Sterile Diet Causes Gut Microbiome Collapse of Cancer Patients Post Hematopoietic Cell Transplantation, But Normal Diet Recovers Them.

Though sterile diet, post-transplantation surgery is a clinical strategy for patient care to prevent the infiltration of gut pathogens, less is known about its effects on the gut microbiome. Here, the gut microbiome dynamics of leukemia patients following a 120-day "sterile-normal" diet strategy posthematopoietic cell transplantation are examined. In contrast to the traditional idea, a sterile diet leads to the lowest gut microbiota diversity (p < 0.05) and short-chain fatty acids, promoted the proliferation of potential pathogens such as Streptococcus (up by 16.93%) and Lactobacillus (up by 40.30%), and 43.32% reduction in nodes and an 85.33% reduction in edges within the microbial interaction's network. Interestingly, a normal diet allows the gut microbiome recovery and significantly promotes the abundance of beneficial bacteria. These results indicate that a sterile diet leads to a collapse of the patient's gut microbiome and promoted the proliferation of potential pathogens. This assay is a starting point for a more sophisticated assessment of the effects of a sterile diet. The work also suggests a basic principle for the re-establishment of microbial equilibrium that supplementation of microbial taxa may be the key to the restoration of the degraded ecosystem.

Pioneering cord blood transplantation in relapsed/refractory HIV-related lymphoma: a case study with concurrent intramuscular antiretroviral therapy.

A 44-year-old HIV-positive man diagnosed with diffuse large B-cell lymphoma in 2021 achieved complete remission with six cycles of R-CHOP therapy but had a relapse in November 2022. ESHAP therapy failed to induce remission, leading to complete remission with four cycles of Pola-BR therapy. Post-failure of autologous stem cell harvest, cord blood transplantation (CBT) was performed in June 2023. Notably, this case used recently approved intramuscular antiretroviral therapy (ART) with cabotegravir and rilpivirine, addressing gastrointestinal complications during CBT. This innovative use of intramuscular ART in the treatment of malignancy represents a first in the field, offering a pioneering approach to HIV-related lymphoma.

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.

Single vs double umbilical cord blood transplantation in acute leukemia: Systematic review and meta-analysis.

BACKGROUND AND AIMS: Umbilical cord blood transplantation (UCBT) has emerged as a promising treatment option for patients with acute leukemia needing hematopoietic stem cell transplantation. Both single (sUCBT) and double cord blood units (dUCBT) demonstrate potential benefits, but studies comparing their effectiveness have shown mixed results. This meta-analysis aimed to determine the comparative safety and efficacy of sUCBT versus dUCBT in acute leukemia patients. METHODS: Electronic databases were systematically examined to identify relevant studies comparing single vs double UCBT published until November 2023. Nine studies involving 3864 acute leukemia patients undergoing UCBT were included. Outcomes analyzed were acute graft-versus-host disease (GVHD), chronic GVHD, relapse, non-relapse mortality, leukemia-free survival and overall survival. Pooled risk ratios (RR) with 95% confidence intervals (CI) were calculated using a random effects model. RESULTS: The risk of Grade II-IV acute GVHD (RR 1.55, 95% CI 1.19-2.03) and Grade III-IV acute GVHD (RR 1.25, 95% CI 1.07-1.46) were significantly higher with dUCBT. Relapse risk was lower with dUCBT (RR 0.57, 95% CI 0.38-0.88) while overall survival favored sUCBT (RR 1.25, 95% CI 1.06-1.46). No significant differences were observed for chronic GVHD, non-relapse mortality or leukemia-free survival. CONCLUSION: Both single and double UCBT have potential as effective treatments for acute leukemia. The choice of treatment should consider various factors, including the risk of GVHD, relapse, and mortality. More research, especially randomized trials, is needed to provide definitive guidance on the optimal use of single and double unit UCBT in patients with acute leukemia.

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.

Two Cases of Painful Thyroiditis With Subsequent Hypothyroidism Following Cord Blood Transplant.

