A randomized controlled trial of cyclosporine and tacrolimus with strict control of blood concentrations after unrelated bone marrow transplantation

Pharmacokinetic Model of Drug Interaction of Tacrolimus with Combined Administration of CYP3A4 Inhibitors Voriconazole and Clarithromycin After Bone Marrow Transplantation

BACKGROUND AND OBJECTIVES

A pharmacokinetic model has been developed to quantify the drug-drug interactions of tacrolimus with concentration-dependent inhibition of cytochrome P450 (CYP) 3A4 from voriconazole and clarithromycin based on the CYP3A5 and CYP2C19 genotypes.

METHODS

This retrospective study recruited unrelated bone marrow transplant recipients receiving oral tacrolimus concomitantly with voriconazole and clarithromycin. The published population pharmacokinetic model that implemented genotypes of CYP3A5 (tacrolimus) and CYP2C19 (voriconazole) was integrated. The tested CYP3A4 inhibition models (Sigmoid efficacy maximum [Emax], Emax, log-linear, and linear) were a function of competitive inhibition of voriconazole and mechanism-based inhibition of clarithromycin in a virtual enzyme compartment.

RESULTS

The total tacrolimus trough concentrations were 119 points, with a median of 4.3 (range: 2.0-9.9) ng/mL (n = 3). The final model comprised the Sigmoid Emax model for voriconazole and clarithromycin, which depicted time-course alterations in tacrolimus concentration and clearance when given voriconazole and clarithromycin.

CONCLUSIONS

These findings could facilitate the model-informed precision dosing of tacrolimus after unrelated bone marrow transplant.

Current Approaches for the Prevention and Treatment of Acute and Chronic GVHD

Whereas aGVHD has strong inflammatory components, cGVHD displays autoimmune and fibrotic features; incidence and risk factors are similar but not identical; indeed, the aGVHD is the main risk factor for cGVHD. Calcineurin Inhibitors (CNI) with either Methotrexate (MTX) or Mycophenolate (MMF) still represent the standard prophylaxis in HLA-matched allogeneic stem cell transplantation (HSCT); other strategies focused on ATG, Post-Transplant Cyclophosphamide (PTCy), Abatacept and graft manipulation. Despite the high rate, first-line treatment for aGVHD is represented by corticosteroids, and Ruxolitinib is the standard second-line therapy; investigational approaches include Microbiota transplant and the infusion of Mesenchymal stem cells. GVHD is a pleiotropic disease involving any anatomical district; also, Ruxolitinib represents the standard for steroid-refractory cGVHD in this setting. It is a pleiotropic disease involving any anatomical district; also, Ruxolitinib represents the standard for steroid-refractory cGVHD in this setting. Extracorporeal Photopheresis (ECP) is still an option used for steroid refractoriness or to achieve a steroid-sparing. For Ruxolitinib-refractory cGVHD, Belumosudil and Axatilimab represent the most promising agents. Bronchiolitis obliterans syndrome (BOS) still represents a challenge; among the compounds targeting non-immune effectors, Alvelestat, a Neutrophil elastase inhibitor, seems promising in BOS. Finally, in both aGVHD and cGVHD, the association of biological markers with specific disease manifestations could help refine risk stratification and the availability of reliable biomarkers for specific treatments.

Single-center randomized trial of T-reg graft alone vs T-reg graft plus tacrolimus for the prevention of acute GVHD

