Blood group chimerismDrexler, Camilla; Wagner, ThomasCurrent Opinion in Hematology: November 2006 - Volume 13 - Issue 6 - p 484–489 doi: 10.1097/01.moh.0000245690.54956.f3 Transfusion medicine Buy Abstract Author InformationAuthors Article MetricsMetrics Purpose of review With improved methods for detecting chimeras and growing numbers of stem cell transplantations, blood group and other forms of chimerism are observed with increasing frequency. This review will focus on the state of science and new insights into the multifaceted subject of blood group chimerism. Recent findings Recognition that the immune system tolerates chimeric cells under certain conditions has led to efforts to elucidate related immune-modulating processes. The chimeric state following transplantation of hematopoietic stem cells, as well as after solid organ transplantation, is of special interest. Also, chimerism is considered to be a potential trigger for certain autoimmune diseases. Natural chimerism is more frequent than previously recognized. Using improved laboratory techniques, investigators can often trace chimeric tissues to their origin. New therapeutic strategies have been applied after stem cell transplantation depending on the chimeric state. Also, recent research has resulted in methods for determining chimerism in maternal peripheral blood that reflect fetal blood type and certain congenital diseases. Summary The subject of human chimerism has evolved from a curiosity of nature to an important field of research and, potentially, holds the key to advancing our understanding of the fundamental mechanisms of immune tolerance. Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria Correspondence to Thomas Wagner MD, MSc, Department of Blood Group Serology and Transfusion Medicine, University Clinics of Graz, Auenbruggerplatz 3, A-8036 Graz, Austria Tel: +43 316 385 81604; fax: +43 316 385 3429; e-mail: email@example.com © 2006 Lippincott Williams & Wilkins, Inc.