The Eagle Biosciences Human Anti Angiotensin Receptor 1 IgG4 ELISA Assay Kit is an antibody screening test. Angiotensin II Receptor has been pre-coated onto a microtiter plate. During the first incubation the anti-Angiotensin II receptor 1-IgG4-Antibodies of the samples are immobilized on the plate. The autoantibodies are detected with a POD labeled anti-human IgG4 antibody. In the following enzymatic substrate reaction the intensity of the color correlates with the concentration and/ or avidity of anti-Angiotensin II receptor 1-IgG4-Antibody. Sample Types: serum, plasma. Range: 2.5 - 40 U/ml. Sensitivity: 2.5 U/mL. Time: 3.5 hours ? Angiotensin II is a peptide hormone which causes vasoconstriction, increased blood pressure, and release of aldosterone from the adrenal cortex. It occupies an important role in the Renin-Angiotensin-System (RAS). Angiotensin II mediates the effects through G-Protein-coupled receptors, the Angiotensin receptors. The occurrence of autoantibodies against AT1 receptor is associated with an increased risk of an immunologic rejection after an organ transplantation. The presence of AT1 autoantibodies correlate with the existence and course of Scleroderma. The Eagle Biosciences Human Anti Angiotensin Receptor 1 IgG4 Antibody Assay Kit anti-Angiotensin receptor 1-IgG4-Antibody EIA is designed for the determination of IgG4-Antibodies against the Angiotensin II receptor subtype I in serum and plasma.