COVID-19 disease in children and adolescents following allogeneic hematopoietic stem cell transplantation: A report from the Turkish pediatric bone marrow transplantation study group.

BACKGROUND: Data on the risk factors and outcomes for pediatric patients with SARS-CoV-2 infection (COVID-19) following hematopoietic stem cell transplantation (HSCT) are limited. OBJECTIVES: The study aimed to analyze the clinical signs, risk factors, and outcomes for ICU admission and mortality in a large pediatric cohort who underwent allogeneic HSCT prior to COVID-19 infection. METHOD: In this nationwide study, we retrospectively reviewed the data of 184 pediatric HSCT recipients who had COVID-19 between March 2020 and August 2022. RESULTS: The median time from HSCT to COVID-19 infection was 209.0 days (IQR, 111.7-340.8; range, 0-3845 days). The most common clinical manifestation was fever (58.7%). While most patients (78.8%) had asymptomatic/mild disease, the disease severity was moderate in 9.2% and severe and critical in 4.4% and 7.6%, respectively. The overall mortality was 10.9% (n: 20). Deaths were attributable to COVID-19 in nine (4.9%) patients. Multivariate analysis revealed that lower respiratory tract disease (LRTD) (OR, 23.20, p: .001) and lymphopenia at diagnosis (OR, 5.21, p: .006) were risk factors for ICU admission and that HSCT from a mismatched donor (OR, 54.04, p: .028), multisystem inflammatory syndrome in children (MIS-C) (OR, 31.07, p: .003), and LRTD (OR, 10.11, p: .035) were associated with a higher risk for COVID-19-related mortality. CONCLUSION: While COVID-19 is mostly asymptomatic or mild in pediatric transplant recipients, it can cause ICU admission in those with LRTD or lymphopenia at diagnosis and may be more fatal in those who are transplanted from a mismatched donor and those who develop MIS-C or LRTD.

Comparison of tacrolimus vs. cyclosporine in pediatric hematopoietic stem cell transplantation for thalassemia.

OBJECTIVES: Graft-versus-host disease (GvHD) is one of the leading causes of morbidity and mortality in patients undergoing allogeneic HSCT, and effective prevention of GvHD is critical for the success of the HSCT procedure. Calcineurin inhibitors (CNI) have been used for decades as the backbone of GvHD prophylaxis. In this study, the efficacy and safety of Cyclosporine A (CsA) and tacrolimus (TCR) were compared in pediatric HSCT for thalassemia. MATERIALS AND METHODS: This is a retrospective analysis of 129 pediatric patients who underwent HSCT with the diagnosis of thalassemia at Medicalpark Göztepe and Antalya Hospitals between January 2017 and December 2020. RESULTS: Despite the GvHD prophylaxis, grade II-IV acute GvHD developed in 29 patients. Of these patients, 12 had only gut, 10 had only skin, 6 had combined gut and skin, and one had only liver GvHD. Fifteen of these 29 patients were in the CsA group, and 14 of them were in the TCR group. There was no significant difference between the groups in terms of acute GvHD occurrence, GvHD stage, or involvement sites. In terms of CNI-related toxicity, neurotoxicity in 15 (CsA n = 9, TCR n = 6) and nephrotoxicity in 18 (CsA n = 4, TCR n = 14) patients were observed. While there was no difference between the two groups in terms of neurotoxicity, more nephrotoxicity developed in patients using TCR (p = .013). There was no significant difference between the groups in terms of engraftment syndrome, veno-occlusive disease, CMV reactivation, PRES, or graft rejection. CONCLUSION: Regarding GvHD, there was no difference in efficacy between TCR and CsA usage. Patients taking TCR experienced noticeably higher nephrotoxicity in terms of adverse effects. This difference should be considered according to the patient's clinical situation while choosing a CNI.

Combined Haploidentical Hematopoetic Stem Cell Transplantation and Liver Transplantation in a Pediatric Patient.

