Model-Based Prediction of Clinically Relevant Thrombocytopenia after Allogeneic Hematopoietic Stem Cell Transplantation

Platelet reconstitution after allogeneic hematopoietic cell transplantation (allo-HCT) is heterogeneous and influenced by various patient- and transplantation-related factors, associated with poor prognoses for poor graft function (PGF) and isolated thrombocytopenia. Tailored interventions could improve the outcome of patients with PGF and post-HCT thrombocytopenia. To provide individual predictions of 180-day platelet counts from early phase data, we developed a model of long-term platelet reconstitution after allo-HCT. A large cohort (n = 1949) of adult patients undergoing their first allo-HCT was included. Real-world data from 1,048 retrospective patients were used for non-linear mixed-effects model development. Bayesian forecasting was used to predict platelet-time profiles for 518 retrospective and 383 prospective patients during internal and external model validation, respectively. Thrombocytopenia was defined as mean platelet count < 75 × 109/L, derived from the last 12 platelet measurements within the first 180 days post-HCT. Thrombocytopenia affected 37% of all patients and was associated with significantly reduced overall survival (P-value < 0.0001). On days +7, +14, +21, and +28, the developed model achieved areas under the receiver-operating characteristic of ≥ 0.68, ≥ 0.75, ≥ 0.78, and 0.81 for the prediction of post-HCT thrombocytopenia, respectively, with anti-thymocyte globulin, donor relation, and total protein measurements representing prognostic markers for post-HCT platelet kinetics. A publicly accessible web-based demonstrator of the model was established (https://hsct.precisiondosing.de). In summary, the developed model predicts individual platelet counts from day +28 post-HCT adequately, utilizing internal and external datasets. The web-based demonstrator provides a basis to implement model-based predictions in clinical practice and to confirm these findings in future clinical studies.

Adverse Impact of Pre-Transplant Liver Dysfunction in Allogeneic Hematopoietic Cell Transplantation

Although the hematopoietic cell transplantation (HCT)-comorbidity index (HCT-CI) score is associated with an increased risk of mortality after allogeneic HCT, it remains unclear how pre-HCT liver dysfunction affects clinical outcomes. We retrospectively compared clinical HCT outcomes among four groups stratified according to the presence of HCT-CI liver and other organ scores, using a Japan transplant registry database between 2010 and 2020. Of the 14235 recipients, 1527 tested positive for an HCT-CI liver score including HBV or HCV hepatitis (n = 503). The 5-year overall survival (OS) was significantly lower in the HCT-CI liver(+) other(+) and HCT-CI liver(-) other(+) groups compared to the HCT-CI liver(+) other(-) and HCT-CI liver(-) other(-) groups [49.9% vs. 59% vs. 66.5% vs. 68.3%, p < 0.001]. A multivariate analysis showed that both the HCT-CI liver(+) other(+) [HR 1.62, p < 0.001] and HCT-CI liver(-) other(+) groups [HR 1.21, p < 0.001] were significantly associated with inferior OS. Similarly, both the HCT-CI liver(+) other(+) [HR 1.89, p < 0.001] and liver(-) other(+) groups [HR 1.26, p < 0.001] were significantly associated with an increased risk of NRM. On the other hand, the HCT-CI liver(+) other(-) group was not associated with either OS or NRM. Separately analyzing the subcohorts with or without HCT-CI other scores, the presence of an HCT-CI liver score alone did not affect survival, while the co-presence of pretransplant liver dysfunction seemed to synergistically increase the adverse impact on OS and NRM among recipients with other organ comorbidities. Further studies will be needed to identify optimal strategies for recipients with pretransplant liver dysfunction.

Incidence, risk factors and clinical outcomes of primary prolonged isolated thrombocytopenia following haploidentical transplantation for severe aplastic anemia

BACKGROUND AIMS

While primary prolonged isolated thrombocytopenia (PT) represents a common complication after haploidentical hematopoietic stem cell transplantation (haplo-HSCT), its clinical significance in severe aplastic anemia (SAA) patients remains underexplored. This study aims to characterize the incidence, prognostic impact and risk factors of PT in SAA patients undergoing haplo-HSCT.

METHODS

The authors retrospectively analyzed the clinical data of 502 patients diagnosed with SAA who underwent haplo-HSCT at our institution between January 2006 and December 2022.

RESULTS

The cumulative incidence of primary PT was 7.6% (38/502). Primary PT significantly correlated with inferior long-term outcomes, demonstrating markedly reduced 5-year overall survival (65.8% vs. 94.1%, P < 0.001) and graft-versus-host disease (GvHD)-free, failure-free survival (44.7% vs. 83.3%, P < 0.001) compared to non-PT counterparts. Multivariate analysis revealed five independent risk factors: pretransplant red blood cell transfusion burden ≥40 units, maternal donor, infused CD34+ cell dose <2 × 10⁶/kg, grade II-IV acute GvHD and refractory cytomegalovirus viremia. A risk stratification model incorporating these factors showed discriminative capacity, with primary PT incidence escalating from 2.3% (low-risk: 0 factors) to 6.9% (intermediate-risk: 1-2 factors) and 31.7% (high-risk: 3-5 factors) (P < 0.001).

CONCLUSIONS

This study establishes primary PT as an independent prognostic marker in SAA patients receiving haplo-HSCT. The developed risk model may facilitate early identification of high-risk patients requiring intensified monitoring and preemptive interventions.

