Short- and long-term outcome of allogeneic stem cell transplantation in infants: A single-center experience over 20 years.

Introduction: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a treatment method for a wide range of malignant and non-malignant diseases. Infants constitute a distinct patient group, especially due to their organ immaturity and differences in drug metabolism. The present paper aims to analyse the short- and long-term outcomes after allo-HSCT in infants. Material and methods: In the study period, 67 patients under 12 months of age underwent allo-HSCT. This study is a retrospective analysis of patient medical records, in the form of paper and electronic documentation. Results: The probability of 5-year OS was 69% and 72% in patients with malignant and non-malignant diseases, respectively. The allo-HSCT from a matched donor was associated with improved OS in comparison to haploidentical donor (0.8 vs. 0.58%, p = 0.0425). The overall incidence of acute graft-vs.-host disease (aGVHD) was 59.3%, and grade III-IV aGVHD was diagnosed in 23% of patients. The 100-day non-relapse mortality (NRM) in the study cohort was 17.9%, while the 5-year NRM was 26.9%. Among the causes of NRM, infections occurred in 83.3% of patients, and aGVHD in 16.3% of individuals. Twenty-two children (32.8%) required hospitalization in the pediatric intensive care unit (PICU). The median length of PICU hospitalization was 6 days (range 1 to 12 days). Late sequelae diagnosed during post-transplant surveillance included ocular disorders in 26.8% of patients, cardiac complications in 4.4%, as well as endocrinopathy with short stature (<3rd percentile) in 37.2% and overt hypothyroidism in 35.4%. In the long-term perspective, 83.3% of survivors were able to attend a regular school. Conclusions: Improvements in unrelated donor availability, and better supportive care resulted in better outcomes. Management of infant allo-HSCT recipients requires the formation of multi-disciplinary specialist teams. In addition, the role of parental empowerment must be acknowledged; for example, in speech therapy and rehabilitation.

Case Report: Liver as a Source of Hematopoietic Stem Cells After Liver Transplantation Following Hematopoietic Stem Cell Transplantation.

We report a child with Fanconi anemia who, after hematopoietic stem cell transplantation (HSCT) complicated by acute graft-versus-host disease (GVHD), underwent orthotopic liver transplantation (OLT). Approximately 1 month after OLT, the presence of third-party genetic material from the liver donor was noted and in the next few weeks, the chimerism assessment revealed 100% liver donor leukocytes in the peripheral blood. The rapidly progressing GVHD with gut involvement resulted in patient's death 6 months after OLT. The liver can act as a clinically significant source of hematopoietic stem cells, and the liver donor's young age must be emphasized as potentially predisposing to this phenomenon. Transfer of OLT hematopoietic stem cells may not have clinical significance unless the patient is not immunocompetent or develops liver-transplantation associated GVHD, that can result in lymphocyte mediated elimination of original hematopoiesis. Patients with preexisting immunity disorder (such as primary or secondary immunodeficiency) might require intensified immunosuppressive therapy in peritransplant period as a prevention of liver-transplantation associated GVHD. Close monitoring of hematopoietic chimerism after OLT is warranted in patients at risk, because cytopenia or OLT hematopoiesis can reflect subclinical GVHD and further studies are necessary to elucidate this phenomenon.

Vedolizumab in highly resistant acute gastrointestinal graft-versus-host disease after allogeneic stem cell transplantation: A single-center pediatric series.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a lifesaving procedure in malignant and nonmalignant diseases. However, it is associated with a considerable risk of graft-versus-host disease (GvHD). Steroids are a first-line therapy for acute GvHD (aGvHD), but there is no standard treatment for steroid-resistant (SR) gastrointestinal (GI) aGvHD, which has a poor prognosis. The anti-integrin antibody, vedolizumab, could help in controlling SR GI aGvHD symptoms by blocking lymphocyte extravasation and infiltration of the intestinal wall. OBJECTIVES: To report the outcomes of 3 children with SR GI aGvHD after allo-HSCT, treated with vedolizumab as the last chance drug. MATERIAL AND METHODS: The study included 3 patients aged from 8 to 10 years who underwent HSCT in Department of Pediatric Bone Marrow Transplantation, Oncology and Hematology at Wroclaw Medical University, Poland, and who developed severe SR GI aGvHD. All patients had grade IV SR aGvHD with GI stage 4 manifestation. Vedolizumab was given as salvage therapy after an ineffective treatment with etanercept, basiliximab, ruxolitinib, extracorporeal photopheresis, and mesenchymal stem cell infusions. Vedolizumab was administered intravenously at a dose of 300 mg. RESULTS: Only 1 patient achieved GvHD remission and was alive and well 9 months after the discontinuation of the therapy. One child developed a relapse of malignant disease and eventually died, and the third child died of severe aGvHD. CONCLUSION: Vedolizumab can be safely used in children with SR GI aGvHD, offering an additional chance for heavily pretreated patients. Prospective pediatric studies on both prophylactic and therapeutic use of the drug are warranted, according to the preliminary results.

Fludarabine-Cyclophosphamide-Based Conditioning with Antithymocyte Globulin Serotherapy Is Associated with Durable Engraftment and Manageable Infections in Children with Severe Aplastic Anemia.

