Autoantibodies Profile 1 Blood Test

Antinuclear antibodies (ANA) are autoantibodies produced when the immune system fails to distinguish between its own cells and foreign invaders. ANA target proteins inside the body's own healthy cells and may be associated with inflammation, joint pain, and fatigue. These antibodies are associated with systemic autoimmune conditions including systemic lupus erythematosus (SLE), Sjögren's syndrome, mixed connective tissue disease, and scleroderma. Found in approximately 95% of people with lupus. However, ANA can also be found in 10-15% of healthy individuals, particularly women and older adults, so a positive result does not automatically confirm autoimmune disease. Levels outside the reference range may require further clinical investigation with your GP.

Thyroid peroxidase (TPO) antibodies target TPO, an enzyme essential for producing thyroid hormones T4 and T3, which regulate metabolism, energy, body temperature, and heart rate. TPO antibodies are associated with Hashimoto's thyroiditis (underactive thyroid, which may cause fatigue, weight gain, cold sensitivity, dry skin, hair loss, and depression) and Graves' disease (overactive thyroid, which may cause weight loss, rapid heartbeat, anxiety, tremors, and heat sensitivity). Found in 90-95% of Hashimoto's cases and 70-80% of Graves' disease cases. TPO antibodies can also appear in 10-15% of healthy individuals. Levels outside the reference range may require further clinical investigation with your GP.

Gastric parietal cell antibodies target parietal cells in the stomach that produce stomach acid and intrinsic factor, a protein essential for vitamin B12 absorption. Damage to these cells may be associated with reduced stomach acid and impaired B12 absorption, leading to vitamin B12 deficiency. These antibodies are associated with autoimmune gastritis and pernicious anaemia. Symptoms may include fatigue, weakness, pale skin, shortness of breath, numbness or tingling in extremities, memory problems, and digestive issues. Found in 85-90% of people with pernicious anaemia. Levels outside the reference range may require further clinical investigation with your GP.

Mitochondrial antibodies (AMA) target the mitochondria, which are the energy-producing structures within cells. These antibodies are highly specific for primary biliary cholangitis (PBC), an autoimmune condition that causes progressive damage to the small bile ducts in the liver. PBC may be associated with fatigue, itching, dry eyes, dry mouth, and eventually jaundice and liver damage if untreated. Found in approximately 95% of people with PBC and can be detected years before symptoms develop. Testing for AMA helps identify PBC early, allowing treatment to slow disease progression and prevent complications. A positive result is highly suggestive of PBC. Levels outside the reference range may require further clinical investigation with your GP.

Smooth muscle antibodies (SMA) are autoantibodies that target proteins in smooth muscle cells, which are found in many organs including blood vessels and the digestive tract. These antibodies are primarily associated with autoimmune hepatitis type 1, the most common form of autoimmune hepatitis, where the immune system affects liver cells. SMA can also be found at low levels in other autoimmune conditions and sometimes in healthy individuals. Autoimmune hepatitis may be associated with fatigue, abdominal discomfort, joint pain, jaundice, and abnormal liver function tests. Levels outside the reference range may require further clinical investigation with your GP.

LKM antibodies (liver kidney microsomal antibodies) are autoantibodies that target enzymes found in liver and kidney cells. They are associated with autoimmune hepatitis type 2, a condition where your immune system affects the liver. This form of autoimmune hepatitis is less common than type 1 and typically affects children and young adults. Symptoms may include fatigue, abdominal pain, jaundice, joint pain, and abnormal liver function tests. Testing for LKM antibodies helps distinguish autoimmune hepatitis type 2 from type 1 and other liver conditions, enabling appropriate treatment to prevent progressive liver damage. Levels outside the reference range may require further clinical investigation with your GP.