Post-transplant strategies to improve relapse-free survival in childhood leukemia: Whole blood donor lymphocyte infusions and lenalidomide for inducing graft-versus-leukemia effect.

INTRODUCTION: Post-transplant graft-versus-leukemia (GVL) effect has been shown to be an important determinant of a successful outcome following hematopoietic stem cell transplantation (HSCT) in children with acute leukemia. PATIENTS AND METHODS: We performed a retrospective analysis of the children up to 18 years of age with acute leukemia who underwent HSCT between November 2002 and November 2018. GVL induction strategies included whole blood donor lymphocyte infusions (DLI) and/or lenalidomide. RESULTS: A total of 134 children were included with engraftment in 125 children (93%). Acute graft-versus-host disease (GVHD) was documented in 85 (63%) children without any induction strategies. GVL induction strategies were employed in 19 children (14%); DLI (n = 12), Lenalidomide (n = 2), DLI + lenalidomide (n = 5). Among the 19, 12 children (63%) are alive without relapse; 6 children died of relapse (31%). Among the 6 who died of relapse despite induction strategies, 5/6 had ALL and one child had AML. GVL induction was effective in preventing relapse in 7/12 (58%) children with ALL and 5/6 (83%) children with AML. Relapse-free survival in the cohort is 73/134 (55%) with a median follow-up of 32 months. GVHD of any grade was significantly associated with a lower risk of relapse (p = .008). Median survival time was 160.3 days (range 132-187) in those with chronic GVHD versus 88.3 days (range 68-107) in those without (p value = .004). CONCLUSION: Pre-emptive whole blood DLIs in graded aliquots, and lenalidomide are important tools for post HSCT GVL induction, which significantly impacts relapse-free survival in childhood leukemia.

Management of Peripheral T-Cell Lymphoma in Children and Adolescents Including STAT 3 Mutation Hyper-IgE Syndrome: One Size Does Not Fit All.

Peripheral T-cell lymphoma (PTCL) is a rare form of lymphoma in children with limited published data on treatment and lack of a uniformly accepted treatment algorithm. We retrospectively analyzed the data in children up to 18 years of age diagnosed to have PTCL from January 2016 to June 2020. The study included six children with a median age of 10 years, the youngest being a 7-month-old girl. According to the WHO-PTCL classification, three had PTCL-not otherwise specified (NOS), 2 had hepatosplenic TCL, and 1 had subcutaneous panniculitis-like TCL. All children had presented with advanced disease, 4 in St. Jude stage IV, 2 in St. Jude stage III. Three children received CHOEP chemotherapy including cyclophosphamide, doxorubicin, vincristine, prednisone, etoposide, while 1 child received CHOP. Two children received induction as per acute lymphoblastic leukemia followed by Bendamustine. Two patients succumbed to progressive disease, the infant with PTCL-NOS and 1 child with hepatosplenic TCL. Three children were in remission (median follow up of 44 mo). One child with PTCL-NOS Stage IV had an underlying STAT3 mutated hyperimmunoglobulin E syndrome and was in remission 12 months post a matched unrelated donor hematopoietic stem cell transplantation. He had grade 4 skin graft versus host disease and required extracorporeal photopheresis and ibrutinib, to which he had responded. CHOEP chemotherapy is well-tolerated and subcutaneous panniculitis-like TCL has the best prognosis thus far.

Augmented immunosuppression and PTCY-based haploidentical hematopoietic stem cell transplantation for thalassemia major.

Alternate donor HSCT for thalassemia major from a matched unrelated donor or haploidentical family donor is a feasible therapeutic option in children with no matched family donor. Aggressive pretransplant immunosuppression, reduced toxicity conditioning, and PTCY result in excellent thalassemia-free survival. We describe here our experience in this cohort. We performed a retrospective analysis of the data on children who underwent a haploidentical HSCT for thalassemia major with PTCY at our center from August 2017 to August 2019. All children received pretransplant immune suppression for 6 weeks with fludarabine and dexamethasone, hypertransfusion and chelation with intravenous desferrioxamine. Conditioning included thiotepa, fludarabine, rabbit ATG, and cyclophosphamide, and GvHD prophylaxis included PTCY with tacrolimus. Twenty children were included and nineteen children engrafted. Acute hypertension occurred in five children, bacterial infection in eight children and viral respiratory infection in three children. Three children suffered from graft rejection. Reactivation of viruses namely CMV, adenovirus, and BK virus was seen in 60% of children. Grades 1-2 acute GvHD of the skin in four children (20%) and limited chronic GvHD of the skin in four children (20%). Immune cytopenia was documented in three children (15%). Haploidentical HSCT offers a therapeutic option for children with thalassemia major with no suitably matched family or unrelated donors. Our reduced toxicity regimen with PTCY offers a DFS of 75% and OS of 95% with low transplant-related mortality of 5%.

