Pretransplant serum FT3 levels in recipients predict early non-relapse mortality after myeloablative allogeneic haematopoietic cell transplantation from matched sibling donors.

OBJECTIVES: Although decreased thyroid function is negatively correlated with clinical outcomes in critically ill patients, its role in allogeneic haematopoietic cell transplantation (allo-HCT) has not been sufficiently described.

METHODS: The associations between pre-conditioning thyroid hormone concentrations and transplant-related complications in 474 adult patients with haematologic malignancies who underwent myeloablative allo-HCT were assessed.

RESULTS: A receiver-operating characteristic curve showed that the baseline serum-free triiodothyronine 3 (FT3) level had an excellent predictive value for non-relapse mortality (NRM) within 100 days in sibling HCT with an area under the curve of 0.73 [95% confidence interval (CI), 0.64-0.82]. With a cut-off value of 4.7 pmol/l, the sensitivity and specificity for early NRM were 68% and 73%, respectively. The cumulative incidences of early NRM within 100 days after sibling HCT were 14% (95% CI, 10-18%) in the low FT3 group and 6% (95% CI, 4-8%) in the high-FT3 group (p = 0.033). In multivariate analysis, a lower FT3 level was significantly associated with high early NRM (HR = 3.19, 95% CI, 1.13-9.03, p = 0.029). The difference was also significant at 3 years after HCT (24% vs. 14%, p = 0.046). Recipients with lower FT3 levels also had a trend towards a lower OS at 3 years after HCT (66% vs. 72%, p = 0.235), although the difference did not reach statistical significance.

CONCLUSION: A low FT3 level before conditioning may be a useful predictive biomarker for higher early NRM among patients undergoing myeloablative sibling transplantation.