Severe aplastic anemia (SAA) is a bone marrow failure syndrome that can be treated with hematopoietic cell transplantation (HCT) or immunosuppressive (IS) therapy. A retrospective cohort of 56 children with SAA undergoing transplantation with fludarabine-cyclophosphamide-ATG-based conditioning (FluCyATG) was analyzed. The endpoints were overall survival (OS), event-free survival (EFS), cumulative incidence (CI) of graft versus host disease (GVHD) and CI of viral replication. Engraftment was achieved in 53/56 patients, and four patients died (two due to fungal infection, and two of neuroinfection). The median time to neutrophil engraftment was 14 days and to platelet engraftment was 16 days, and median donor chimerism was above 98%. The overall incidence of acute GVHD was 41.5%, and that of grade III-IV acute GVHD was 14.3%. Chronic GVHD was diagnosed in 14.2% of children. The probability of 2-year GVHD-free survival was 76.1%. In the univariate analysis, a higher dose of cyclophosphamide and previous IS therapy were significant risk factors for worse overall survival. Episodes of viral replication occurred in 33/56 (58.9%) patients, but did not influence OS. The main advantages of FluCyATG include early engraftment with a very high level of donor chimerism, high overall survival and a low risk of viral replication after HCT.

SARS-CoV-2 viral clearance during bone marrow aplasia after allogeneic hematopoietic stem cell transplantation-A case report.

Respiratory viral infections are known causes of mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Here, we report a unique case of a child with viral pneumonia caused by coinfection with human metapneumovirus (MPV), respiratory syncytial virus (RSV), and SARS-CoV-2 after HSCT. A 9-year-old girl with acute lymphoblastic leukemia underwent allogeneic HSCT from a matched, unrelated donor. During the post-transplant period, in profound leukopenia (below 10 leukocytes/µL), she was diagnosed with SARS-CoV-2, MPV, and RSV pneumonia and was treated with ribavirin and chloroquine. Before leukocyte recovery, the girl became asymptomatic, and SARS-CoV-2 and RSV clearance was achieved. The shedding of SARS-CoV-2 stopped before immune system recovery, and one may hypothesize that the lack of an inflammatory response might have been a contributing factor to the mild clinical course. Post-transplant care in HSCT recipients with COVID-19 infection is feasible in regular transplant units, provided the patient does not present with respiratory failure. Early and repeated testing for SARS-CoV-2 in post-transplant patients with concomitant infection mitigation strategies should be considered in children after HSCT who develop fever, respiratory symptoms, and perhaps gastrointestinal symptoms to control the spread of COVID-19 both in patients and in healthcare workers in hospital environments. Training of staff and the availability of personal protective equipment are crucial for containing SARS-CoV-2 infection.

Short Course of Eculizumab May Be Effective in Dialysis-Dependent Transplantation-Associated Thrombotic Microangiopathy After Hematopoietic Stem Cell Transplantation: A Case Report.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (alloHSCT) could induce several complications. The most frequent viral infections and graft-vs-host disease (GvHD) sometimes lead to thrombotic microangiopathy (TMA). It is associated with significant morbidity and mortality with the risk of death reaching 90%. Effective prevention and treatment are not available to date. Recent attempts at using antibody against C5 have been made. CASE REPORT: A 19-year-old girl with acute myeloid leukemia twice underwent alloHSCTs from her 10/10 HLA-matched sister. After the second HSCT severe acute steroid-resistant grade 4 GvHD occurred. Despite treatment with high doses of steroids, mycophenolate mofetil, biological therapy, and extracorporeal photopheresis, the patient developed TMA with acute kidney injury and the need for renal replacement therapy. The concentration of complement component 3 and activity of ADAMTS 13 were normal, and infection with Escherichia coli (E. coli) 0157H7 was excluded. Due to failure of all ordered therapies and severity of the condition, an attempt was taken to use eculizumab. Two 900-mg doses of eculizumab (Soliris) were administered at an interval of 2 weeks, which resulted in the improvement of renal function and amelioration of hemolysis and thrombocytopenia. Dialysis therapy was finished after 5 weeks, and then a third dose of the drug was administered. Eighteen months later, the patient is alive and well, with limited chronic GvHD. eGFR remains stable at 40 to 46 mL/min/1.73 m2, and mild hypertension requires treatment with angiotensin converting enzyme inhibitors and furosemide. CONCLUSION: Even a short course of eculizumab can be sufficient in controlling the TMA after HSCT, provided that the TMA-triggering factors are well controlled.

Severe, Reversible Acute Lung Injury During Autologous Hematopoietic Stem Cell Mobilization After Filgrastim in a Child With Neuroblastoma: A Case Report.

