The antinuclear antibody (ANA) is a defining feature of autoimmune connective tissue disease. ANAs are a class of antibodies that bind to cellular components in the nucleus, including proteins, DNA, RNA, and nucleic acid-protein complexes. ANA identification has been the foundation of diagnosis for autoimmune connective tissue disease, including systemic lupus erythematosus (SLE), Sjogren's syndrome, and polymyositis/dermatomyositis.

Nucleosome-specific T cells induce antinucleosome antibodies, anti-double-stranded deoxyribonucleic acid (dsDNA) and antihistone antibodies due to epitope spreading. Complexes of nucleosomes and antinuclear antibodies are nephritogenic because these complexes can bind via their positively charged histones to the negatively charged heparin sulfate in the glomerular basement membrane. Antinucleosome antibodies comprise autoantibodies that can bind to all accessible components of the nucleosome (i.e., dsDNA, histones, and conformational epitopes created by DNA and histones). These latter antibodies are called nucleosome-specific antibodies.

The M-type phospholipase A2 receptor (PLA2R) was identified as the major target podocyte antigen involved in adult autoimmune idiopathic membranous nephropathy

Anti-Saccharomyces cerevisiae antibodies (ASCA) had been known to be specific for Crohn's disease but it has been found in many other autoimmune diseases like systemic lupus erythematosus (SLE).

AIH-1 is characterized by the presence of anti-smooth muscle antibodies (ASMA) with specificity to Factin (AAA) and/or antinuclear (ANA) antibodies, whereas reactivity to anti-liver kidney microsome antibodies type-1 (anti-LKM1) and/or anti-liver cytosol antibodies type-1 (antiLC1) defines AIH-2 (1-4). Antibodies against soluble liver-pancreas antigens (anti-SLA/LP) were observed in some patients with AIH in association with ASMA or ANA, and in a small subset of individuals with AIH without the aforementioned autoantibodies

Antibodies (Abs) to soluble liver antigen/liver pancreas (anti-SLA/LP) are considered markers of worse prognosis and outcome in patients with autoimmune hepatitis (AIH).

Among the Coeliac Disease markers that have been identified over the years, only three are currently used in clinical practice, i.e., anti-tissue transglutaminase (atTG) IgA, anti-endomysial (EmA) IgA, and anti-deamidated gliadin (DGP) antibodies IgA and IgG.

The apelin system is a broad regulator of physiology. It consists of the apelin receptor and its two endogenous ligands, apelin and elabela (also known as Toddler). The system is a particularly appealing target for cardiovascular disease as it promotes endothelium-dependent vasodilatation, inotropy, lowers blood pressure, and increases aqueous diuresis. Activating the apelin system also has metabolic and renal benefits.

Anti-MDA-5 antibody are specifically associated with dermatomyositis, and define a skin-lung syndrome with a frequent severe disease course. Anti-TIF1-γ is also associated with dermatomyositis but its presence is frequently predictive of a cancer association whereas anti-MI2 is associated with the classical dermatomyositis. Two specific antibodies, anti-SRP and anti-HMGCR, are observed in patients with immune-mediated necrotizing myopathies and may be very useful to distinguish acquired myopathies from dystrophic muscular diseases in case of a slow onset and to allow the initiation of effective therapy.