ABSTRACT

Allogeneic hematopoietic cell transplantation (HCT) is a curative therapy for hematological malignancies for which graft-versus-host disease (GVHD) remains a major complication. The use of donor T-regulatory cells (Tregs) to prevent GVHD appears promising, including in our previous evaluation of an engineered graft product (T-reg graft) consisting of the timed, sequential infusion of CD34+ hematopoietic stem cells and high-purity Tregs followed by conventional T cells. However, whether immunosuppressive prophylaxis can be removed from this protocol remains unclear. We report the results of the first stage of an open-label single-center phase 2 study (NCT01660607) investigating T-reg graft in myeloablative HCT of HLA-matched and 9/10-matched recipients. Twenty-four patients were randomized to receive T-reg graft alone (n = 12) or T-reg graft plus single-agent GVHD prophylaxis (n = 12) to determine whether T-reg graft alone was noninferior in preventing acute GVHD. All patients developed full-donor myeloid chimerism. Patients with T-reg graft alone vs with prophylaxis had incidences of grade 3 to 4 acute GVHD of 58% vs 8% (P = .005) and grade 3 to 4 of 17% vs 0% (P = .149), respectively. The incidence of moderate-to-severe chronic GVHD was 28% in the T-reg graft alone arm vs 0% with prophylaxis (P = .056). Among patients with T-reg graft and prophylaxis, CD4+ T-cell-to-Treg ratios were reduced after transplantation, gene expression profiles showed reduced CD4+ proliferation, and the achievement of full-donor T-cell chimerism was delayed. This study indicates that T-reg graft with single-agent tacrolimus is preferred over T-reg graft alone for the prevention of acute GVHD. This trial was registered at www.clinicaltrials.gov as #NCT01660607.

Prophylaxis and management of graft-versus-host disease after stem-cell transplantation for haematological malignancies: updated consensus recommendations of the European Society for Blood and Marrow Transplantation

Graft-versus-host disease (GVHD) is a major factor contributing to mortality and morbidity after allogeneic haematopoietic stem-cell transplantation (HSCT). In the last 3 years, there has been regulatory approval of new drugs and considerable change in clinical approaches to prophylaxis and management of GVHD. To standardise treatment approaches, the European Society for Blood and Marrow Transplantation (EBMT) has updated its clinical practice recommendations. We formed a panel of one methodologist and 22 experts in the field of GVHD management. The selection was made on the basis of their role in GVHD management in Europe and their contributions to the field, such as publications, presentations at conferences, and other research. We applied the GRADE process to ten PICO (patient, intervention, comparator, and outcome) questions: evidence was searched for by the panel and graded for each crucial outcome. In two consensus meetings, we discussed the evidence and voted on the wording and strengths of recommendations. Key updates to the recommendations include: (1) primary use of ruxolitinib in steroid-refractory acute GVHD and steroid-refractory chronic GVHD as the new standard of care, (2) use of rabbit anti-T-cell (thymocyte) globulin or post-transplantation cyclophosphamide as standard GVHD prophylaxis in peripheral blood stem-cell transplantations from unrelated donors, and (3) the addition of belumosudil to the available treatment options for steroid-refractory chronic GVHD. The EBMT proposes to use these recommendations as the basis for routine management of GVHD during allogenic HSCT. The current recommendations favour European practice and do not necessarily represent global preferences.

Systemic calcineurin inhibitors tacrolimus and voclosporin: A review of off-label dermatologic uses

BACKGROUND

Systemic calcineurin inhibitors, cyclosporine, tacrolimus, and voclosporin, have been utilized in various dermatologic conditions. Although there have been numerous off-label dermatologic indications with published guidelines for cyclosporine, there is no established strong consensus for tacrolimus and voclosporin.

OBJECTIVE

To conduct a review of off-label use of systemic tacrolimus and voclosporin in various dermatoses to better inform treatment methods.

METHODS

A literature search was conducted using PubMed and Google Scholar. Relevant clinical trials, observational studies, case series, and reports regarding off-label dermatologic uses of systemic tacrolimus and voclosporin were included.

RESULTS

Tacrolimus shows promise for numerous dermatologic conditions, including psoriasis, atopic dermatitis/eczema, pyoderma gangrenosum, chronic urticaria, and Behcet's disease. Randomized controlled trial data are only available for voclosporin in psoriasis, which showed efficacy but did not meet noninferiority to cyclosporine.

LIMITATIONS

Data were limited and extracted from published papers. Studies differed in methodology, and nonstandardized outcomes limited the conclusions drawn.

CONCLUSIONS

In comparison to cyclosporine, tacrolimus can be considered for treatment-refractory disease or in patients with cardiovascular risk factors or inflammatory bowel disease. Voclosporin has only been utilized in psoriasis currently, and clinical trials in psoriasis show voclosporin's efficacy. Voclosporin can be considered for patients with lupus nephritis.