We report two rare cases of painful thyroiditis approximately 100 days after unrelated cord blood transplantation (CBT), which progressed to hypothyroidism. Patient one, a 45-year-old woman, developed goiter, tenderness, and thyrotoxicity on day 100 after CBT for relapsed acute lymphocytic leukemia. Scintigraphy suggested destructive thyroiditis; symptoms improved with one-month beta-blocker and prednisolone treatment. Two months later, hypothyroidism developed which required supplementation-based treatment. Patient two, a 49-year-old man, developed goiter, tenderness, and thyrotoxicosis on day 96 after CBT for acute myelogenous leukemia. Hypothyroidism developed after nonsteroidal anti-inflammatory drug treatment. Thyroiditis and hypothyroidism should be considered in patients who develop neck pain after CBT.

Nipping cytomegalovirus in the bud for umbilical cord blood transplantation.

Real data confirm an excellent toxicity profile and effectiveness of letermovir prophylaxis with decreased cytomegalovirus reactivation and resistance in umbilical cord blood transplantation for both paediatric and adult patients. Commentary on: Yan et al. Letermovir prophylaxis reduced cytomegalovirus reactivation and resistance post umbilical cord blood transplantation. Br J Haematol 2024;204:2378-2389.

Lymphocyte Crossmatch Testing or Donor HLA-DP and -DQ Allele Typing Effectiveness in Single Cord Blood Transplantation for Patients With Anti-HLA Antibodies Other Than Against HLA-A, -B, -C, and -DRB1.

Anti-human leukocyte antigen (HLA) antibodies other than those against HLA-A, -B, -C, and DRB1 are a risk factor for engraftment delay and failure, especially in cord blood transplantation (CBT). The primary objective of this study was to assess the impact of the presence of anti-HLA antibodies on CBT and to evaluate the utility of lymphocyte crossmatch testing or additional HLA-DP and -DQ typing of CB units in improving transplant outcomes. We retrospectively assessed the engraftment rates and transplant outcomes of 772 patients who underwent their first CBT at our hospital between 2012 and 2021. Donors were routinely typed for HLA-A, -B, -C, and-DRB1 alleles, and the anti-HLA antibodies of recipients were screened before donor selection in all cases. Among patients who had antibodies against other than HLA-A, -B, -C, and DRB1 (n = 58), lymphocyte crossmatch testing (n = 32) or additional HLA-DP/-DQ alleles typing of CB (n = 15) was performed to avoid the use of units with corresponding alleles. The median patient age was 57 years (16 to 77). Overall, 75.7% had a high-risk disease status at transplantation, 83.5% received myeloablative conditioning regimens, and >80% were heavily transfused. Two hundred twenty-nine of the 772 recipients (29.6%) were positive for anti-HLA antibodies. There were no statistical differences in the number of infused CD34-positive cells between the anti-HLA antibody-positive and the anti-HLA antibody-negative patients. Of the 229 patients with anti-HLA antibodies, 168 (73.3%) had antibodies against HLA-A, -B, -C, and-DRB1 (Group A), whereas 58 (25.3%) had antibodies against HLA-DP, HLA-DQ, or -DRB3/4/5 with or without antibodies against HLA-A, -B, -C, and -DRB1 (Group B). No patients in both Groups A and B exhibited donor-specific anti-HLA antibodies against HLA-A, -B, -C, and -DRB1. The neutrophil engraftment rate was lower in patients with anti-HLA antibodies than in those without antibodies (89.9% versus 94.1%), whereas nonrelapse mortality (NRM) before engraftment was higher in antibody-positive patients (9.6% versus 4.9%). In patients who received 2 or more HLA allele-mismatched CB in the host-versus-graft (HVG) direction (n = 685), the neutrophil engraftment rate was lower in the anti-HLA antibody-positive recipients than in the antibody-negative recipients with significant differences (88.8% versus 93.8%) (P = .049). Similarly, transplant outcomes were worse in the antibody-positive patients with respect to 2-year overall survival (OS) (43.1% versus 52.3%) and NRM (44.0% versus 30.7%) than in the antibody-negative patients. In contrast, the results of Group B were comparable to those of the antibody-negative patients, while those of Group A were statistically worse than the antibody-negative patients in terms of all engraftment rate (88.6%), OS (34.2%), and NRM (49.0%). The presence of anti-HLA antibodies negatively impacts engraftment, NRM, and OS in CBT. However, HLA-DP/-DQ allele typing of CB units or lymphocyte crossmatch testing could be a useful strategy to overcome poor engraftment rates and transplant outcomes, especially in patients with anti-HLA antibodies against HLA-DP, HLA-DQ, or -DRB3/4/5.

