Levels of C-Reactive Protein and Body Temperature Elevation During Neutropenia Predict Engraftment and Non-Relapse Mortality for Unrelated Single-Unit Cord Blood Transplantation in Adults.

Cord blood transplantation (CBT) presents unique challenges related to inflammation during neutropenia, such as mucosal damage, infections, and the potential development of pre-engraftment syndrome or pre-engraftment immune reaction. These factors can contribute to significant inflammation and infection shortly after CBT. However, the effect of severe inflammation during neutropenia, specifically elevated C-reactive protein (CRP) level and body temperature, on post-transplant outcomes after CBT remains unclear. This retrospective study aimed to investigate the association between maximum CRP level, maximum body temperature during neutropenia, and post-transplantation outcomes in adult patients undergoing single-unit CBT. We retrospectively evaluated the impact of maximum CRP level and maximum body temperature during neutropenia on post-transplantation outcomes in adults who underwent single-unit unrelated CBT between 1998 and 2023 at our institution. A total of 336 adult patients were included in this study. The median maximum CRP level before neutrophil recovery was 7.75 mg/dL (interquartile range [IQR], 4.70 to 12.05 mg/dL) at a median of 14 d (IQR, 8 to 16 d). The median maximum body temperature before neutrophil recovery was 39.5°C (IQR, 39.0 to 40.0°C) at a median of 15 d (IQR, 12 to 17 d). In the multivariate analysis, a maximum CRP level≥20 mg/dL was significantly associated with lower neutrophil recovery (hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.23 to 0.59; P < .001), lower platelet recovery (HR, 0.28; 95% CI, 0.16 to 0.48; P < .001), and a higher incidence of veno-occlusive disease/sinusoidal obstruction syndrome (HR, 16.42; 95% CI, 4.11 to 65.54; P < .001), which resulted in higher non-relapse mortality (NRM) (HR, 5.16; 95% CI, 2.62 to 10.15; P < .001) and worse overall survival (HR, 2.81; 95% CI, 1.66 to 4.78; P < .001). Similarly, a maximum body temperature≥40.5°C was significantly associated with lower neutrophil recovery (HR, 0.51; 95% CI, 0.33 to 0.79; P = .002), lower platelet recovery (HR, 0.55; 95% CI, 0.38 to 0.79; P = .001), higher incidence of grades III to IV acute GVHD (HR, 2.93; 95% CI, 1.24 to 6.88; P = .013), and extensive chronic GVHD (HR, 2.47; 95% CI, 1.22 to 4.97; P = .011), which resulted in higher NRM (HR, 3.43; 95% CI, 1.53 to 7.67; P = .002). Maximum CRP level and maximum body temperature during neutropenia were significantly associated with lower hematopoietic recovery and higher NRM following single-unit CBT in adults. Further studies are warranted to explore early intervention strategies aimed at preventing severe inflammation and improving post-transplant outcomes in single-unit CBT.

Prognostic Value of the Pretransplant Fibrosis-4 Index on Non-Relapse and Overall Mortality following Unrelated Single-Unit Cord Blood Transplantation in Adults.

INTRODUCTION: The fibrosis-4 (FIB-4) index is a noninvasive marker of liver fibrosis. The FIB-4 index predicts poor outcomes in patients with hepatic and non-hepatic diseases. However, the association of the FIB-4 index with mortality and liver-related clinical outcomes following cord blood transplantation (CBT) is unclear. METHODS: We retrospectively evaluated the impact of the pretransplant FIB-4 index on outcomes in 336 adults following single-unit unrelated CBT at our institution. RESULTS: In multivariate analyses, when the FIB-4 index <1.3 group was used as the reference, non-relapse mortality was significantly higher in the FIB-4 index 1.3-2.67 (hazard ratio [HR], 2.51; 95% confidence interval [CI], 1.19-5.30) and FIB-4 index >2.67 (HR, 2.34; 95% CI, 1.12-4.90) groups. Overall mortality was significantly higher in the FIB-4 index >2.67 group (HR, 1.66; 95% CI, 1.00-2.73), but with only marginal significance in the FIB-4 index 1.3-2.67 group (HR, 1.59; 95% CI, 0.96-2.64). Hematopoietic recovery, acute and chronic graft-versus-host disease of the liver, and veno-occlusive disease/sinusoidal obstruction syndrome were not associated with the pretransplant FIB-4 index. CONCLUSION: The pretransplant FIB-4 index is accurate and useful in predicting mortality in adult patients undergoing single-unit unrelated CBT.

