Pretransplantation Plasma ST2 Level as a Prognostic Biomarker of 1-Year Nonrelapse Mortality in Allogeneic Hematopoietic Cell Transplantation.

Soluble ST2 is established as a prognostic biomarker of nonrelapse mortality (NRM) when measured early after allogeneic hematopoietic cell transplantation (HCT). However, less is known about the prognostic value of ST2 measured before transplantation. We hypothesized that pretransplantation plasma ST2 level was associated with 1-year NRM and could add to our current prognostic assessment. Moreover, we aimed to investigate the associations between pretransplantation plasma ST2 levels and patient characteristics and other plasma biomarkers and to reproduce previous associations between post-transplantation plasma ST2 levels and outcomes of HCT. We conducted this cohort study of 374 adults who underwent allogeneic HCT at our center between July 2015 and December 2019 (median age, 59 years; 55% with a nonmyeloablative conditioning regimen). ST2 levels were measured by enzyme-linked immunosorbent assay in stored plasma samples obtained at a median of 23 days before HCT and also in samples obtained on days +7 and +14 post-HCT. A logistic regression model of 1-year NRM was fitted using an a priori defined set of covariates consisting of age, Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI), and conditioning intensity (myeloablative versus nonmyeloablative), to which the pretransplantation ST2 level was added as a variable to assess its incremental prognostic value. Models also were fitted of 1-year all-cause mortality, relapse, and grade II-IV acute graft-versus-host disease (GVHD) for pretransplantation and post-transplantation ST2 levels. The median pretransplantation plasma ST2 level was 20.4 ng/mL (interquartile range, 15.2 to 27.2 ng/mL). Pretransplantation ST2 levels were higher in males compared with females (median, 22.2 ng/mL versus 18.1 ng/mL; P < .001) and were correlated with HCT-CI (Spearman ρ = .18; P < .001), body mass index (ρ = .10; P = .05), and plasma levels of C-reactive protein (ρ = .34; P < .001), creatinine (ρ = .17; P = .001), and albumin (ρ = -.17; P < .001). Pretransplantation ST2 levels added prognostic information about 1-year NRM to age, HCT-CI, and conditioning intensity (adjusted odds ratio [OR] of 1-year NRM per 10 ng/mL increase in ST2, 1.32; 95% confidence interval [CI], 1.05 to 1.65; P = .02). Although adding pretransplantation ST2 levels did not notably improve model discrimination (.674 to .675, ΔAUC = .001), it increased the diversity of the predicted risks (P = .02, likelihood ratio test). Pretransplantation ST2 levels also were prognostic of 1-year all-cause mortality (adjusted OR per 10-ng/mL increase, 1.23; 95% CI, 1.02 to 1.48; P = .03), but not of relapse (P = .47) or acute GvHD (P = .81). Plasma ST2 levels at day +7 were prognostic of 1-year NRM, all-cause mortality, relapse, and acute GVHD, whereas levels at day +14 were prognostic of 1-year NRM and all-cause mortality. Our results show that pretransplantation plasma ST2 levels added prognostic information about 1-year NRM to age, HCT-CI, and conditioning intensity, and suggest that ST2 has potential as a biomarker of pretransplantation vulnerability and should be considered in future developments of prediction models of NRM after allogeneic HCT.

Pulmonary function is a strong predictor of 2-year overall survival and non-relapse mortality after allogenic hematopoietic cell transplantation.

OBJECTIVES: The purpose of the study was to assess the validity of the hematopoietic cell transplantation-specific comorbidity index (HCT-CI) and of pulmonary comorbidity prior to HCT in terms of predicting non-relapse mortality (NRM) and overall survival (OS). METHODS: In this retrospective single-center study of 663 consecutive adult recipients of HCT, we stratified patients into groups by pulmonary comorbidity: low-risk, intermediate-risk, and high-risk. The predictive value of this pulmonary comorbidity score (PCS) was compared to HCT-CI. RESULTS: In univariate analysis, the HCT-CI and the PCS were associated with OS after transplantation when comparing patients in high-risk groups with patients in low-risk groups. Using the PCS, the hazard ratios (HRs) of the 2-year OS in the entire population and in the myeloablative conditioning (MAC) group were 1.98 (p < .001) and 3.27 (p < .001), respectively, whereas the HRs using the HCT-CI were 1.83 (p < .001) and 2.57 (p = .002). The 2-year NRM incidence in the three risk-groups in the entire population was significant using both indexes. In the MAC group, the 2-year NRM was significant using the PCS (p = .003), but not using the HCT-CI (p = .23). CONCLUSIONS: Our study suggest that pulmonary function alone is a strong predictor of 2-year OS and NRM after HCT.

Pre-transplantation vitamin E levels and acute graft-versus-host disease after non-myeloablative allogeneic hematopoietic cell transplantation.

BACKGROUND: Low pre-transplantation plasma vitamin E levels have been associated with increased risk of acute graft-versus-host disease (GvHD) after myeloablative allogeneic hematopoietic cell transplantation (allo-HCT). We aimed to investigate the association between pre-transplantation plasma vitamin E levels and acute GvHD in patients undergoing allo-HCT with non-myeloablative conditioning. METHODS: In a cohort of 194 adults who underwent non-myeloablative allo-HCT at Rigshospitalet between July 2015 and December 2019, we measured pre-transplantation plasma vitamin E levels by high-performance liquid chromatography in stored plasma samples. Univariable ordinary least squares linear models were used to investigate associations between vitamin E levels and patient characteristics. A multivariable logistic regression model was used to estimate the association between vitamin E levels and grade II-IV acute GvHD, adjusted for recipient age, donor age, female-male donor-recipient pairing, and donor type. RESULTS: The median (Q1, Q3) pre-transplantation plasma vitamin E level was 32.3 (26.4, 40.4) µmol/L. No patients had a vitamin E level below the normal reference range. Vitamin E levels were higher in females (mean difference: 8.0 µmol/L, 95% confidence interval [CI]: 4.9, 11.1 µmol/L) and in patients transplanted for acute leukemia (mean difference: 6.2 µmol/L, CI: 3.0, 9.4 µmol/L). Grade II-IV acute GvHD developed in 33 (17%) patients. Patients who developed acute GvHD had similar pre-transplantation vitamin E levels compared with patients who did not develop grade II-IV acute GvHD (mean difference: 0.7 µmol/L, bootstrap CI: -3.3, 4.7 µmol/L). In the adjusted logistic regression model, an increase in the pre-transplantation vitamin E level from 26.4 (Q1) to 40.4 (Q3) µmol/L was associated with an odds ratio of grade II-IV acute GvHD of 1.17 (CI: 0.64, 2.12). CONCLUSIONS: Contrary to the previously reported association between pre-transplantation vitamin E levels and acute GvHD after myeloablative allo-HCT, we did not find support for an association in patients who received non-myeloablative conditioning. The potential protective effects of vitamin E may not be efficacious in the reduced inflammatory response following non-myeloablative conditioning.