Teenagers and young adults with a past of allogenic hematopoietic stem cell transplantation are at significant risk of chronic kidney disease.

BACKGROUND: Allogenic hematopoietic stem cell transplantation (aHSCT) remains the treatment of choice for some malignant hemopathies in children, albeit with the risk of long-term consequences, including chronic kidney disease (CKD). METHODS: In our single tertiary referral center, we retrospectively assessed the long-term renal outcome in a cohort of children and adolescents who had undergone aHSCT for malignant hemopathies between 2003 and 2017. We distinguished glomerular and tubular dysfunctions and assessed the accuracy of the most common formula(s) to estimate glomerular filtration rate (GFR) during standard clinical follow-up. RESULTS: Among the 166 patients who had received aHSCT, 61 underwent kidney functional assessment 1 to 10 years post-transplantation. Twenty-seven patients (44.3%) had a CKD with glomerular impairment, including 20 patients with a GFR < 90 mL/min/1.73 m2, and among these, 5 patients < 60 mL/min/1.73 m2. Patients with tubular signs had a significantly higher baseline GFR: 112 mL/min/1.73 m2 [100; 120] versus 102 [99.0; 112.5] for patients without kidney involvement, and 76 [61; 86] for patients with CKD (p < 0.01). Schwartz, CKiDU25, and EKFC formulas significantly overestimated mGFR, with a P30% ≤ 30%, which could lead to overlooking CKD diagnosis in this population. No patient reached kidney failure. CONCLUSIONS: In conclusion, our study shows that CKD represents an important long-term sequela for children and adolescents who undergo aHSCT for malignant hemopathies, either with glomerular dysfunction or with the more insidious tubular dysfunction which could potentially impact growth. These patients could benefit from specialized long-term nephrology follow-up. A higher resolution version of the Graphical abstract is available as Supplementary information.

Goal-Oriented Monitoring of Cyclosporine Is Effective for Graft-versus-Host Disease Prevention after Hematopoietic Stem Cell Transplantation in Sickle Cell Disease and Thalassemia Major.

Graft-versus-host disease (GVHD) is an important challenge and a major cause of morbidity and mortality in children after hematopoietic stem cell transplant (HSCT). Herein we report our institution's experience of goal-oriented Bayesian monitoring for cyclosporine (CsA) used alone as GVHD prophylaxis during the post-transplant period in pediatric patients with thalassemia major (TM) or sickle cell anemia (SCA) undergoing HLA-matched HSCT. We also studied evolution of chimerism. Twenty-six consecutive patients (SCA, 14; TM, 12) underwent matched sibling donor (MSD) HSCT from 2004 to 2014. All patients received a myeloablative conditioning regimen. GVHD prophylaxis consisted of 20 mg/kg antithymocyte globulin in the conditioning regimens and then CsA alone in the post-transplant period. Target CsA trough blood concentration (TBC) was 150 ± 20 ng/mL. At last follow-up, all patients were alive and free of disease, even in cases of mixed chimerism. Engraftment occurred in all patients. No patient developed grades II to IV acute GVHD, 4 patients developed acute grade I skin GVHD, and only 1 presented with chronic pulmonary GVHD. A better control of GVHD and immunosuppression by a strict monitoring of CsA TBC as described herein is promising and could play a crucial role. Further investigations are required, but this study opens new perspectives to improve survival and safety of HSCT from alternative donors in TM and SCA to levels compatible with that obtained with MSDs.

Impact of a change in protected environment on the occurrence of severe bacterial and fungal infections in children undergoing hematopoietic stem cell transplantation.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a procedure with a high infection risk. Strict isolation of patients is the rule to prevent such condition. OBJECTIVE: We compared the occurrence of severe infections (bacteremia and invasive fungal infection, IFI) in children undergoing alloHSCT before and after the move to a new protected unit with decreases in isolation methods. METHODS: The study was conducted over a 10-year period. Unit 1 (2002-2007) consisted of laminar airflow rooms where caregivers were required to wear a sterile outfit (gown, gloves, hat, and mask). Unit 2 (2008-2012) included spacious positive air pressure rooms with HEPA filters where only a clean gown and mask were required to be worn. RESULTS: Two hundred eighty-six alloHSCTs were performed (144 in Unit 1 and 142 in Unit 2). We reported a total incidence of 4.78 infections/1000 hospital-days including 4.4 episodes of bacteremia and 0.38 episodes of IFI. There was no statistical difference in the incidence of infections: n = 4.98/1000 hospital-days in Unit 1 vs. n = 4.6/1000 in Unit 2 (P = 0.63). CONCLUSION: The lack of difference in the occurrence of severe infection supports our decision to decrease unnecessary high protection in alloHSCT units to improve children's daily life.