Effect and safety of recombinant human thrombopoietin on haematopoietic reconstitution after allogeneic haematopoietic cell transplantation

Delayed platelet engraftment (DPE) and thrombocytopenia are common complications following myeloablative conditioning in the advanced stage of allogeneic haematopoietic cell transplantation (allo-HCT), and they are associated with transplantation-related mortality and poor prognosis. Therefore, promoting haematopoietic reconstitution after allo-HCT plays a key role in improving patient outcomes. The aim of this retrospective study was to assess the effectiveness and safety of recombinant human thrombopoietin (rhTPO) in promoting haematopoietic reconstruction after allo-HCT. The study included 210 patients who underwent transplantation, with 158 in the rhTPO group and 52 in the control group. Of the total patient population, 120 were males and 90 were females, with a median age of 31 years (range=6 to 59 years). The results showed that the rhTPO group had a median platelet engraftment time that was 14.1 days shorter than that of the control group (14.1 days vs. 21.9 days; P < 0.001). The time for platelet count recovery to 50 × 10^9/L was also shorter in the rhTPO group than in the control group (21.7 days vs. 30.3 days; P < 0.001). Additionally, the granulocyte engraftment time was shorter in the rhTPO group (14.3 days vs. 18.2 days; P < 0.001). There was no significant difference in overall survival (OS) between the rhTPO group and the control group at 2 years after transplantation (77.2% vs. 65.4 %; P = 0.08). Furthermore, there were no significant differences in the amount of platelet transfusions, the rate of platelet engraftment, the rate of DPE, or the incidence of Grade 4 haemorrhage between the groups. Moreover, no adverse reactions were found in the rhTPO group. This study demonstrated that rhTPO administration after allo-HCT effectively reduced the time required for platelet and granulocyte engraftment and was safe.

Immature platelet fraction levels predict the development of prolonged thrombocytopenia after haematopoietic stem cell transplantation

Prolonged thrombocytopenia (PT) is a serious complication after haematopoietic stem cell transplantation (HSCT). PT has been suggested to be associated with an increased platelet transfusion requirement and poor outcomes after transplantation. Due to the complex mechanism of PT development, it is difficult to diagnose in the early post-transplant period. Our study aimed to identify an early predictive marker for PT after HSCT. Previous studies showed that the clinical utility of immature platelet fraction (IPF) predicts platelet recovery after chemotherapy and successful engraftment. However, the relationship between IPF and PT after HSCT remains unclear. Fifty-two patients with malignant haematological diseases who underwent HSCT were included in the study. We observed the kinetics of recovery of haematological parameters after transplantation and performed receiver operating characteristics (ROC) curve analysis using data from the 52 HSCT patients. The days to rise and peak of IPF, absolute IPF count (A-IPF) and highly fluorescent IPF (H-IPF) were almost synchronised in all patients, at day 10 and day 15, respectively. The begin to rise levels of IPF, H-IPF and A-IPF were all significantly lower in the PT group than in the good engraftment (GE) group (p=0.0016, p=0.0094, p=0.0086, respectively). The peak levels of IPF were significantly lower in the PT group than the GE group (p=0.0036). However, the peaks of H-IPF and A-IPF were not statistically significant between the two groups (p=0.3383, p=0.0887, respectively). The area under the ROC curve (AUC) of IPF rise was 0.739 (95% CI 0.583-0.896; p<0.05) and the cut-off value was 3.5%, while the AUC of IPF peak was 0.800 (95% CI 0.637-0.962; p<0.01) and the cut-off value was 8.0%. In conclusion, early low levels of IPF predict the development of PT after HSCT. These findings may help improve the management and treatment strategies for PT after HSCT.

[Allogeneic hematopoietic stem cell transplantation for Shwachman-Diamond syndrome: a report of three cases and literature review]

This study reports on three patients with Shwachman-Diamond syndrome (SDS) who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the First Affiliated Hospital of Zhejiang University School of Medicine. Based on relevant literature, the clinical manifestations and genetic mutation characteristics of SDS were summarized, and the efficacy and timing of allo HSCT for such patients were explored. Three SDS patients were all male, with transplant ages of 32, 33, and 32 years old, respectively. All three patients were diagnosed in childhood. Case 1 presented with anemia as the initial clinical manifestation, which gradually progressed to a decrease in whole blood cells; Case 2 and 3 both present with a decrease in whole blood cells as the initial clinical manifestation. Case 1 and 3 have intellectual disabilities, while case 3 presents with pancreatic steatosis and chronic pancreatitis. All three patients have short stature. Three patients all detected heterozygous mutations in the SBDS: c.258+2T>C splice site. The family members of the three patients have no clinical manifestations of SDS. All three patients were treated with a reduced dose pre-treatment regimen (Fludarabine+Busulfan+Me-CCNU+Rabbit Anti-human Thymocyte Globulin). Case 1 and case 2 underwent haploid hematopoietic stem cell transplantation, while case 3 underwent unrelated donor hematopoietic stem cell transplantation. Case 1 was diagnosed with myelodysplastic syndrome transforming into acute myeloid leukemia before transplantation, but experienced early recurrence and death after transplantation; Case 2 is secondary implantation failure, dependent on platelet transfusion; Case 3 was removed from medication maintenance treatment after transplantation, and blood routine monitoring was normal.

