Outcome and risk factors for late-onset complications 24 months beyond allogeneic hematopoietic stem cell transplantation

Exploring the Bio-Functional Effect of Single Nucleotide Polymorphisms in the Promoter Region of the TNFSF4, CD28, and PDCD1 Genes

In a prior study, we discovered that hematopoietic stem cell transplantation (HSCT) and/or autoimmune diseases, such as systemic lupus erythematosus, were associated with the rs1234314 C/G and rs45454293 C/T polymorphisms of TNFSF4, the rs5839828 C > del and rs36084323 C > T polymorphisms of PDCD1, and the rs28541784C/T, rs200353921A/T, rs3181096C/T, and rs3181098 G/A polymorphisms of CD28. However, the association does not imply causation. These single nucleotide polymorphisms (SNPs) are all located in the promoter region of these genes, so we used the dual-luminescence reporter assay to explore the effect of single nucleotide polymorphisms (SNPs) on transcriptional activity. For each promoter–reporter with a single SNP mutation, more than 10 independent experiments were carried out, and the difference in transcription activity was compared using one-way ANOVA and Tukey’s honestly significant difference test. The results showed that the G-allele of rs1234314 had 0.32 ± 0.09 times the average amount of relative light units (RLU) compared to the C-allele (p = 0.003), the T-allele of rs45454293 had 4.63 ± 0.92 times the average amount of RLU compared to the C-allele (p < 0.001), the del-allele of rs5839828 had 1.37 ± 0.24 times the average amount of RLU compared to the G-allele (p < 0.001), and the T-allele of rs36084323 had 0.68 ± 0.07 times the average amount of RLU compared to the C-allele (p < 0.001). The CD28 SNPs studied here did not affect transcriptional activity. In conclusion, the findings of this study could only confirm that the SNP had a bio-functional effect on gene expression levels. According to the findings, several SNPs in the same gene have bio-functions that affect transcriptional activity. However, some increase transcriptional activity while others decrease it. Consequently, we inferred that the final protein level should be the integration result of the co-regulation of all the SNPs with the effect on transcriptional activity.

Pharmacotherapy in Pediatric Hematopoietic Cell Transplantation

Hematopoietic cell transplantation (HCT) is a curative treatment option for both malignant and nonmalignant diseases. Success of the procedure mainly depends on disease control and treatment-related complications. Pharmacotherapy plays a major role in HCT and significantly impacts the outcomes. Main drug use within HCT includes conditioning, GvHD prophylaxis, and prevention/treatment of infections.Increasing evidence suggests individualized dosing in (pediatric) HCT may improve outcome. Dose individualization may result in a better predictable drug treatment in terms of safety and efficacy, including timely immune reconstitution after HCT and optimal tumor or disease control, which may result in improved survival chances.

Predictors and Outcome of Pericardial Effusion After Hematopoietic Stem Cell Transplantation in Children

Pericardial Effusion (PE) is a potentially life-threatening complication of Hematopoietic Cell Transplantation (HCT). Our study aim was to identify incidence, risk factors, response to treatment, and outcome of PE after pediatric HCT. All patients after HCT at our tertiary center between 2005 and 2010 were included. Endpoints were PE development and overall survival. We analyzed patient factors, HCT details, and complications and used Cox proportional hazard regression modeling to identify predictors for PE. Twelve out of 129 patients (9.3%) developed PE. Multivariate analysis demonstrated that young age at HCT was a predictor for PE: expressed per year increase in age HR = 0.66 (95% CI 0.46-0.95, p = 0.03). PE had no impact on overall mortality of HCT. Mild respiratory symptoms and vomiting were presenting symptoms for PE. Discontinuation of calcineurin inhibitors-with or without pericardiocentesis-was the only effective treatment for PE, in contrast to diuretics or increased immunosuppression. Seven of 12 PE patients had pericardiocentesis, which was safe and effective in all. Pericardial effusion is not rare after HCT, and young age is the only significant risk factor. Calcineurin inhibitor toxicity appears to be the primary cause of PE after HCT, and discontinuation is effective in the reduction of PE. Pericardiocentesis for PE is a safe and effective procedure. Pericardial effusion did not have an impact on survival after HCT.

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.

Quality of Life After Hematopoietic Stem Cell Transplantation in Pediatric Survivors: Comparison With Healthy Controls and Risk Factors

BACKGROUND

Hematopoietic stem cell transplantation has prolonged life for children with life-threatening diseases. Quality of life is an essential outcome for evaluating the long-term effects of transplantation.

OBJECTIVE

The aims of this study were to compare the quality of life of children posttransplantation to that of healthy peers and explore the variables associated with the quality of life of posttransplant children.

METHODS

A cross-sectional study was conducted with 43 pediatric transplantation survivors and 43 age- and sex-matched healthy peers.

RESULTS

The mean age of the transplant group was 12.06 years. The mean time since transplant was 3.73 years. After covariate adjustment, there was no difference between posttransplant and healthy children in each domain and overall quality of life, except for physical functioning where the posttransplant children had lower scores than did the healthy group. Chronic graft-versus-host disease was found to be the primary factor associated with poor posttransplant overall quality of life and emotional and social functioning. Sociodemographic variables, symptom distress, and caregiver depression were not correlated with posttransplant quality of life.

CONCLUSIONS

The quality of life of pediatric transplantation survivors was comparable to that of healthy peers.

IMPLICATIONS FOR PRACTICE

The finding that children after transplant may achieve quality of life similar to their healthy peers is important information for parents to consider as they consider treatment options. For those sick children who cannot regularly attend school, their emotional and social functioning should be closely monitored.

