Fludarabine-Based Low-Intensity Conditioning for Fanconi Anemia is Associated with Good Outcomes in Aplastic Anemia but not in MDS - a Single-Center Experience.

Background: Hematopoietic stem cell transplantation (HSCT) is the only curative option for patients with Fanconi Anemia (FA) with hematological abnormalities. Materials and Methods: This is a retrospective analysis of patients with FA who underwent a matched-related donor HSCT. Results: Sixty patients underwent 65 transplants between 1999-2021 using a fludarabine-based low-intensity conditioning regimen. The median age at transplant was 11 years (range: 3-37). Aplastic anemia (AA) was the underlying diagnosis in 55 (84.6%), while 8 (12.4%) had myelodysplastic syndrome (MDS) and 2 (3%) had acute myeloid leukemia (AML). The conditioning regimen used was Fludarabine with low-dose Cyclophosphamide for aplastic anemia and Fludarabine with low-dose Busulfan for MDS/AML. Graft versus host disease (GVHD) prophylaxis consisted of Cyclosporine and methotrexate. Peripheral blood was the predominant stem cell graft source (86.2%). Engraftment occurred in all but one patient. The median time to neutrophil and platelet engraftment was 13 days (range: 9-29) & 13 days (range: 5-31), respectively. Day 28 chimerism analysis showed complete chimerism in 75.4 % and mixed chimerism in 18.5%. Secondary graft failure was encountered in 7.7%. Grade II-IV acute GVHD occurred in 29.2%, while Grade III-IV acute GVHD occurred in 9.2%. Chronic GVHD was seen in 58.5% and was limited in most patients. The median follow-up is 55 months (range: 2-144) & the 5-year estimated overall survival (OS) is 80.2 ± 5.1%. Secondary malignancies were noted in 4 patients. The 5-year OS was significantly higher in patients undergoing HSCT for AA (86.6 + 4.7%) as compared to MDS/AML (45.7+16.6%) (p= 0.001). Conclusion: SCT using a fully matched donor provides good outcomes with low-intensity conditioning regimens in patients with FA who have aplastic marrow.

Endothelial Activation and Stress Index-Measured Pretransplantation Predicts Transplantation-Related Mortality in Patients with Thalassemia Major Undergoing Transplantation with Thiotepa, Treosulfan, and Fludarabine Conditioning.

The use of thiotepa-treosulfan-fludarabine conditioning regimen and peripheral blood stem cell grafts is associated with improved outcomes of hematopoietic stem cell transplantation (HCT) in patients with high-risk thalassemia major. However, there remains a need to identify predictors of poor outcomes in this cohort to further optimize outcomes. The Endothelial Activation and Stress Index (EASIX) is a biomarker shown to predict survival in various settings, including graft-versus-host disease, veno-occlusive disease, and nonrelapse mortality following allogeneic HCT. In this retrospective analysis, we evaluated the role of EASIX-PreTx (measured before conditioning therapy) as a biomarker in predicting day +100 transplantation-related mortality (TRM+100) in 281 patients with thalassemia major who underwent HCT with a uniform conditioning regimen using thiotepa-treosulfan-fludarabine at our center between January 2012 and December 2019. The median patient age was 9 years (range, 1 to 25 years), and 109 (38.8%) were females. According to the Pesaro classification (with Vellore modification), 3 patients (1.1%) were class I, 34 (12.1%) were class II, 134 (47.7%) were class III low risk, and 110 (39.1%) were class III high risk. Stem cell donors were matched sibling (n = 218; 77.6%), matched related nonsibling (n = 23; 8.2%), or matched unrelated (n = 40; 14.2%). Five patients (1.8%) received a bone marrow graft, and the others received a peripheral blood stem cell graft. Thirty-eight patients (13.5%) had TRM+100. EASIX-PreTx was available for 184 patients (65.5%). The median EASIX-PreTx was significantly higher in patients with TRM+100 compared with those without TRM+100 (1.09 versus .75; P = .008). An EASIX-PreTx cutoff of .85 had 70.4% sensitivity and 62% specificity for predicting TRM+100. The TRM+100 for patients with EASIX-PreTx >.85 was significantly higher than those with EASIX <.85 (24.4% versus 7.5%; P = .003). In a uniform subgroup of class III patients undergoing allogeneic HCT (n = 156), EASIX-PreTx was an independent predictor of TRM+100.

Hematopoietic Stem Cell Transplantation is a cost-effective alternative to enzyme replacement therapy in Gaucher Disease.