Recombinant Human Thrombopoietin Promotes Platelet Engraftment in Severe Aplastic Anemia Patients Following Treatment With Haploid Hematopoietic Stem Cell Transplantation using Modified Post-Transplantation Cyclophosphamide

BACKGROUND

Recombinant human TPO (rhTPO) promotes platelet engraftment in patients after allogeneic HSCT (allo-HSCT). However, the effects of rhTPO on platelet recovery after Haplo-HSCT in patients with severe aplastic anemia (SAA) have not been intensively studied.

OBJECTIVE

We aimed to evaluate the efficacy of rhTPO on platelet engraftment in patients with SAA who were treated with Haplo-HSCT using post-transplantation cyclophosphamide (PTCy).

STUDY DESIGN

SAA patients who received Haplo-HSCT plus PTCy regimen were divided into the rhTPO group (with subcutaneous injection of rhTPO, n = 28) and Control group (no rhTPO administration, n = 27). The engraftment of platelet/neutrophil, platelet infusion amount, and transplant-related complications between the 2 groups were compared.

RESULTS

All 55 patients showed successful hematopoietic reconstitution. The median time of platelet engraftment was 11 (9 to 29) days in the rhTPO group and 14 (9 to 28) days in the Control group (P = .003). The rhTPO group had a significantly reduced amount of infused platelets compared to the Control group (2 (1 to 11.5) versus 3 (1 to 14) therapeutic doses; P = .004). There was no significant difference between the 2 groups regarding median time of neutrophil engraftment, incidence of acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD), incidence of cytomegalovirus or Epstein-Barr virus reactivation, 3-yr overall survival rate, and failure-free-survival rate. No obvious adverse reactions were observed in the rhTPO group.

CONCLUSION

rhTPO promoted platelet engraftment, reduced the amount of transfused platelets, and demonstrated good safety profiles without evidence of adverse reactions in patients with SAA who received Haplo-HSCT using PTCy regimen.

Outcomes with HLA-matched unrelated donor versus haploidentical hematopoietic cell transplantation

We investigated the outcomes after adult haploidentical (haplo) and matched unrelated donor (MUD) hematopoietic cell transplantation (HCT) in a single-center study (n = 452) including 276 MUD and 176 haplo transplants. Myeloablative (37%) and reduced-intensity conditioning (63%) were performed. Graft sources included peripheral blood (50%) and bone marrow (50%). GVHD prophylaxis included tacrolimus/methotrexate (53%) and post-transplant cyclophosphamide-based (47%). In MUD versus haplo HCT recipients, a similar incidence of neutrophil engraftment (18 vs 17 days, p = 0.895), grade II-IV acute GVHD (51% vs 50%, p = 0.773), relapse (26% vs 23%, p = 0.578), non-relapse mortality (22% vs 23%, p = 0.817), 1-year disease-free survival (62% vs 63%. p = 0.921), and 1-year overall survival (73% vs 74%, p = 0.744) were observed. Earlier platelet engraftment (22 vs 27 days, p < 0.001) and higher chronic GVHD (45% vs 35%, p = 0.040) were noted in MUD as compared to haplo HCT. Allogeneic transplantation should be done promptly whenever indicated, utilizing either matched unrelated or haploidentical donors.

Thrombopoietin level predicts the response to avatrombopag treatment for persistent thrombocytopenia after haploidentical haematopoietic stem cell transplantation

Persistent thrombocytopenia (PT) has an unsatisfactory response to therapy after haploidentical haematopoietic stem cell transplantation (haplo-HSCT). We retrospectively evaluated the safety and efficacy of avatrombopag treatment in 69 patients with PT following haplo-HSCT and assessed whether baseline thrombopoietin (TPO) levels could predict treatment response. Overall response (OR) and complete response (CR) were defined as increased platelet levels to over 20 × 109/L or 50 × 109/L independent of platelet transfusion during or within 7 days of the end of avatrombopag treatment, respectively. The incidences of OR and CR were 72.5% and 58.0%, with a median of 11 and 29 days to OR and CR, respectively. ROC analysis suggested that the optimally discriminant baseline TPO level threshold for both OR and CR to avatrombopag was ≤ 1714 pg/mL. In multivariate analysis, a lower baseline TPO level (P = 0.005) was a significant independent factor of response to avatrombopag. For patients resistant to other TPO receptor agonists (TPO-RAs), 9/16 (56.3%) exhibited a response after switching to avatrombopag. Avatrombopag was well tolerated, and responders achieved improved overall survival (79.0% vs. 91.1%, P = 0.001). In conclusion, avatrombopag is a potential safe and effective treatment for PT after haplo-HSCT, and lower baseline TPO levels predicted a better response.

Adverse impact of delay of platelet recovery after autologous hematopoietic cell transplantation for aggressive non-Hodgkin lymphoma and multiple myeloma

BACKGROUND AIMS

The prognostic impact of platelet recovery after autologous hematopoietic cell transplantation (AHCT) on clinical outcomes remains to be elucidated. We aimed to clarify the impact of platelet recovery on clinical outcomes, risk factors of delayed platelet recovery and the necessary dose of CD34+ cells for prompt platelet recovery in each patient.

