title: Characteristics of photopheresis treatments for the management of rejection in heart and lung transplant recipients.
abstract: Photopheresis has been used in the management of rejection of heart and/or lung transplants. Although its mechanism of action remains unknown, irradiated T-helper cell-induced immunosuppression is the main theory. Since transplant recipients are often lymphopenic and lymphocytes are the target cells in phototherapy, we performed this study to determine which factors affect the cellular yield to undergo irradiation. We reviewed the records of all photophereses performed in our institution between July 1998 and April 2000 using the UVAR (first generation) or XTS (second generation) instruments (Therakos, Exton, PA). Our data included patient's blood volume, absolute lymphocyte count and hematocrit, catheter type, flow rate of collection cycles and centrifuge bowl size, as well as volume, hematocrit, and lymphocyte count of the cell suspension. With a mixed model multivariate analysis we sought to determine which variables predicted the lymphocyte yield. A total of 406 procedures in 25 adult patients was analyzed. There was no significant difference between the lymphocyte yield among the procedures performed with the first- and the second-generation instruments. The patient's absolute lymphocyte count was the only parameter, which positively correlated with the total number of lymphocytes collected for irradiation (P < 0.0001). Indeed, based on the mixed model, the total number of lymphocytes for irradiation can be predicted from the pre-procedure lymphocyte count. Additional studies are necessary to correlate the number of treated cells with patient outcome.
authors.affiliation: Department of Pathology, University of Alabama at Birmingham Hospital, 619 South 19th Street, Birmingham, AL 35233, USA.
authors.forename: Hanh M
authors.initials: HM
authors.lastname: Khuu
authors.forename: Renee
authors.initials: R
authors.lastname: Desmond
authors.forename: Shu T
authors.initials: ST
authors.lastname: Huang
authors.forename: Marisa B
authors.initials: MB
authors.lastname: Marques
mesh_terms: D000328:Adult; D000368:Aged; D003432:Cross-Linking Reagents / Q000494:pharmacology; D005260:Female; D006084:Graft Rejection / Q000097:blood / Q000276:immunology / Q000628:therapy*; D016027:Heart Transplantation; D016041:Heart-Lung Transplantation; D006801:Humans; D007165:Immunosuppression Therapy / Q000379:methods*; D007937:Leukapheresis; D016040:Lung Transplantation; D018655:Lymphocyte Count; D017710:Lymphocyte Transfusion; D008214:Lymphocytes / Q000187:drug effects / Q000528:radiation effects; D008297:Male; D008730:Methoxsalen / Q000494:pharmacology; D008875:Middle Aged; D018448:Models, Immunological; D017893:Photopheresis / Q000295:instrumentation; D012189:Retrospective Studies; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D008730:Methoxsalen