Unrelated umbilical cord blood transplantation with low-dose anti-thymocyte globulin for children with severe aplastic anemia: A case series.

OBJECTIVE: This study aimed to investigate the prognosis of unrelated umbilical cord blood transplantation (UCBT) using low-dose anti-thymocyte globulin (ATG) in children diagnosed with severe aplastic anemia (SAA). METHODS: This retrospective case series study was conducted involving pediatric SAA patients treated at the Capital Institute of Pediatrics from January 2020 to February 2023. All patients underwent a reduced-intensity conditioning (RIC) regimen alongside low-dose ATG. RESULTS: The study comprised nine patients (five males) with a median age of 5 years (range: 1.7 to 7 years). The median follow-up duration was 799 days (range: 367 to 1481 days), during which all patients survived. The median time interval from diagnosis to transplantation was 3 months (range: 1 to 9 months). The median dosage of ATG administered was 5 mg/kg (range: 2.5 to 7.5 mg/kg). The median durations for granulocyte and platelet engraftment were 15 days (range: 12 to 23 days) and 26 days (range: 12 to 41 days), respectively. Three patients experienced grade 2-4 acute graft-versus-host disease (aGVHD). Epstein-Barr virus (EBV) reactivation was observed in three patients, while cytomegalovirus (CMV) reactivation occurred in seven patients, with no cases of CMV disease or post-transplant lymphoproliferative disorder (PTLD). One patient experienced recurrence 15 months after transplantation due to influenza A infection. CONCLUSION: These findings indicate that SAA patients may attain a favorable prognosis following UCBT with a RIC regimen combined with low-dose ATG.

CAR-T from cord blood in a patient with Ph+ acute lymphoblastic leukemia relapsing after hematopoietic stem cell transplantation.

While there is intense interest in the production of allogeneic CAR-T cells from umbilical cord units, little is known about the reactivity and persistence of CAR-T cells of umbilical origin. We report the case of a patient at our hematological center with multiple relapsing Ph+ B-ALL, notably a Blinatunomab non-responder, who underwent therapy with Brexucabtagene Autoleucel following relapse on Ponatinib post-allogeneic hematopoietic stem cell transplantation. The patient achieved a rapid CAR-T expansion and durable remission presenting in good clinical conditions 6 months post-CAR-T infusion, without manifestations of graft-versus-host disease. The case report provides insight into the reactivity and persistence of CAR-T cells of umbilical origin, confirming the potential promise of allogeneic umbilical cord-derived CAR-T cells.

Letermovir prophylaxis reduced cytomegalovirus reactivation and resistance post umbilical cord blood transplantation.

To explore the impact of letermovir (LET) prophylaxis on cytomegalovirus (CMV) reactivation and resistance in both adult and paediatric umbilical cord blood transplantation (UCBT) patients, we retrospectively compared 43 UCBT patients who received LET as CMV prophylaxis with a historical cohort of 207 UCBT patients without LET usage. LET was administered from Day +1 to Day +100. The 180-day cumulative incidence of CMV reactivation (47.3% vs. 74.4%, p < 0.001) and the proportion of refractory CMV reactivation (15.0% vs. 42.9%, p = 0.016) were significantly lower than those in the control group. However, more frequent late CMV infection (31.0% vs. 4.3%, p = 0.002) and the 180-day cumulative incidence of Epstein-Barr virus (EBV) reactivation (9.3% vs. 3.4%, p = 0.087) were observed in UCBT patients with LET prophylaxis. Meanwhile, older age (>15 years old) and the occurrence of pre-engraftment syndrome were identified as the significant risk factors for CMV reactivation, and in patients at high risk, the incidence of CMV reactivation in the LET group was lower than that in the control group (46.7% vs. 86.5%, p < 0.001), while this decline was less pronounced among patients at low risk (47.8% vs. 62.1%, p = 0.120).