METHODS

Using a nationwide Japanese registry database, we retrospectively analyzed clinical outcomes of 5222 patients with aggressive non-Hodgkin lymphoma (NHL) or multiple myeloma (MM).

RESULTS

At a landmark of 28 days after AHCT, a delay of platelet recovery was observed in 1102 patients (21.1%). Prompt platelet recovery was significantly associated with superior overall survival (hazard ratio [HR] 0.32, P < 0.001), progression-free survival (HR 0.48, P < 0.001) and decreased risks of disease progression (HR 0.66, P < 0.001) and non-relapse/non-progression mortality (HR 0.19, P < 0.001). The adverse impacts of a delay of platelet recovery seemed to be more apparent in NHL. In addition to the dose of CD34+ cells/kg, disease status, performance status and the hematopoietic cell transplant-specific comorbidity index in both diseases were associated with platelet recovery. We then stratified the patients into three risk groups according to these factors. For the purpose of achieving 70% platelet recovery by 28 days in NHL, the low-, intermediate- and high-risk groups needed more than 2.0, 3.0 and 4.0 × 106 CD34+ cells/kg, respectively. In MM, the low-risk group needed approximately 1.5 × 106 CD34+ cells/kg, whereas the intermediate- and high-risk groups required 2.0 and 2.5 × 106 CD34+ cells/kg to achieve about 80% platelet recovery by 28 days.

CONCLUSIONS

A delay of platelet recovery after AHCT was associated with inferior survival outcomes.

Safety of romiplostim administered immediately after cord-blood transplantation: a phase 1 trial

Graft failure and delayed hematopoietic recovery are the major limitations of cord-blood transplantation (CBT). Romiplostim, a thrombopoietin-receptor agonist, promotes megakaryopoiesis and multilineage hematopoiesis in aplastic anemia. The decreased number of hematopoietic stem cells in the early phase after CBT and aplastic anemia share certain characteristics. Therefore, we hypothesized that romiplostim administration immediately after CBT may promote multilineage hematopoietic recovery. We investigated the safety and preliminary efficacy of administering romiplostim a day after CBT. This phase 1 dose-escalation study included six adults with hematologic malignancies in remission. Romiplostim was administered subcutaneously within 7 days after single-unit CBT, initially at doses of 5 µg/kg or 10 µg/kg in three patients, then once a week for 14 weeks or until platelet recovery. The maximum dose was 20 µg/kg. The median number of romiplostim administrations was 6 (range, 3-15). Romiplostim-related adverse events included bone pain (3/6) and injection site reaction (1/6). Non-hematological grade ≥ 3 toxicities were observed in four patients; febrile neutropenia was the most common (4/6). All patients achieved neutrophil engraftment and the median time was 14 days (range, 12-32). Platelet counts ≥ 50 × 109 /L were recorded in all patients except for one who died on day 48; the median time was 34 days (range, 29-98). No relapse, thrombosis, or bone marrow fibrosis was observed during a median follow-up of 34 months. Romiplostim may be safely administered in the early phase of CBT. Further phase 2 trial is warranted for its efficacy evaluation. Trial registration number: UMIN000033799, August 18, 2018.

The nuclear factor erythroid 2-related factor 2 agonist tert-butylhydroquinone improves bone marrow mesenchymal stromal cell function in prolonged isolated thrombocytopenia after allogeneic haematopoietic stem cell transplantation

Prolonged isolated thrombocytopenia (PT) is a life-threatening comorbidity associated with allogeneic haematopoietic stem cell transplantation (allo-HSCT). Our previous study indicated that dysfunctional bone marrow mesenchymal stromal cells (BM MSCs) played a role in PT pathogenesis and that reactive oxygen species (ROS) accumulation was related to BM MSC senescence and apoptosis. However, the mechanism of the increase in ROS levels in the BM MSCs of PT patients is unknown. In the current case-control study, we investigated whether nuclear factor erythroid 2-related factor 2 (NRF2), which is a central regulator of the cellular anti-oxidant response that can clear ROS in human BM MSCs, was associated with PT after allo-HSCT. We evaluated whether an NRF2 agonist (tert-butylhydroquinone, TBHQ) could enhance BM MSCs from PT patients in vitro. We found that BM MSCs from PT patients exhibited increased ROS levels and reduced NRF2 expression. Multivariate analysis showed that low NRF2 expression was an independent risk factor for primary PT [p = 0.032, Odds ratio (OR) 0.868, 95% confidence interval (CI) 0.764-0.988]. In-vitro treatment with TBHQ improved the quantity and function of BM MSCs from PT patients by downregulating ROS levels and rescued the impaired BM MSC support of megakaryocytopoiesis. In conclusion, these results suggested that NRF2 downregulation in human BM MSCs might be involved in the pathogenesis of PT after allo-HSCT and that BM MSC impairment could be improved by NRF2 agonist in vitro. Although further validation is needed, our data indicate that NRF2 agonists might be a potential therapeutic approach for PT patients after allo-HSCT.

