A prospective randomized trial comparing cyclosporine/methotrexate and tacrolimus/sirolimus as graft-versus-host disease prophylaxis after allogeneic hematopoietic stem cell transplantation

Neurologic Complications of the Central Nervous System after Allogeneic Stem Cell Transplantation: The Role of Transplantation-Associated Thrombotic Microangiopathy as a Potential Underreported Cause

Neurologic complications (NCs), especially those of the central nervous system (CNS), represent a severe complication after allogeneic stem cell transplantation (allo-HSCT) and are associated with relevant morbidity and mortality. We aimed to characterize the potential risk factors for the development of CNS-NC, with a special focus on the role of calcineurin inhibitors (CNIs) as a predisposing factor. For this purpose, we compared cyclosporin A (CsA) versus tacrolimus (TAC) with respect to their influence on the incidence and type of CNS-NC after allo-HSCT. We retrospectively analyzed the incidence, risk factors, and impact on outcomes of CNS-NC diagnosed during the post-transplantation follow-up in patients with different high-risk hematologic malignancies who underwent allo-HSCT at our institution over a 20-year period. All patients included in the analysis received CNI (CsA or TAC) as graft-versus-host disease (GVHD) prophylaxis. We evaluated a total of 739 consecutive patients who underwent transplantation between December 1999 and April 2019. During a median follow-up of 6.8 years, we observed a CNS-NC incidence of 17%. The development of CNS-NC was associated with decreased overall survival (OS) and increased transplantation-related mortality (TRM). The most frequent CNS-NCs were infections (30%) and neurologic adverse events related to the administration of CNI, TAC, or CsA as GVHD prophylaxis (42%). In the multivariable analysis, age, total body irradiation (TBI), and severe acute GVHD and chronic GVHD were significant risk factors in the development of CNS-NCs. TAC compared with CsA emerged as an independent predisposing factor for CNS-NCs. The TAC-associated risk of CNS-NCs was related mostly to the occurrence of transplantation-associated thrombotic microangiopathy (TA-TMA) with neurologic manifestations (neuro-TA-TMA), although the general TA-TMA incidence was comparable in the 2 CNI subgroups. CNS-NCs are associated with poor prognosis after allo-HSCT, with TAC emerging as a potential yet insufficiently characterized predisposing factor.

Comparison of tacrolimus vs. cyclosporine in pediatric hematopoietic stem cell transplantation for thalassemia

OBJECTIVES

Graft-versus-host disease (GvHD) is one of the leading causes of morbidity and mortality in patients undergoing allogeneic HSCT, and effective prevention of GvHD is critical for the success of the HSCT procedure. Calcineurin inhibitors (CNI) have been used for decades as the backbone of GvHD prophylaxis. In this study, the efficacy and safety of Cyclosporine A (CsA) and tacrolimus (TCR) were compared in pediatric HSCT for thalassemia.

MATERIALS AND METHODS

This is a retrospective analysis of 129 pediatric patients who underwent HSCT with the diagnosis of thalassemia at Medicalpark Göztepe and Antalya Hospitals between January 2017 and December 2020.

RESULTS

Despite the GvHD prophylaxis, grade II-IV acute GvHD developed in 29 patients. Of these patients, 12 had only gut, 10 had only skin, 6 had combined gut and skin, and one had only liver GvHD. Fifteen of these 29 patients were in the CsA group, and 14 of them were in the TCR group. There was no significant difference between the groups in terms of acute GvHD occurrence, GvHD stage, or involvement sites. In terms of CNI-related toxicity, neurotoxicity in 15 (CsA n = 9, TCR n = 6) and nephrotoxicity in 18 (CsA n = 4, TCR n = 14) patients were observed. While there was no difference between the two groups in terms of neurotoxicity, more nephrotoxicity developed in patients using TCR (p = .013). There was no significant difference between the groups in terms of engraftment syndrome, veno-occlusive disease, CMV reactivation, PRES, or graft rejection.

CONCLUSION

Regarding GvHD, there was no difference in efficacy between TCR and CsA usage. Patients taking TCR experienced noticeably higher nephrotoxicity in terms of adverse effects. This difference should be considered according to the patient's clinical situation while choosing a CNI.

Chronic GVHD: review advances in prevention, novel endpoints, and targeted strategies

Allogeneic hematopoietic cell transplantation (allo-HCT) is a curative therapy for many malignant and non-malignant hematologic disorders. Chronic graft-versus-host (cGVHD) disease remains a significant hurdle for long-term survival in patients post allo-HCT, and it remains the leading cause of late non-relapse mortality. The risk factors for development of cGVHD include degree of human leukocyte antigen (HLA) disparity, increasing recipient age, use of peripheral blood stem cells as a source, myeloablative conditioning regimens, prior acute GVHD (aGVHD), and female donor to male recipient. Our biological understanding of cGVHD is mostly derived from transplantation mouse models and patient data. There are three distinct phases in the development of cGVHD. Approaches to prevent GVHD include pharmacologic strategies such as calcineurin inhibitors (cyclosporine, tacrolimus) combined with methotrexate or mTOR inhibitors (sirolimus), and IMP dehydrogenase inhibitors (mycophenolate mofetil). Increasingly, posttransplant cyclophosphamide is emerging as a promising strategy for GVCHD prevention especially in a setting of reduced intensity conditioning. Other approaches include serotherapy (ATG, Campath) and graft manipulation strategies. A significant obstacle to evaluating the response of novel GVHD-directed therapies has been standardized response assessments. This has functioned as a barrier to designing and interpreting clinical trials that are structured around the treatment of cGVHD. Novel endpoints including failure-free survival, Graft-versus-host disease-free, relapse-free survival (GRFS), and current GVHD-free, relapse-free survival (CGRFS) may create a clearer picture for post-HCT outcomes. Targeted therapies including Bruton's tyrosine kinase inhibition, JAK1/2 inhibition, and ROCK2 inhibitors have improved cGVHD therapy, especially in the steroid refractory setting. Continued improvement in prophylactic strategies for cGVHD, identification of accurate cGVHD treatment endpoints, and access to novel therapeutic agents are expected to improve cGVHD outcomes.

Incidence, severity, and temporal development of oral complications in pediatric allogeneic hematopoietic stem cell transplant patients - a multicenter study

PURPOSE

Oral mucositis is a common complication for patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) and causes pain and difficulties in functions like eating and swallowing, resulting in lower quality of life and greater need of treatment with opioids and parenteral nutrition. This prospective multicenter study focused on pediatric recipients of HSCT in the neutropenic phase concerning oral complications, timing, severity, and patient experience.

METHODS

The cohort comprised 68 patients, median age 11.1 years (IQR 6.3) receiving allogeneic HSCT at three clinical sites. Medical records were retrieved for therapy regimens, concomitant medications, oral and dental history, and subjective oral complaints. Calibrated dentists conducted an oral and dental investigation before HSCT. After HSCT graft infusion, study personnel made bedside assessments and patients filled out a questionnaire once or twice a week until neutrophil engraftment.

RESULTS

We followed 63 patients through the neutropenic phase until engraftment. 50% developed oral mucositis of grades 2-4. Peak severity occurred at 8-11 days after stem cell infusion. Altogether, 87% had subjective oral complaints. The temporal distribution of adverse events is similar to the development of oral mucositis. The most bothersome symptoms were blisters and oral ulcerations, including mucositis; 40% reported severe pain and major impact on activities of daily living despite continuous use of opioids.

CONCLUSION

This study highlights the burden of oral complications and their negative effect on the health and quality of life of HSCT recipients.