Umbilical Cord Blood Transplantation for Fanconi Anemia With a Special Focus on Late Complications: a Study on Behalf of Eurocord and SAAWP-EBMT.

Hematopoietic cell transplantation (HCT) remains the sole available curative treatment for Fanconi anemia (FA), with particularly favorable outcomes reported after matched sibling donor (MSD) HCT. This study aimed to describe outcomes, with a special focus on late complications, of FA patients who underwent umbilical cord blood transplantation (UCBT). In this retrospective analysis of allogeneic UCBT for FA performed between 1988 and 2021 in European Society for Blood and Marrow Transplantation (EBMT)-affiliated centers, a total of 205 FA patients underwent UCBT (55 related and 150 unrelated) across 77 transplant centers. Indications for UCBT were bone marrow failure in 190 patients and acute leukemia/myelodysplasia in 15 patients. The median age at transplantation was 9 years (range, 1.2 to 43 years), with only 20 patients aged >18 years. Among the donor-recipient pairs, 56% (n = 116) had a 0 to 1/6 HLA mismatch. Limited-field radiotherapy was administered to 28% (n = 58) and 78% (n = 160) received a fludarabine (Flu)-based conditioning regimen. Serotherapy consisted of antithymocyte globulin (n = 159; 78%) or alemtuzumab (n = 12; 6%). The median follow-up was 10 years for related UCBT and 7 years for unrelated UCBT. Excellent outcomes were observed in the setting of related UCBT, including a 60-day cumulative incidence (CuI) of neutrophil recovery of 98.1% (95% confidence interval [CI], 93.9% to 100%), a 100-day CuI of grade II-IV acute graft-versus-host disease (GVHD) of 17.3% (95% CI, 9.5% to 31.6%), and a 5-year CuI of chronic GVHD (cGVHD) of 22.7% (95% CI, 13.3% to 38.7%; 13% extensive). Five-year overall survival (OS) was 88%. In multivariate analysis, none of the factors included in the model predicted a better OS. In unrelated UCBT, the 60-day CuI of neutrophil recovery was 78.7% (95% CI, 71.9% to 86.3%), the 100-day CuI of grade II-IV aGVHD was 31.4% (95% CI, 24.6% to 40.2%), and the 5-year CuI of cGVHD was 24.3% (95% CI, 17.8% to 32.2%; 12% extensive). Five-year OS was 44%. In multivariate analysis, negative recipient cytomegalovirus serology, Flu-based conditioning, age <9 years at UCBT, and 0 to 1/6 HLA mismatch were associated with improved OS. A total of 106 patients, including 5 with acute leukemia/myelodysplasia, survived for >2 years after UCBT. Nine of these patients developed subsequent neoplasms (SNs), including 1 donor-derived acute myelogenous leukemia and 8 solid tumors, at a median of 9.7 years (range, 2.3 to 21.8 years) post-UCBT (1 related and 8 unrelated UCBT). In a subset of 49 patients with available data, late nonmalignant complications affecting various organ systems were observed at a median of 8.7 years (range, 2.7 to 28.8 years) post-UCBT. UCB is a valid source of stem cells for transplantation in patients with FA, with the best results observed after related UCBT. After unrelated UCBT, improved survival was observed in patients who underwent transplantation at a younger age, with Flu-based conditioning, and with better HLA parity. The incidence of organ-specific complications and SNs was relatively low. The incidence of SNs, mostly squamous cell carcinoma, increases with time. Rigorous follow-up and lifelong screening are crucial in survivors of UCBT for FA.

