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Post-transplant lymphoproliferative disorders (PTLDs) are life-threatening complications of iatrogenic immune impairment after allogeneic hematopoietic stem cell transplantation (HSCT). In the pediatric setting, the majority of PTLDs are related to the Epstein–Barr virus (EBV) infection, and present as B-cell lymphoproliferations. Although considered rare events, PTLDs have been increasingly observed with the widening application of HSCT from alternative sources, including cord blood and HLA-haploidentical stem cell grafts, and the use of novel agents for the prevention and treatment of rejection and graft-vs.-host disease. The higher frequency initially paralleled a poor outcome, due to limited therapeutic options, and scarcity of controlled trials in a rare disease context. In the last 2 decades, insight into the relationship between EBV and the immune system, and advances in early diagnosis, monitoring and treatment have changed the approach to the management of PTLDs after HSCT, and significantly ameliorated the prognosis. In this review, we summarize literature on the impact of combined viro-immunologic assessment on PTLD management, describe the various strategies for PTLD prevention and preemptive/curative treatment, and discuss the potential of novel immune-based therapies in the containment of this malignant complication.

Aim: The aim of this study was to describe the characteristics of Posterior Reversible Encephalopathy Syndrome (PRES) in infants and young children (

Diamond-Blackfan anemia (DBA) is a rare congenital disorder presenting remarkable phenotypic overlap with other inherited bone marrow failure syndromes, making differential diagnosis challenging and its confirmation often reached with great delay. By whole exome sequencing, we unraveled the presence of pathogenic variants affecting genes already known to be involved in DBA pathogenesis (RPL5 and RPS19) in three patients with otherwise uncertain clinical diagnosis, and provided new insights on DBA genotype-phenotype correlations. Remarkably, the RPL5 c.482del frameshift mutation has never been reported before, whereas the RPS19 c.3G > T missense mutation, although previously described in a 2-month-old DBA patient without malformations and refractory to steroid therapy, was detected here in the mosaic state in different bodily tissues for the first time in DBA patients.

We traced the neoplastic history (from 5 to 11 years of age) of a child with concomitant Fanconi anemia and Li-Fraumeni syndrome. Interestingly, the patient developed a highly malignant T-cell non-Hodgkin lymphoma (NHL), which does not represent the typical tumor type in the two aforementioned syndromes, presumably due to the underlying genomic instability. By using a combination of molecular and immunohistochemical approaches, we characterized the accumulation of multiple genetic alterations in a single patient, with both germline (parentally inherited biallelic FANCA variants and a likely de novo nonsense variant in TP53) and somatic (TP53 loss of heterozygosity and 5q interstitial deletion) contributions. Our findings support the interplay of TP53 and FANC genes in DNA damage response pathways and further highlight the genetic heterogeneity of lymphomas as well as the contribution of genomic instability to lymphomagenesis.

Transient myeloproliferative disorder (TMD) is a spontaneously resolving clonal myeloid proliferation characterized by circulating megakaryoblasts in the peripheral blood that is restricted to neonates with Down syndrome (DS) or those with trisomy 21 mosaicism. Cutaneous manifestations of TMD are observed in only 5% of affected neonates and present as a diffuse eruption of erythematous, crusted papules, papulovesicles, and pustules, often with prominent and initial facial involvement. We describe the case of a male infant with DS and TMD, associated with a vesiculopustular eruption, which appeared on day 36 of life, and review previous cases.

Hematopoietic stem cell transplantation (HSCT) is the only therapy for a subset of patients with malignant and nonmalignant diseases. Central nervous system (CNS) complications continue to be an important cause of morbidity and significantly contribute to mortality after HSCT. These complications include infections, cerebrovascular lesions, therapy-induced diseases, metabolic disturbances, and post-HSCT carcinogenesis. Following HSCT, three phases can be identified on the basis of the patient's immune status: the pre-engraftment period (30 days after HSCT), the early postengraftment period (30-100 days after HSCT), and the late postengraftment period (100 days after HSCT). There is a distinct relationship between the patient's degree of immunodeficiency after HSCT and the incidence of various complications that may occur. Early diagnosis of CNS complications is crucial for successful management and a good prognosis, and computed tomography and magnetic resonance imaging play an important role in achieving these goals. The global increase in the use of HSCT requires radiologists to be familiar with CNS complications, their relationship to the patient's immune status, and their imaging appearances. This article describes the clinical background of HSCT; reviews the incidence, causes, and timeline of brain complications in children who underwent allogenic HSCT; and identifies the characteristic imaging findings of these disorders.