Acute graft-versus-host disease

Acute graft-versus-host disease (GVHD) is a common immune complication that can occur after allogeneic haematopoietic cell transplantation (alloHCT). Acute GVHD is a major health problem in these patients, and is associated with high morbidity and mortality. Acute GVHD is caused by the recognition and the destruction of the recipient tissues and organs by the donor immune effector cells. This condition usually occurs within the first 3 months after alloHCT, but later onset is possible. Targeted organs include the skin, the lower and upper gastrointestinal tract and the liver. Diagnosis is mainly based on clinical examination, and complementary examinations are performed to exclude differential diagnoses. Preventive treatment for acute GVHD is administered to all patients who receive alloHCT, although it is not always effective. Steroids are used for first-line treatment, and the Janus kinase 2 (JAK2) inhibitor ruxolitinib is second-line treatment. No validated treatments are available for acute GVHD that is refractory to steroids and ruxolitinib, and therefore it remains an unmet medical need.

AAV-mediated expression of HLA-G for the prevention of experimental ocular graft vs. host disease

Ocular graft versus host disease (OGvHD) develops after allogeneic hematopoietic stem cell transplantation (HSCT) and manifests as ocular surface inflammatory disease. This study evaluated the efficacy of adeno-associated virus (AAV) gene therapy encoding human leukocyte antigen G (HLA-G) to inhibit OGvHD. A major histocompatibility mismatch chronic OGvHD murine model was evaluated. 7 days after HSCT, mice were dosed subconjunctivally with scAAV8-HLA-G1/5 (1 x 109 vg/eye), topical cyclosporine (twice daily), or left untreated. Body weights and tear production (red thread test) were recorded, and eyelid, corneal opacity, and corneal fluorescein retention were scored through day 44 after HSCT. Tissues were collected for vector biodistribution, ocular histology, and immunofluorescence. Compared with untreated HSCT eyes, those dosed with scAAV8-HLA-G1/5 had significantly reduced clinical inflammatory signs of OGvHD. On histology, eyes that received scAAV8-HLA-G1/5 or cyclosporine had a significantly lower mean limbal mononuclear cell count when compared with non-treated HSCT eyes. HLA-G immunofluorescence was detected in the subconjunctiva and peripheral cornea in HSCT animals treated with scAAV8-HLA-G1/5. Vector genomes were detected in the lacrimal gland, but not in the other tested organs. These results provide evidence that subconjunctival AAV targets ocular surface and corneal disease and support that HLA-G-based gene therapy may be an effective treatment for OGvHD.

Acute Graft-versus-Host Disease: An Update on New Treatment Options

Acute graft-versus-host disease (GVHD) occurs in approximately 50% of patients and remains a primary driver of non-relapse and transplant-related mortality. The best treatment remains prevention with either in vivo or ex vivo T-cell depletion, with multiple strategies used worldwide based on factors such as institution preference, ability to perform graft manipulation, and ongoing clinical trials. Predicting patients at high risk for developing severe acute GVHD based on clinical and biomarker-based criteria allows for escalation or potential de-escalation of therapy. Modern therapies for treatment of the disease include JAK/STAT pathway inhibitors, which are standard of care in the second-line setting and are being investigated for upfront management of non-severe risk based on biomarkers. Salvage therapies beyond the second-line remain suboptimal. In this review, we will focus on the most clinically used GVHD prevention and treatment strategies, including the accumulating data on JAK inhibitors in both settings.

Effect of mTOR Inhibition with Sirolimus on Natural Killer Cell Reconstitution in Allogeneic Stem Cell Transplantation

Sirolimus is an inhibitor of the mammalian target of rapamycin (mTOR) and is emerging as a promising component of graft-versus-host disease (GVHD) prophylaxis regimens in the context of allogeneic hematopoietic stem cell transplantation (HSCT). Multiple studies have explored the clinical benefits of adding sirolimus to GVHD prophylaxis; however, detailed immunologic studies have not yet been carried out in this context. Mechanistically, mTOR is at the center of metabolic regulation in T cells and natural killer (NK) cells and is critical for their differentiation to mature effector cells. Therefore, close evaluation of the inhibition of mTOR in the context of immune reconstitution post-HSCT is warranted. In this work, we studied the effect of sirolimus on immune reconstitution using a biobank of longitudinal samples from patients receiving either tacrolimus/sirolimus (TAC/SIR) or cyclosporin A/methotrexate (CSA/MTX) as conventional GVHD prophylaxis. Healthy donor controls, donor graft material, and samples from 28 patients (14 with TAC/SIR, 14 with CSA/MTX) at 3 to 4 weeks and 34 to 39 weeks post- HSCT were collected. Multicolor flow cytometry was used to perform broad immune cell mapping, with a focus on NK cells. NK cell proliferation was evaluated over a 6-day in vitro homeostatic proliferation protocol. Furthermore, in vitro NK cell responses to cytokine stimulation or tumor cells were evaluated. Systems-level assessment of the immune repertoire revealed a deep and prolonged suppression (weeks 34 to 39 post-HSCT) of the naïve CD4 T cell compartment with relative sparing of regulatory T cells and enrichment of CD69⁺Ki-67⁺HLA-DR⁺ CD8 T cells, independent of the type of GVHD prophylaxis. Early after transplantation (weeks 3 to 4), while patients were still on TAC/SIR or CSA/MTX, we found a relative increase in less-differentiated CD56^bright NK cells and NKG2A⁺CD57^-KIR^- CD56^dim NK cells and a distinct loss of CD16 and DNAM-1 expression. Both regimens led to suppressed proliferative responses ex vivo and functional impairment with preferential loss of cytokine responsiveness and IFN-γ production. Patients who received TAC/SIR as GVHD prophylaxis showed delayed NK cell reconstitution with lower overall NK cell counts and fewer CD56^bright and NKG2A⁺ CD56^dim NK cells. Treatment with sirolimus- containing regimens generated similar immune cell profiles as conventional prophylaxis; however, the NK cell compartment seemed to be composed of slightly more mature NK cells. These effects were also present after the completion of GVHD prophylaxis, suggesting that mTOR inhibition with sirolimus leaves a lasting imprint on homeostatic proliferation and NK cell reconstitution following HSCT.

T cell receptor excision circles are potential predictors of survival in adult allogeneic hematopoietic stem cell transplantation recipients with acute myeloid leukemia

Background

Lymphocyte neogenesis from primary lymphoid organs is essential for a successful reconstitution of immunity after allogeneic hematopoietic stem cell transplantation (HSCT). This single-center retrospective study aimed to evaluate T cell receptor excision circles (TREC) and kappa-deleting recombination excision circles (KREC) as surrogate markers for T and B cell recovery, as predictors for transplantation-related outcomes in adult acute myeloid leukemia (AML) patients.

Methods

Ninety adult patients diagnosed with AML and treated with HSCT between 2010 and 2015 were included in the study. TREC and KREC levels were measured by quantitative PCR at 1, 3, 6, and 12 months after transplantation.

Results

Overall, excision circle levels increased between 3 and 6 months post-HSCT for TREC (p = 0.005) and 1 and 3 months for KREC (p = 0.0007). In a landmark survival analysis at 12 months post-HSCT, TREC levels were associated with superior overall survival (HR: 0.52, 95% CI: 0.34 - 0.81, p = 0.004). The incidence of viral infections within the first 100 days after transplantation was associated with lower TREC levels at 6 months (p = 0.0002). CMV reactivation was likewise associated with lower TREC levels at 6 months (p = 0.02) post-HSCT. KREC levels were not associated with clinical outcomes in statistical analyzes.