Sustained remission after cord blood transplantation for breast cancer with lung metastases and myelodysplastic syndrome.

Allogenic hematopoietic stem cell transplantation (allo-HSCT) is not a standard therapy for solid cancer because of its high toxicity and insufficient evidence levels. However, the potential graft-versus-solid-tumor (GVT) effect of this therapy has been discussed. Many case reports have also described treatment effects of allo-HSCT in patients with hematologic malignancies and active solid tumors. A 38-year-old woman treated with fulvestrant and abemaciclib for recurrent breast cancer with multiple lung metastases was diagnosed with myelodysplastic syndrome (MDS) with increased blasts 2. She was classified as adverse risk by the 2017 European LeukemiaNet risk stratification and as very high risk by the Molecular International Prognostic Scoring System. Breast cancer treatment was interrupted and venetoclax and azacitidine therapy was started. Complete hematologic response was achieved after three cycles. However, multiple lung metastases from the breast cancer remained. The patient then underwent umbilical cord blood transplantation. She has maintained complete remission of MDS as of 1 year post-transplantation, without serious complications. Lung metastatic activity on FDG-PET/CT scan also completely disappeared by half a year post-transplantation, and this response has continued as of 1 year post-transplantation. This favorable treatment course suggests the existence of a GVT effect.

Cord Blood Transplantation for Very Early-Onset Inflammatory Bowel Disease Caused by Interleukin-10 Receptor Deficiency.

PURPOSE: Interleukin-10 receptor (IL-10R) deficiency can result in life-threatening very early-onset inflammatory bowel disease (VEO-IBD). Umbilical cord blood transplantation (UCBT) is a curative therapy for patients with IL-10R deficiency. This study aimed to investigate the efficacy of UCBT in treating IL-10R deficiency and develop a predictive model based on pre-transplant factors. METHODS: Eighty patients with IL-10R deficiency who underwent UCBT between July 2015 and April 2023 were retrospectively analyzed. Cox proportional hazards regression and random survival forest were used to develop a predictive model. RESULTS: Median age at transplant was 13.0 months (interquartile range [IQR], 8.8-25.3 months). With a median follow-up time of 29.4 months (IQR, 3.2-57.1 months), the overall survival (OS) rate was 65.0% (95% confidence interval [CI], 55.3%-76.3%). The engraftment rate was 85% (95% CI, 77%-93%). The cumulative incidences of acute and chronic graft-versus-host disease were 48.2% (95% CI, 37.1%-59.4%) and 12.2% (95% CI, 4.7%-19.8%), respectively. VEO-IBD-associated clinical symptoms were resolved in all survivors. The multivariate analysis showed that IL-6 and stool occult blood were independent prognostic risk factors. The multivariate Cox proportional hazards regression model with stool occult blood, length- or height-for-age Z-score, medical history of sepsis, and cord blood total nucleated cells showed good discrimination ability, with a bootstrap concordance index of 0.767-0.775 in predicting OS. CONCLUSION: Better inflammation control before transplantation and higher cord blood total nucleated cell levels can improve patient prognosis. The nomogram can successfully predict OS in patients with IL-10R deficiency undergoing UCBT.

Machine Learning Prediction Model for Neutrophil Recovery after Unrelated Cord Blood Transplantation.