Both Th1 and Th2 CD4 + T-Cell Lineage Infiltrations Decrease in Post-hematopoietic Stem Cell Transplantation Colon Adenoma.

PURPOSE: As long-term survival improves after allogeneic hematopoietic stem cell transplantation (HSCT), the risk for secondary solid cancers, including colon cancer, also increases. However, the pathogenesis of secondary solid cancers in post-HSCT patients remains unclear. This study aimed to investigate the involvement of local immunity in colon carcinogenesis in post-HSCT patients by assessing the infiltrating T cells in colon adenomas as premalignant lesions of colon cancer in adenoma-carcinoma sequence. METHODS: Colon adenoma samples obtained from 19 post-HSCT patients and 57 non-HSCT participants were analyzed via immunohistochemistry. Double staining of CD4/T-bet, CD4/GATA3, and CD4/FoxP3 was performed for evaluation of helper T-cell lineages (Th1, Th2, and regulatory T cells, respectively) and CD8 staining for CD8+ T cells. RESULTS: There were no significant between-group differences in the number of infiltrating CD4+ T cells and CD8+ T cells in adenomas. However, the number of both CD4+/T-bet+ and CD4+/GATA3+ T cells was significantly lower in the post-HSCT adenomas than in the non-HSCT adenomas (P = 0.0171 and 0.0009, respectively), whereas no significant differences were found in the number of CD4+/FoxP3+ cells. CONCLUSION: Although the number of infiltrating CD4+ and CD8+ T cells, and even Treg cell counts, is sufficiently recovered post-HSCT, CD4+ T-cell dysfunction due to suppressed activation and differentiation in colon adenomas might be involved in colon carcinogenesis in post-HSCT patients. Elucidating the pathogenesis will contribute to the development of effective screening and prevention programs for secondary colon cancer in post-HSCT patients.

Recipient IL-17A polymorphism rs2275913 is associated with acute graft-versus-host disease after single-unit cord blood transplantation.

BACKGROUND: Interleukin-17 (IL-17) is elevated in human inflammatory and autoimmune diseases. The polymorphism in the promoter region of the IL-17 A gene is associated with susceptibility to several inflammatory diseases, including acute graft-versus-host disease (GVHD) following allogeneic hematopoietic cell transplantation from adult donors. However, the impacts of IL-17 A polymorphism on cord blood transplantation (CBT) outcomes remain unclear. OBJECTIVE: The objective of this study was to assess the impact of IL-17 A polymorphism rs2275913 on GVHD, survival, relapse, non-relapse mortality (NRM), and hematopoietic recovery after CBT. STUDY DESIGN: We conducted a retrospective analysis of data from adult patients who underwent single-unit CBT at our institution from January 2005 to March 2023 for whose recipient or donor DNA samples were available. IL-17 A genotyping was performed using real-time polymerase chain reaction with the TaqMan® SNP genotyping assay for rs2275913. RESULTS: A total of 158 recipients and 136 donors were evaluated in this study. Multivariate analysis showed that rs2275913 GA or AA recipients were associated with increased risk of grades II to IV acute GVHD compared to GG recipients (hazard ratio [HR], 1.46; 95% confidence interval [CI], 1.00-2.13; P = 0.047). Serum IL-17 A levels at eight weeks were significantly higher in rs2275913 GA or AA recipients compared to GG. The rs2275913 polymorphism did not affect survival, relapse, NRM, or hematopoietic recovery after single-unit CBT. CONCLUSION: Our data showed recipient IL-17 A polymorphism rs2275913 was associated with the risk of grade II to IV acute GVHD in adults undergoing single-unit CBT. However, the rs2275913 polymorphism in recipients and donors did not affect survival or relapse. Thus, the polymorphism of IL-17 A rs2275913 in recipients might predict the risk of acute GVHD after single-unit CBT.

Survival impact of response within the first year in a multicenter prospective observational study of chronic GVHD in a Japanese cohort.