Solid organ transplantation from the same donor is an established procedure for end-stage organ failure that developed after a previous hematopoietic stem cell transplantation (HSCT); however, it is rarely done in patients transplanted with unmanipulated haplo-HSCT. There are no pediatric reports regarding the long-term performance of organ transplantation after haplo-HSCT with post-transplant cyclophosphamide (PTCY). A juvenile myelomonocytic leukemia patient, who underwent unmanipulated haplo-HSCT with PTCY from her mother at the age of 3 years, developed chronic liver graft versus host disease (GvHD) which was refractory to specific GvHD treatment. Liver transplantation (LT) from her mother (the donor of her haplo-HSCT) was decided as the next line of treatment. LT was performed on day 540 post-HSCT, and the donor's left lateral segment was appropriately removed and attached to the recipient. The symptoms of GvHD completely regressed in a month. The patient died on day 121 after LT, because of a possible hepato-pulmonary syndrome. Organ failure can develop after allo-HSCT secondary to GvHD and therefore performing HSCT from a haplo-donor may be superior to a matched unrelated donor in terms of subsequent organ transplantation for organ failure.

Pre-transplantation vitamin D deficiency increases acute graft-versus-host disease after hematopoietic stem cell transplantation in thalassemia major patients.

BACKGROUND: Although there are many studies on the role of vitamin D deficiency (VDD) in hematopoetic stem cell transplantation (HSCT), outcomes have often reported conflicting results because of the heterogeneity of the patients in the studies. METHODS: We investigated the association between VDD prior to HSCT and outcomes after HSCT in a relatively homogenous group of patients with thalassemia major (TM) who received identical treatment for TM before transplantation, and the same conditioning regimen and GVHD prophylaxis during and after transplantation. All patients, including the patients with normal vitamin D3 levels received 400 to 800 IU per day of vitamin D for the first 6 months after HSCT. RESULTS: Pre-HSCT VDD increased the frequency of aGVHD after transplantation, particularly in HSCTs performed with PBSC for the stem cell source. Pre-transplant low vitamin D3 levels had no association with transplant outcomes such as engraftment, viral infections, alloimmunization, chronic GvHD, total days of hospitalization, and success in terms of transfusion independence. CONCLUSIONS: Low vitamin D3 levels before HSCT carry a significant risk for aGVHD. All patients with TM should be screened for VDD before HSCT, and every effort should be made to supplement vitamin D before the transplant in VDD patients.

Hematopoietic stem cell transplantation in serine/threonine kinase 4 (STK4) deficiency: Report of two cases and literature review.

BACKGROUND: Serine/threonine kinase 4 (STK4) deficiency is a combined immunodeficiency (CID) characterized by early onset recurrent bacterial, viral, and fungal infections. Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapy for CID; however, little is known about the necessity and benefits of HSCT in patients with STK4 deficiency. METHODS: We report two siblings with STK4 deficiency transplanted from two unrelated donors with the same conditioning regimen. RESULTS: In the conditioning regimen, rituximab was given on Day -11 (375 mg/m2 ), and sirolimus was added on the same day. Busulfan was administered at a myeloablative dose (3.2 mg/kg; Days -7 to -4) with 150 mg/m2 of fludarabine (Days -7 to -3). They were transplanted with peripheral blood stem cells, and graft-versus-host disease (GVHD) prophylaxis was administered with 10 mg/m2 methotrexate on Days 1, 3, and 6. In addition, mycophenolate mofetil (MMF) was started on Day 1 with ongoing use of sirolimus. We did not encounter veno-occlusive disease (VOD), high-grade acute GVHD, or significant organ toxicity in either patient. Both patients were well at the end of the first year after HSCT with complete donor chimerism. CONCLUSIONS: Serine/threonine kinase 4 deficiency is a disease with high mortality post-HSCT; therefore, the conditioning regimen and GVHD prophylaxis strategies are important considerations in these patients. In our opinion, the conditioning regimen, which includes rituximab and busulfan and fludarabine (BU-FLU), GVHD prophylaxis with sirolimus and MMF, and short-term methotrexate, offers favorable outcomes and is well tolerated in our STK4-deficient patients.

Thalassemia-free and graft-versus-host-free survival: outcomes of hematopoietic stem cell transplantation for thalassemia major, Turkish experience.

We report the national data on the outcomes of hematopoietic stem cell transplantation (HSCT) for thalassemia major (TM) patients in Turkey on behalf of the Turkish Pediatric Stem Cell Transplantation Group. We retrospectively enrolled 1469 patients with TM who underwent their first HSCT between 1988 and 2020 in 25 pediatric centers in Turkey. The median follow-up duration and transplant ages were 62 months and 7 years, respectively; 113 patients had chronic graft versus host disease (cGVHD) and the cGVHD rate was 8.3% in surviving patients. Upon the last visit, 30 patients still had cGvHD (2.2%). The 5-year overall survival (OS), thalassemia-free survival (TFS) and thalassemia-GVHD-free survival (TGFS) rates were 92.3%, 82.1%, and 80.8%, respectively. cGVHD incidence was significantly lower in the mixed chimerism (MC) group compared to the complete chimerism (CC) group (p < 0.001). In survival analysis, OS, TFS, and TGFS rates were significantly higher for transplants after 2010. TFS and TGFS rates were better for patients under 7 years and at centers that had performed over 100 thalassemia transplants. Transplants from matched unrelated donors had significantly higher TFS rates. We recommend HSCT before 7 years old in thalassemia patients who have a matched donor for improved outcomes.