Substitution of calcineurin inhibitors with corticosteroids after allogeneic hematopoietic cell transplantation

Combination of calcineurin inhibitors (CIs) with short-term methotrexate is a standard prophylactic regimen for graft-versus-host disease (GVHD). However, it is sometimes difficult to continue CIs due to adverse effects, such as renal impairment and fluid overload. In such cases, we replace CIs with corticosteroids, considering that full dose of CIs is equivalent to prednisolone (PSL) at 1 mg/kg. We retrospectively evaluated the clinical significance of replacement of CIs with corticosteroids after allogeneic hematopoietic cell transplantation (HCT). We evaluated 42 patients switched from CIs to corticosteroids within 90 days among the 479 patients who underwent allogeneic HCT at our center between 2007 and 2019. Renal impairment (n = 33), fluid overload (n = 13), and thrombotic microangiopathy (n = 3) were the main reasons for switching. Although creatinine and body weight returned to baseline at 4 weeks after switching, 100-day non-relapse mortality was high (57.1%). Grade II-IV acute GVHD was seen in 10 (24.4%) patients who did not have it before switching treatment (n = 41). In conclusion, CIs were switched to corticosteroids in patients with severe clinical conditions. The incidence of acute GVHD was acceptable. Although the short-term mortality rate was high, improvement of renal function or fluid overload was observed in a certain proportion of the patients.

Factors Affecting Day-to-Day Variations in Tacrolimus Concentration among Children and Young Adults Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Tacrolimus is widely used as prophylaxis for graft-versus-host disease (GVHD) in allogeneic stem cell transplantation (allo-HSCT). It has a narrow therapeutic index range; high tacrolimus concentrations are associated with toxicity, whereas low concentrations are associated with an increased risk of GVHD. Although dose adjustments based on therapeutic drug monitoring are performed, unexpected large variations in tacrolimus concentration are sometimes encountered. The available evidence suggests that the factors affecting tacrolimus concentration are not fully understood. This study was aimed primarily at investigating the factors affecting day-to-day variations in tacrolimus concentration in children and young adults who received continuous tacrolimus infusion after allo-HSCT. The secondary objective was to identify the factors causing large variations (>20%) in tacrolimus concentrations. This retrospective cohort study comprised 123 consecutive pediatric and young adult patients (age <25 years) who received continuous i.v. tacrolimus infusion after allo-HSCT at Shinshu University Hospital, Matsumoto, Japan, between January 2009 and December 2021. To compare day-to-day variations in tacrolimus concentration without consideration of the tacrolimus dose, 2 consecutive days when the tacrolimus dose was not changed were selected from between the first post-allo-HSCT day of a tacrolimus concentration >7 ng/mL and day 28 post-allo-HSCT. Subsequently, information for the subsequent 24 hours was collected along with the tacrolimus concentrations and hematocrit values. Tacrolimus concentration was determined using whole blood samples. Tacrolimus concentrations were significantly higher in patients who received red blood cell concentrate (RCC) transfusions (P < .0001) and methotrexate (P = .0162), patients with persistent fever (P = .0056), and patients with a decline in fever (P = .0003). In contrast, tacrolimus concentrations were significantly lower in patients who received platelet concentrate (PC) transfusions (P < .0001), who redeveloped fever (P = .0261), and who had a replaced tacrolimus administration route set (P = .0008). Variations in tacrolimus concentration were significantly correlated with variations in hematocrit (r = .556; P < .0001). Body weight (P < .0001), RCC transfusion (P < .0001), methotrexate use (P = .0333), persistent fever (P = .0150), and decline in fever (P = .0073) were associated with a sharp increase in tacrolimus concentration. In contrast, body weight (P < .0001), PC transfusion (P = .0025), and replacement of the tacrolimus administration route set (P = .0025) were associated with a sharp decrease in tacrolimus concentration. RCC and PC transfusions, fever, methotrexate administration, and replacement of the tacrolimus administration route set were independent factors affecting day-to-day variations in tacrolimus concentration. In addition to these factors, low body weight was a risk factor for both sharp increases and decreases in tacrolimus concentration. These findings suggest the need for better control of tacrolimus concentration using whole blood samples.