A prospective multicenter observational study of organ response was conducted in patients with chronic GVHD diagnosed by the NIH criteria. When response was assessed at 12 months (12 M) in 118 patients, 74.6% were classified as responders and 25.4% as non-responders. The skin and oral cavity were the most frequent organs used as the basis for determining overall response. The lungs, liver, and eyes were also used in 20% of patients. Non-response decisions at 12 M were most frequent in the lungs. A significantly higher percentage of responders than non-responders completed systemic treatment (24.3% vs. 3.3%, P = 0.02). Global scoring showed significant changes, with improvement in responders and worsening in non-responders throughout the observation period. Two-year transplant-related mortality, using the 12 M assessment as the landmark, was significantly worse in non-responders (28.5% vs. 2,7%, P = 0.0001), while the 2-year recurrence rate was equivalent (5.4% vs. 4.8%, P = 0.78). Consequently, the 2-year overall survival rate from the 12 M assessment was significantly better in responders than non-responders (95% vs. 65.3%, P = 0.0001). Our data suggests that patients who do not achieve a response within the first year should be candidates for clinical studies on chronic GVHD.

Influence of interruption of oral mycophenolate mofetil for graft-versus-host disease prophylaxis on outcomes after single cord blood transplantation.

Mycophenolate mofetil (MMF), in combination with a calcineurin inhibitor, is used as the prophylaxis for graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). Compared to intravenous methotrexate (MTX), MMF is associated with a lower incidence of mucositis and shorter time for hematopoietic engraftment but comparable incidence of acute GVHD, resulting in the preferred use of MMF for GVHD prophylaxis in elderly patients or those undergoing cord blood transplantation (CBT). Although several studies have evaluated the clinical impact of MTX omission due to toxicity after allogeneic HCT, the impact of oral MMF interruption for GVHD prophylaxis on transplant outcomes remains unclear. Therefore, in this study, we retrospectively analyzed the consecutive data of adult patients who underwent single-unit unrelated CBT and received oral MMF in combination with cyclosporine for GVHD prophylaxis at our hospital. Among the 53 patients, the planned dose of MMF was interrupted in 14 with a median of 19.5 d (range, 3-27 d) of CBT. In multivariate analysis, MMF interruption, which was treated as a time-dependent covariate, was significantly associated with poorer overall survival (hazard ratio [HR], 5.41; 95% confidence interval [CI], 2.03-14.43; P < 0.001) and higher non-relapse mortality (HR, 7.56; 95% CI, 1.99-28.79; P = 0.002). Further studies with larger cohorts are necessary to confirm the clinical significance of oral MMF interruption in GVHD prophylaxis.

Cellular and humoral immunogenicity against SARS-CoV-2 vaccination or infection is associated with the memory phenotype of T- and B-lymphocytes in adult allogeneic hematopoietic cell transplant recipients.

We conducted a cross-sectional study to evaluate cellular and humoral immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination or infection and examine how lymphocyte subpopulations in peripheral blood correlate with cellular and humoral immunogenicity in adult allogeneic hematopoietic cell transplantation (HCT) recipients. The median period from SARS-CoV-2 vaccination or infection to sample collection was 110.5 days (range, 6-345 days). The median SARS-CoV-2 spike-specific antibody level was 1761 binding antibody units (BAU)/ml (range, 0 to > 11,360 BAU/ml). Enzyme-linked immunosorbent spot (ELISpot) assay of T cells stimulated with SARS-CoV-2 spike antigens showed that interferon-gamma (IFN-γ)-, interleukin-2 (IL-2)-, and IFN-γ + IL-2-producing T cells were present in 68.9%, 62.0%, and 56.8% of patients, respectively. The antibody level was significantly correlated with frequency of IL-2-producing T cells (P = 0.001) and IFN-γ + IL-2-producing T cells (P = 0.006) but not IFN-γ-producing T cells (P = 0.970). Absolute counts of CD8+ and CD4+ central memory T cells were higher in both IL-2- and IFN-γ + IL-2-producing cellular responders compared with non-responders. These data suggest that cellular and humoral immunogenicity against SARS-CoV-2 vaccination or infection is associated with the memory phenotype of T cells and B cells in adult allogeneic HCT recipients.

Effect of IL-2 polymorphism rs2069762 on single-unit cord blood transplant outcomes.

