Side effects and efficacy of renal sparing immunosuppression in pediatric liver transplantation-A single center matched cohort study

Immunosuppressant indulges EBV reactivation and related lymphoproliferative disease by inhibiting Vδ2+ T cells activities after hematopoietic transplantation for blood malignancies

Background

Following the extensive use of immunosuppressive drugs in the clinic, immunosuppression-associated side effects have received increasing attention. Epstein-Barr virus (EBV) reactivation and related lymphoproliferative diseases (LPD) are the lethal complications observed after allogeneic hematopoietic cell transplantation (alloHCT). While studies generally suggest an association between immunosuppressants and EBV reactivation, the effects of specific immunosuppressive drugs and which T-cell subsets mediate these correlations are unclear. Vδ2⁺ T cells are correlated with EBV reactivation after alloHCT. Researchers have not determined whether Vδ2⁺ T-cell activities are affected by immunosuppressants and thereby facilitate EBV reactivation and related LPD.

Methods

A clinical cohort study of 170 patients with hematopoietic malignancies who received haploidentical hematopoietic cell transplantation (haploHCT) was performed to investigate whether the early cessation of mycophenolate mofetil (MMF) decreases EBV reactivation and related LPD and to determine whether this change is associated with the recovery of Vδ2 ⁺ T cells after transplantation. The effects of MMF on the expansion and anti-EBV capacity of Vδ2⁺ T cells were detected in vitro and in an immunodeficient mouse model.

Results

A reduction in the course of MMF significantly improved the recovery of Vδ2⁺ T cells from 30 to 90 days after haploHCT (p=0.002, p=0.042 and p=0.035, respectively), accompanied by a significant decrease in EBV reactivation (from 26% to 13%, p=0.033) and EBV-LPD (from 10.6% to 2.4%, p=0.029). The day-30 Vδ2⁺ T level remained an independent factor for EBV reactivation in patients with different MMF durations (p=0.007). In the in-vitro experiments, MMF inhibited Vδ2⁺ T-cell expansion and its cytotoxicity on EBV-transformed malignant cells. Furthermore, the therapeutic and prophylactic effects of adoptively transferred human Vδ2⁺ T cells were attenuated by the MMF treatment in immunodeficient mice with EBV-LPD.

Conclusions

These results elucidated a negative effect of immunosuppressants on the anti-EBV capacity of Vδ2⁺ T cells. Strategies that appropriately relieve the immunosuppression may improve anti-EBV immunity by increasing the activity of Vδ2⁺ T cells after alloHCT.

Proceedings of the 25th Annual Congress of the International Liver Transplantation Society

The 25th Annual Congress of the International Liver Transplantation Society was held in Toronto, Canada, from May 15 to 18, 2019. Surgeons, hepatologists, anesthesiologists, critical care intensivists, radiologists, pathologists, and research scientists from all over the world came together with the common aim of improving care and outcomes for liver transplant recipients and living donors. Some of the featured topics at this year's conference included multidisciplinary perioperative care in liver transplantation, worldwide approaches to organ allocation, donor steatosis, and updates in pediatrics, immunology, and radiology. This report presents excerpts and highlights from invited lectures and select abstracts, reviewed and compiled by the Vanguard Committee of International Liver Transplantation Society. This will hopefully contribute to further advances in clinical practice and research in liver transplantation.

High Burden of Subclinical Cardiovascular Target Organ Damage After Pediatric Liver Transplantation

Cardiovascular (CV) events account for 8%-13% of deaths after liver transplantation (LT) in adulthood. Although CV risk factors (RFs) are present, little is known about the prevalence of subclinical CV target organ damage (TOD) in children after LT. The aim of this prospective observational study was to assess the prevalence of subclinical CV TOD in children after LT and to identify RFs contributing to CV damage as potential targets for clinical intervention. In this study, 104 children after LT (54% female, 46% male; aged 11.5 ± 3.8 years) underwent cross-sectional assessment of subclinical TOD by carotid-femoral pulse wave velocity (PWV), carotid intima-media thickness (IMT), and left ventricular mass index (LVMI). Results were correlated with the presence of CV RFs (obesity, hypertension, dyslipidemia, renal impairment, anemia, and microinflammation). Of the patients, 22% were exposed to 2 CV RFs, and 36% displayed 3 or more CV RFs. Pathological results for PWV, IMT, and LVMI were found in 21.9%, 57.0%, and 11.1% of patients, respectively. In the multivariate analysis, diastolic blood pressure (P = 0.01) and estimated glomerular filtration rate (eGFR; P = 0.03) were independently associated with PWV, eGFR (P = 0.005), and age at LT (P = 0.048) with IMT and body mass index with LVMI (P = 0.004). In conclusion, patients after pediatric LT carry a substantial burden of subclinical CV TOD. Identification of modifiable CV RFs opens opportunities for targeted intervention in order to reduce CV morbidity and mortality in the future.

Impact of Immunosuppression on Executive Functioning After Pediatric Liver Transplantation: An Observational Cohort Study

OBJECTIVES

Children after liver transplantation show increased rates of impaired cognitive functioning. We aimed to assess the potential effects of immunosuppressive therapy on executive functioning measured by the Children's Color Trail Test and the cognitive functioning module of the PedsQL (cogPedsQL) in liver transplanted children to explore potential targets for intervention to improve executive functioning.

METHODS

We performed a cross-sectional study in 155 children (78 girls) aged 10.4 (2-18) years at 5.0 (0.1-17) years after liver transplantation, with follow-up at 6 months in n = 114. Executive functioning was assessed by Children's Color Trail Test (ages 8-16) and by patients and parent-proxy cogPedsQL (ages 5-18/2-18, respectively). Results were correlated with clinical parameters. Stability of results over time was compared between n = 23 patients who for clinical reasons switched from twice daily calcineurin inhibitor (CNI) to once-daily slow-release tacrolimus (Tac) during the study period, and patients with unchanged CNI.

RESULTS

Worse executive functioning was associated with longer stay in the intensive care unit and longer time elapsed since transplantation. No difference was found between users of cyclosporine and Tac. Children on once-daily slow-release Tac performed better than children on twice-daily Tac. In children who switched from twice-daily CNI to once-daily Tac, parent-proxy cogPedsQL improved significantly compared to stable results in the nonswitch group.

CONCLUSIONS

In addition to a strong impact of disease burden around transplantation, executive functioning appears to deteriorate over time. Although there is no clear-cut advantage of any CNI, once-daily Tac appears to be advantageous compared to twice-daily Tac.