ORIGINAL ARTICLE Outpatient allografting using non-myeloablative conditioning: the Mexican experience OG Cantu´-Rodrı´guez 1 , JC Jaime-Pe´rez 1 , CH Gutie´rrez-Aguirre 1 , O Gonza´lez-Llano 1 , C Mancı´as-Guerra 1 , LC Tarı´n-Arzaga 1 , GJ Ruiz-Delgado 1 , CC Sandoval-Villa 1 , J Marfil-Rivera 1 , A Morales-Toquero 2 , GJ Ruiz-Argu¨elles 2 and D Go´mez-Almaguer 1 1 Servicio de Hematologı´a,Hospital Universitario ‘Dr Jose´Eleuterio Gonza´lez’, Universidad Auto´nomade Nuevo Leo´n, Nuevo Leo´n, Me´xico and 2 Centro de Hematologı´a y Medicina Interna de Puebla, Puebla, Me´xico A group of 132 patients with both malignant and nonmalignant conditions was allografted using the ‘Mex- ican’ method of non-ablative conditioning. The condition- ing was delivered on an outpatient basis and the procedure was planned to be conducted on outpatients in all cases. While 103 patients (78%) were able to complete the procedure totally as outpatients, 29 (22%) were hospita- lized because of fever, mucositis or acute graft-versus-host disease. In a multivariate analysis, although differences were not statistically significant, it was found that the patients who were allografted as outpatients had higher levels of hemoglobin (12 versus 11.8 g/dl), higher platelet counts (248 versus 191  10 9 /l), lower white blood cell counts (11.7 versus 12.4  10 9 /l), higher Karnofsky scale scores (100 versus 90%) and lower creatinine levels (0.9 versus 0.93 mg/dl). A total of 86% of the patients with normal values for these variables could be allografted as outpatients, whereas only 67% of those with abnormal values completed the entire procedure as outpatients. It is concluded that allografting can be accomplished totally on an outpatient basis using the ‘Mexican’ reduced intensity- conditioning regimen. Bone Marrow Transplantation (2007) 40, 119–123; doi:10.1038/sj.bmt.1705700;publishedonline28May2007 Keywords: outpatient; allogeneic; stem cell allografting; non-myeloablative Introduction Traditionally,allogeneichematopoieticstemcelltransplant- ation has relied on intensive and toxic cytoreductive conditioning therapy, thus requiring 3–5 weeks of hospita- lization for the treatment and management of various complications. The cost of this procedure is beyond the reach of the majority of patients in the developing world; 1 furthermore, in Mexico, there are few hospitals with the traditional bone marrow transplantation unit designed to perform myeloablative allogeneic stem cell transplantation (ASCT). ASCT using reduced intensity conditioning or non-myeloablative stem cell transplantation (NST) has been developed to induce host versus graft transplantation tolerance with fast engraftment of donor stem cells and subsequently graft-versus-host and graft-versus-tumor effect. 2,3 NST can be used in elderly individuals and other high-risk patients otherwise excluded from conventional allografting; furthermore, as it is more affordable, NST has become the method of choice in locations with limited resources. 4 SeveralmethodsofconductingNSThavebeendescribed worldwide; we have used the ‘Mexican’ method for the last 8 years. 5 NST can be accomplished partially or totally on an outpatient basis because it leads to less toxicity; therefore neutropenia and the risk of infection are reduced. 6 In a country like Mexico, where a significant percentageofthepopulationdoesnothaveaccesstopublic social security or to sufficient funds to cover the cost of transplantation,theconceptofemployingcheapereffective proceduresisveryimportanttoreachthegoalofcuringas many patients as possible. One hundred and thirty-two patients were allografted using the ‘Mexican’ method. All of the procedures were started on outpatients, but some individuals had to be admitted to the hospital. In this article, we describe our experience and analyze certain characteristics of patients who were allografted totally as outpatients and compare themwiththosewhowerenot,toidentifyvariables,which could enable us to predict the feasibility of completing the allograft totally on an outpatient basis. Materials and methods Patients and donors ThestudyaccruesallthepatientsgivenanallogeneicHSC transplant consecutively at the Hospital Universitario ‘Dr Jose E Gonzalez’ (Monterrey, Mexico) and at the Centro de Hematologı´a y Medicina Interna de Puebla (Puebla, Received 15 January 2007; revised 13 March 2007; accepted 21 March 2007; published online 28 May 2007 Correspondence: Dr D Go´mez-Almaguer, Servicio de Hematologı´a, Hospital Universitario UANL, Parı´s 3029 Col.Cumbres CP64610, Monterrey, Nuevo Leo´n , Me´xico. E-mail: dr_gomez@infosel.net.mx Bone Marrow Transplantation (2007) 40, 119–123 & 2007 Nature Publishing Group All rights reserved 0268-3369/07 $30.00 www.nature.com/bmt