BACKGROUND: Interleukin-2 (IL-2) is one of the most important cytokines that regulate the activation and proliferation of T cells and natural killer cells. The production of IL-2 may be affected by polymorphisms in the promoter region of the IL-2 gene (rs2069762). In allogeneic hematopoietic cell transplantation (HCT) from adult donors, rs2069762 has been associated with the incidence of acute and chronic graft-versus-host disease (GVHD). However, the impacts of IL-2 polymorphism on cord blood transplantation (CBT) outcomes remain unclear. OBJECTIVE: The objective of this study was to assess the impact of IL-2 polymorphism rs2069762 on transplant outcomes, such as hematopoietic recovery, GVHD, overall survival, relapse, and non-relapse mortality (NRM) after CBT. STUDY DESIGN: We conducted a retrospective analysis of data from adult patients who underwent single-unit CBT at our institution from November 2005 to March 2023 for whom DNA samples from recipients and donors were available. IL-2 genotyping was performed using real-time polymerase chain reaction with the TaqMan® SNP genotyping assay for rs2069762. RESULTS: A total of 143 recipient and donor pairs were included in this study. The proportion of recipient IL-2 polymorphism rs2069762 was 48 % (n = 69) for AA, 42 % (n = 60) for CA, and 10 % (n = 14) for CC. The proportion of donor IL-2 polymorphism rs2069762 was 43 % (n = 61) for AA, 48 % (n = 69) for CA, and 9 % (n = 13) for CC. In the multivariate analysis, the use of an rs2069762 CA + CC donor was associated with lower neutrophil recovery compared to an rs2069762 AA donor (hazard ratio [HR], 0.66; 95 % confidence interval [CI], 0.50-0.88; P = 0.004). Furthermore, recipients of rs2069762 CA + CC were associated with higher NRM compared to recipients of rs2069762 AA (HR, 2.32; 95 % CI, 1.01-5.34; P = 0.047). Serum IL-2 levels at 8 weeks were significantly higher in rs2069762 CA + CC recipients compared to those with rs2069762 AA recipients (P = 0.014). CONCLUSION: Our data showed that donor IL-2 polymorphism affects neutrophil recovery and recipient IL-2 polymorphism affects NRM in adults undergoing single-unit CBT. The polymorphism of IL-2 rs2069762 in recipients and donors might be associated with the clinical outcomes of single-unit CBT.

Feasibility and safety of the discontinuation of systemic immunosuppressive treatment after single-unit cord blood transplantation in adults.

We retrospectively evaluated the incidence, factors, and clinical outcomes of the discontinuation of immunosuppressive treatment (IST) after single-unit unrelated cord blood transplantation (CBT) in adults receiving cyclosporine-based graft-versus-host disease (GVHD) prophylaxis at our institute. Among the 309 patients who achieved engraftment, 247 were able to discontinue IST with a median follow-up of 121 months for survivors. The cumulative incidence of the discontinuation of IST was 46.2% at 180 days, 72.8% at 2 years, and 79.3% at 5 years post-CBT. In the multivariate analysis, discontinuation of IST after CBT was significantly associated with the requirement for steroid therapy (hazard ratio [HR]: 0.46; P < 0.001) and the recent calendar year of CBT (HR: 1.79; P < 0.001). In the conditional landmark analysis at 180 days, discontinuation of IST was not associated with the development of extensive chronic GVHD (HR: 1.00; P = 0.989), non-relapse mortality (HR: 0.49; P = 0.122), relapse (HR: 1.46; P = 0.388), or overall survival (HR: 1.91; P = 0.065). Our data showed that successful discontinuation of IST is common after single-unit CBT in adults. Discontinuation of IST did not affect subsequent outcomes, suggesting that discontinuation of IST is both feasible and safe in adults undergoing single-unit CBT.

Low urinary sodium-to-potassium ratio in the early phase following single-unit cord blood transplantation is a predictive factor for poor non-relapse mortality in adults.

