TY - CHAP U1 - Buchbeitrag A1 - Singh, Anjana A1 - Blank, Miri A1 - Shoenfeld, Yehuda A1 - Illges, Harald T1 - Antiphospholipid Syndrome Patients Display Reduced Titers of Soluble CD21 in Their Sera Irrespective of Circulating Anti-β2-Glycoprotein-I Autoantibodies T2 - Zacharias, terHorst et al. (Hg.): Forschungsspitzen und Spitzenforschung. Innovationen an der FH Bonn-Rhein-Sieg, Festschrift für Wulf Fischer N2 - A soluble form of the complement receptor CD21 (sCD21) is shed from the lymphocyte surface. The sCD21 is able to bind all known ligands such as CD23, sCD23, Epstein-Barr virus and C3d in immune complexes. Here, we show the serum levels of sCD21 in sera the of antiphospholipid syndrome (APS) patients. Antiphospholipid syndrome is an autoimmune disorder in which autoantibodies cause heart attack, stroke and miscarriage. Antiphospholipid syndrome may appear as primary or in association with systemic lupus erythromatosus (SLE) and other autoimmune diseases. Here, we ask whether APS patients have different sCD21 titers compared to healthy persons and whether sCD21 levels correlate with the presence of anti-β2-GPI autoantibodies. We show that autoimmune APS patients have significantly reduced amounts of sCD21 in their sera, irrespective of the presence of anti-β2-GPI autoantibodies. In our APS patients cohort additional SLE, vasculities, DVT (deep vein thrombosis), fetal loss or thrombosis did not correlate to the reduced level of sCD21. Y1 - 2009 SN - 978-3-7908-2126-0 SB - 978-3-7908-2126-0 U6 - https://doi.org/10.1007/978-3-7908-2127-7_30 DO - https://doi.org/10.1007/978-3-7908-2127-7_30 SP - 339 EP - 348 PB - Physica-Verlag CY - Heidelberg ER -