Oral eltrombopag versus subcutaneous recombinant human thrombopoietin for promoting platelet engraftment after allogeneic stem cell transplantation: A prospective, non-inferiority, randomized controlled trial

Delayed platelet engraftment (DPE) is associated with poor survival and increased transplantation-related mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Therefore, treatments are needed to improve platelet engraftment and prevent DPE. We performed a phase three, non-inferior, randomized controlled study of eltrombopag or recombinant human thrombopoietin (rhTPO) to promot platelet engraftment after allo-HSCT. Candidates for allo-HSCT were randomly assigned to receive oral eltrombopag (50 mg daily) or subcutaneous rhTPO (15000U daily) from the first-day post-transplantation. The primary endpoint was the cumulative numbers of platelet engraftment (platelet recovery ≥20 × 10⁹ /L, without transfusion, for seven consecutive days) on day 60 after transplantation. We performed intention-to-treat analyses with a non-inferior margin of -15%. A total of 92 participants underwent randomization. 44 and 48 patients were randomized to the eltrombopag and rhTPO groups, respectively. The median duration of follow-up was 360 days (range: 12-960 days). The cumulative incidence of platelet engraftment on day 60 after transplantation in eltrombopag group was 86.4% (38/44) compared with 85.4% (41/48) in the rhTPO group (absolute risk difference [ARD] 1%, one-sided lower limit of 95% confidence interval [CI] -13.28%, P_{non-inferirioty}  = 0.014). The rate of DPE in the eltrombopag group was 6.8% (3/44) compared with 12.5% (6/48) in the rhTPO group (ARD -5.7%, one-sided higher limit of 95% CI 6.28%, P_{non-inferirioty}  = 0.063). Approximately, three-fourths of non-hematologic adverse events were not observed in the eltrombopag group but three patients (3/48, 6%) experienecd them in the rhTPO group. In addition, platelet transfusions unite from day 0 to day 21, or from day 22 to day 60, progression-free survival, overall survival were not significantly different between both groups. Eltrombopag was non-inferior to rhTPO in promoting platelet engraftment post allo-HSCT for patients with hematological malignancy. Oral eltrombopag was more convenient for patients than subcutaneous rhTPO (NCT03515096).

Donor CSF3R with the rs3917980A/G or G/G genotype is correlated with better leukemia-free survival after allogenic hematopoietic stem cell transplantation

Polymorphisms in the granulocyte colony-stimulating factor receptor gene (GCSFR, CSF3R) have been reported to be associated with peripheral blood stem cell enrichment and hematological diseases. The aim of our study was to investigate the effects of donor CSF3R allelic polymorphisms on the outcomes of allogeneic stem cell transplantation. A total of 273 patients who were diagnosed with hematological diseases and treated with allogeneic hematopoietic stem cell transplantation(allo-HSCT) were enrolled in this study. Single-nucleotide polymorphisms in CSF3R were genotyped by targeted next-generation sequencing. There were six types of CSF3R genotypes with percentages over 1%. LFS and OS analyses showed that recipients receiving grafts from healthy donors with a rs3917980 G/G or A/G genotype had higher LFS rates than those receiving grafts from donors carrying a rs22754272 T/C genotype and the double-negative group (p = 0.036). Univariate cox analysis showed that donor CSF3R with the rs2275472 T/C genotype was associated with higher transplantation-related mortality (TRM) rates (HR = 2.853, 95% CI: 1.405-5.792, p = 0.00371) and lower rates of leukemia-free survival (LFS) (HR = 1.846; 95% CI: 1.018-3.347, p = 0.0435). In addition, donor CSF3R with the rs3917980G/G or A/G genotype was associated with better overall survival (OS) rates (HR = 0.560, 95% CI: 0.3162-0.9916, p = 0.047) and lower TRM rates (HR = 0.497, 95% CI: 0.2628-0.9397, p = 0.0315). Furthermore, multivariate cox analysis found that rs2275472 T/C genotype was an independent risk factors for TRM rates (HR = 3.210, 95% CI: 1.573-6.55, p = 0.001), while no statistical difference was found between rs3917980G/G or A/G genotype and clinical outcomes. Our findings demonstrate the important prognostic value of genetic variations in donor CSF3R to predict clinical outcomes in patients undergoing allo-HSCT.

Photobiomodulation and Antimicrobial Photodynamic Therapy for Oral Ulcers in a Patient With Thrombocytopenia Following Bone Marrow Transplantation

Introduction: Thrombocytopenia is usually seen after allogeneic hematopoietic stem cell transplantation (HSCT) and may favor the development of oral bleeding, infections, and ulcerations. Case Report: A patient with chronic myelomonocytic leukemia had been submitted to allogeneic HSCT. Within a few days, she developed severe thrombocytopenia and an extensive ulcerative area comprising both lips, which bled spontaneously, as well as smaller ulcers on the tongue mucosa. The lesions were managed using a combination of phototherapies (photobiomodulation and antimicrobial photodynamic therapies), totalizing 4 laser sessions. After 4 days, there was an important reduction in the severity of the lesions, with spontaneous disappearance of the crusts and reepithelization. Conclusion: The proposed combination of phototherapies would be a suitable therapeutic modality for the management of oral lesions related to platelet disorders induced by oncologic treatments.