Relapse remains the leading cause of treatment failure in children with acute lymphoblastic leukaemia (ALL) undergoing allogeneic haematopoietic stem cell transplantation (HSCT). We retrospectively investigated the prognostic role of minimal residual disease (MRD) before and after HSCT in 119 children transplanted in complete remission (CR). MRD was measured by polymerase chain reaction in bone marrow samples collected pre-HSCT and during the first and third trimesters after HSCT (post-HSCT1 and post-HSCT3). The overall event-free survival (EFS) was 50%. The cumulative incidence of relapse and non-relapse mortality was 41% and 9%. Any degree of detectable pre-HSCT MRD was associated with poor outcome: EFS was 39% and 18% in patients with MRD positivity

Although allogeneic haematopoietic stem cell transplantation (HSCT) still represents the only consolidated possibility of cure for sickle cell disease (SCD) patients, its use has been limited by the risk of morbidity and mortality associated with conventional myeloablative therapy. The introduction of treosulfan to replace busulfan in conditioning regimens has recently been explored by virtue of its lower toxicity profile. We report our experience with a treosulfan/thiotepa/fludarabine conditioning for human leucocyte antigen (HLA)-matched sibling or unrelated donor-HSCT in 15 children with SCD, and compare patient outcomes with those of a historical cohort (15 patients) given a busulfan-based regimen. Engraftment was achieved in 28 out of 30 patients (93%), with one case of graft failure in either group. The conditioning regimen was well tolerated in both groups, with no cases of grade III-IV regimen-related toxicity. The 7-year overall survival (OS) and disease-free survival (DFS) for the whole cohort were 100% and 93%, respectively, with a 93% DFS in both busulfan and treosulfan groups. No SCD-related adverse events occurred after engraftment in patients with complete or mixed donor chimerism. This retrospective analysis suggests that a treosulfan-based conditioning regimen is able to ensure engraftment with excellent OS/DFS and low regimen-related toxicity in patients with SCD.

Objective To compare uterine and ovarian volumes and uterine artery (UA) Doppler blood flow among women who were treated with antineoplastic regimens when pediatric aged versus healthy controls. Design Case-control study. Setting Tertiary obstetric and gynecologic center. Patient(s) One hundred twenty-seven women who were treated for childhood cancer with bone marrow transplantation (BMT) and∖or chemotherapy and total body irradiation (TBI) and 64 age-matched healthy controls. Intervention(s) Ultrasonographic and clinical evaluations. Main Outcome Measure(s) Uterine and ovarian volume, detection of follicles, and UA pulsatility index (PI). Result(s) Median uterus and ovarian volumes were reduced by 64% (95% CI, 56.6–70.6) and 83.6% (95% CI, 79.6–86.7), respectively, among cases compared with controls. Median UA PI among cases was increased by 30.3% (95% CI, 19.6–40.8) compared with controls. Ovarian follicles were identified in 24 (18.9%) of 127 cases and 25 (39%) of 64 controls. Uterine volume was reduced after TBI (percent reduction 81.9%; 95% CI, 71.8–87.8) or busulfan (percentage reduction 67.4%; 95% CI, 58.5–75.6) compared with those who had not received a conditioning regimen (percentage reduction 24.4%; 95% CI, 7.6–38.2). The only factors independently associated with reduced uterine and ovarian volumes compared with controls were TBI, busulfan, and BMT. The worst effect on UA PI resulted from BMT and a diagnosis of hematologic disease. Conclusion(s) Bone marrow transplantation as main treatment and TBI and busulfan as conditioning regimens had the worst effect on uterine and ovarian sizes compared with controls. These data should be considered in counseling families on preserving future fertility in children undergoing BMT.

Objective: Multipotent mesenchymal stromal cells (MSCs) are endowed with multilineage differentiative potential and immunomodulatory properties. It is still a matter of debate whether donor MSCs have sustained engraftment potential in host bone marrow (BM) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The aim of this study was to analyze the donor/recipient origin of MSCs in children receiving allogeneic either BM or cord blood (CB) transplantation. Methods: Thirty-seven pediatric patients undergoing allo-HSCT for either a malignant or a nonmalignant disorder were enrolled in the study; 19 received CB and 18 BM transplantation. Results were compared with those obtained in 14 adults given BM transplantation for either malignant or nonmalignant disorders. MSCs were grown from BM aspirates obtained 1-17 and 2-192 months after allo-HSCT in pediatric and adult patients, respectively. MSC samples at the third-fourth passage were phenotypically characterized. Donor/recipient origin of MSCs was assessed by amelogenin assay and microsatellite analysis. Results: MSCs could be grown from 30 of 37 children; at the third-fourth passage MSCs resulted positive (≥98%) for CD73, CD105, CD106, CD29, CD13, CD44 and negative (≤1%) for CD34, CD45, CD14. Mixed chimerism with donor cells was observed in 4 BM and 5 CB transplantation recipients, respectively; full recipient chimerism was detected in the remaining children. Full recipient MSC chimerism was observed also in all assessable (12/14) adult patients. Conclusions: BM of pediatric patients might be a more favorable milieu than that of adults for sustained engraftment of transplanted MSCs. MSCs able to engraft in the host can be transferred with cryopreserved CB units. © 2006 International Society for Experimental Hematology.

Human leucocyte antigen (HLA)-C molecules regulate the function of natural killer cells and may be subdivided into two groups, C(1) and C(2), based on their specificity for inhibitory killer immunoglobulin-like receptors. We analysed the impact of the HLA-C genotype on outcome of HLA-C-matched unrelated donor haematopoietic stem cell transplantation (URD-HSCT) recipients. HLA-C(2) homozygous patients (n = 18) had lower probability of overall survival (P = 0.01) and disease-free survival (P = 0.02), resulting from increased relapse rate (P = 0.02) when compared with both HLA-C(1) homozygous (n = 43) and HLA-C(1),C(2) heterozygous (n = 50) subgroups. Patients lacking HLA-C(1) should, therefore, be considered at increased risk of relapse following HLA-C-matched URD-HSCT.