Population Pharmacokinetics and Initial Dosage Optimization of Tacrolimus in Pediatric Hematopoietic Stem Cell Transplant Patients

Background: There is a substantial lack of tacrolimus pharmacokinetic information in pediatric hematopoietic stem cell transplant (HSCT) patients. This study aimed to develop population pharmacokinetics (PopPK) of tacrolimus in pediatric HSCT patients and to devise model-guided dosage regimens. Methods: A retrospective analysis was performed on 86 pediatric HSCT patients who received tacrolimus intravenously or orally. A total of 578 tacrolimus trough concentrations (C₀) were available for pharmacokinetic analysis using a non-linear mixed-effects modeling method. Demographic and clinical data were included and assessed as covariates via the stepwise method. Bayesian estimators were used to devise pediatric dosage regimens that targeted C₀ of 5-15 ng mL^-1. Results: A one-compartment model with first-order absorption adequately described the tacrolimus pharmacokinetics. Clearance (CL), volume of distribution (V), and typical bioavailability (F) in this study were estimated to be 2.42 L h^-1 (10.84%), 79.6 L (16.51%), and 19% (13.01%), respectively. Body weight, hematocrit, post-transplantation days, and caspofungin and azoles concomitant therapy were considered significant covariates for tacrolimus CL. Hematocrit had a significant impact on the V of tacrolimus. In the subgroup cohort of children (n = 24) with CYP3A5 genotype, the clearance was 1.38-fold higher in CYP3A5 expressers than in non-expressers. Simulation indicated that the initial dosage optimation of tacrolimus for intravenous and oral administration was recommended as 0.025 and 0.1 mg kg^-1 d^-1 (q12h), respectively. Conclusion: A PopPK model for tacrolimus in pediatric HSCT patients was developed, showing good predictive performance. Model-devised dosage regimens with trough tacrolimus concentrations provide a practical strategy for achieving the therapeutic range.

Risk factors for adverse outcomes following haploidentical hematopoietic cell transplantation with posttransplant cyclophosphamide: a two-center analysis

Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative therapy for several malignant hematologic diseases and alternative donors, including haploidentical, play a significant role in HCT. Despite the increasing use of haplo-HCT with PTCy, some questions remain open. The objective of the present study was to investigate risk factors for adverse outcomes after haplo-HCT with PTCy. This is a retrospective study conducted at two Brazilian centers. A total of 103 patients with hematologic malignancies who underwent first allogeneic, haploidentical HCT with PTCy were included. Risk factors for death were age at transplant (HR = 1.03 for each year; p = 0.002) and high/very high disease risk index (DRI; HR = 2.77; p = 0.0007) and mother as the donor compared with other donors (HR = 3.53; p = 0.005). In multivariate analysis, PFS was significantly poorer for older patients (HR = 1.02; p = 0.006), high/very high DRI (HR = 2.39; p = 0.003), and mother as the donor compared with other donors (HR = 3.18; p = 0.006). Relapse rate was higher for high/very high DRI (HR = 4.01; p = 0.002) and mother as the donor compared with other donors (HR = 2.52; p = 0.05). NRM was higher for older patients (HR = 1.03 for each year; p = 0.03). Tacrolimus was a protective factor for grades II-IV aGVHD (HR = 0.46; p = 0.04) compared with cyclosporine. Peripheral blood (PBSC) was a risk factor for cGVHD (HR = 3.48; p = 0.006), while tacrolimus was protective (HR = 0.30; p = 0.009). Mother as the donor compared with other donors was also a risk factor for poorer OS, PFS, and relapse, suggesting that this combination should be avoided. Tacrolimus was protective for both grades II-IV aGVHD and cGVHD, suggesting that tacrolimus may be more effective than cyclosporine in preventing GVHD. PBSC was a risk factor for cGVHD without any impact on relapse. Prospective studies comparing tacrolimus with cyclosporine are awaited.

