such as antiphospholipid syndrome (aPS). Antibodies to PS/PT correlate with the presence of lupus anticoagulants (LA) and this test may be useful in cases with difficult LA test interpretation. This assay may also assist in the determination of risk for thrombosis as well as obstetric complications in patients with antiphospholipid antibodies.

This test is used as an aid in the diagnosis of certain autoimmune thrombotic disorders, such as antiphospholipid syndrome (aPS). Antibodies to PS/PT correlate with the presence of lupus anticoagulants (LA) and this test may be useful in cases with difficult LA test interpretation. This assay may also assist in the determination of risk for thrombosis as well as obstetric complications in patients with antiphospholipid antibodies.

For diagnosis and monitoring inflammatory activity in primary systemic small vessel vasculitides. Antineutrophil antibodies are best demonstrated in these diseases by using a combination of IFA and EIAs that detect ANCA specific for PR3-ANCA or MPO-ANCA. Presence of anti-MPO antibodies are highly specific for idiopathic and vasculitis associated crescentic glomerulonephritis, classic polyarteritis nodosa, Churg-Strauss syndrome, and polyangiitis overlap syndrome without renal involvement.

Antiscleroderma-70 antibodies (also called SCL-70 antibody or anti-topoisomerase I antibody) are autoantibodies that target DNA topoisomerase I — an enzyme involved in DNA replication. They are highly specific for systemic sclerosis (scleroderma), particularly the diffuse cutaneous form. On the LabCorp/RDL assay, results are reported as negative (below 0.2 U/mL) or positive (0.2 U/mL and above). A positive result does not diagnose scleroderma by itself — the antibody can occasionally be positive in other conditions and requires clinical correlation — but a positive SCL-70 in the right clinical context is a strong marker for diffuse systemic sclerosis. A negative result does not exclude scleroderma, as only 30–40% of patients with systemic sclerosis are SCL-70 positive.

The ASO test is primarily used to help determine whether a recent strep infection with group A Streptococcus:

Antithrombin Activity (ATIII), also known as AT III or AT 3, is a key biomarker that measures how effectively antithrombin, a natural anticoagulant protein, functions in the blood. Antithrombin is crucial for regulating clot formation by inhibiting thrombin and clotting factors like factor Xa, helping maintain a balance between clotting and bleeding. Normal ATIII activity ranges from 80% to 120%.

A decrease in ATIII activity may indicate inherited or acquired deficiencies and is often linked to conditions like deep vein thrombosis (DVT), pulmonary embolism, liver disease, nephrotic syndrome, disseminated intravascular coagulation (DIC), or vitamin K deficiency. While elevated ATIII activity is less common, it may occur during inflammation, certain stages of pregnancy, or after antithrombin supplementation or anticoagulant therapy.

Antithyroid antibodies are crucial biomarkers for diagnosing and managing autoimmune thyroid diseases like Hashimoto's thyroiditis and Graves' disease. Detecting these antibodies early can lead to better treatment outcomes, helping to prevent long-term complications related to thyroid dysfunction. If you have symptoms of thyroid imbalance or a family history of autoimmune disorders, testing for antithyroid antibodies is a key step in protecting your thyroid health.

Studies have shown that the ratio of apolipoprotein A-1:apolipoprotein B may correlate better with increased risk of coronary artery disease (CAD) than total cholesterol, and LDL:HDL ratio.

ApoA-I, or Apolipoprotein A-I, plays a crucial role in understanding heart health and managing potential risks related to cardiovascular diseases. ApoA-I is the main protein component of high-density lipoprotein (HDL) in the blood. HDL is often referred to as "good cholesterol" because it helps transport cholesterol from the arteries to the liver, where it can be processed and removed from the body. This process is essential for maintaining healthy artery walls and preventing the build-up of plaques that can lead to heart attacks and strokes. Higher levels of ApoA-I and consequently HDL are generally associated with a lower risk of heart disease. The measurement of ApoA-I in a lipid panel provides valuable information about a person's HDL levels and overall cardiovascular health. By assessing ApoA-I, healthcare providers can better understand an individual's risk for heart disease and tailor treatment plans to improve heart health, such as recommending lifestyle changes or prescribing medication to manage cholesterol levels effectively. 

Apolipoprotein A is a protein carried in HDL ("good") cholesterol. It helps start the process for HDL to remove bad types of cholesterol from your body. In this way, apolipoprotein A can help to lower your risk for cardiovascular disease. Apolipoprotein A levels can be measured. But it's more common to measure the HDL and LDL ("bad") cholesterol when looking at cardiovascular risk.

This biomarker is useful for:

- Evaluating risk for atherosclerotic cardiovascular disease

- Aiding in the detection of Tangier disease

Apolipoprotein A is a protein carried in HDL ("good") cholesterol. It helps start the process for HDL to remove bad types of cholesterol from your body. In this way, apolipoprotein A can help to lower your risk for cardiovascular disease. Apolipoprotein A levels can be measured. But it's more common to measure the HDL and LDL ("bad") cholesterol when looking at cardiovascular risk.

This biomarker is useful for:

- Evaluating risk for atherosclerotic cardiovascular disease

- Aiding in the detection of Tangier disease

Studies have shown that the ratio of apolipoprotein A-1:apolipoprotein B may correlate better with increased risk of coronary artery disease (CAD) than total cholesterol, and LDL:HDL ratio.

Apolipoprotein E (APOE) is a protein that plays a crucial role in the metabolism of fats (lipids) in the body. It is primarily involved in transporting cholesterol and other lipids through the bloodstream to be used, stored, or eliminated. APOE is a key component of lipoproteins, which are molecules that carry cholesterol and fats to and from cells.

APOE is also known for its genetic variations, which can influence cholesterol levels, cardiovascular health, and even neurological function. However, in lab tests, the focus is usually on APOE levels in the blood, which may indicate how effectively the body manages lipid metabolism.

Apolipoprotein B100 (apoB100) is a building block of very low-density lipoproteins (VLDLs), intermediate-density lipoproteins (IDLs), and low-density lipoproteins (LDLs). These related molecules all transport fats and cholesterol in the bloodstream.

Cerebrospinal fluid (CSF) is a clear, watery liquid that flows around the brain and spinal cord, surrounding and protecting them. CSF testing is performed to evaluate the level or concentration of different substances and cells in CSF in order to diagnose conditions affecting the brain and spinal cord (central nervous system).

The appearance of the sample of CSF is usually compared to a sample of water.

Normal joints contain a small volume of synovial fluid that is highly viscous, clear, and essentially acellular.

Clarity: Increased opacity of the fluid is usually due to abnormally large numbers of nucleated or red blood cells (RBCs). However, translucent or even opaque fluid may be the result of acellular material. Examples include lipids in fat necrosis, chyle droplets, or innumerable monosodium urate (MSU) crystals aspirated from gouty tophi.