A Comparative Analysis of Low Dose Grafalon® Versus Thymoglobuline® as Serotherapy in Hematopoietic Stem Cell Transplant in Pediatric and Young Adult Population.

Anti-thymocyte globulin (ATG) forms an essential component of conditioning in hematopoietic stem cell transplantation (HSCT). Due to the shift of donor preference to alternate donors, reliance on rabbit-ATG (rATG) has increased. Two different forms of rATG (Thymoglobuline® and Grafalon®) are available for clinical use but data to support the use of one over the other is sparse. We retrospectively analyzed data of 144 patients who underwent allogenic-HSCT for benign hematological conditions at our center, from August 2019 to August 2023. Of these, 87 received Grafalon® and 57 received Thymoglobuline®. The majority (77.7%) underwent HSCT for hemoglobinopathies and all received pre-transplant immunosuppression. Engraftment kinetics was similar in 2 cohorts. Six patients had primary graft failure (PGF). There was no difference in the incidence of PGF stratified by serotherapy. Overall survival(OS) for the cohort was 74.9%. Kaplan-Meier estimate of OSand EFSwas significantly better in Grafalon® group than Thymoglobuline® (84.4 ± 0.04% vs 64.1% ±0.065%) (p-value= 0.04%) and (84.4 ± 0.04% and 61.2%±0.065% (p-value = 0.01)). Extensive chronic GVHD was (14%) higher in Thymoglobuline® group and (2.3%) in Grafalon®. Immune reconstitution at day + 100 was not statistically different between the two groups. On univariate analysis, Thymoglobuline® serotherapy (OR (95% CI) =4.665 (1.2-18.04))was associated with increased risk of acute grade III-IV GvHD. In our study, Grafalon® tended to have better OS, decreased incidence of acute grade III-IV GvHD, and extensive cGVHD. There was no difference in engraftment kinetics, PGF, and immune reconstitution between 2 cohorts of serotherapy.

Successful Haploidentical Stem Cell Transplant With Posttransplant Cyclophosphamide in Wiskott-Aldrich Syndrome With Myeloablative Conditioning.

Hematopoietic stem cell transplant (HSCT) is the only curative treatment modality for Wiskott-Aldrich syndrome. Haploidentical HSCT with posttransplant cyclophosphamide (PTCy) is an upcoming option in children with nonmalignant conditions. However, only few cases have been reported for Wiskott-Aldrich syndrome HSCT with PTCy approach. Here we report a 4-year-old boy, treated successfully by haploidentical HSCT with myeloablative conditioning (busulfan, fludarabine, and thiotepa) and PTCy. Posttransplant chimerism was fully donor. Of 13 cases (current case and other 12 published cases) 10 are alive and disease free after haploidentical HSCT with PTCy. Haploidentical HSCT with PTCy using myeloablative conditioning is feasible and safe.

Successful Haploidentical Stem Cell Transplant With Posttransplant Cyclophosphamide for Isolated Central Nervous System Blast Crisis in a Child With Chronic Myeloid Leukemia.

Chronic myelogenous leukemia (CML) is a myeloproliferative disorder. The extramedullary blast crisis (BC) is a known complication of CML, but it usually accompanies a systemic disease. However, an isolated central nervous system (CNS) BC at relapse is very rare and has a very poor prognosis. Salvage is even more difficult for patients who relapse with a CNS BC after an allogeneic stem cell transplant (SCT). Here, we report successful treatment of an isolated CNS BC of CML in a 14-year-old boy who relapsed with isolated a CNS BC after matched sibling donor SCT by haploidentical SCT with posttransplant cyclophosphamide.

Haploidentical Stem Cell Transplantation With Post-transplant Cyclophosphamide for Pediatric Acute Leukemia is Safe and Effective.

BACKGROUND: Haploidentical family donor is universally available and is fast emerging as an alternative donor choice for children with leukemia needing hematopoietic stem cell transplant (HSCT). Here we describe our experience of treating children with acute leukemia by haploidentical HSCT with posttransplant cyclophosphamide (PTCy). METHODS: We retrospectively analyzed the outcome data of 17 children with acute leukemia who underwent related haploidentical HSCT. Fifteen were in complete remission (CR) before HSCT: CR1-6, CR2-7, and CR3-2 and 2 were not in remission. Donors were mobilized with granulocyte colony stimulating factor. The conditioning was nonmyeloablative in 4 and myeloablative in 13. All received PTCy 50 mg/kg on days 3 and 4 as graft-versus-host disease (GVHD) prophylaxis along with tacrolimus or cyclosporine and mycophenolate mofetil. A median of 8.94 million of CD34+ cells/kg was infused. RESULTS: All patients were engrafted for neutrophil and platelets, except 1 child with refractory acute myeloid leukemia disease who relapsed before engraftment. Five children relapsed (4 died and 1 child with CD20-positive leukemia is disease free after Rituximab therapy). There was 1 transplant-related mortality due to grade IV GVHD. Remaining 11 patients are in CR. Acute GVHD was seen in 4 patients. Of 4, 3 children later developed chronic GVHD and all are alive and disease free. Three of 4 children who received nonmyeloablative conditioning have relapsed. Overall survival is 70.5% and event-free survival is 64.7%. Median follow-up of all patients was 393 days. CONCLUSION: Haploidentical HSCT with PTCy is a safe and effective therapy for children with acute leukemia. Myeloablative conditioning and chronic GVHD lead to improved disease-free survival.

Portal vein thrombosis in a child with essential thrombocythemia seven years after diagnosis.

Portal vein thrombosis in children with essential thrombocythemia (ET) is a rarity. Here, we describe the long-term follow up of our previously reported case that since has developed portal vein thrombosis (PVT) 7-years after diagnosis. Our patient had presented with PVT with normal platelet counts and massive asymptomatic splenomegaly. Ultrasound and Computerized tomography confirmed presence of PVT. Our case highlights the importance of long-term follow up of children with ET for thrombosis, especially PVT, as it can happen without symptoms and normal platelet counts.