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.

Comparison of Tacrolimus and Cyclosporine Combined With Methotrexate for Graft Versus Host Disease Prophylaxis After Allogeneic Hematopoietic Cell Transplantation

BACKGROUND

After patients receive hematopoietic stem cell transplantation (HSCT), both cyclosporine (CsA) and tacrolimus (TAC) in combination with methotrexate (MTX) are recommended as the standard prophylaxis strategy for graft versus host disease (GVHD) by the European Group of Blood and Marrow Transplantation. However, the advantage of TAC combined with MTX lacks conclusive evidence.

METHODS

We searched online databases for studies comparing CsA + MTX and TAC + MTX in patients who received HSCT. The odds ratio (OR) and 95% confidence interval (CI) were applied to compare the pooled data.

RESULTS

We found a significant reduction in the grade II to IV acute GVHD (aGVHD) rate (OR, 0.42; CI, 0.28-0.61; P < 0.00001), grade III to IV aGVHD rate (OR, 0.59; CI, 0.38-0.92; P = 0.02), chronic GVHD rate (OR, 0.79; CI, 0.62-1.00; P = 0.05), and nonrelapse mortality rate (OR, 0.62; CI, 0.40-0.95; P = 0.03) and an increase in the overall survival (OS) rate (only in those received from unrelated donor) (OR, 1.30; CI, 1.15-1.48; P < 0.0001) in the TAC + MTX group. Similar outcomes occurred for the relapse rate and disease-free survival rate in both groups.

CONCLUSIONS

TAC + MTX has a superior effect in the prevention of aGVHD in patients who received HSCT and further prolongs the OS in patients who received from unrelated donor transplants. CsA + MTX prolongs the OS in patients who received HSCT from HLA-identical sibling donors. The leukemic relapse and disease-free survival rate were not different between the 2 regimens. Thus, we conclude that TAC + MTX was superior to CsA + MTX, especially for HSCT patients with nonmalignant disorders. Further studies are still required to evaluate the effect of TAC or CsA combined with other suppressors in the treatment regimen following HSCT.

Prophylaxis and management of graft versus host disease after stem-cell transplantation for haematological malignancies: updated consensus recommendations of the European Society for Blood and Marrow Transplantation

Graft-versus-host disease (GVHD) is a major factor contributing to mortality and morbidity after allogeneic stem-cell transplantation. Because of the small number of results from well designed, large-scale, clinical studies there is considerable variability in the prevention and treatment of GVHD worldwide. In 2014, to standardise treatment approaches the European Society of Blood and Marrow Transplantation published recommendations on the management of GVHD in the setting of HLA-identical sibling or unrelated donor transplantation in adult patients with haematological malignancies. Here we update these recommendations including the results of study published after 2014. Evidence was searched in three steps: first, a widespread scan of published trials, meta-analyses, and systematic reviews; second, expert opinion was added for specific issues following several rounds of debate; and third, a refined search to target debated or rapidly updating issues. On the basis of this evidence and the 2014 recommendations, five members of the EBMT Transplant Complications Working Party created 38 statements on GVHD prophylaxis, drug management, and treatment of acute and chronic GVHD. Subsequently, they created the EBMT GVHD management recommendation expert panel by recruiting 20 experts with expertise in GVHD management. An email-based, two-round Delphi panel approach was used to manage the consensus. Modified National Comprehensive Cancer Network categories for evidence and consensus were applied to the approved statements. We reached 100% consensus for 29 recommendations and 95% consensus for nine recommendations. Key updates to these recommendations include a broader use of rabbit anti-T-cell globulin; lower steroid doses for the management of grade 2 acute GVHD with isolated skin or upper gastrointestinal tract manifestations; fluticasone, azithromycin, and montelukast should be used for bronchiolitis obliterans syndrome; and the addition of newer treatment options for resteroid-refractory acute and chronic GVHD. In addition, we discuss specific aspects of GVHD prophylaxis and management in the setting of haploidentical transplantation and in paediatric patients, but no formal recommendations on those procedures have been provided in this Review. The European Society of Blood and Marrow Transplantation proposes to use these recommendations as a basis for the routine management of GVHD during stem-cell transplantation.