Timing of Initiation of Calcineurin Inhibitors in Pediatric Haploidentical Transplantation with Post-Transplantation Cyclophosphamide: Effects on Survival, Relapse, and Cytokine Release Syndrome.

BACKGROUND: The use of unmanipulated haploidentical hematopoietic stem cell transplantations (haplo-HSCT) with post-transplant cyclophosphamide (PTCY) in children has emerged as an acceptable alternative to the patients without a matched donor. However, the timing of calcineurin inhibitors (CNIs) used in combination with PTCY is increasingly becoming a topic of controversy. METHOD: We evaluated 49 children with acute leukemia who underwent unmanipulated haplo-HSCT with PTCY according to the initiation day of CNIs (pre- or post-cyclophosphamide [CY]). RESULTS: There were no significant differences in the overall survival analysis between the 2 groups. The cumulative incidence of relapse at 2 years was 21.2% in the pre-CY group and 38.9% in the post-CY group (p = 0.33). Cytokine release syndrome (CRS) was observed more frequently in the post-CY group (p = 0.04). The overall survival and event-free survival at 2 years in patients with and without CRS in the pre-CY group were 42.9% versus 87.5% (p = 0.04) and 38.1% versus 87.5% (p = 0.04), respectively. CONCLUSION: Our study shows that the argument for starting CNI administration after CY is tenuous, and the rationale for not starting CNIs before CY needs to be reconsidered.

Epstein-Barr virus-related lymphoproliferative disorders in T-cell repleted haploidentical transplantation with post-transplant cyclophosphamide.

EBV-associated lymphoproliferative disorders (LPDs) are common in hematopoietic stem cell transplantation (HSCT) with T-cell-depleted grafts, but are extremely rare in HSCT patients with T-cell-replete grafts with post-transplant cyclophosphamide (PTCy). Here we present the cases of two pediatric patients who developed EBV-related LPD after T-cell-replete haplo-HSCT with PTCy. One of these is the first reported case of EBV-positive mucocutaneous ulcer (EBVMCU) developing after PTCy. EBV-related diseases are rare in T-cell-replete haplo-HSCT patients with PTCy. However, in patients with risk factors, it is reasonable to screen for EBV viremia for LPD.

Pearson syndrome in a child transplanted for Diamond-Blackfan anemia. / Síndrome de Pearson en un niño trasplantado debido a anemia de Diamond-Blackfan.

Pearson syndrome (PS), shares a number of overlapping features with Diamond-Blackfan anemia (DBA), including early onset of severe anemia, making differential diagnosis important. Differential diagnosis of DBA and PS is critical, since those with DBA may respond to treatment with steroids, may undergo remission, or may benefit from hematopoietic stem cell transplantation (HSCT). However, patients with PS have a different prognosis, with a very high risk of developing acidosis, metabolic problems, and pancreatic dysfunction, and a shorter life expectancy than those with DBA. Here we present a patient who underwent HSCT for DBA but was subsequently diagnosed with PS after developing some complications.

El síndrome de Pearson (SP) comparte varias características con la anemia de Diamond-Blackfan (ADB), incluida la anemia grave de inicio temprano, por lo que es importante hacer un diagnóstico diferencial. El diagnóstico diferencial de la ADB y el SP es fundamental, ya que los pacientes con ADB podrían responder al tratamiento con corticoesteroides, presentar remisión o beneficiarse del trasplante de células madre hematopoyéticas (TCMH). Sin embargo, los pacientes con SP tienen un pronóstico diferente, con un riesgo muy elevado de acidosis, problemas metabólicos y disfunción pancreática, y una expectativa de vida menor en comparación con aquellos con ADB. En este artículo, presentamos el caso de un paciente sometido a TCMH para la ADB, pero que luego fue diagnosticado con SP tras desarrollar algunas complicaciones.