[Haematopoietic stem cell donation from minor donor: Respecting laws, assessing fitness, delivering information and good care (SFGM-TC)]. / Don de cellules souches hématopoïétiques à partir d'un donneur mineur : cadre réglementaire, information, évaluation de l'aptitude au don et parcours (SFGM-TC).

Haematopoietic stem cell collection from paediatric donors is a common and life-saving practice, as evidenced by the fact that there is a growing annual number of cases of transplants from minor donors among SFGM-TC centers over the last decade. Still, medical use of human tissue from a healthy and underage donor requires proper regulations and medical management. The guidelines below aim at underlining the importance of pondering the legal, medical and ethical aspects of using stem cells from healthy paediatric donors and stress out the importance of obtaining informed consent at the time of assessing HLA compatibility. Combined medical and psychological assessments are required before the donation, as well as one month later and one year later to ensure of the child's physical and mental wellbeing. Bone marrow harvest under general anaesthetics remains the preferred method of collection for children. Peripheral blood stem cell collection should only be considered for children who will not require a central venous access for collection. We aim at offering guidelines centered on the healthy child donating stem cells and his/her wellbeing, and these should be regularly reviewed as medical practices evolve.

New Perspectives on Primary Prophylaxis of Invasive Fungal Infection in Children Undergoing Hematopoietic Stem Cell Transplantation: A 10-Year Retrospective Cohort Study.

BACKGROUND: Allogenic hematopoietic stem cell transplantation (a-HCT) remains a therapeutic treatment for many pediatric hematological diseases. The occurrence of invasive fungal infections (IFIs) is a complication for which ECIL-8 recommends primary antifungal prophylaxis. In this study, we evaluated the impact of our local strategy of not systematically administering primary antifungal prophylaxis in children undergoing a-HCT on the occurrence and mortality of IFIs. METHODS: We performed a retrospective monocentric study from 2010 to 2020. We retained all proven and probable IFIs diagnosed during the first year post a-HCT. RESULTS: 308 patients were included. Eighteen patients developed twenty IFIs (thirteen proven, seven probable) (6.5%) among which aspergillosis (n = 10, 50%) and candidosis (n = 7, 35%) were the most frequently diagnosed infections. Only 2% of children died because of an IFI, which represents 14% of all deaths. Multivariate analysis found that age > 10 years (OR: 0.29), the use of a therapeutic antiviral treatment (OR: 2.71) and a low neutrophil count reconstitution (OR: 0.93) were significantly associated with the risk of IFI occurrence. There was also a trend of malignant underlying disease and status ≥ CR2 but it was not retained in multivariate analysis. CONCLUSIONS: IFI occurrence was not higher in our cohort than what is reported in the literature with the use of systematic antifungal prophylaxis, with a good survival rate nonetheless. Thus, a prophylaxis could be considered for children with a high risk of IFI such as those aged over 10 years.

Lymphocyte subset reconstitution after unrelated cord blood or bone marrow transplantation in children.

We report the post-transplant lymphocyte subset recovery of 226 children treated with Unrelated Cord Blood transplant (UCBT) (n = 112) or Unrelated Bone Marrow Transplant (UBMT) (n = 114) for malignant or non-malignant diseases. Absolute numbers of natural killer (NK), B and T cells were monitored by flow cytometry up to 5 years post-transplant. Immunological endpoints were: time to achieve a CD3(+) cell count > 0·5 and 1·5 × 109/l, CD4(+) > 0·2 and 0·5 × 109/l, CD8(+) > 0·25 ×109/l, CD19(+) > 0·2 × 109/l, NK > 0·1 × 109/l. These endpoints were analysed through the use of cumulative incidence curves in the context of competing risks. CD8(+) T cell recovery was delayed after UCBT with a median time to reach CD8(+) T cells > 0·25 × 109/l of 7·7 months whereas it was 2·8 months in UBMT (P < 0·001). B cell recovery was better in UCBT, with a median time to reach CD19(+) cells > 0·2 × 109/l of 3·2 months in UCBT and 6·4 months in UBMT (P = 0·03). Median time for CD4(+) T cell and NK cell recovery was similar in UCBT and UBMT. CD4(+) T cells recovery was negatively correlated to age (better reconstitution in younger patients, P = 0·002). CD8(+) T cells recovery was shorter in recipients with a positive cytomegalovirus serology (P =0·001).