Conclusions

Results from the present study indicate that TREC measurement could be considered as part of the post-HSCT monitoring to identify AML patients with inferior survival after transplantation. Further prospective studies are warranted to validate these findings.

The Importance of Secretor-Status in Norovirus Infection Following Allogeneic Hematopoietic Stem Cell Transplantation

Background. Human secretor-status is a strong susceptibility factor for norovirus infection in immunocompetent people. The predominant norovirus genotype GII.4 almost exclusively infects secretors and is also associated with more severe symptoms. However, it is not known to what extent this also applies to immunocompromised individuals. Our objective was to determine the importance of secretor-status and norovirus genotype for the susceptibility and/or the clinical course of norovirus infection in allogeneic hematopoietic stem cell transplant (HCT) patients. Methods: This was a retrospective study of 89 HCT patients diagnosed with norovirus infection. Secretor-status and norovirus genotype were determined using stored extracted DNA or blood (n = 89) and fecal samples (n = 22), respectively. Results: Seven of eighty-nine (8%) of the patients were secretor-negative, a small proportion compared to the expected rate of at least 20% non-secretors in the general Swedish population. Among the genotyped samples, norovirus genotype GII.4 was predominant (n = 12) and only detected in secretor-positive individuals. Patients with norovirus GII.4 had a median symptom duration of 36 (3–681) days compared to 15 (1–94) days in patients infected with other norovirus genotypes (n = 10, p = 0.1). Conclusions: The results suggest that secretor-status affects the susceptibility to norovirus infection even when the immune system is severely compromised. The norovirus genotype may also be a risk factor for chronic norovirus symptoms in immunocompromised patients.

Efficacy of azacitidine in preventing relapse after hematopoietic stem cell transplantation for advanced myeloid malignancies: a systematic review and meta-analysis

BACKGROUND

Relapse is the leading cause of death from myeloid malignancies after allogeneic hematopoietic stem cell transplantation (HSCT). Azacitidine has gained attention in recent years in the prophylaxis of relapsed refractory hematologic malignancies. This study evaluated the efficacy of AZA in preventing relapse after HSCT in patients with myeloid malignancies.

METHODS

A systematic review and meta-analysis of all available cohort studies were performed regarding the application of AZA for prophylaxis of relapse after HSCT for advanced MDS and AML. Databases were searched for relevant studies. Endpoints included 2-year relapse rate, survival, relapse-related mortality, as well as the incidence of graft-versus-host disease (GVHD).

RESULTS

A total of 444 patients from 13 studies were included in this analysis. The pooled estimate of the cumulative incidence of relapse after two years in enrolled patients was 25% (95% confidence interval [CI], 18%-33%). The pooled estimates of 2-year survival probabilities were 65% (95% CI, 50%-79%). The pooled cumulative incidence of relapse-related mortality was 28% (95% CI, 22%-34%). The pooled estimated incidence of acute and chronic GVHD, respectively, were 28% (95% CI, 22%-34%) and 38% (95% CI, 27%-49%).

CONCLUSION

AZA administration is efficacious for relapse prevention after HSCT in myeloid malignancies.

Different recovery patterns of CMV-specific and WT1-specific T cells in patients with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplantation: Impact of CMV infection and leukemia relapse

In allogeneic hematopoietic cell transplantation (allo-HSCT), both virus-specific T cells and leukemia-specific T cells need to be reconstituted to protect patients from virus infections and primary disease relapse. Cytomegalovirus (CMV) infection remains an important cause of morbidity and mortality after allo-HSCT. Emerging data indicate that CMV reactivation is associated with reduced risk of leukemia relapse in patients with acute myeloid leukemia (AML) undergoing allo-HSCT. In a cohort of 24 WT1+ AML patients during the first year following HSCT, CMV specific CD8+ T cells (CMV-CTL) reconstituted much faster than WT1-specific CD8+ T cell (WT1-CTL) after allo-SCT. Moreover, CMV-CTL expressed lower levels of exhaustion markers and were more functional as identified by production of IFN-γ/TNF-α and expression of Eomes/T-bet. Interestingly, our patients with CMV reactivation presented higher frequency of CMV-CTL, lower levels of Eomes+T-bet- and higher levels of Eomes+T-bet+ expression in response to WT1 and CMV pp65 antigen during the first year after transplantation as compared to patients without CMV reactivation. Kinetics of CMV-CTL and WT1-CTL after transplantation might be associated with measurable residual disease and later leukemia relapse. Our results support that CMV reactivation, aside from the CMV-CTL reconstitution, could influence WT1-CTL reconstitution after allo-HSCT, thus potentially contributing to the remission/relapse of AML.

Hematopoietic Cell Transplantation, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Hematopoietic cell transplantation (HCT) involves the infusion of hematopoietic progenitor cells into patients with hematologic disorders with the goal of re-establishing normal hematopoietic and immune function. HCT is classified as autologous or allogeneic based on the origin of hematopoietic cells. Autologous HCT uses the patient's own cells while allogeneic HCT uses hematopoietic cells from a human leukocyte antigen-compatible donor. Allogeneic HCT is a potentially curative treatment option for patients with certain types of hematologic malignancies, and autologous HCT is primarily used to support patients undergoing high-dose chemotherapy. Advances in HCT methods and supportive care in recent decades have led to improved survival after HCT; however, disease relapse and posttransplant complications still commonly occur in both autologous and allogeneic HCT recipients. Allogeneic HCT recipients may also develop acute and/or chronic graft-versus-host disease (GVHD), which results in immune-mediated cellular injury of several organs. The NCCN Guidelines for Hematopoietic Cell Transplantation focus on recommendations for pretransplant recipient evaluation and the management of GVHD in adult patients with malignant disease.

Allogeneic Stem Cell Transplantation in Mature T Cell and Natural Killer/T Neoplasias: A Registry Study from Spanish GETH/GELTAMO Centers

Despite advances in understanding the biology of mature T and natural killer (NK)/T cell neoplasia, current therapies, even the most innovative ones, are still far from ensuring its cure. The only treatment to date that has been shown to control aggressive T cell neoplasms in the long term is allogeneic stem cell transplantation (alloSCT). We aim to report the results of alloSCT for advanced mature T and NK/T neoplasias performed in centers from our national GELTAMO/GETH (Grupo Español de Linfoma y Trasplante de Médula Ósea/Grupo Español de Trasplante Hematopoyético y Terapia Celular) over the past 25 years. As a secondary objective, we analyzed the results of alloSCT from haploidentical donors. We performed a retrospective analysis of all patients who received an alloSCT in Spanish centers (n = 201) from September 1995 to August 2018. The 2-year overall survival (OS) and disease-free survival (DFS) were 65.5% and 58.2%, respectively. The univariate for OS and DFS showed statistically different hazard ratios for conditioning intensity, response pre-alloSCT, comorbidity index, donor/receptor cytomegalovirus status and Eastern Cooperative Oncology Group (ECOG) pre-alloSCT, but only a better ECOG pre-alloSCT remained significant in the multivariate analysis. There was an increased incidence of relapse in those patients who did not develop chronic graft-versus-host disease (GVHD) and an increased risk of death in those developing moderate to severe acute GVHD. The 1-year nonrelapse mortality was 21.9% and was mainly due to GVHD (30%) and bacterial infections (17%). When comparing unrelated donors with haploidentical donors, we found similar results in terms of OS and DFS. There was, however, a reduction of acute GVHD in the haploidentical group (P = .04) and trend to a reduction of chronic GVHD. In conclusion, alloSCT is the only curative option for most aggressive T cell neoplasias. Haploidentical donors offer similar results to related donors in terms of survival with a reduction of acute GVHD.