Síndrome de Pearson en un niño trasplantado debido a anemia de Diamond-Blackfan / Pearson syndrome in a child transplanted for Diamond-Blackfan anemia

El síndrome de Pearson (SP) comparte varias características con la anemia de Diamond-Blackfan (ADB), incluida la anemia grave de inicio temprano, por lo que es importante hacer un diagnóstico diferencial. El diagnóstico diferencial de la ADB y el SP es fundamental, ya que los pacientes con ADB podrían res-ponder al tratamiento con corticoesteroides, presentar remisión o beneficiarse del trasplante de células madre hematopoyéti-cas (TCMH). Sin embargo, los pacientes con SP tienen un pronós-tico diferente, con un riesgo muy elevado de acidosis, problemas metabólicos y disfunción pancreática, y una expectativa de vida menor en comparación con aquellos con ADB. En este artículo, presentamos el caso de un paciente sometido a TCMH para la ADB, pero que luego fue diagnosticado con SP tras desarrollar algunas complicaciones.

Pearson syndrome (PS), shares a number of overlapping features with Diamond-Blackfan anemia (DBA), including early onset of severe anemia, making differential diagnosis important. Differential diagnosis of DBA and PS is critical, since those with DBA may respond to treatment with steroids, may undergo remission, or may benefit from hematopoietic stem cell transplantation (HSCT). However, patients with PS have a different prognosis, with a very high risk of developing acidosis, metabolic problems, and pancreatic dysfunction, and a shorter life expectancy than those with DBA. Here we present a patient who underwent HSCT for DBA but was subsequently diagnosed with PS after developing some complications

Analyzing the clinical outcomes of switching from cyclosporine to tacrolimus in pediatric hematopoietic stem cell transplantation.

OBJECTIVE: The selection of graft-vs. -host disease (GvHD) prophylaxis is vital for the success of hematopoetic stem cell transplantation (HSCT), and calcineurin inhibitors (CNI) have been used for decades as the backbone of GvHD prophylaxis. The aim of this study is to analyze the results of switching cyclosporine (CSA) to tacrolimus because of acute GvHD, engraftment syndrome (ES), persistent low level of CSA, or various CSA-associated adverse events in the first 100 days of pediatric HSCT. MATERIALS AND METHODS: This is a retrospective analysis of 192 patients who underwent allogeneic hematopoietic stem cell transplantation at Medicalpark Göztepe and Antalya Hospitals between April 2014 and May 2019 had therapy switched from CSA to tacrolimus-based immunosuppression within 100 days of transplant. RESULTS: The reasons for conversion to tacrolimus were low level of CSA (n = 70), aGvHD (n = 63), CSA-associated neurotoxicity (n = 15), CSA-associated nephrotoxicity (n = 10), hypertension (n = 10), allergic reactions (n = 9), ES (n = 7), CSA-associated hepatotoxicity (n = 5), and vomiting (n = 3). The median day after transplant for conversion to tacrolimus for all patients was day 20 (range 0-100 days). Response rates to conversion were 38% for GvHD, 86% for neurotoxicity, 50% for nephrotoxicity, 60% for hepatotoxicity, 80% for hypertension, 66% for vomiting, and 57% for ES. Twenty-nine patients (15%) experienced tacrolimus-associated toxicities after therapy conversion to tacrolimus. Neurotoxicity emerged as posterior reversible encephalopathy syndrome (PRES), which was the most common toxicity observed after conversion (18/29 patients). CONCLUSION: Our data support the quick conversion to tacrolimus in the condition of persistent low CSA levels with acceptable efficacy and safety. Although both drugs are CNI and share a very similar mechanism of action, the conversion could be preferred especially in specific organ toxicities with special attention for neurotoxicity after conversion.

Allogeneic hematopoietic stem cell transplantation in patients with childhood cerebral adrenoleukodystrophy: A single-center experience "Better prognosis in earlier stage".

