title: Molecular detection of circulating beta-cells after islet transplantation.
abstract: Islet transplantation is a promising treatment for type 1 diabetes. However, islet grafts are submitted to multiple injuries, including immunosuppressive drug toxicity, hyperglycemia, hypoxia, unspecific inflammatory reactions, as well as allo- and autoimmune destruction. Therapeutic approaches to these damage mechanisms require early detection of islet injury, which is currently not feasible because of the lack of efficient markers. Based on the hypothesis of islet dissociation and release of islet cells into the circulation during islet injury, we designed a highly sensitive and specific molecular assay, able to detect two beta-cells per milliliter of venous blood by RT-PCR of insulin mRNA. We report that circulating beta-cells can be demonstrated up to 10 weeks after intraportal islet transplantation, as assessed after six islet grafts in four type 1 diabetic patients. Furthermore, our results suggest that the time during which circulating islet cells can be detected may depend on the graft environment and the immunosuppressive regimen. This test may allow better estimation of islet cell loss and identification of factors involved in islet graft injury.
authors.affiliation: Diabetes Unit, Department of Internal Medecine, University Hospital Geneva, Geneva, Switzerland. beate.laser@medecine.unige.ch
authors.forename: Beate
authors.initials: B
authors.lastname: Ritz-Laser
authors.forename: José
authors.initials: J
authors.lastname: Oberholzer
authors.forename: Christian
authors.initials: C
authors.lastname: Toso
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Brulhart
authors.forename: Katerina
authors.initials: K
authors.lastname: Zakrzewska
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ris
authors.forename: Pascal
authors.initials: P
authors.lastname: Bucher
authors.forename: Philippe
authors.initials: P
authors.lastname: Morel
authors.forename: Jacques
authors.initials: J
authors.lastname: Philippe
mesh_terms: D000328:Adult; D000368:Aged; D002096:C-Peptide / Q000097:blood; D002452:Cell Count; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000601:surgery*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D007328:Insulin / Q000235:genetics*; D007515:Islets of Langerhans / Q000737:chemistry / Q000473:pathology*; D016381:Islets of Langerhans Transplantation; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D002096:C-Peptide; D006442:Glycated Hemoglobin; D007166:Immunosuppressive Agents; D007328:Insulin; D012333:RNA, Messenger