Cytokine levels following allogeneic hematopoietic cell transplantation: a match-pair analysis of home care versus hospital care

Following allogeneic hematopoietic cell transplantation (HCT), patients living near the hospital were treated at home instead of in isolation in the hospital. We analyzed cytokines using Luminex assays for the first 3 weeks after HCT and compared patients treated at home (n = 42) with matched patients isolated in the hospital (n = 37). In the multivariate analysis, patients treated at home had decreased GM-CSF, IFN-γ (p < 0.01), IL-13, IL-5 (p < 0.05), and IL-2 (p < 0.07). Bloodstream infections, anti-thymocyte globulin, G-CSF treatment, immunosuppression, reduced-intensity conditioning (RIC), related vs. unrelated donors, and graft source affected various cytokine levels. When patients with RIC were analyzed separately, home care patients had reduced G-CSF (p = 0.04) and increased vascular endothelial growth factor (VEGF, p = 0.001) at 3 weeks compared with hospital care patients. Patients with low GM-CSF (p < 0.036) and low IFNγ (p = 0.07) had improved survival. Acute GVHD grades III-IV was seen in 7% and 16% of home care and hospital care patients, respectively. One-year transplantation-related mortality was 7% and 16% and survival at 5 years was 69% and 57% in the two groups, respectively. To conclude, patients treated in the hospital showed varying increased levels of GM-CSF, IFN-γ, IL-13, G-CSF, IL-5, and IL-2 and decreased VEGF, which may contribute to acute GVHD.

Evaluating risk factors for acute graft versus host disease in pediatric hematopoietic stem cell transplant patients receiving tacrolimus

To identify the clinical and pharmacological risk factors associated with tacrolimus pharmacodynamics for acute graft‐versus‐host disease (aGVHD) in pediatric patients receiving allogeneic hematopoietic stem cell transplantation (HSCT) from a matched related donor. A retrospective cohort single center chart review study was conducted with pediatric patients who received tacrolimus prophylaxis after allogeneic HSCT between January 1, 2017, and December 31, 2019. Potential risk factors were tested separately between aGVHD and non‐aGVHD cohorts and were further analyzed in a logistic regression model with backward elimination and a partial least squares discriminant analysis. Thirty‐three patient cases were included in our study and 52% (17/33) developed aGVHD while on tacrolimus prophylaxis. When tested independently, donor age and sibling versus parent donor/recipient relation were shown to be statistically significant between aGVHD and non‐aGVHD patients (p < 0.005). Pharmacological factors associated with tacrolimus treatment failed to demonstrate a significant impact on patient’s risk of aGVHD. Using a best fit logistic regression model that tested all the variables together, donor age was the only significant variable predicting patient’s risk of aGVHD (p < 0.01). Donor relationship and donor age were unable to be evaluated separately and are therefore confounding variables. Among pediatric patients receiving allogeneic HSCT, aGVHD risk is significantly decreased by either sibling donor and/or younger donors. Although no conclusions were drawn on the effect of tacrolimus therapy (p = 0.08), results warrant additional research with a larger sample size to evaluate the accuracy of monitoring tacrolimus serum trough levels.

Dipeptidyl Peptidase 4 Inhibition for Prophylaxis of Acute Graft-versus-Host Disease

BACKGROUND

Dipeptidyl peptidase 4 (DPP-4; also known as CD26), a transmembrane receptor expressed on T cells, has a costimulatory function in activating T cells. In a mouse model, down-regulation of CD26 prevented graft-versus-host disease (GVHD) but preserved graft-versus-tumor effects. Whether inhibition of DPP-4 with sitagliptin may prevent acute GVHD after allogeneic stem-cell transplantation is not known.

METHODS

We conducted a two-stage, phase 2 clinical trial to test whether sitagliptin plus tacrolimus and sirolimus would reduce the incidence of grade II to IV acute GVHD from 30% to no more than 15% by day 100. Patients received myeloablative conditioning followed by mobilized peripheral-blood stem-cell transplants. Sitagliptin was given orally at a dose of 600 mg every 12 hours starting the day before transplantation until day 14 after transplantation.

RESULTS

A total of 36 patients who could be evaluated, with a median age of 46 years (range, 20 to 59), received transplants from matched related or unrelated donors. Acute GVHD occurred in 2 of 36 patients by day 100; the incidence of grade II to IV GVHD was 5% (95% confidence interval [CI], 1 to 16), and the incidence of grade III or IV GVHD was 3% (95% CI, 0 to 12). Nonrelapse mortality was zero at 1 year. The 1-year cumulative incidences of relapse and chronic GVHD were 26% (95% CI, 13 to 41) and 37% (95% CI, 22 to 53), respectively. GVHD-free, relapse-free survival was 46% (95% CI, 29 to 62) at 1 year. Toxic effects were similar to those seen in patients undergoing allogeneic stem-cell transplantation.

CONCLUSIONS

In this nonrandomized trial, sitagliptin in combination with tacrolimus and sirolimus resulted in a low incidence of grade II to IV acute GVHD by day 100 after myeloablative allogeneic hematopoietic stem-cell transplantation. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT02683525.).

Current Prophylaxis and Treatment Approaches for Acute Graft-Versus-Host Disease in Haematopoietic Stem Cell Transplantation for Children With Acute Lymphoblastic Leukaemia

Acute graft-versus-host disease (aGvHD) continues to be a leading cause of morbidity and mortality following allogeneic haematopoietic stem cell transplantation (HSCT). However, higher event-free survival (EFS) was observed in patients with acute lymphoblastic leukaemia (ALL) and grade II aGvHD vs. patients with no or grade I GvHD in the randomised, controlled, open-label, international, multicentre Phase III For Omitting Radiation Under Majority age (FORUM) trial. This finding suggests that moderate-severity aGvHD is associated with a graft-versus-leukaemia effect which protects against leukaemia recurrence. In order to optimise the benefits of HSCT for leukaemia patients, reduction of non-relapse mortality-which is predominantly caused by severe GvHD-is of utmost importance. Herein, we review contemporary prophylaxis and treatment options for aGvHD in children with ALL and the key challenges of aGvHD management, focusing on maintaining the graft-versus-leukaemia effect without increasing the severity of GvHD.

Oral mucositis after tacrolimus/sirolimus or cyclosporine/methotrexate as graft-versus-host disease prophylaxis

OBJECTIVES

To determine whether treatment with tacrolimus plus sirolimus (Tac/Sir) as a prophylaxis for graft-versus-host disease worsens severe oral mucositis and delays healing compared to cyclosporine plus methotrexate (CsA/Mtx) following haematopoietic stem cell transplantation.

SUBJECTS AND METHODS

The study comprised 141 patients: 73 randomized to receive Tac/Sir and 68 to receive CsA/Mtx. The oral mucositis assessment scale and toxicity grading according to WHO were used to assess the severity, peak and duration of oral mucositis from the day -3 to day 24 post-transplant.

RESULTS

Eighty-seven patients developed oral mucositis in the first 24 days post-transplant. No significant difference in oral mucositis severity between the Tac/Sir and CsA/Mtx groups was observed. The peak oral mucositis score occurred on day 10 in both groups. Although oral mucositis scores had returned to baseline in the CsA/Mtx group on day 24 post-transplant, no significant difference compared with the Tac/Sir group was found.

CONCLUSIONS

The introduction of tacrolimus/sirolimus as a graft-versus-host disease prophylaxis in haematopoietic stem cell transplantation increased neither the incidence nor severity of oral mucositis compared with cyclosporine/methotrexate. Furthermore, oral mucositis healing was not prolonged and followed the same time pattern as cyclosporine/methotrexate.

