Comprehensive evaluation of taste dysfunction in allogeneic hematopoietic cell transplant recipients: a combined subjective and objective assessment

PURPOSE: Taste dysfunction is a common but underrecognized complication in patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT). Taste dysfunction can adversely affect oral intake, nutritional status, and overall quality of life. This study aimed to comprehensively evaluate taste function in allo-HCT recipients using both objective and subjective measures and to identify clinical factors associated with taste disturbances. METHODS: We conducted a prospective observational study of 21 adult allo-HCT recipients. Taste function was assessed at two time points (pre-conditioning and pre-discharge) using the whole-mouth taste testing method for the five basic tastes and the Chemotherapy-induced Taste Alteration Scale (CiTAS). All 21 patients completed the CiTAS, and 19 patients underwent whole-mouth taste testing. RESULTS: Most patients exhibited objective taste dysfunction before transplantation, particularly for sweet, salty, sour, and bitter taste qualities. The objective taste thresholds remained stable post-transplantation, but the subjective CiTAS scores worsened for basic taste, general alterations, and discomfort. There was a trend (p = 0.057) for objective umami taste to be better preserved in patients with gastrointestinal graft-versus-host disease (GI-GVHD). Oral mucositis was associated with higher phantogeusia/parageusia scores, while high malnutrition risk or weight loss correlated with lower subjective symptom scores. CONCLUSION: The discrepancy between subjective and objective assessments of taste dysfunction highlights that taste perception is regulated by multifactorial and complex mechanisms. Intensive supportive care, which is often provided to severely ill patients, may offer psychological reassurance that indirectly improves self-reported taste symptoms. Whether umami sensitivity is influenced by systemic factors such as GI-GVHD requires further study.