Updated Clinical Outcomes of Hematopoietic Stem Cell Transplantation Using Myeloablative Total Body Irradiation with Ovarian Shielding to Preserve Fertility

Myeloablative conditioning regimens are associated with severe gonadal toxicity. To preserve ovarian function, we have been investigating ovarian shielding during total body irradiation (TBI) with a myeloablative dose. In this report, we update the clinical outcomes. Female patients with standard-risk hematologic diseases, aged 40 years or younger, who desired to have children, were included (n = 19). The conditioning regimen consisted of TBI at 12 Gy with ovarian shielding and cyclophosphamide (120 mg/kg) or cytarabine (24 g/m²). Ovarian shielding reduced the actual irradiation dose applied to the ovaries from 12 Gy to 2 to 3 Gy. The median age at hematopoietic stem cell transplantation (HSCT) was 24 years (range, 19 to 33 years). With a median follow-up period of 1449 days (range, 64 to 3694) after HSCT, 5-year overall survival and 1- and 5-year relapse rates were 67%, 17%, and 31%, respectively. Only 2 of 14 patients with acute myeloid or lymphoid leukemia in remission have relapsed thus far. The 6-month and 1-year cumulative rates of menstrual recovery were 42% and 78%, respectively. In all patients with menstrual recovery, menstruation recovered within 1 year. The serum anti-Müllerian hormone (AMH) level tended to gradually increase after menstrual recovery. Three patients with extensive chronic graft-versus-host disease experienced delayed recovery of menstruation and serum AMH. Five pregnancies in 3 patients resulted in normal delivery in 1, selective cesarean operation in 1, current pregnancy in 1, and natural abortion in 2. These results suggest that a myeloablative TBI regimen with ovarian shielding could preserve fertility after HSCT without an apparent increase in relapse in standard-risk patients. Because serum AMH recovered gradually over time, the AMH level during the early phase after HSCT may have little value as a marker of ovarian reserve.

Negative impact of chronic graft-versus-host disease and glucocorticoid on the recovery of physical function after allogeneic hematopoietic stem cell transplantation

Quality of life of patients who undergo allogeneic hematopoietic stem cell transplantation (HSCT) temporally deteriorates and recovers over several years. We retrospectively evaluate the impact of chronic graft-versus-host disease (GVHD) and glucocorticoid on physical recovery. We included 162 patients who underwent their first allogeneic HSCT between October 2010 and December 2015 in a single hospital. All patients are planned to undergo physical function tests before and 1, 3, 12 months after allogeneic HSCT. Scores of knee extension strength and distance covered in the 6-min walk test (6MWT) recovered at the 12-month assessment. Both chronic GVHD and high dose glucocorticoid were associated with delayed recovery of body mass index (BMI), hand grip strength, knee extension strength, and duration of standing on one foot. Lung GVHD and high dose glucocorticoid had negative impact on the distance covered in the 6MWT. A multivariate analysis revealed that chronic GVHD and glucocorticoid was an independent risk factor for decreased BMI and delayed recovery of muscle strength, respectively. Our results suggest that high-risk patients who have chronic GVHD or who receive glucocorticoid therapy may require reduced dose of glucocorticoid and long-term physical support to recover physical function after transplantation.

Kidney dysfunction after hematopoietic cell transplantation-Etiology, management, and perspectives

Kidney dysfunction is a common complication of hematopoietic cell transplantation (HCT) with proven negative impact on early and long-term mortality. Causes of this complication are diverse, usually overlapping, and poorly understood. Therefore, management implicates multidirectional investigations and simultaneous treatment of suspected causes. The etiology is frequently unconfirmed due to a lack of specific markers and prevalence of contraindications to renal biopsy among HCT recipients. Herein, we provide a summary of etiology and propose an algorithm for evaluation of kidney injury after HCT. We also map out the most urgent areas for research that aim to identify patients at risk of severe renal injury and develop nephroprotective strategies.