Targeting Signal 3 Extracellularly and Intracellularly in Graft-Versus-Host Disease

Allogeneic hematopoietic stem cell transplantation (allo-HCT) holds curative potential for many hematological disorders. However, the pathophysiology of the desired graft-versus-tumor effect is linked to life-threatening complications of acute graft-versus-host disease (GVHD). Allogeneic donor T lymphocytes are essential for causing GVHD, and their activation relies on the coordination of TCR engagement and co-stimulation, also known as Signal 1 and Signal 2. In addition to these signals, a network of secreted cytokines by immune cells provides a third signal, Signal 3, that is critical for the initiation and maintenance of GVHD. Strategies to target Signal 3 in human diseases have shown therapeutic benefit for inflammatory disorders such as Rheumatoid Arthritis and Inflammatory Bowel Disease. However, despite our growing understanding of their role in GVHD, the success of targeting individual cytokines has been modest with some notable exceptions. This review aims to describe current approaches toward targeting Signal 3 in clinical GVHD, and to highlight emerging studies in immune cell biology that may be harnessed for better clinical translation.

The CD34+ Cell Dose Matters in Hematopoietic Stem Cell Transplantation with Peripheral Blood Stem Cells from Sibling Donors

The effect of CD34⁺ cell dose in allogeneic hematopoietic stem cell transplantation (HSCT) on overall survival (OS) and incidence of acute and chronic graft-versus-host disease (GvHD) has not been established and few studies have been performed. Our single center analysis included 189 patients with hematological malignancies who received peripheral blood stem cell (PBSC) grafts from sibling donors. Myeloablative conditioning was used in 88 cases and 101 received reduced intensity conditioning. The median CD34⁺ cell dose was 5.6 × 10⁶/kg (0.6–17.0). In the multivariate analysis, a CD34 cell dose of 6–7 × 10⁶/kg was associated with better OS and lower transplant-related mortality (TRM), while a dose of <5 × 10⁶/kg led to increased relapse and reduced chronic GVHD (cGVHD). A high CD34 cell-dose (>6.5 × 10⁶/kg) correlated with less acute GVHD (aGVHD) II–IV. We conclude that the CD34 cell dose has an impact on the outcome of HSCT from sibling donor PBSCs.

Hepatitis E virus is an infrequent but potentially serious infection in allogeneic hematopoietic stem cell transplant recipients

Hepatitis E virus (HEV) can cause chronic infection and liver cirrhosis in immunocompromised individuals. The frequency and clinical importance of HEV was studied retrospectively in a cohort of 236 Swedish allogeneic hematopoietic stem cell transplantation (HSCT) recipients. In blood samples collected at 6 months after HSCT, HEV RNA was identified in 8/236 (3.4%) patients, and 11/236 (4.7%) patients had detectable anti-HEV IgG and/or IgM, eight of whom were HEV RNA negative. Two of the patients with positive HEV RNA died with ongoing signs of hepatitis: one of acute liver and multiple organ failure, the other of unrelated causes. The remaining six patients with HEV RNA had cleared the infection at 7-24 (median 8.5) months after HSCT. HEV infection was associated with elevated alanine aminotransferase at 6 months after HSCT (OR 15, 1.3-174, p = 0.03). Active graft-versus-host disease of the liver at 6 months after HSCT was present in 3/8 (38%) patients with HEV RNA, but was not significantly associated with HEV infection. In conclusion, HEV infection is an important differential diagnosis in patients with elevated liver enzymes after HSCT. Although spontaneous clearance was common, the clinical course may be severe.

Calcineurin Inhibitors Replacement by Ruxolitinib as Graft-versus-Host Disease Prophylaxis for Patients after Allogeneic Stem Cell Transplantation

Graft-versus-host disease (GVHD) is a common complication of allogeneic stem cell transplantation (allo-SCT) that carries a high mortality. Although calcineurin inhibitors (CNIs) have been widely used in GVHD prophylaxis, the incidence of acute GVHD (aGVHD) remains at roughly 30% to 50%. Moreover, some allo-SCT recipients cannot tolerate CNI. Thus, improved GVHD prevention methods are needed. Our study aimed to determine the prophylactic value of ruxolitinib for GVHD in CNI-intolerant patients after allo-SCT. Between September 2017 and March 2019, 10 patients with hematopoietic malignancies after allo-SCT who were intolerant to CNI at our center were enrolled in this study. The regimens were based on a myeloablative busulfan and cyclophosphamide regimen. Antithymocyte globulin was administered to patients with an HLA-haploidentical related donor (HRD) at a dosage of 6 mg/kg. All received ruxolitinib to replace CNI as GVHD prophylaxis. Ruxolitinib was initiated at 5 to 10 mg twice daily until 2 to 3 months post-transplantation and then tapered gradually, and in the absence of GVHD, discontinued by day +180. Eight patients had acute leukemia, 1 patient had myeloproliferative neoplasm, and 1 patient had natural killer T cell (NK/T) lymphoma. The donor type was a matched sibling donor in 3 patients and an HLA-haploidentical related donor (HRD) in 7 patients. All patients received CNI plus short-course of methotrexate as GVHD prophylaxis, but showed intolerance to CNI within 45 days post-transplantation. After ruxolitinib replacement, only 1 patient (10%) developed grade II skin aGVHD within 100 days, and only 1 patient developed severe aGVHD after 100 days. Two patients developed moderate/severe chronic GVHD (cGVHD) after tapering or stopping ruxolitinib, resulting in a 1-year cumulative incidence of moderate/severe cGVHD of 21.4%. Cytomegalovirus (CMV) reactivation occurred in 4 patients (40%), and Epstein-Barr virus (EBV) reactivation occurred in 3 patients (30%). None of the patients developed CMV disease or EBV post-transplantation lymphoproliferative disorder. After a median follow-up of 11 months (range, 2 to 15.5 months), 2 patients (20%) relapsed and 7 (70%) were alive, of whom 6 (60%) were negative for minimal residual disease and 4 were off immunosuppressant therapy. The prophylactic application of ruxolitinib for CNI-intolerant patients after allo-SCT appears to be safe and effective in preventing GVHD, but this awaits further study in larger cohorts.

Prevention and Treatment of Acute Graft-versus-Host Disease in Children, Adolescents, and Young Adults

Acute graft-versus-host disease (GVHD) continues to be a major cause of morbidity and mortality after allogeneic hematopoietic cell transplant (HCT) in pediatric patients (ie, children and adolescent and young adults) and limits broader application of the therapy. Pediatric HCT patients have faced major obstacles to access clinical trials that test new agents for GVHD prevention and treatment. According to a recent search, only 6 clinical trials of interventions for prevention or treatment of acute GVHD were conducted specifically in pediatric patients in the United States over the past decade, with 8 internationally. In this review, we summarize the studies that were performed and specifically enrolled and reported on pediatric patients after allogeneic HCT and provide a listing of studies currently under way.

The underreporting of phase III chemo-therapeutic clinical trial data of older patients with cancer: A systematic review

PURPOSE

Inspired by the American Society of Clinical Oncology's recommendations to strengthen the evidence base for older adults with cancer, the purpose of this systematic review is to identify the reporting of treatment efficacy and adverse events specific to older adults with cancer in Phase III chemo-therapeutic clinical trials. This review also investigates the frequency with which these data points were reported in the literature to identify gaps in reporting and opportunities to expand the knowledge base on clinical outcomes for older adults with cancer.

