Anti-Mi-2 Antibody Test: Dermatomyositis Marker and Meaning
The anti-Mi-2 antibody test looks for an immune protein strongly associated with dermatomyositis, an autoimmune disease that can inflame skin and skeletal muscle. A...
Antinuclear Antibody (ANA) Test for Lupus: Positive, Negative, Titer, and Pattern
The antinuclear antibody test is the most sensitive blood screening test for systemic lupus erythematosus, but it is not a lupus diagnosis. More than...
Anti-Nucleosome Antibody Test: Lupus Activity, Positive Result, and Meaning
The anti-nucleosome antibody test detects immune proteins directed against nucleosomes, the DNA-and-histone units that package genetic material inside cells. These antibodies are strongly associated...
Anti-NXP2 Antibody Test: Dermatomyositis Marker, Muscle Disease, and Meaning
The anti-NXP2 antibody test helps identify a dermatomyositis subgroup that can have substantial muscle weakness, swallowing problems, tissue swelling, and calcinosis. NXP2 stands for...
Anti-PM/Scl Antibody Test: Myositis, Scleroderma Overlap, and Meaning
The anti-PM/Scl antibody test helps identify an autoimmune overlap pattern that can combine inflammatory muscle disease with features of systemic sclerosis, also called scleroderma....
Anti-Ribosomal P Antibody Test: Lupus Marker, Neuropsychiatric Risk, and Meaning
The anti-ribosomal P antibody test detects autoantibodies against three related proteins on the large ribosomal subunit. These antibodies are uncommon but relatively specific markers...
Anti-RNA Polymerase III Antibody Test: Scleroderma, Kidney Crisis Risk, and Meaning
The anti-RNA polymerase III antibody test is a highly specific marker for systemic sclerosis, also called scleroderma. A positive result often points toward a...
Anti-RNP Antibody Test: Mixed Connective Tissue Disease, Lupus, and Meaning
An anti-RNP antibody test looks for immune proteins directed against ribonucleoproteins, especially the U1 small nuclear ribonucleoprotein complex. A strong anti-U1 RNP result can...
Anti-Ro52 Antibody Test: Autoimmune Disease, Myositis, Lung Disease Risk, and Meaning
An anti-Ro52 antibody test detects immune reactivity against Ro52, a protein also called TRIM21. The result can appear in many autoimmune conditions, including inflammatory...
Anti-Ro60 Antibody Test: Lupus, Sjogren Syndrome, Positive Result, and Meaning
An anti-Ro60 antibody test looks for immune proteins directed against Ro60, an RNA-binding protein involved in cellular RNA quality control and stress responses. The...
Anti-Scl-70 Antibody Test: Systemic Sclerosis, Lung Fibrosis Risk, and Meaning
The anti-Scl-70 antibody test looks for an autoantibody strongly associated with systemic sclerosis, especially the diffuse cutaneous form and interstitial lung disease. Anti-Scl-70 is...
Anti-Smith Antibody (Anti-Sm) Test: Lupus Marker, Positive Result, and Meaning
The anti-Smith antibody test is a highly specific blood marker for systemic lupus erythematosus, commonly called lupus. It detects antibodies against Smith nuclear proteins,...
Anti-SRP Antibody Test: Necrotizing Myopathy Marker and Meaning
The anti-SRP antibody test helps identify a severe autoimmune muscle disease called anti-SRP immune-mediated necrotizing myopathy. SRP stands for signal recognition particle, a cell...
Anti-SSA/Ro Antibody Test: Sjögren Syndrome, Lupus, Pregnancy Risk, and Meaning
The anti-SSA/Ro antibody test looks for autoantibodies linked most strongly to Sjögren disease and systemic lupus erythematosus. These antibodies may also appear in subacute...
Anti-SSB/La Antibody Test: Sjögren Syndrome, Lupus, Positive Result, and Meaning
The anti-SSB/La antibody test detects autoantibodies against the La protein, an RNA-binding protein found inside cells. Anti-SSB is most often seen together with anti-SSA/Ro...
Anti-Th/To Antibody Test: Systemic Sclerosis Marker and Meaning
An anti-Th/To antibody result can be useful when systemic sclerosis is suspected but the better-known antibodies—anticentromere, anti-Scl-70, and anti-RNA polymerase III—are absent. Anti-Th/To antibodies...
Anti-TIF1-Gamma Antibody Test: Dermatomyositis, Cancer Risk, and Meaning
A positive anti-TIF1-gamma antibody result can carry two different messages at once. First, it may support a diagnosis within the dermatomyositis spectrum, especially when...
Anti-U1 RNP Antibody Test: MCTD, Lupus, Overlap Disease, and Meaning
Anti-U1 RNP antibodies are central to the diagnosis of mixed connective tissue disease, but they are not exclusive to it. The same antibody can...
CH50 Test for Lupus: Complement Activity, Low Levels, and Immune Meaning
The CH50 test asks a functional question: can the proteins in the classical complement pathway work together to complete a full immune reaction? In...
Complement C3 Test for Lupus: Low Levels, Disease Activity, Flares, and Kidney Risk
Complement C3 is one of the laboratory markers clinicians follow in systemic lupus erythematosus because it sits at the center of the complement system....