Poor survival and prediction of prolonged isolated thrombocytopenia post umbilical cord blood transplantation in patients with hematological malignancies

Prolonged isolated thrombocytopenia (PIT) is a common complication after umbilical cord blood transplantation (UCBT). However, data on PIT prediction and impacts on transplantation outcomes for UCBT patients are rare. We retrospectively analyzed 244 patients with hematological malignancies who received single-unit UCBT at the First Affiliated Hospital of USTC between August 2018 and December 2019. Among them, PIT occurred in 49 recipients, with a crude incidence of 20.1%. In the PIT patients, the 2-year cumulative incidence of transplant-related mortality (TRM) was significantly higher, and the probabilities of 2-year overall survival, leukemia-free survival and graft-versus-host disease (GVHD)-free relapse-free survival were significantly poorer (57.1% vs. 88.6%; 53.1% vs. 81.9%; 22.4% vs. 59.8%; p < 0.001), without remarkable increases in the cumulative incidence of relapse or chronic GVHD. Importantly, the multivariate analysis revealed that lower high-resolution HLA compatibility (≤6/10), lower infused CD34⁺ cell count (≤1.78 × 10⁵ /kg), grade II-IV acute GVHD preplatelet engraftment, a lower pretransplantation platelet count (≤100 × 10⁹ /L), and a longer neutrophil engraftment time (≥17 days) were independent risk factors for PIT after UCBT. These results demonstrate that PIT is common after UCBT, predicting inferior survival and the need for more monitoring during the early phase.

Non-genotoxic conditioning facilitates hematopoietic stem cell gene therapy for hemophilia A using bioengineered factor VIII

Hematopoietic stem and progenitor cell (HSPC) lentiviral gene therapy is a promising strategy toward a lifelong cure for hemophilia A (HA). The primary risks associated with this approach center on the requirement for pre-transplantation conditioning necessary to make space for, and provide immune suppression against, stem cells and blood coagulation factor VIII, respectively. Traditional conditioning agents utilize genotoxic mechanisms of action, such as DNA alkylation, that increase risk of sterility, infection, and developing secondary malignancies. In the current study, we describe a non-genotoxic conditioning protocol using an immunotoxin targeting CD117 (c-kit) to achieve endogenous hematopoietic stem cell depletion and a cocktail of monoclonal antibodies to provide transient immune suppression against the transgene product in a murine HA gene therapy model. This strategy provides high-level engraftment of hematopoietic stem cells genetically modified ex vivo using recombinant lentiviral vector (LV) encoding a bioengineered high-expression factor VIII variant, termed ET3. Factor VIII procoagulant activity levels were durably elevated into the normal range and phenotypic correction achieved. Furthermore, no immunological rejection or development of anti-ET3 immunity was observed. These preclinical data support clinical translation of non-genotoxic antibody-based conditioning in HSPC LV gene therapy for HA.

Recombinant human thrombopoietin promotes platelet engraftment after umbilical cord blood transplantation

Delayed platelet engraftment is a common complication after umbilical cord blood transplantation (UCBT) accompanied by increased transplant-related complications or death. This study was designed to determine the safety and efficacy of recombinant human thrombopoietin (rhTPO) in promoting platelet engraftment after UCBT. A total of 120 patients scheduled to receive UCBT were randomly assigned to the rhTPO group (300 U/kg once daily from days 14 to 28 after UCBT, n = 60) or the control group (n = 60). The primary outcome was the 60-day cumulative incidence of platelet engraftment after single-unit cord blood transplantation. The 60-day cumulative incidence of platelet engraftment (platelet count ≥20 × 109/L) and the 120-day cumulative incidence of platelet recovery (platelet count ≥50 × 109/L) were both significantly higher in the rhTPO group than in the control group (83.1% vs 66.7%, P = .020; and 81.4% vs 65.0%, P = .032, respectively). In addition, the number of required platelet infusions was significantly lower in the rhTPO group than in the control group (6 vs 8 units, respectively; P = .026). The cumulative incidence of neutrophil engraftment and the probability of 2-year overall survival, disease-free survival, and graft-versus-host disease-free relapse-free survival did not differ between the 2 groups. Other transplant-related outcomes and complications did not differ between the 2 groups, and no severe adverse effects were observed in patients receiving rhTPO. This study demonstrated that rhTPO is well tolerated in patients and could effectively promote platelet engraftment after UCBT. This study was registered on the Chinese Clinical Trial Registry (http://www.chictr.org.cn/index.aspx) as ChiCTR-IPR-16009357.

Interleukin-18 and Hematopoietic Recovery after Allogeneic Stem Cell Transplantation

Simple Summary

We have previously shown that high pre-conditioning levels of Interleukin-18 were associated with worse survival after allogeneic stem cell transplantation due to increased non-relapse mortality. While no correlations with acute graft-versus-host disease were observed, interleukin-18-related excess mortality was mainly driven by fatal infectious complications. In multiple studies, delayed hematopoietic recovery and poor graft function following allogeneic stem cell transplantation has been demonstrated as a powerful predictor of non-relapse mortality. The present study links high interleukin-18 to delayed platelet recovery in allografted patients. Given the functions of interleukin-18 in regulating the quiescence of hematopoietic stem/progenitor cells, our findings may be explained by Interferon gamma-independent inhibitory effects of interleukin-18 on stem cell proliferation and hematopoietic reconstitution in allografted patients. Importantly, considering recent successful interleukin-18-neutralizing approaches in autoimmune disorders, our results provide a rationale to explore modulation of interleukin-18 for improving hematopoietic recovery and outcomes in allogeneic stem cell transplantation recipients.

