Autoimmunity

Antibodies that can signal the immune system targeting your own tissues, including celiac disease.

41 tests explained

Common follow-up tests

Acetylcholine Receptor (AChR) Binding AntibodyLooks for antibodies that attack the acetylcholine receptor on muscle cells. A positive result is linked to myasthenia gravis, a condition that causes muscle weakness.
ANA Pattern (ICAP)Describes how the antibodies in a positive ANA test look under a microscope, such as smooth, speckled or dotted. The pattern helps guide which tests come next.
ANA Titer (IFA)Shows how strong a positive ANA result is, written as a dilution such as 1:80 or 1:320. A bigger second number means more antibody was present.
ANCA Screen (IFA)Checks for antibodies that target neutrophils, a type of white blood cell. A positive result is linked to some forms of blood vessel inflammation and leads to more specific tests.
Anti-CCP (Cyclic Citrullinated Peptide) AntibodyMeasures antibodies against citrullinated proteins. A positive result is closely linked to rheumatoid arthritis and can appear years before joint symptoms.
Anti-Centromere B (CENP-B) AntibodyMeasures antibodies against CENP-B, a protein at the center of chromosomes. They are linked to limited systemic sclerosis (CREST) and, in some people, to primary biliary cholangitis.
Anti-dsDNA Antibody (quantitative)Antibodies that target your own DNA. A positive result is linked to lupus, and in people with lupus the level is sometimes followed over time.
Anti-Glomerular Basement Membrane (GBM) AntibodyAntibodies against a protein in the filters of your kidneys. A positive result is linked to anti-GBM disease, a rare condition that clinicians usually follow up quickly.
Anti-Mitochondrial Antibody (AMA), screen/titerAntibodies against part of the cell's energy machinery. A positive result is the best-known blood marker for primary biliary cholangitis, a chronic bile duct condition of the liver.
Anti-Mitochondrial M2 AntibodyAntibodies against the M2 part of mitochondria, measured by ELISA. They are strongly linked to primary biliary cholangitis, a chronic bile duct condition of the liver.
Anti-Parietal Cell Antibody (APCA)Antibodies against the cells that make stomach acid. They are linked to autoimmune gastritis and pernicious anemia, but also appear in people who have neither.
Anti-PLA2R Antibody (Phospholipase A2 Receptor)Antibodies against a protein on the kidney's filter cells. A positive result is strongly linked to primary membranous nephropathy, a cause of protein leaking into the urine.
Anti-Scl-70 (Topoisomerase I) AntibodyAntibodies against an enzyme called topoisomerase I. A positive result is linked to systemic sclerosis (scleroderma), especially the diffuse form of the disease.
Anti-Smith (Sm) AntibodyLooks for antibodies to the Smith (Sm) protein. A positive result is uncommon and is most closely linked with lupus.
Anti-Smooth Muscle Antibody (ASMA) titerLooks for antibodies that react with smooth muscle proteins. Mostly used when checking for autoimmune hepatitis, a liver condition. Reported as a titer.
Anti-SSA/Ro AntibodyLooks for antibodies to the Ro (SSA) protein. They are common in Sjögren's disease and lupus, and they matter for pregnancy planning.
Anti-SSB/La AntibodyLooks for antibodies to La (SSB), which often appear together with anti-Ro. They are linked to Sjögren's disease and lupus and matter for pregnancy planning.
Anti-U1-RNP Antibody (RNP)Looks for antibodies to U1-RNP. They are most closely linked with mixed connective tissue disease and can also appear in lupus and related conditions.
Anticardiolipin Antibody IgGMeasures IgG antibodies to cardiolipin, a fat in cell membranes. Levels above your lab's cutoff are one piece of testing for antiphospholipid antibodies.
Anticardiolipin Antibody IgMMeasures IgM antibodies to cardiolipin, a fat in cell membranes. Levels above your lab's cutoff are one piece of testing for antiphospholipid antibodies.