BACKGROUND: ALD is a rare X-linked peroxisomal metabolic disorder with many distinct phenotypes of disease that emerge on a wide scale from adrenal insufficiency to fatal cALD which progresses to a vegetative state within a few years. Currently, HSCT is the only treatment method known to stabilize disease progression in patients with cALD. In this study, we aim to report our HSCT experience in patients with cALD and the factors that determine the success of HSCT, as a single-center experience. METHODS: The study cohort involves 23 boys with cALD and three patients with ALD trait and new-onset abnormal behavior who underwent allogeneic HSCT between January 2012 and September 2019 in our transplantation center. Loes scoring, NFS, scale and MFD were performed for evaluating the severity of the cerebral disease. The study cohort was divided into two groups according to baseline NFS and Loes score: early-stage (NFS ≤ 1 and Loes score <9) and advanced stage (NFS > 1 or Loes score ≥9). RESULTS: The pretransplant stage of disease impacted both OS and MFD-free survival. The estimated OS and MFD-free survival at 3 years in patients with advanced disease were 46.1% (95% CI 19.0-73.2) and 23.1% (95% CI 0.2-46.0), respectively, and all patients with the early disease were alive (p: .004) and MFD-free (p < .001) at 3 years. CONCLUSION: This study demonstrated that early HSCT is vital in patients with cALD. The early-stage disease had a significant survival advantage and free from disease progression after HSCT.

Use of low cell dose for unmanipulated donor lymphocyte for management of cytomegalovirus infection: A single-center experience.

Although advancements have been made in monitoring and preventing viral infections in HSCT patients, CMV reactivation still remains a critical post-transplant complication. Adoptive cell therapy is an alternative to pharmacotherapy of CMV infection in refractory patients. We retrospectively reviewed CMV infection cases after allogeneic HSCT who received U-DLI as treatment. In total, five pediatric patients between the ages of 0.5-16 years that received U-DLI for a post-HSCT CMV infection were evaluated. The dose of CD3+ lymphocytes administered in DLI was 5 × 104 /kg, except in one patient transplanted from his sibling. One patient, who was transplanted from an unrelated donor, received U-DLI from his haploidentical mother. CMV titers dramatically reduced after U-DLI. If the availability of CMV-specific CTL is an issue, we propose that one should consider using the U-DLI therapy with low cell dose from a seropositive donor. In case the stem cell donor is seronegative and a seropositive donor is unavailable, using the U-DLI therapy from seropositive, haploidentical donors is a promising way of treatment. More studies need to be conducted to further confirm the safety and efficacy of this treatment procedure.

Hematopoietic stem cell transplantation in CD40 ligand deficiency: A single-center experience.

Deficiency of the CD40L, expressed on the surface of T lymphocytes, is caused by mutations in the glycoprotein CD40L (CD154) gene. Resulting defective humoral and cellular responses cause a clinical presentation that includes recurrent sinopulmonary bacterial infections, opportunistic infections, sclerosing cholangitis, neutropenia, and autoimmune manifestations. HSCT represents the only curative treatment modality. However, the therapeutic decision to use HSCT proves challenging in many cases, mainly due to the lack of a phenotype-genotype correlation. We retrospectively reviewed patients with CD40L deficiency who were transplanted in Antalya and Göztepe MedicalPark Pediatric HSCT units from 2014 to 2019 and followed by Akdeniz University School of Medicine Department of Pediatric Immunology. The records of eight male cases, including one set of twins, were evaluated retrospectively. As two transplants each were performed on the twins, a total of ten transplants were evaluated. Conditioning regimens were predominantly based on myeloablative protocols, except for the twins, who received a non-myeloablative regimen for their first transplantation. Median neutrophil and platelet engraftment days were 13 (range 10-19) and 14 (range 10-42) days, respectively. In seven of ten transplants, a CMV reactivation was developed without morbidity. None of the patients developed GVHD, except for one mild case of acute GVHD. All patients survived, and the median follow-up was 852 days. Our data show that HSCT for patients with CD40 ligand deficiency is a potentially effective treatment for long-term disease control.

Ruxolitinib salvage therapy is effective for steroid-refractory graft-versus-host disease in children: A single-center experience.

BACKGROUND: Despite the increasing performance of allogeneic hematopoietic cell transplantation over the last decades, graft-versus-host disease (GVHD) remains the main cause of morbidity and mortality. The efficacy of ruxolitinib against GVHD has been demonstrated in adult studies; however, very few studies have been conducted in children. PROCEDURE: This study aimed to evaluate the efficacy of ruxolitinib in 29 children with steroid-refractory acute or chronic GVHD. Twenty-five (87%) patients received at least three different immune modulator agents, including methylprednisolone, before initiating ruxolitinib. RESULTS: All grade 2 acute GVHD patients completely responded to ruxolitinib treatment; 82% of high-grade (3-4) acute GVHD patients and 80% of chronic GVHD (moderate-severe) patients had at least a partial response. Of seven patients with bronchiolitis obliterans, five had a partial response after ruxolitinib. Of 29 patients, 22 were administered steroids at any time in the first month of acute GVHD or the first three months of chronic GVHD during ruxolitinib usage, which was significantly tapered by the end of the observation period. CONCLUSION: Steroid-refractory acute and chronic pediatric GVHD patients treated with ruxolitinib had a high overall response rate, with the additional benefit of steroid sparing.