Although daily higher urinary sodium (Na) and potassium (K) excretion ratio is associated with the risk of cardiovascular disease in the general population, a low Na/K ratio is associated with renal dysfunction in critically ill patients. Thus, we retrospectively analyzed the impact of daily urinary Na and K excretion and their ratio on non-relapse mortality (NRM) and overall mortality in 172 adult single-unit cord blood transplantation (CBT) patients treated at our institution between 2007 and 2020. Multivariate analysis showed that a low urinary Na/K ratio at both 14 days (hazard ratio [HR], 4.82; 95% confidence interval [CI], 1.81-12.83; P = 0.001) and 28 days (HR, 4.47; 95% CI 1.32-15.12; P = 0.015) was significantly associated with higher NRM. Furthermore, a low urinary Na/K ratio at 28 days was significantly associated with higher overall mortality (HR, 2.38; 95% CI 1.15-4.91; P = 0.018). Patients with a low urinary Na/K ratio had decreased urine volume, more weight gain, experienced more grade III-IV acute graft-versus-host disease, and required corticosteroids by 28 days after CBT. These findings indicate that a low urinary Na/K ratio early after single-unit CBT is associated with poor NRM and survival in adults.

Clinical implications of augmented renal clearance after unrelated single cord blood transplantation in adults.

Augmented renal clearance (ARC) is a phenomenon characterized by increased renal functionality, which can impact the pharmacokinetics and pharmacodynamics of antimicrobial drugs eliminated by the kidneys. It is a potential concern for infection treatment. Cord blood transplantation (CBT) is primarily impeded by delayed neutrophil recovery and immune reconstitution, thereby increasing susceptibility to infection. However, the clinical implications of ARC following CBT remain unexplored. We retrospectively assessed the influence of ARC on post-transplant outcomes at various time points in 194 adult recipients of single-unit unrelated CBT between 2007 and 2022 at our institution. ARC was observed in 52.9% of patients at 1 day, 39.8% at 15 days, and 26.5% at 29 days post-CBT. ARC was not significantly associated with bloodstream infection, acute graft-versus-host disease, or veno-occlusive disease/sinusoidal obstruction syndrome at any time point. ARC at 1 day, 15 days, and 29 days post-CBT was not significantly associated  with overall survival, non-relapse mortality, or relapse rates. These findings suggest that ARC is common in adults during the early stages of CBT, but does not discernibly influence clinical outcomes or post-CBT complications.

Pretransplantation EASIX Score Predicts Nonrelapse and Overall Mortality of Adult Patients Undergoing Single-Unit Unrelated Cord Blood Transplantation.

The Endothelial Activation and Stress Index (EASIX) is a laboratory-based score used to estimate endothelial damage occurring after hematopoietic cell transplantation (HCT). The EASIX score exhibits dynamic changes during the course of transplantation and has been identified as a predictor of nonrelapse mortality (NRM) and worse overall survival (OS) in studies focused mainly on patients who received matched related or unrelated donor allogeneic HCT. However, the role of EASIX score in the setting of cord blood transplantation (CBT) is unclear. This study examined the association between pretransplant EASIX score and post-transplantation outcomes in adult patients undergoing single-unit CBT. We retrospectively evaluated the impact of EASIX score at different time points on post-transplantation outcomes in adults following single-unit unrelated CBT between 1998 and 2022 at our institution. EASIX scores were calculated at the start of conditioning (EASIX-PRE), at day 30 post-CBT (EASIX-d30), at day 100 post-CBT (EASIX-d100), and at the onset of grade II-IV acute graft-versus-host disease (GVHD) (EASIX-GVHD II-IV). A total of 317 patients were included in this study. In the multivariate analysis, log2-EASIX-PRE (continuous variable) was significantly associated with lower risks of neutrophil engraftment (hazard ratio [HR], .87; 95% confidence interval [CI], .80 to .94; P < .001) and platelet engraftment (HR, .91; 95% CI, .83 to .99; P = .047), lower risk of grade II-IV acute GVHD (HR, .85; 95% CI, .76 to .94; P = .003), and higher risk of veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) (HR, 1.44; 95% CI, 1.03 to 2.02; P = .032). Log2-EASIX-PRE also was significantly associated with higher NRM (HR, 1.42; 95% CI, 1.08 to 1.86; P = .011) and worse OS (HR, 1.26; 95% CI, 1.08 to 1.46; P = .003), but not with relapse (HR, 1.02; 95% CI, .88 to 1.18; P = .780). Similarly, log2-EASIX-d30 (HR, 1.60; 95% CI, 1.26 to 2.05; P < .001), and log2-EASIX-d100 (HR, 2.01; 95% CI, 1.63 to 2.48; P < .001) were also significantly associated with higher NRM, but log2-EASIX-GVHD II-IV was not (HR, 1.15; 95% CI, .85 to 1.55; P = .360). Pretransplantation EASIX score is a powerful predictor of engraftment, VOS/SOS, NRM, and OS in adult patients undergoing single-unit unrelated CBT who mainly received intensified conditioning regimens. EASIX is an easily evaluable and dynamic prognostic score for accurately predicting post-transplantation outcomes in patients at any time during the course of allogeneic HCT, particularly for CBT.