Delayed neutrophil recovery is an important limitation to the administration of cord blood transplantation (CBT) and leaves the recipient vulnerable to life-threatening infection and increases the risk of other complications. A predictive model for neutrophil recovery after single-unit CBT was developed by using a machine learning method, which can handle large and complex datasets, allowing for the analysis of massive amounts of information to uncover patterns and make accurate predictions. Japanese registry data, the largest real-world dataset of CBT, was selected as the data source. Ninety-eight variables with observed values for >80% of the subjects known at the time of CBT were selected. Model building was performed with a competing risk regression model with lasso penalty. Prediction accuracy of the models was evaluated by calculating the area under the receiver operating characteristic curve (AUC) using a test dataset. The primary outcome was neutrophil recovery at day (D) 28, with recovery at D14 and D42 analyzed as secondary outcomes. The final cord blood engraftment prediction (CBEP) models included 2991 single-unit CBT recipients with acute leukemia. The median AUC of a D28-CBEP lasso regression model run 100 times was .74, and those for D14 and D42 were .88 and .68, respectively. The predictivity of the D28-CBEP model was higher than that of 4 different legacy models constructed separately. A highly predictive model for neutrophil recovery by 28 days after CBT was constructed using machine learning techniques; however, identification of significant risk factors was insufficient for outcome prediction for an individual patient, which is necessary for improving therapeutic outcomes. Notably, the prediction accuracy for post-transplantation D14, D28, and D42 decreased, and the model became more complex with more associated factors with increased time after transplantation.

Effects of human herpesvirus 6B reactivation on cognitive function in cord blood transplant recipients: a prospective multicenter study.

This prospective multicenter study aimed to determine the effects of human herpesvirus-6B (HHV-6B) reactivation on central nervous system (CNS) function in cord blood transplant (CBT) recipients. Our focus was to track HHV-6B reactivation and evaluate its association with delirium and cognitive function, specifically in the domains of verbal memory, attention/processing speed, and quality of life (QOL). A cohort of 38 patients participated in this study. Of the 37 patients evaluated, seven (18.9%) developed delirium, with six of these cases emerging after HHV-6B reactivation (median lag, 7 days). Evaluation of verbal memory showed that the final trial score for unrelated words at 70 days after transplantation was significantly lower than that before preconditioning (P = 0.004) among patients (n = 15) who experienced higher-level HHV-6B reactivation (median or higher maximum plasma HHV-6 DNA load for participating patients). Patients without higher-level reactivation did not show significant declines in verbal memory scores. QOL was assessed using the 36-item Short-Form Health Survey, and the social functioning score 1 year post-transplantation was significantly lower in patients who experienced higher-level HHV-6B reactivation than in those who did not. Our findings suggest that higher-level HHV-6B reactivation can detrimentally affect certain cognitive functions in CBT recipients.

Long-term lymphocyte subset number reconstitution is unique but comparable between umbilical cord blood and unrelated bone marrow transplantation.

The number of umbilical cord blood transplantation (U-CBT) procedures has been growing annually, but little research has been done on long-term immune recovery after U-CBT. Infection risk is high in U-CBT recipients, and this can be partially attributed to immature immunocompetent cells in umbilical cord blood. In this study, we analyzed lymphocyte subset (LST) number to determine the long-term recovery timeline. We included 36 U-CBT and 10 unrelated bone marrow transplantation (U-BMT) recipients who survived more than 2 years after transplantation, and followed them for up to 10 years post-transplant. Recovery kinetics in the early phase post-transplant was different for each LST. Recovery of CD19+ B cells was faster after U-CBT than after U-BMT in the first 5 years after transplantation. Although CD4+ T cells increased in the first several months after U-CBT, long-term cell count recovery was impaired in approximately 20% of patients. Thus, although the LST recovery pattern after U-CBT was unique, LST number recovery was statistically comparable between U-CBT and U-BMT past 5 years post-transplantation.

[Successful cord blood transplantation for refractory gamma-delta hepatosplenic T-cell lymphoma developed during treatment of Crohn's disease].