Antinuclear Antibodies (ANA) ScreenA first-step blood test that looks for antibodies to the cell nucleus. A positive result is common and does not by itself mean you have an autoimmune disease.
Aquaporin-4 (AQP4/NMO) IgGA blood test for an antibody to a water channel in the brain and spinal cord. It helps tell neuromyelitis optica spectrum disorder (NMOSD) from other nerve conditions.
Beta-2 Glycoprotein I Antibody IgGMeasures IgG antibodies against beta-2 glycoprotein I, a blood protein. It is one of the tests used when a clinician is looking into antiphospholipid syndrome (APS).
Beta-2 Glycoprotein I Antibody IgMMeasures IgM antibodies against beta-2 glycoprotein I, a blood protein. It is one of the tests used when a clinician is looking into antiphospholipid syndrome (APS).
c-ANCA (cytoplasmic) TiterA microscope test for antibodies that make a type of white blood cell glow in a cytoplasmic pattern. It is mostly linked to PR3 antibodies and to a vasculitis called GPA.
Deamidated Gliadin Peptide (DGP) IgAAn antibody test for celiac disease that looks for IgA antibodies to a modified gluten protein. It is usually a second-line test, with tTG-IgA used first.
Deamidated Gliadin Peptide (DGP) IgGAn antibody test for celiac disease that looks for IgG antibodies to a modified gluten protein. It is often chosen when a person has low or missing IgA.
ENA Screen (extractable nuclear antigens)Looks for antibodies to several proteins inside the cell nucleus at once; a positive screen is followed by tests that name the exact antibody.
Endomysial Antibody IgA (EMA)A blood test for IgA antibodies that are very specific for celiac disease, usually used to back up a positive tTG-IgA result.
GAD65 Antibody (Glutamic Acid Decarboxylase)Measures antibodies to GAD65, an enzyme in insulin-making cells and nerves; it is one of the islet antibodies used to look for autoimmune (type 1) diabetes.
IA-2 Antibody (Islet Antigen-2)Measures antibodies to IA-2, a protein in insulin-making cells, which is one of the islet antibodies used to look for autoimmune (type 1) diabetes.
Insulin Autoantibodies (IAA)Measures antibodies to insulin, used to look for autoimmune (type 1) diabetes before insulin treatment or to find antibodies to injected insulin.
Intrinsic Factor Blocking AntibodyLooks for antibodies that block intrinsic factor, a stomach protein needed to absorb vitamin B12; a positive result supports pernicious anemia.
MOG-IgG (Myelin Oligodendrocyte Glycoprotein Antibody)Looks for antibodies to MOG, a protein on the coating of nerve fibers; a clear positive can support a MOGAD diagnosis when symptoms fit.
MPO-ANCA (Anti-Myeloperoxidase Antibody)A blood test for antibodies against myeloperoxidase, a protein in white blood cells. A positive result is linked to some types of blood vessel inflammation (vasculitis).
p-ANCA (perinuclear) TiterA microscope test for antibodies that make white blood cells glow around the nucleus. It is linked to vasculitis, ulcerative colitis and some autoimmune liver conditions.
PR3-ANCA (Anti-Proteinase 3 Antibody)A blood test for antibodies against proteinase 3, a protein in white blood cells. A positive result is most linked to granulomatosis with polyangiitis, a type of vasculitis.
Rheumatoid Factor (RF)A blood test for rheumatoid factor, an antibody often found in rheumatoid arthritis but also in other conditions and in some healthy people.
Tissue Transglutaminase (tTG) IgAA blood test for antibodies to tissue transglutaminase, a gut enzyme. It is the main blood test used when celiac disease is suspected.
Tissue Transglutaminase (tTG) IgGA blood test for IgG antibodies to tissue transglutaminase, a gut enzyme. It is used for celiac disease testing mainly when IgA is low or missing.
ZnT8 Antibody (Zinc Transporter 8)A blood test for antibodies against zinc transporter 8 (ZnT8), a protein in insulin-making cells. A positive result is linked to type 1 diabetes.