METHODS

Chemo-therapeutic clinical trial data published from July 1, 2016 to June 30, 2017 was reviewed. Manuscripts (n = 929) were identified based on keyword searches of EMBASE and PubMed. After removal of duplicates (n = 116) and articles that did not meet this study's inclusion criteria (n = 654), 159 articles were identified for review.

RESULTS

Reviewed papers were published in 36 different scientific journals and included twenty-five different cancer types. Of the 159 articles, 117 (73.6%) reported age-specific medians and 75 (47.2%) included stratifications of data by age. Treatment efficacy was reported in 96.2% of the articles with 39.9% reporting effectiveness of treatment by age. Reporting of adverse events was included in 84.9% of the articles with only 8.9% reporting these events stratified by age.

CONCLUSION

Results suggest inadequate reporting of treatment efficacy and adverse events as well as basic descriptive statistics about the age distribution of study subjects. Conscious efforts are needed to address these deficiencies at every level of planning and conducting clinical trials as wells as reporting outcomes stratified by age. Ultimately, standardized reporting could lead to improved treatment decisions and outcomes for older adults with cancer.

Reduced Risk of Sinusoidal Obstruction Syndrome of the Liver after Busulfan-Cyclophosphamide Conditioning Prior to Allogeneic Hematopoietic Stem Cell Transplantation

The aim of this study is to evaluate the incidence of sinusoidal obstruction syndrome (SOS) of the liver and the clinical outcome after hematopoietic stem cell transplantation (HSCT) based on several modifications in our protocols. We retrospectively investigated 372 patients undergoing myeloablative conditioning with oral busulfan (Bu) and cyclophosphamide before allogeneic HSCT during 1990–2015. Patients' supportive care was changed in order to reduce the regimen‐related toxicities. Norethisterone use was terminated in 1998, therapeutic drug monitoring of Bu was initiated in 2000, and the use of liver supportive drugs, such as ursodeoxycholic acid and N‐acetyl‐L‐cysteine, were started in 2002 and 2009, respectively. In total, 26 patients (7.0%) developed SOS at a median of 19 days after transplantation. Of these 26 patients, 20 died at a median of 119 days after HSCT and 102 days after the diagnosis of SOS. The incidence of SOS decreased over time in accordance with the improvements in supportive care. The highest incidence of SOS was during 1995–1999 (16.2%) compared with 2.3% during 2010–2015. Overall survival for patients with SOS was 62%, 46%, and 27% at 100 days, 1 year, and 5 years after HSCT, respectively, compared with 92%, 77%, and 66% for those who did not develop SOS (P < 0.001). In conclusion, the incidence of SOS and related deaths were significantly decreased over the last years. Our institution pursues massive preventative and personalized measures for SOS. This strategy may also be applicable in other conditioning protocols in order to reduce the incidence of SOS and, hence, improve the clinical outcome.

Tacrolimus in adult hematopoietic stem cell transplantation

Introduction: Graft-versus-host disease (GVHD) is the most common complication of hematopoietic stem cell transplantation (HSCT); therefore, the prevention of GVHD is important for a successful treatment. Tacrolimus (Tac), a calcineurin inhibitor, has been widely used for the prophylaxis of GVHD in HSCT recipients. Areas covered: This review introduces phase II/III of clinical trials related with Tac's roles in the prevention of GVHD in HSCT. Furthermore, we discuss the normal ranges of Tac concentrations, pharmacogenetics, and drug interactions of Tac, as well as its side effects in adult HSCT recipients. Expert opinion: A series of studies has established the efficacy and safety of Tac alone or in combination with other agents in HSCT. However, successful administration of Tac is complicated by its narrow therapeutic window, inter-patient pharmacokinetic variability, and a spectrum of undesirable side effects. It is necessary to maintain concentrations of Tac within the desired ranges for GVHD prophylaxis. Moreover, various factors contribute to significant variability in Tac pharmacokinetics, including drug interactions and genomic variation.

Long-Term Follow-Up of a Pilot Study Using Placenta-Derived Decidua Stromal Cells for Severe Acute Graft-versus-Host Disease

There is a need for effective therapy with few side effects for severe acute graft-versus-host disease (GVHD). The placenta protects the fetus from the mother's haploidentical immune system during pregnancy. We found that maternal stromal cells from the fetal membrane, so-called decidua stromal cells (DSCs), are more immunosuppressive than other sources of stromal cells. We prospectively treated 21 patients (median age, 49 years; range, 1.6 to 72 years) for grade II-IV acute GVHD. All 21 patients had biopsy-proven gastrointestinal GVHD. The majority of patients were either steroid-refractory or had progressive GVHD, 11 patients after >7 days or with progression after 3 days, and 10 were refractory to steroids after >3 days. We used an improved protocol in which DSCs were thawed and infused in a buffer with 5% human albumin. DSCs were given at a median dose of 1.2 (range, 0.9 to 2.9) × 10⁶ cells/kg body weight with a median of 2 (range, 1 to 6) doses, given 1 week apart. The median viability of thawed DSCs was 93% (range, 69% to 100%), and the median cell passage number was 4 (range, 2 to 4). Complete resolution of GVHD was seen in 11 patients, with a partial response in the other 10. The cumulative incidence of chronic GVHD was 52%. GVHD was mild in 6 patients, moderate in 4 patients, and severe in 1 patient based on National Institutes of Health chronic GVHD severity scoring. Nine patients died, including 3 from relapse and 1 each from acute GVHD and septicemia, Zygomycetes infection, liver insufficiency, cerebral hemorrhage, multiple organ failure, and chronic GVHD with obstructive bronchiolitis. Four-year transplantation-related mortality was 28.6%, and overall survival was 57%. Survival was similar (P = .33) to that for all 293 patients who underwent allogeneic hematopoietic cell transplantation during the same period (2012 to 2015), with 66% overall survival. DSC infusion is a novel therapy for acute GVHD grade II-IV, and a randomized trial is currently underway (ClinicalTrials.gov NCT02172937).

Sirolimus-associated pericardial effusion with cardiac tamponade and interstitial pneumonitis in a hematopoietic stem cell transplant recipient

Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, is a potent immunosuppressant that is increasingly used in prevention and treatment of graft-vs-host disease (GVHD) in allogeneic hematopoietic stem cell transplant (HSCT) patients. However, data regarding its adverse effects in HSCT patients remain limited. We describe an 18-year-old HSCT patient with a history of invasive fungal infection, who developed pericardial effusion with cardiac tamponade and interstitial pneumonitis while receiving sirolimus for GVHD prophylaxis. Our case illustrates potentially life-threatening complications of sirolimus use in allogeneic HSCT patients.