The patient was a 21-year-old man who had been diagnosed with Crohn's disease and received infliximab and azathioprine six years earlier. He was admitted with fever and fatigue. Peripheral blood examination showed LDH 2,473 U/l and thrombocytopenia, and contrast-enhanced computed tomography (CT) showed hepatosplenomegaly. Bone marrow biopsy and liver biopsy showed CD4+CD56+TCRγδ＋CD8- atypical cells, leading to a diagnosis of hepatosplenic T-cell lymphoma (HSTCL). The patient was refractory to CHOP and DA-EPOCH, and therefore received cord blood transplantation with myeloablative conditioning. CT showed reduced in hepatosplenomegaly and peripheral blood examination showed LDH 165 U/l and plt 180,000/µl, so the patient was discharged on day117. HSTCL is a tumor of immature γδT cells with a Vδ1 mutation in the spleen, and immunodeficiency has been implicated in its pathogenesis. Patients with inflammatory bowel disease treated with azathioprine are known to have an increased risk of lymphoproliferative disease. In this case, use of immunosuppressive drugs for Crohn's disease may have caused malignant transformation of γδ cells in the intestinal epithelium. Although the patient was refractory to chemotherapy, he was able to achieve remission with early cord blood transplantation and long-term survival is expected.

Development of progressive multifocal leukoencephalopathy after cord blood transplantation in a patient with refractory angioimmunoblastic T-cell lymphoma.

A patient undergoing cord blood transplantation for refractory angioimmunoblastic T-cell lymphoma was subsequently managed with long-term immunosuppressants for chronic graft-versus-host disease (GVHD). On day 591 post-transplant, she exhibited disorientation and cognitive dysfunction. Magnetic resonance imaging (MRI) of the brain revealed two hyperintense foci in the white matter, suggestive of progressive multifocal leukoencephalopathy (PML). However, we did not include PML in the differential diagnosis at that time. Unfortunately, she developed progressive cognitive impairment, and repeated brain MRIs showed a progression in lesion size. She was still taking immunosuppressants to control her GVHD, therefore we suspected PML. The diagnosis of PML was confirmed through the detection of a John Cunningham (JC) virus in the cerebrospinal fluid on day 640 post-transplant. This report highlights the critical need to consider PML in differential diagnoses for post-allogeneic transplant patients, especially those who exhibit progressive neurological symptoms while on prolonged immunosuppressant therapy.

A Nationwide Retrospective Analysis of Allogeneic Hematopoietic Stem Cell Transplantation for Adult Hemophagocytic Lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disorder characterized by systemic hyperinflammation. Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only potentially curative treatment for primary and relapsed/refractory HLH, the optimal strategy has not been established. We retrospectively analyzed 56 adult patients (≥18 years) with primary and secondary HLH (mainly consisting of Epstein-Barr virus-associated HLH) who underwent allo-HSCT using the registry database of the Japanese Society for Transplantation and Cellular Therapy, including 26 patients who underwent cord blood transplantation (CBT). One-fourth of patients received myeloablative conditioning (MAC), mainly consisting of total body irradiation-based regimens. The 3-year overall survival (OS) was 40.6%, while the 3-year cumulative incidences of relapse and non-relapse mortality (NRM) were 19.8% and 39.6%, respectively. In univariable analysis, age at allo-HSCT (the 3-year OS: 27.5% for ≥ 25 years old vs 58.0% for < 25 years old, P = .025), conditioning intensity (7.1% for MAC vs 51.8% for reduced-intensity conditioning (RIC), P = .002), and donor source (26.0% for CBT vs 52.9% for bone marrow or peripheral blood stem cell transplantation (BMT/PBSCT), P = .030) were associated with significantly inferior OS. In multivariable analysis, older age at allo-HSCT (≥ 25 years old) (Hazard ratio [HR], 2.37; 95% CI, 1.01 to 5.58; P = .048), MAC (HR, 2.45; 95% CI, 1.09 to 5.53; P = .031), and CBT (HR, 2.21; 95% CI, 1.04 to 4.71; P = .040) were independently associated with worse OS. In addition, only conditioning intensity predicted higher NRM (the 3-year NRM: 78.6% for MAC vs 26.6% for RIC), while no factors were associated with the relapse rate. This study includes the largest number of adult HLH patients undergoing CBT. Although the use of CBT is acceptable, BMT/PBSCT are more favorable strategies in allo-HSCT in adult HLH. Regarding conditioning intensity, RIC regimens are more beneficial in this setting.