CD34+ selection and the severity of oropharyngeal mucositis in total body irradiation-based allogeneic stem cell transplantation

Objective: The purpose of the present study was to evaluate the impact of ex vivo T cell depleted (TCD) by CD34+ selection on the incidence and severity of oropharyngeal mucositis (OM) after myeloablative allogeneic stem cell transplant (allo-SCT) with total body irradiation (TBI) conditioning. This approach has the advantage of avoiding methotrexate for graft versus host disease (GVHD) prophylaxis. Patients and Methods: We analyzed the incidence and severity of OM in a cohort of 105 consecutive patients who underwent CD34+ selected (peripheral blood stem cells (PBSCs) from human leukocyte antigen (HLA)-identical siblings) allo-SCT with total body irradiation (TBI) conditioning. OM was graded by the World Health organization (WHO) and the Bearman regimen-related toxicity (RRT) scales. Results: The incidence of WHO grade 3–4 OM was 34.3 %. There were no cases of grade 3–4 OM by the RRT scale. Significant correlation was found between the severity of OM and the use of intravenous (IV) narcotic medications (r² = 0.15, p = 0.004), total parenteral nutrition (TPN; r² = 0.68, p < 0.001), and hospital length of stay (LOS) (r² = 0.12, p = 0.01). Discussion: TBI-induced OM can inflict significant morbidity in the early transplant period, and the incidence of WHO grade 3–4 OM can exceed 50 % when methotrexate is used for GVHD prophylaxis. In the CD34+ selected setting, methotrexate is avoided and the incidence of WHO grade 3–4 OM, use of TPN, and need for narcotic analgesia appear to be lower than historic evidence from standard T-replete allogeneic transplantation. Conclusion: We conclude that toxicity from OM is tolerable in CD34+ selected allo-SCT and should be prospectively measured in randomized trials comparing CD34+ selection versus T-replete transplantation.