Lupus and Connective Tissue Disease Markers

Lupus and connective tissue disease markers help clinicians investigate autoimmune conditions that can affect the joints, skin, muscles, lungs, kidneys, blood vessels, and other organs. This category explains the blood tests and antibody panels commonly used to support diagnosis, assess risk patterns, and monitor disease activity. Explore core tests such as antinuclear antibodies (ANA), anti-double-stranded DNA, anti-Smith, anti-chromatin, anti-nucleosome, complement C3, complement C4, and CH50. You will also find clear guidance on SSA/Ro and SSB/La antibodies in Sjögren syndrome and lupus, RNP antibodies in mixed connective tissue disease, and specialized markers linked to systemic sclerosis, including anticentromere, Scl-70, RNA polymerase III, fibrillarin, Th/To, and PM/Scl antibodies. The category also covers myositis-related antibodies such as Jo-1, MDA5, Mi-2, NXP2, TIF1-gamma, SRP, and HMGCR, including their associations with muscle inflammation, interstitial lung disease, necrotizing myopathy, and cancer risk. Broader panel guides explain how ANA, ENA antibodies, complement tests, symptoms, examination findings, and organ-specific studies work together in lupus, scleroderma, Sjögren syndrome, overlap disease, and undifferentiated connective tissue disease. Each article focuses on what the test measures, why it may be ordered, how to interpret positive or abnormal results, important limitations, and the follow-up questions to discuss with a healthcare professional.