Abstract

Interleukin-18 (IL-18) is an immunoregulatory cytokine and a context-dependent regulator of hematopoietic stem/progenitor cell (HSPC) quiescence in murine models. In a previous study, high pre-conditioning levels of IL-18 were associated with increased non-relapse mortality (NRM) after allogeneic stem cell transplantation (alloSCT). To investigate the clinical impact of IL-18 status on hematopoietic function, the associations of pre-conditioning and day 0–3 cytokine levels with platelet and neutrophil recovery were analyzed in a training cohort of 714 allografted patients. In adjusted logistic regression analyses, both increasing pre-conditioning and day 0–3 IL-18 levels had a significantly higher adjusted odds ratio (aOR) of delayed platelet and neutrophil recovery on day +28 post-transplant (aOR per two-fold increase: 1.6–2.0). The adverse impact of high pre-conditioning IL-18 on day +28 platelet recovery was verified in an independent cohort of 673 allografted patients (aOR per two-fold increase: 1.8 and 1.7 for total and free IL-18, respectively). In both cohorts, a platelet count ≤20/nL on day +28 was associated with a significantly increased hazard of NRM (hazard ratio 2.13 and 2.94, respectively). Our findings support the hypothesis that elevated peritransplant IL-18 levels affect post-transplant HSPC function and may provide a rationale to explore modulation of IL-18 for improving alloSCT outcomes.

[Impact of splenomegaly on outcomes of allogeneic hematopoietic stem cell transplantation in patients with chronic myelomonocytic leukemia]

目的

探讨脾肿大对慢性粒-单核细胞白血病（CMML）异基因造血干细胞移植（allo-HSCT）预后的影响。

方法

对2004年至2018年在北京大学血液病研究所接受allo-HSCT后的25例CMML患者进行回顾性分析，根据预处理前2周是否伴有脾脏肿大分为脾肿大组和非脾肿大组，比较两组患者在植入、移植物抗宿主病（GVHD）、复发以及生存方面的差异。

结果

①脾肿大组15例（男8例，女7例），中位年龄45（23~61）岁；非脾肿大组10例（男、女各5例），中位年龄39（12~56）岁。两组患者基线特征差异无统计学意义（P>0.05）。②脾肿大组、非脾肿大组粒细胞植入率分别为93.3%（14/15）、100.0%（10/10），中位植入时间分别为17（11~20）d、14（11~18）d（χ²=5.303，P=0.021）；脾肿大组、非脾肿大组血小板植入率分别为80.0%（12/15）、90.0%（9/10）（P=0.212），中位植入时间分别为17（12~33）d、15（12~19）d（χ²=0.470，P=0.493）。③脾肿大组5例发生急性GVHD（Ⅰ/Ⅱ度4例，Ⅲ/Ⅳ度1例），非脾肿大组6例发生急性GVHD（Ⅰ/Ⅱ度5例，Ⅲ/Ⅳ度1例）（χ²=0.204，P=0.652）。脾肿大组、非脾肿大组移植后100 d的急性GVHD累积发生率分别为33.3%（95%CI 14.9%~51.7%）、20.0%（95%CI 2.8%~37.2%）（P=0.635）。脾肿大组5例发生慢性GVHD（广泛型3例），非脾肿大组未发生慢性GVHD（P=0.041）。④脾肿大组、非脾肿大组3年累积复发率分别为（42.7±2.6）%、（11.1±1.2）%（χ²=1.824，P=0.122），3年总生存率分别为（61.5±13.5）%、（68.6±15.1）%（χ²=0.351，P=0.554），3年无白血病生存率分别为（56.3±14.8）%、（80.0±17.9）%（χ²=1.148，P=0.284）。

结论

脾肿大可致CMML患者allo-HSCT后粒细胞植入延迟，对生存及复发无影响。

Incidence, Risk Factors, and Outcomes of Primary Prolonged Isolated Thrombocytopenia after Haploidentical Hematopoietic Stem Cell Transplant

The aim of this study was to evaluate the incidence, risk factors, and outcomes of primary prolonged isolated thrombocytopenia (PT) after haploidentical hematopoietic stem cell transplant (haplo-HSCT). We retrospectively analyzed patients who received haplo-HSCT for various hematologic malignancies at Peking University Institute of Hematology between January 2015 and December 2016. Of the 918 patients, 93 (10.1%) developed primary PT. We designed a propensity score method-based study. For each primary PT patient control subjects (1:3) were selected using a propensity score-matching method. A total of 372 recipients were enrolled in the study: 93 in the PT group and 279 in the control group. Multivariate analysis showed that age older than 25 years (P = .002), median mononuclear cells (P = .000), median CD34⁺ counts (P = .003), history of grades II to IV acute graft-versus-host disease (GVHD; P = .000), and Epstein-Barr virus (EBV) infection after haplo-HSCT (P = .016) were independent risk factors for primary PT. Primary PT was significantly associated with higher transplant-related mortality (TRM; P < .001), inferior overall survival (P = .001), and disease-free survival (P = .005). In conclusion, the incidence of primary PT after haplo-HSCT was 10.1%. Primary PT was associated with poorer survival and higher TRM along with older age, grades II to IV acute GVHD, and EBV infection after haplo-HSCT.

