Taste alterations after hematopoietic cell transplantation: a scoping review

Purpose: This review aimed to evaluate the prevalence and characteristics of dysgeusia after hematopoietic cell transplantation (HCT). Methods: A literature search (in PubMed, Embase.com and Web of Science) for clinical studies evaluating taste before and after HCT was performed up to June 22, 2023, in collaboration with a medical information specialist. After title and abstract review (N = 807) followed by full-text review (N = 61), articles that met the inclusion criteria were summarized in a table and synthesized narratively. Results: 11 articles were analyzed in this review. All studies had a prospective design and patient populations included children (N = 3) and adults (N = 8) undergoing allogeneic or autologous HCT. Taste was assessed objectively (N = 6) and/or subjectively (N = 8) between baseline and 12 months after HCT. Before HCT, the self-reported (0–31%) and objective (2.4–10%) prevalence of dysgeusia was low. During the neutropenic phase, self-reported (20–100%) and objective (21.4%) dysgeusia was highest. In the post-engraftment period, the self-reported (18%) and objective (0–33%) prevalence of dysgeusia decreased. Different taste qualities were assessed in six studies including salt, sour, bitter, sweet, and umami. Conclusions: Some patients undergoing HCT experience dysgeusia prior to treatment. During the neutropenic phase, they had highest complaints, with recovery occurring in the post-engraftment period. All basic tastes, except bitter, were affected. Umami and salt were most affected during treatment. These findings have implications for patient management.