Dynamical system modeling to simulate donor T cell response to whole exome sequencing-derived recipient peptides: Understanding randomness in alloreactivity incidence following stem cell transplantation

Quantitative relationship between the magnitude of variation in minor histocompatibility antigens (mHA) and graft versus host disease (GVHD) pathophysiology in stem cell transplant (SCT) donor-recipient pairs (DRP) is not established. In order to elucidate this relationship, whole exome sequencing (WES) was performed on 27 HLA matched related (MRD), & 50 unrelated donors (URD), to identify nonsynonymous single nucleotide polymorphisms (SNPs). An average 2,463 SNPs were identified in MRD, and 4,287 in URD DRP (p<0.01); resulting peptide antigens that may be presented on HLA class I molecules in each DRP were derived in silico (NetMHCpan ver2.0) and the tissue expression of proteins these were derived from determined (GTex). MRD DRP had an average 3,670 HLA-binding-alloreactive peptides, putative mHA (pmHA) with an IC50 of <500 nM, and URD, had 5,386 (p<0.01). To simulate an alloreactive donor cytotoxic T cell response, the array of pmHA in each patient was considered as an operator matrix modifying a hypothetical cytotoxic T cell clonal vector matrix; each responding T cell clone’s proliferation was determined by the logistic equation of growth, accounting for HLA binding affinity and tissue expression of each alloreactive peptide. The resulting simulated organ-specific alloreactive T cell clonal growth revealed marked variability, with the T cell count differences spanning orders of magnitude between different DRP. Despite an estimated, uniform set of constants used in the model for all DRP, and a heterogeneously treated group of patients, higher total and organ-specific T cell counts were associated with cumulative incidence of moderate to severe GVHD in recipients. In conclusion, exome wide sequence differences and the variable alloreactive peptide binding to HLA in each DRP yields a large range of possible alloreactive donor T cell responses. Our findings also help understand the apparent randomness observed in the development of alloimmune responses.

Antifungal prophylaxis with fluconazole in allogeneic stem cell transplantation recipients who had prior invasive aspergillosis with subsequent complete resolution by computed tomography

BACKGROUND

Consensus has yet to be reached regarding secondary prophylaxis in allogeneic hematopoietic stem cell transplantation (HSCT) with a complete resolution of invasive aspergillosis (IA) confirmed by chest computed tomography (CT).

METHODS

We retrospectively evaluated the feasibility of antifungal prophylaxis with fluconazole in allogeneic HSCT recipients who had previously developed IA which showed complete resolution as confirmed by chest CT before HSCT. Consecutive adult patients who underwent allogeneic HSCT at our institution and who had received fluconazole as systemic antifungal prophylaxis from June 2007 to January 2015 were included. We compared the clinical outcomes between patients with a past history of IA who showed a complete resolution of chest CT abnormalities (n = 13) and those without a previous history of IA (n = 137).

RESULTS

The cumulative incidence of proven or probable IA was 8.8% in the group without a past history of IA and 0.0% in the group with a past history of IA (p = .268). The cumulative incidence of proven or probable invasive fungal disease (IFD) within 100 days after allogeneic HSCT was 10.9% in the group without a past history of IA and 15.4% in the group with a past history of IA (p = .647). Fluconazole was switched to anti-mould agents in two-thirds of the patients in each group by day 100 after HSCT.

CONCLUSIONS

Fluconazole was confirmed to be an acceptable prophylactic agent early after allogeneic HSCT in appropriately selected patients.