Pulmonary Infection Within 100 Days After Transplantation Impaired Platelet Recovery in Patients with Hematologic Malignancies: A Propensity-Score-Matched Analysis

Background

Pulmonary infection is one of the life-threatening complications occurring during allogeneic hematopoietic stem cell transplantation (alloHSCT), even when prophylactic measures have been employed. Few studies have investigated whether pulmonary infection affects platelet recovery during alloHSCT.

Material/Methods

We retrospectively reviewed 253 consecutive patients with hematologic diseases who received alloHSCT in our institute. Among them, 62 patients (25%) had pulmonary infection within 100 days after alloHSCT. Using the one-to-two propensity-score matching logistic model, 50 patients with pulmonary infection and 100 patients without were included based on age, disease and stage, time from diagnosis to transplantation, infused CD34⁺ cells, and mononuclear cells.

Results

The incidences of prolonged thrombocytopenia in patients with pulmonary infection were 44% (22/50) and 9% (9/100) in the corresponding matched group (P<0.001). The mean time for platelet engraftment in patients with and without pulmonary infection were 19.29±13.96 days and 13.94±4.12 days (P=0.012), respectively. Multivariable logistic regression showed that pulmonary infection was an independent risk factor for impaired platelet recovery (OR: 5.335, 95% CI: 2.735–10.407, P<0.001). Impaired platelet recovery was associated with shorter survival and higher treatment-related mortality.

Conclusions

Our results indicate that patients with pulmonary infection within 100 days after alloHSCT are more likely to suffer from impaired platelet recovery and have inferior long-term survival.

Prediction of delayed platelet engraftment after autologous stem cell transplantation for B-cell non-Hodgkin lymphoma

Delayed platelet engraftment (DPE) is occasionally observed despite prompt neutrophil engraftment after autologous peripheral blood stem cell transplantation (auto-PBSCT). To identify risk factors for DPE and to develop a simple and clinically applicable system for predicting the time required for platelet recovery, we conducted a multi-institutional retrospective study in 144 patients with B-cell non-Hodgkin lymphoma who underwent auto-PBSCT. In a median observation period of 930 days (range: 25-5272 days), 139 patients successfully achieved platelet engraftment (≥50.0 × 10⁹/L). The median duration for platelet engraftment was 19 days, and 130 patients had platelet engraftment within 40 days after auto-PBSCT; however, the other 14 patients failed to achieve platelet engraftment within 60 days. These 14 patients with DPE required a significantly greater number of apheresis procedures and had a lower pre-apheresis absolute lymphocyte count (PA-ALC) compared to those without DPE. Importantly, multivariate analysis revealed that the number of transplanted CD34⁺ cells (≤2.0 × 10⁶/kg), number of required apheresis procedures (≥3 days), and PA-ALC (≤1.0 × 10⁹/L) were independently associated with a longer time for platelet engraftment after auto-PBSCT. By incorporating these three independent factors as variables, we generated a new scoring system for prediction of the time and probability for platelet engraftment after auto-PBSCT.

Eltrombopag for Delayed Platelet Recovery and Secondary Thrombocytopenia Following Allogeneic Stem Cell Transplantation in Children

The delay in platelet recovery after hematopoietic stem cell transplantation (HSCT) is closely related to the overall survival rate of transplanted children. The use of platelet-producing agents such as eltrombopag and romiplostim has made great progress in treating diseases such as immune thrombocytopenia and aplastic anemia. However, the use of such drugs in patients with thrombocytopenia after transplantation, especially in children, is rare. This study aimed to report eltrombopag treatment for 3 children with primary platelet engraftment failure and secondary thrombocytopenia after allogeneic HSCT. Of these patients, 2 had platelets stabilized at ≥50×10/L after eltrombopag treatment and subsequent withdrawal of eltrombopag. All 3 patients showed no clear adverse reactions. The results indicated a wide application prospect of eltrombopag treatment in children with thrombocytopenia after allogeneic HSCT.

Platelet Transfusion Refractoriness in Single-Unit Cord Blood Transplantation for Adults: Risk Factors and Clinical Outcomes

Platelet transfusion refractoriness (PTR) is frequently observed after allogeneic hematopoietic cell transplantation (HCT). However, the incidence of and risk factors for PTR, and impact of PTR on transplant outcomes after cord blood transplantation (CBT) have not been fully investigated. We retrospectively analyzed 185 adult patients who received single-unit CBT in our institute. The mean 16-hour corrected count increment (CCI) for the 5840 platelet transfusions was 3.68 × 10⁹/L. Among them, 3196 transfusions (54.7%) were associated with a PTR with 16-hour-CCI <4.5 × 10⁹/L. Results of multivariate analysis indicated that the following factors were significantly associated with decreased platelet transfusion responses: female sex with pregnancy history, male sex, the presence of HLA class I antibody, lower cord blood total nucleated cell dose, lower cord blood CD34⁺ cell dose, 3 locus HLA disparities, body temperature ≥38°C, C-reactive protein ≥10 mg/dL, cytomegalovirus reactivation, use of foscarnet, and use of liposomal amphotericin B. By contrast, graft-versus-host disease prophylaxis including methotrexate, ABO minor mismatch, use of ganciclovir, and use of linezolid were significantly associated with better platelet transfusion responses. PTR had a significant effect on poor neutrophil and platelet recovery, and overall mortality after CBT. These data suggest that early phase PTR may be predictive of engraftment and mortality after single-unit CBT for adults.