National Institutes of Health Hematopoietic Cell Transplantation Late Effects Initiative: The Subsequent Neoplasms Working Group Report

Subsequent neoplasms (SN) after hematopoietic cell transplantation (HCT) cause significant patient morbidity and mortality. Risks for specific SN types vary substantially, with particularly elevated risks for post-transplantation lymphoproliferative disorders, myelodysplastic syndrome/acute myeloid leukemia, and squamous cell malignancies. This document provides an overview of the current state of knowledge regarding SN after HCT and recommends priorities and approaches to overcome challenges and gaps in understanding. Numerous factors have been suggested to affect risk, including patient-related (eg, age), primary disease-related (eg, disease type, pre-HCT therapies), and HCT-related characteristics (eg, type and intensity of conditioning regimen, stem cell source, development of graft-versus-host disease). However, gaps in understanding remain for each of these risk factors, particularly for patients receiving HCT in the current era because of substantial advances in clinical transplantation practices. Additionally, the influence of nontransplantation-related risk factors (eg, germline genetic susceptibility, oncogenic viruses, lifestyle factors) is poorly understood. Clarification of the magnitude of SN risks and identification of etiologic factors will require large-scale, long-term, systematic follow-up of HCT survivors with detailed clinical data. Most investigations of the mechanisms of SN pathogenesis after HCT have focused on immune drivers. Expansion of our understanding in this area will require interdisciplinary laboratory collaborations utilizing measures of immune function and availability of archival tissue from SN diagnoses. Consensus-based recommendations for optimal preventive, screening, and therapeutic approaches have been developed for certain SN after HCT, whereas for other SN, general population guidelines are recommended. Further evidence is needed to specifically tailor preventive, screening, and therapeutic guidelines for SN after HCT, particularly for unique patient populations. Accomplishment of this broad research agenda will require increased investment in systematic data collection with engagement from patients, clinicians, and interdisciplinary scientists to reduce the burden of SN in the rapidly growing population of HCT survivors.

Analysis of a Genetic Polymorphism in the Costimulatory Molecule TNFSF4 with Hematopoietic Stem Cell Transplant Outcomes

Despite stringent procedures to secure the best HLA matching between donors and recipients, life-threatening complications continue to occur after hematopoietic stem cell transplantation (HSCT). Studying single nucleotide polymorphism (SNP) in genes encoding costimulatory molecules could help identify patients at risk for post-HSCT complications. In a stepwise approach we selected SNPs in key costimulatory molecules including CD274, CD40, CD154, CD28, and TNFSF4 and systematically analyzed their association with post-HSCT outcomes. Our discovery cohort analysis of 1157 HLA-A, -B, -C, -DRB1, and -DQB1 matched cases found that patients with donors homozygous for the C variant of rs10912564 in TNFSF4 (48%) had better disease-free survival (P = .029) and overall survival (P = .009) with less treatment-related mortality (P = .006). Our data demonstrate the TNFSF4C variant had a higher affinity for the nuclear transcription factor Myb and increased percentage of TNFSF4-positive B cells after stimulation compared with CT or TT genotypes. However, these associations were not validated in a more recent cohort, potentially because of changes in standard of practice or absence of a true association. Given the discovery cohort, functional data, and importance of TNFSF4 in infection clearance, TNFSF4C may associate with outcomes and warrants future studies.

Late toxicity of a novel allogeneic stem cell transplant using single fraction total body irradiation for hematologic malignancies in children

Single fraction total body irradiation (SFTBI) as part of a myeloablative preparative regimen in allogeneic hematopoietic stem cell transplantation (HSCT) for hematopoietic malignancies was shown to have similar survival compared with fractionated total body irradiation (FTBI)-containing regimens, with less acute toxicity. The objective of this study was to determine long-term toxicity >2 years following SFTBI-based HSCT. Twenty-one patients were evaluated at a median follow-up of 6.8 years. Thyroid dysfunction was found in 21% of patients, 1 of whom (5.2%) was symptomatic; 23% had gonadal failure; 50% of patients with growth potential had linear growth disturbance; 27% had mild to moderate pulmonary disease; and 25% had cataracts. Intelligence quotient was stable. cGVHD was present in 28%, and 4 patients (19%) were on immune suppression 2 years posttransplant. Overall survival subsequent to 2 years posttransplant was 76% in this cohort of patients. No secondary malignancies were observed. In conclusion, the toxicities of SFTBI occurred at similar or reduced frequency compared with FTBI. SFTBI should be considered for patients who may benefit from a radiation-containing HSCT preparative regimen.

Late mortality after hematopoietic SCT for a childhood malignancy

Hematopoietic SCT (HSCT) has been used as a curative therapy for pediatric malignancies. Survivors of HSCT are at risk for disease recurrence, late morbidity and mortality. We assessed late mortality (≥2 years post-HSCT) in a population-based cohort of children who underwent HSCT for a malignancy. Mortality outcomes were determined by linking a clinical transplant database with the Canadian province of Ontario's pediatric cancer mortality files. Seven hundred and fifty-four children underwent HSCT (371 allogeneic, 383 autologous). Of the 479 (63.5%) who were alive ≥2 years post HSCT, 98 (20.5%) suffered a late death. Late mortality in the allogeneic HSCT group was 14.9% (median follow-up 10.0 years; range: 2.0-25.6 years), mainly due to relapse of the primary malignancy (64.7%). Chronic GVHD and second malignancies were not major causes of late mortality. A total of 25.5% suffered a late death following autologous HSCT (median follow-up 6.7 years; range: 2.0-22.2 years). Recurrence of the primary malignancy accounted for 87.5% of these deaths. Recurrence of the primary malignancy is the predominant cause of late mortality after HSCT. In contrast to studies of adult patients, non-relapse mortality is less common in children, and death due to chronic GVHD and secondary malignancies is uncommon.