Pharmacokinetic comparison of cyclosporin A and tacrolimus in graft-versus-host disease prophylaxis

A number of studies were published with contradictory results comparing tacrolimus (Tac) and cyclosporine A (CsA) for graft-versus-host disease (GVHD) prophylaxis, but there are only few that accounted for pharmacokinetic (PK) parameters. In this study, we created a model based on median concentrations, variability of concentrations, and failures to maintain target levels that distinguished patients with low, intermediate, and high risks of acute GVHD (hazard ratios (HR) 1.77, 95%CI 1.36-2.32, p < 0.0001). This model was used to compare 95 patients with CsA and 239 with Tac GVHD prophylaxis. In the multivariate analysis, incorporating PK risk, no differences were observed for grade II-IV acute GVHD (HR 0.73, 95%CI 0.48-1.10, p = 0.13), but grade III-IV acute GVHD was lower in the Tac group (HR 0.47, 95%CI 0.28-0.78, p = 0.004). The observed difference was due to patients with high PK risk (HR 0.377, 95%CI 0.19-0.75, p = 0.005), but not with low and intermediate PK risk (p > 0.05). Patients in the Tac group had better GVHD relapse-free survival (HR = 0.659, p = 0.01) and comparable overall survival (p > 0.05). In conclusion, PK risk should be accounted for in comparisons of GVHD prophylaxis regimens with calcineurin inhibitors, and Tac was superior to CsA in patients with high, but not intermediate and low PK risk.

Comparison of cyclosporine and tacrolimus combined with mycophenolate mofetil in prophylaxis for graft-versus-host disease after reduced-intensity umbilical cord blood transplantation

Umbilical cord blood transplantation with a reduced-intensity conditioning regimen (RIC-UCBT) is used increasingly in patients who have comorbid organ functions and lack human leukocyte antigen-identical donors. We compared the outcomes in 35 patients who received mycophenolate mofetil plus cyclosporine (MMF/CSP, n = 17) or MMF plus tacrolimus (MMF/TAC, n = 18) for graft-versus-host disease (GVHD) prophylaxis after RIC-UCBT. Cumulative incidence of neutrophil engraftment was 94 and 89 % in MMF/CSP and MMF/TAC groups, respectively (p = 0.34). The incidence of pre-engraftment immune reaction did not differ between the MMF/CSP (41 %) and MMF/TAC (39 %, p = 1.00) groups; however, patients in the MMF/TAC group tended to have a lower incidence of grade II-IV acute GVHD than those in MMF/CSP group (28 vs 53 %, p = 0.11). Overall survival (OS) at 1 year was 43 and 60 % in MMF/CSP and MMF/TAC groups, respectively (p = 0.39). Progression-free survival, non-relapse mortality, and relapse rate were comparable between the two groups (p = 0.76, 0.59, and 0.88, respectively). In multivariate analyses, MMF/TAC GVHD prophylaxis was closely associated with improved OS, but not with incidence of engraftment and acute GVHD. These results suggest that more intensive GVHD prophylaxis with MMF/TAC decreased acute GVHD without affecting other clinical outcomes, resulting in improved OS after RIC-UCBT.

Improved overall survival for pediatric patients undergoing allogeneic hematopoietic stem cell transplantation - A comparison of the last two decades

Pediatric protocols for allogeneic hematopoietic SCT have been altered during the last two decades. To compare the outcomes in children (<18 yr old), who underwent SCT at our center during 1992-2002 (P1) and 2003-2013 (P2). We retrospectively analyzed 188 patients in P1 and 201 patients in P2. The most significant protocol changes during P2 compared with P1 were a decrease in MAC protocols, particularly those containing TBI, an increase in RIC protocols, and altered GvHD prophylaxis. In addition, P2 had more patients with nonmalignant diagnoses (p = 0.002), more mismatched (MM) donors (p = 0.01), and more umbilical CB grafts (p = 0.03). Mesenchymal or DSCs were used for severe acute GvHD during P2. Three-yr OS in P1 was 58%, and in P2, it was 78% (p < 0.001). Improved OS was seen in both malignant disorders (51% vs. 68%; p = 0.05) and nonmalignant disorders (77% vs. 87%; p = 0.04). Multivariate analysis showed that SCT during P2 was associated with reduced mortality (HR = 0.57; p = 0.005), reduced TRM (HR = 0.57; p = 0.03), unchanged relapse rate, similar rate of GF, less chronic GvHD (HR = 0.49; p = 0.01), and more acute GvHD (HR = 1.77, p = 0.007). During recent years, OS has improved at our center, possibly reflecting the introduction of less toxic conditioning regimens and a number of other methodological developments in SCT.