Inferior Outcomes with Cyclosporine and Mycophenolate Mofetil after Myeloablative Allogeneic Hematopoietic Cell Transplantation

Combination therapy with a calcineurin inhibitor (CNI), such as cyclosporine (CSA) or tacrolimus (Tac), and methotrexate (MTX) or mycophenolate mofetil (MMF) is a widely used approach to graft-versus-host disease (GVHD) prevention. Data on the comparative effectiveness of MMF compared with MTX are limited and conflicting, however. We analyzed data from the Center for International Blood and Marrow Transplant Research for adult patients undergoing first myeloablative hematopoietic cell transplantation (HCT) from an HLA-identical matched related donor (MRD; n = 3979) or matched unrelated donor (URD; n = 4163) using CSA+MMF, CSA+MTX, Tac+MMF, or Tac+MTX for GVHD prevention between 2000 and 2013. Within the MRD cohort, 2252 patients received CSA+MTX, 1391 received Tac+MTX, 114 received CSA+MMF, and 222 received Tac+MMF. Recipients of CSA+MMF had a higher incidence of acute GVHD grade II-IV (hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.24 to 2.20; P < .001) and grade III-IV (HR, 1.92; 95% CI, 1.31 to 2.83; P < .001) compared with Tac+MTX. The use of CSA+MMF was also associated with inferior overall survival (OS) (HR, 2.31; 95% CI, 1.73 to 3.09; P < .001) due to higher transplantation-related mortality (TRM) (HR, 4.03; 95% CI, 2.61 to 6.23; P < .001) compared with Tac+MTX. Within the URD cohort, 974 patients received CSA+MTX, 2697 received Tac+MTX, 68 received CSA+MMF, and 424 received Tac+MMF. CSA+MMF was again significantly associated with a higher incidence of grade III-IV acute GVHD (HR, 2.31; 95% CI, 1.57 to 3.42; P <0001), worse OS (HR, 2.36; 95% CI, 1.67 to 3.35; P < .001), and higher TRM (HR, 3.09; 95% CI, 2.00 to 4.77; P < .001), compared with Tac+MTX and other regimens. Thus, this large retrospective comparison of MMF versus MTX in combination with CSA or Tac demonstrates significantly worse GVHD and survival outcomes with CSA+MMF compared with Tac+MTX.

Corticosteroids and methotrexate as adjuvants to costimulation blockade in non-human primate renal transplantation

Belatacept, the CD28-B7 costimulation pathway inhibitor, has been approved as a calcineurin inhibitor (CNI) alternative in kidney transplantation. Although costimulation blockade (CoB) allows for CNI avoidance, it is associated with increased rates of early rejection, prompting a search for agents to pair with belatacept. Methotrexate (MTX) is an antimetabolite that has been found to be complimentary with abatacept, a lower affinity CD28-B7-specific analogue of belatacept, in the treatment of rheumatoid arthritis (RA). We examined whether this synergy would extend to prevention of kidney allograft rejection. Rhesus macaques underwent kidney transplantation treated with abatacept maintenance therapy with either a steroid taper, MTX, or both. The combination of abatacept maintenance with steroids prolonged graft survival compared to untreated historical controls and previous reports of abatacept monotherapy. The addition of MTX did not provide additional benefit. These data demonstrate that abatacept with adjuvant therapy may delay the onset of acute rejection, but fail to show synergy between abatacept and MTX beyond that of steroids. These findings indicate that MTX is unlikely to be a suitable adjuvant to CoB in kidney transplantation, but also suggest that with further modification, a CoB regimen used for advanced RA may suffice for RA patients requiring kidney transplantation.

T-cell frequencies of CD8+ γδ and CD27+ γδ cells in the stem cell graft predict the outcome after allogeneic hematopoietic cell transplantation

The impact of intra-graft T cells on the clinical outcome after allogeneic hematopoietic cell transplantation has been investigated. Most previous studies have focused on the role of αβ cells while γδ cells have received less attention. It has been an open question whether γδ cells are beneficial or not for patient outcome, especially with regards to graft versus host disease. In this study, graft composition of γδ cell subsets was analyzed and correlated to clinical outcome in 105 recipients who underwent allogeneic hematopoietic cell transplantation between 2013 and 2016. We demonstrate for the first time that grafts containing higher T-cell proportions of CD8⁺γδ cells were associated with increased cumulative incidence of acute graft versus host disease grade II-III (50% vs 22.6%; P = 0.008). Additionally, graft T-cell frequency of CD27⁺γδ cells was inversely correlated with relapse (P = 0.006) and CMV reactivation (P = 0.05). We conclude that clinical outcome after allogeneic hematopoietic cell transplantation is influenced by the proportions of distinct γδ cell subsets in the stem cell graft. We also provide evidence that CD8⁺γδ cells are potentially alloreactive and may play a role in acute graft versus host disease. This study illustrates the importance of better understanding of the role of distinct subsets of γδ cells in allogeneic hematopoietic cell transplantation.

Sirolimus exposure and the occurrence of cytomegalovirus DNAemia after allogeneic hematopoietic stem cell transplantation

Sirolimus appears to protect against cytomegalovirus (CMV) in organ transplant recipients. The effect of this drug in allogeneic hematopoietic stem cell transplantation recipients remains unexplored. By means of multivariate continuous-time Markov model analyses, we identified 3 independent covariates that significantly impacted the risk of CMV DNAemia: recipient/donor CMV serostatus, tacrolimus exposure, and sirolimus exposure. CMV-seropositive recipients with CMV-seronegative donors had a significantly higher probability of having detectable CMV DNAemia. Increasing the tacrolimus trough concentration from 0 to 16 ng/mL increased the probability of patients having detectable CMV DNAemia by 40% (from 40% to 80%), whereas this probability decreased by 25% (from 40% to 15%) when trough concentrations of sirolimus increased from 0 to 16 ng/mL. Sensitivity analysis showed that sirolimus exposure between 0 and 6 ng/mL has no or negligible effect on CMV DNAemia, but levels >8 ng/mL significantly decreased the number of detectable CMV DNAemia cases (the risk ratios decreased from 0.68 to 0.21 when whole blood sirolimus concentrations changed from 8 to 18 ng/mL, P < .01). In conclusion, we used a pharmacometric statistical tool to provide the first clinical evidence that fewer CMV DNAemia events become detectable as sirolimus exposure increases.

Cytomegalovirus Infection Incidence and Risk Factors Across Diverse Hematopoietic Cell Transplantation Platforms Using a Standardized Monitoring and Treatment Approach: A Comprehensive Evaluation from a Single Institution

Human cytomegalovirus (CMV) infection and disease remains a significant cause of morbidity and mortality for hematopoietic cell transplantation (HCT) recipients. Disruption of or weak reconstitution of virus-specific cellular immune function, such as with certain HCT approaches, poses significant risk for CMV-related complications. The incidence of and risk factors for CMV infection and the nature of CMV disease were evaluated retrospectively among 356 consecutive HCT recipients transplanted at the National Institutes of Health using all graft sources, including bone marrow, peripheral blood stem cell (PBSC), and umbilical cord blood (UCB), and a range of in vivo and ex vivo approaches for graft-versus-host disease (GVHD) prophylaxis. The cumulative incidence of CMV infection was higher for CMV-seropositive recipients at 33%, regardless of donor CMV serostatus. Patients transplanted with CMV-seropositive donors had a significantly shorter duration of antiviral therapy. Among graft sources UCB was associated with the highest cumulative incidence of CMV infection at 65% and significantly longer treatment duration at a median of 36days, whereas PBSC HCT was associated with the lowest incidence at 26% and the shortest CMV treatment duration at a median of 21days. There were significant differences in the cumulative incidence of CMV infection by T cell manipulation strategy when systemic steroids were included as a risk-modifying event. Over one-third of CMV infections occurred in the setting of systemic steroid administration. CMV disease occurred in 5% of HCT recipients, with 70% of cases in the setting of treatment for GVHD. Although factors related to serostatus, graft source, and GVHD prophylaxis were associated with varied CMV infection incidence, unplanned post-HCT corticosteroid therapy contributed greatly to the incidence of both CMV infection and disease across HCT approaches, highlighting this post-HCT intervention as a key time to potentially tailor the approach to monitoring, preemptive therapy, and even prophylaxis.