Haploidentical hematopoietic stem cell transplantation with post-transplant high-dose cyclophosphamide in high-risk children: A single-center study.

BACKGROUND: Post-Cy administration for GVHD prophylaxis in unmanipulated haploidentical HSCT has resulted in improved outcomes in recent years. Studies in children are lacking and accordingly we present the outcomes of 62 haploidentical transplantation for high-risk children. PROCEDURE: We retrospectively assessed 62 transplants in 60 patients who underwent haploidentical-related HSCT with unmanipulated stem cells and for whom Post-Cy was used for GVHD prophylaxis. RESULTS: Myeloid reconstitution was achieved on day + 30 for 57 of the 62 patients. The median follow-up of the surviving 39 patients (63%) was 26 months, with a range of 6-57 months. The OS and EFS at 2 years were 64.6% (52.0%-77.2%, 95% CI) and 58.9% (46.1%-71.7%, 95% CI), respectively. The only factor in our multivariate analysis that contributed to an inferior EFS was a poor remission status prior to HSCT (HR, 8.30; 1.08-63.56; P = 0.041, 95% CI). CONCLUSION: The results of T-cell replete haploidentical transplantation with Post-Cy GVHD prophylaxis in high-risk pediatric patients are promising. However, further research is needed to determine the factors that have affect HLA compatibility for predicting the success of haploidentical transplantations.

Hematopoietic Stem Cell Transplantation From Unrelated Donors in 2 Cases of Interleukin-10 Receptor Deficiency: Is Surgery Not a Requirement?

Mutations in interleukin-10 and its receptors cause infantile inflammatory bowel disease (IBD), a hyperinflammatory disorder characterized by severe, treatment-refractory colitis, multiple abscesses, and enterocutaneous fistulas. Patients with infantile IBD often require several surgical interventions, including complete colectomy, and hematopoietic stem cell transplantation is currently the only known medical therapy. Traditionally, operative management has been preferred before stem cell transplantation because of the latter's increased susceptibility to procedural complications; however, surgical intervention could be delayed, and possibly reconsidered, because our 2 patients with infantile IBD demonstrated a rapid response to treatment via engraftment.

Chronic neutrophilic leukemia, an extremely rare cause of neutrophilia in childhood: Cure with hematopoietic stem cell transplantation.

CNL is a rare myeloproliferative disorder frequently seen in older adults. A significant proportion of patients show progression to AML. Here, we report the case of a patient with FA who was monitored for leukopenia but who developed leukocytosis during the follow-up and was diagnosed with CNL probably after an acquired CSF3R mutation. Because the patient had FA, which could accelerate the progression to AML, an HSCT was performed, which resulted in cure. This patient (aged 12 years) is one of the youngest patients reported to develop CNL as well as the first FA patient with a diagnosis of CNL.

Immune Reconstitution Inflammatory Syndrome After DLI in a SCID Patient After Hematopoetic Stem Cell Transplantation.

Immune reconstitution inflammatory syndrome (IRIS) is a clinical condition emerging after immune recovery of an immunocompromised status, mostly in human immunodeficiency virus infected patients but also in several other settings, such as the recovery from the severe combined immunodeficiency status after hematopoietic stem cell transplantation. Herein, we report a patient transplanted for severe combined immunodeficiency who developed IRIS for 2 times, namely shortly after transplantation and after donor lymphocyte infusion. Pediatric transplant teams need to be aware of the previous IRIS phenomenon of BCG-adenitis while making the decision of donor lymphocyte infusions.

Three relapses after a haploidentical transplantation in a pediatric patient: Cure with no further transplantation.

Isolated extramedullary relapse (EMR) after hematopoietic stem cell transplantation (HSCT) is a highly fatal condition that creates uncertainty regarding treatment options. Although certain approaches such as repeat HSCT and donor lymphocyte infusion are recommended, we report a patient with acute lymphoblastic leukemia who had three isolated EMRs after HSCT at different locations and at different times that were responsive to local and systemic therapies, without the need for a second transplantation.