Higher Cryopreserved CD34+ Cell Dose Is Associated with Decreased Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome after Single-Unit Cord Blood Transplantation in Adults Given Prophylactic Ursodeoxycholic Acid and Intravenous Heparin.

Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is one of the most serious complications to occur early after allogeneic hematopoietic cell transplantation (HCT). However, detailed data on VOD/SOS after cord blood transplantation (CBT) are not available. The objective of this retrospective study was to evaluate the incidence, risk factors, and clinical impact of VOD/SOS after single-unit unrelated CBT for adult patients at our institution. We retrospectively evaluated the incidence, risk factors, and outcomes of VOD/SOS after 390 single-unit unrelated CBTs performed in 332 adults under a prophylactic strategy of ursodeoxycholic acid (UDCA) and i.v. heparin at our institution between 1998 and 2021. VOD/SOS was observed in 24 of the 390 CBTs. The cumulative incidence of VOD/SOS was 5.9% at 30 days and 6.2% at 100 days after CBT. Multivariate analysis showed that cryopreserved CD34+ cell dose ≥1.0 × 105/kg was significantly associated with a decreased risk of VOD/SOS after CBT (hazard ratio [HR], 0.33; 95% confidence interval [CI], 0.12 to 0.91; P = .032). In multivariate analysis, the development of VOD/SOS was significantly associated with higher overall mortality (HR, 6.19; 95% CI, 3.61 to 10.65; P < .001), treatment failure (HR, 4.79; 95% CI, 2.95 to 7.76; P < .001), and nonrelapse mortality (HR, 12.60; 95% CI, 6.90 to 23.00; P < .001). Our study shows that the incidence of hepatic VOD/SOS was relatively low after unrelated single-unit CBT under a prophylactic strategy of UDCA and i.v. heparin. A higher cryopreserved cord blood CD34+ cell dose was associated with a reduction in VOD/SOS, suggesting that selection of a higher cord blood unit CD34+ cell dose could be efficient in preventing hepatic VOD/SOS in adults undergoing single-unit CBT.

Longitudinal proteomics study of serum changes after allogeneic HSCT reveals potential markers of metabolic complications related to aGvHD.

Even though hematopoietic stem cell transplantation (HSCT) allows successful treatment for many malignant and non-malignant disorders, its curative potential remains limited by severe side effects, including infections and other transplant-related complications such as graft-versus-host disease (GvHD). This study examined changes in serum proteome via high-performance two-dimensional gel electrophoresis (2-DE) during HSCT to search for diagnostic biomarkers for post-HSCT complications. Longitudinal proteomic analysis revealed proteins related to metabolic complications and hemolytic anemia. Retinol-binding protein 4 (RBP4), a reliable marker of insulin resistance, was identified, and is possibly associated with the onset mechanism of acute graft-versus-host disease (aGvHD) and/or skin GvHD. Although the cause of insulin resistance is not fully understood, it is thought to be associated with adipocytes inflammation induced by RBP4, iron overload and hemolytic anemia after HSCT, as observed in this study. The present study has demonstrated that insulin resistance and metabolic complications could be immediate complications after transplantation and are associated with aGvHD. The biomarkers revealed in this study are promising tools to be used for improving the early diagnosis of HSCT-associated complications, especially aGvHD, possibly even before clinical manifestations.

Optimal time and threshold of absolute lymphocyte count recovery as a prognostic factor after single-unit cord blood transplantation in adults.

We retrospectively evaluated the optimal time and threshold of absolute lymphocyte count (ALC) recovery as a prognostic factor in 174 adult patients who received single-unit cord blood transplantation (CBT) at our institute. We analyzed the impact of ALC ≥300, ≥600, and ≥900/µl by 30 and 60 days on transplant outcomes. Multivariate analysis showed that only ALC ≥300/µl at 60 days was significantly associated with overall mortality (hazard ratio, 0.24; p = 0.001) following CBT. The optimal time point to use ALC recovery as a prognostic tool following CBT could be later than those following adult donor transplantation.