Peripheral blood hematopoietic stem cell mobilization is widely performed in a variety of clinical facilities and is believed to be a safe outpatient procedure. In this report, we describe a child with neuroblastoma who developed an extremely severe acute lung injury after granulocyte colony-stimulating factor was used for peripheral hematopoietic stem cell mobilization. A 3-year-old boy with a medical history of patent foramen ovale and secundum atrial septal defect was diagnosed with an MYCN-amplified neuroblastoma and treated with chemotherapy. During stem cell mobilization with filgrastim, the boy was in very good clinical condition, with a peripheral white blood cell (WBC) count of 57.17 K/µL, but he suddenly deteriorated, and nausea, seizures, and nystagmus were observed. The patient developed dyspnea with hemoptysis, and lung computed tomography showed bilateral asymmetrical pulmonary opacification demonstrating an anteroposterior density gradient. Because of rapidly progressing circulatory and respiratory failure, the child was hospitalized in the intensive care unit. Corticosteroid therapy, broad-spectrum antibiotic therapy, and cardiovascular support with mechanical ventilation were immediately instituted, and the child recovered without sequelae. The presented case emphasizes that life-threatening complications can occur during granulocyte colony-stimulating factor administration, and patient surveillance is warranted, especially if high leukocyte counts are observed or the patient exhibits cardiopulmonary signs.

Successful Bone Marrow Recovery After an Immunoablative Regimen With Autologous Cord Blood Transplant in a Child With Idiopathic Severe Aplastic Anemia: A Case Report.

BACKGROUND: Aplastic anemia is a rare disease that manifests as bone marrow failure. The current treatment options include immunoablative therapy or allogeneic hematopoietic stem cell transplantation. We report a successful immunoablative regimen with autologous umbilical cord blood (auto-UCB) transplant in a 3-year-old boy with severe aplastic anemia. CASE REPORT: The immunoablation procedure consisted of 5 × 3.75 mg/kg antithymocyte globulin (Thymoglobulin) (total 18.75 mg/kg), methylprednisolone for 4 days, and cyclosporine A. The patient received auto-UCB containing 0.3 × 105 CD34+ cells per kilogram of body weight. Recovery of leukocyte count above 1000/µL was reached on post-transplant day +39, and recovery of granulocytes above 500/µL was reached on day +40. The final regular transfusions of packed red blood cells and platelet concentrate were performed on day +55. The complications that occurred in the post-transplant period were nausea, diarrhea, septic fever, and hepatic abscess formation. Post-transplant immunosuppression with cyclosporine A was discontinued 17.5 months after auto-UCB, and the patient remained in complete remission with normal blood counts and bone marrow morphology. SUMMARY: Auto-UCB transplantation without chemotherapy conditioning can be considered a therapeutic option for children with stored cord blood cells.

Feasibility and Safety of Treosulfan, Melphalan, and Thiotepa-Based Megachemotherapy with Autologous or Allogeneic Stem Cell Transplantation in Heavily Pretreated Children with Relapsed or Refractory Neuroblastoma.

The prognosis of resistant or relapsing children with neuroblastoma remains very poor, and the search for new therapies is ongoing. In this analysis, we assessed the toxicity of a treosulfan, melphalan, and thiotepa (TMT) regimen in 17 children with recurrent or refractory neuroblastoma who underwent stem cell transplantation (SCT). For allogeneic SCT, fludarabine and antithymocyte globulin were added. The stem cell source was autologous in 8 patients, haploidentical in 8 patients, and a matched unrelated donor in 1 patient. The reported nonhematologic toxicities included grade 3 mucositis, grade 1 to 3 hypertransaminasemia, and in 3 patients, veno-occlusive disease. No neurologic, cardiac, or dermatologic toxicities were observed. The probability of overall survival (OS) in patients with primary resistance was superior to that in patients with relapsed disease (100% versus 22.6%; P = .046). Post-transplantation dinutuximab beta immunotherapy was associated with superior 5-year OS (66.7% versus 11.4%; P = .0007). The use of an allogeneic donor, previous autologous SCT with busulfan and melphalan, and pretreatment with high-dose metaiodobenzylguanidine therapy demonstrated no effect on outcomes. In 4 patients, TMT megatherapy alone was enough to achieve complete remission. The TMT conditioning regimen was well tolerated in heavily pretreated patients with neuroblastoma. The manageable toxicity and addition of new anticancer drugs with optional post-SCT immunotherapy or chemotherapy support further trials with the TMT regimen in patients with neuroblastoma.

Follow-Up of Pediatric Liver Transplant Patients After Reaching Adulthood.

BACKGROUND Despite excellent transplantation results, there is a vulnerable period of time in the post-transplant management of pediatric liver recipients, which is the time when a child becomes an adolescent. This period of psychological distress influences compliance and may result in premature transplant failure and graft loss. We performed a retrospective review of pediatric liver transplant recipients, transferred to our service for adults, in order to identify key issues associated with transition into the adult care. MATERIAL AND METHODS We analyzed medical files of 20 liver recipients transferred from pediatric post-transplant outpatient clinic to the post-transplant service for adults, since year 2000 until December 2015. For survival analyses, Kaplan-Meier model with log-rank test and Cox proportional hazards regression model, to calculate hazard ratio (HR), were used. RESULTS Survival rate exceeds 90% in the study population. The major complication was late acute rejection, in most instances due to non-compliance. There were single cases of recurrent liver disease and de novo graft disorders. CONCLUSIONS Dedicated service for young people may be needed to optimize outcomes.