Placenta-Derived Decidua Stromal Cells for Treatment of Severe Acute Graft-Versus-Host Disease

Severe acute graft‐versus‐host disease (GVHD) is a life‐threatening complication after allogeneic hematopoietic stem cell transplantation (HSCT). The placenta protects the fetus from the mother's immune system. We evaluated placenta‐derived decidua stromal cells (DSCs), which differ from bone marrow mesenchymal stromal cells (BM‐MSCs), as a treatment for severe acute GVHD. DSCs were obtained from term placentas. The DSCs were given to 38 patients with severe acute GVHD; 25 were steroid refractory (SR). DSCs were thawed and infused in buffer supplemented with either 10% AB plasma (group 1, n = 17), or 5% albumin (group 2, n = 21). The viability of cells was higher when thawed in albumin rather than AB plasma (p < .001). Group 1 received a higher cell dose (p < .001), cells of lower passage number (p < .001), and fewer infusions (p = .002) than group 2. The GVHD response (no/partial/complete) was 7/5/5 in group 1 and 0/10/11 in group 2 (p = .01). One‐year survival in the two groups was 47% (95% confidence interval [CI] 23–68) and 76% (95% CI 51–89), respectively (p = .016). For the SR patients, 1‐year survival was 73% (95% CI 37–90) in SR group 2 (n = 11), which was better than 31% (95% CI 11–54) in SR group 1 (n = 13; p = .02), 20% (95% CI 5–42) in BM‐MSC treated (n = 15; p = .0015), and 3% (95% CI 0–14) in historic controls (n = 32; p < .001). DSCs are a promising new treatment for severe acute GVHD. Prospective randomized trials are needed for evaluation of efficacy. (Clinical trial NCT‐02172937.) stemcellstranslationalmedicine2018;7:325–332

Change of apheresis device decreased the incidence of severe acute graft-versus-host disease among patients after allogeneic stem cell transplantation with sibling donors

BACKGROUND

The composition of the graft used for allogeneic hematopoietic stem cell transplantation (HSCT) is important for the treatment outcome. Different apheresis devices may yield significant differences in peripheral blood stem cell graft cellular composition. We compared stem cell grafts produced by Cobe Spectra (Cobe) and Spectra Optia (Optia) with use of the mononuclear cell (MNC) protocol, and evaluated clinical outcome parameters such as graft-versus-host disease (GvHD), transplant-related mortality (TRM), relapse, and overall survival.

STUDY DESIGN AND METHODS

During 5 years, 31 Cobe Spectra and 40 Spectra Optia grafts were analyzed for CD34, CD3, CD4, CD8, CD19, and CD56 cell content. Clinical outcome parameters were correlated and compared between the two patient groups using different apheresis devices.

RESULTS

Optia grafts contained fewer lymphocytes compared to Cobe (p < 0.001). Optia grafts had a significantly lower incidence of acute GvHD Grades II through IV (Cobe 45% vs. Optia 23%; p = 0.039) and TRM (16% vs. 2.5%; p < 0.05) but higher chronic GvHD (32% vs. 67%; p = 0.005) compared to Cobe grafts. Finally, the multivariate analysis showed a significant correlation among the different apheresis devices and both acute GvHD II through IV and severe chronic GvHD. The multivariate analysis also showed a significant correlation between the CD3+ cell dose and the incidence of severe acute GvHD.

CONCLUSION

Optia-obtained grafts yielded a lower acute GvHD Grades II-IV and TRM risk, but had no impact on relapse or overall survival in this study. Understanding and further improvement of peripheral blood stem cell (PBSC) apheresis techniques may be used in the future to personalize HSCT by, for example, fine-tuning the GvHD incidence.

Mucosal-Associated Invariant T Cells Display a Poor Reconstitution and Altered Phenotype after Allogeneic Hematopoietic Stem Cell Transplantation

Mucosal-associated invariant T (MAIT) cells are innate-like T cells which are important in the defense against certain bacteria and yeast. The reconstitution of MAIT cells after allogeneic hematopoietic stem cell transplantation (HSCT) is not known. We investigated MAIT cell phenotype and function in 17 patients devoid of relapse and severe graft-versus-host disease (GvHD) in paired samples collected 1-2, 3-6, 12, and 24 months after transplantation. Data were compared to 17 healthy controls (HC), as well as 22 patients with acute GvHD grade 2-3. The frequency of MAIT cells within CD3⁺ cells was approximately 10-fold lower than in HC and did not increase over the 2 years following HSCT. MAIT cells in HSCT patients displayed an elevated expression of CD69 and intracellular granzyme B and were predominantly composed of CD4/CD8 double-negative cells. The expression of PD-1 on MAIT cells was low and did not change during the observational time, whereas the CD3⁺CD161^dim/negTCRVα7.2^dim/neg cells (non-MAIT T cells) displayed a high expression early after HSCT that decreased to normal levels at 24 months. MAIT cells collected 2-6 months post-HSCT showed an impaired IFN-γ and perforin response after bacterial stimulation, but the response was restored at 24 months. Patients with acute GvHD had similar proportions of MAIT cells as patients with grade 0-1, but consisted mainly of CD8⁺ cells. Finally, MAIT cells were more sensitive to cyclosporine A and sirolimus than non-MAIT T cells. To conclude, MAIT cell reconstitution following HSCT is deficient compared to non-MAIT T cells and GvHD grade ≥2 is not correlated with MAIT cell frequency. MAIT cell functionality was impaired early after HSCT, but restored at 24 months post-HSCT. MAIT cells have an increased sensibility to common immunosuppressive drugs, which maybe could explain their hampered reconstitution after HSCT.

Long-term outcome in patients treated at home during the pancytopenic phase after allogeneic haematopoietic stem cell transplantation

Patients undergoing allogeneic haematopoietic stem cell transplantation (HSCT) were given the option to be treated at home during the pancytopenic phase. Daily visits by a nurse and phone calls from a physician from the unit were part of the protocol. During almost two decades, 252 patients with haematological malignancies and non-malignant disorders were included. Median age was 47 (range 0-72) years. Myeloablative conditioning was given to 102 patients and reduced intensity to 150. Donors were matched unrelated (n = 160), HLA-identical siblings (n = 71), or HLA-mismatched (n = 21). Cumulative incidence of acute graft-versus-host disease (GVHD) was 35% and that of chronic GVHD was 46%. Non-relapse mortality was 14% 10 years after HSCT. In patients with haematological malignancies (n = 229), the 10-year probability of relapse was 34%. No patients died at home. Overall survival was 59% and relapse-free survival was 50% after 10 years. We conclude that patients treated at home after HSCT have an encouraging long-term outcome.

Safety and Side Effects of Using Placenta-Derived Decidual Stromal Cells for Graft-versus-Host Disease and Hemorrhagic Cystitis

Mesenchymal stromal cells (MSCs) are increasingly used in regenerate medicine. Placenta-derived decidual stromal cells (DSCs) are a novel therapy for acute graft-versus-host-disease (GVHD) and hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (HSCT). DSCs are more immunosuppressive than MSCs. We assessed adverse events and safety using DSCs among 44 treated patients and 40 controls. The median dose of infused cells was 1.5 (range 0.9–2.9) × 10⁶ DSCs/kg. The patients were given 2 (1–5) doses, with a total of 82 infusions. Monitoring ended 3 months after the last DSC infusion. Three patients had transient reactions during DSC infusion. Laboratory values, hemorrhages, and transfusions were similar in the two groups. The frequency of leukemic relapse (2/2, DSC/controls) and invasive fungal infections (6/6) were the same in the two groups. Causes of death were those seen in HSCT patients: infections (5/3), respiratory failure (1/1), circulatory failure (3/1), thromboembolism (1/0), multiorgan failure (0/1), and GVHD and others (2/7). One-year survival for the DSC patients with GVHD was 67%, which was significantly better than achieved previously at our center. One-year survival was 90% in the DSC-treated HC group. DSC infusions appear safe. Randomized studies are required to prove efficacy.