Risk-adapted therapy for the management of cytokine release syndrome in children undergoing unmanipulated haploidentical stem cell transplantation.

BACKGROUND: We aimed to describe an algorithm for the management of cytokine release syndrome (CRS) associated with haploidentical hematopoietic stem cell transplantation (haploSCT). PATIENTS AND METHODS: We performed a prospective study where children up to 18 years of age undergoing haploSCT with post-transplant cyclophosphamide from September 2014 to March 2020 were included. Supportive care included low-dose adrenaline, high-flow nasal cannula, and N-acetylcysteine (NAC). Methylprednisolone and tocilizumab were administered in the peri-engraftment phase for grade 2 CRS or one-log increase and grade 3 CRS or a two-log increase in ferritin, respectively. RESULTS: Data were analyzed in 135/148 children as 13 children died before engraftment due to sepsis. CRS was noted in 97% transplants (grade 1-74.1%, grade 2-15.6%, grade 3-6.7%, grade 4-1.4%). Grade 2 and above CRS was higher in non-malignant conditions (33% vs 13%, P-value .009). The percentage median rise in ferritin was 129%-grade 1, 171%-grade 2, and 344%-grade 3. Seven children received tocilizumab, and two of whom had ferritin values greater than 100 000 ng/mL with no mortality in this group. Low-dose adrenaline, high-flow nasal cannula, and ventilator support were needed in 13%, 10%, and 4%, respectively. Mortality in our cohort was 3/135 (2.2%), with two deaths due to sepsis and one due to grade 4 CRS. CONCLUSIONS: A risk-stratified approach using steroids in grade 2 and tocilizumab in grade 3/4 in the setting of haploSCT with NAC infusion and early use of low-dose adrenaline and HFNC can help provide adequate control of CRS, thereby ensuring optimal outcomes and survival.

Mendelian susceptibility to mycobacterial disease-Challenges in hematopoietic stem cell transplantation.

We present our experience in the hematopoietic stem cell transplantation (HSCT) in two children diagnosed with Mendelian susceptibility to mycobacterial diseases. The first child underwent a haploidentical HSCT with posttransplant cyclophosphamide using a reduced intensity conditioning following which he had primary graft failure. He was subsequently found to have interferon-γ1 receptor deficiency. He had immune reconstitution and is on antitubercular therapy. The second child diagnosed with IL12RB1 gene mutation underwent matched sibling donor HSCT with myeloablative conditioning following pretransplant immunosuppression with fludarabine and dexamethasone. He is 13 months post-HSCT with complete and remains disease free.

Treosulfan-based reduced toxicity hematopoietic stem cell transplantation in X-linked agammaglobulinemia: A cost-effective alternative to long-term immunoglobulin replacement in developing countries.

X-linked agammaglobulinemia (XLA) is a primary antibody disorder due to a mutation in the Bruton tyrosine kinase gene that requires lifelong immunoglobulin replacement resulting in a significant economic burden and treatment abandonment. Hematopoietic stem cell transplantation (HSCT) offers an alternative option for complete cure. In our series, two children with XLA underwent successful HSCT using a myeloablative conditioning with thiotepa, treosulfan, and fludarabine from a matched sibling donor. The second child had rejected his first graft following a busulfan-based regimen with resultant autologous reconstitution. At 6 months post-HSCT, serum IgG were normal, off IVIG, and had no infections. Both children after a median follow-up of 20 months have 100% chimerism. Treosulfan-based reduced toxicity myeloablative HSCT has encouraging results with a positive impact on the socioeconomics in developing countries.

Successful Treatment of Relapsed Isolated Extraocular Retinoblastoma in the Right Fibula With High-dose Chemotherapy and Autologous Stem Cell Transplantation.

Literature on high-dose chemotherapy followed by autologous stem cell rescue in relapsed retinoblastoma is limited to <150 cases reported so far. We present our experience and the challenges faced in the management of a 7-year-old boy with relapsed isolated extraocular retinoblastoma in the right fibula who received salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell rescue. Electrolyte disturbances, renal tubulopathy, and seizures were the most significant transplant-related morbidity. The child is now 3 years postautograft in remission. Monitoring for second malignant neoplasm and late side effects remain the main challenges in the years to come.