Graft-versus-Host-Disease after Double Cord Blood Transplantation: A New Look at Its Characteristics

Abstract

Umbilical cord blood transplantation (UCBT) has become a widely available and accepted alternative stem cell source for pediatric and adult patients with malignant and nonmalignant hematologic diseases [1-4]. Over the last several years, multiple studies have reported lower rates of graft-versus-host disease (GVHD), both grade III-IV acute GVHD (aGVHD) and chronic GVHD (cGVHD), in UCBT recipients compared with recipients of unrelated donor peripheral blood or bone marrow hematopoietic cell transplantation (HCT) [5-7]. However, the more recent decreased use of antithymocyte globulin as part of the conditioning regimen, the almost uniform use of combination cyclosporine and mycophenolate mofetil therapy for GVHD prophylaxis, and the increased use of 2 cord blood units (versus 1 unit) warrant a reevaluation of the incidence of aGVHD and cGVHD after UCBT. Furthermore, the rate of cGVHD reported after UCBT in the previous studies was determined using the traditional clinical diagnostic criteria (limited versus extensive), without taking in consideration the 2005 National Institutes of Health (NIH) consensus criteria [8]. Ponce et al. [9] conducted a single-center study in 115 pediatric and adult patients with hematologic malignancies who underwent double UCBT (dUCBT) to assess the incidence and manifestations of both aGVHD and cGVHD. The authors reported an incidence of grade II-IV acute GVHD of 53% at day þ180, which was similar to the rate previously reported by MacMillan et al. [5]. However, the data of Ponce et al. identify the gastrointestinal (GI) tract, not the skin, as the most commonly affected organ, with GI involvement in 80% of patients with grade II-IV aGVHD. This finding confirms previously reported results in a cohort of 79 pediatric UCBT recipients [10]. The propensity of isolated GI aGVHD reinforces the importance of using endoscopic biopsy for diagnosis when symptoms are limited to this single organ system.