Allogeneic hematopoietic stem cell transplantation (HSCT) is a feasible treatment option for Gaucher disease (GD). Among 60 patients diagnosed with GD over 15 years (2004-2019), three children who underwent HSCT (January-November 2017) were analyzed. Two boys (cases 1 and 2) and one girl (case 3) received HSCT at 3, 7, and 10 years of age, respectively. Cases 1 and 3 received haplo-HSCT, while case 2 received HLA-identical related-donor transplantation. The CD 34 cell dose was 5-10×106/kg. Neutrophil and platelet engraftment were between days +14 to +21 and days +15 to +76. Post-HSCT chimerism was a 100% donor. None of the patients developed acute or significant chronic graft versus host disease (GVHD). All patients had febrile episodes with negative blood cultures. Major post-HSCT complications included EBV-viremia and recurrent lobar pneumonia in case 1, delayed engraftment and pure red cell aplasia (PRCA) in case 2, and pericardial effusion with tamponade in case 3. At a median of 49 months post-HSCT, all patients were stable with improved growth, absent organomegaly, and had completed immunization. The median cost of treatment was $23,038.96, which is 10.7%-13% of the yearly enzyme replacement therapy (ERT) cost. In a resource-limited setting like India, ERT is a financial burden and not a sustainable option. With improved treatment outcomes, haplo-HSCT is now a possible option for almost every patient, even if no HLA-identical donor is identified.

An Antithymocyte Globulin-Free Conditioning Regimen Using Fludarabine and Cyclophosphamide Is Associated with Good Outcomes in Patients Undergoing Matched Related Family Donor Transplantation for Aplastic Anemia.

Allogeneic hematopoietic stem cell transplantation (HSCT) using fludarabine (Flu)-based conditioning regimens are being increasingly being used in patients with aplastic anemia (AA). We describe an antithymocyte globulin (ATG)-free conditioning regimen consisting of Flu and cyclophosphamide (Cy) in patients undergoing matched related donor (MRD) HSCT for AA. Between 2004 and 2019, 212 patients underwent MRD HSCT using Flu (30 mg/m2/day for 6 days) and Cy (60 mg/kg/day for 2 days) for conditioning. The graft source was peripheral blood stem cells in all patients. Graft-versus-host disease (GVHD) prophylaxis consisted mainly of cyclosporine and methotrexate, although 41 patients received post-transplantation Cy as part of a study. Engraftment occurred in 91% of patients at a median of 16 days, whereas 4 patients (1.8%) experienced primary graft failure and 15 (7.1%) died before achieving engraftment. Toxicity was minimal. The incidence of grade II-IV acute GVHD (aGVHD) was 27.9%, and that of grade III-IV aGVHD was 11.3%. Chronic GVHD occurred in 41.6%. 80% were free of immunosuppression at 60 months and long-term complications were seen in 8.4%. At a median of 46 months, 158 patients were alive and well, with a 5-year overall survival (OS) of 75.3 ± 3.0%. The 5-year OS was 80.6 ± 4.1% for patients age <20 years (n = 93), 74.5 ± 4.6% for those age 20 to 40 years (n = 91), and 59.7 ± 9.5% for those age >40 years (n = 28) (P = .11). Patients classified as low risk had better OS compared with those at high risk (93.2 ± 2.9% versus 65.7 ± 4.1%; P = .000). Factors affecting OS on multivariate analysis included aGVHD (P = .02) and graft failure (P = .000). This large series using Flu/Cy for conditioning before MRD HSCT confirms good outcomes in patients with AA, with excellent outcomes in low-risk patients. Suitable modifications are needed to improve outcomes in high-risk patients.

Sitosterolemia: Four Cases of an Uncommon Cause of Hemolytic Anemia (Mediterranean Stomatocytosis with Macrothrombocytopenia).

Sitosterolemia is a rare autosomal recessively inherited lipid metabolic disorder that is characterized by hyper absorption of plant sterols from the intestinal mucosa leading to toxic levels in the blood. Four patients of age ranging from 11 to 29 years presented to the outpatient department with clinical features of hemolytic anemia. There were no features of hypercholesterolemia in any of the patients. Peripheral smear examination of all four patients showed stomatocytes and macrothrombocytopenia. Qualitative testing for plant sterols was performed in one case. Next generation sequencing revealed a compound heterozygous mutation in ABCG5 gene (c.1222C>T and c.1255C>T) in one case and homozygous mutations in ABCG5 gene (c.727C>T), (c.332G>A (p.G111E)), (c.1222C>T) in the other three cases. Ezetimibe (10 mg/day) was administered in one case, with complete resolution of symptoms. All patients were advised a low plant sterol diet and regular monitoring of hemoglobin and lipid profile. Our cases highlight a rare but important cause of hemolytic anemia that can be suspected from careful peripheral blood examination but only conclusively established by molecular genetic diagnosis.

Second Hematopoietic Stem Cell Transplant for Thalassemia Major: Improved Clinical Outcomes with a Treosulfan-Based Conditioning Regimen.

Graft rejection (GR) after allogeneic stem cell transplantation (allo-SCT) occurs in 10% to 20% of patients with ß-thalassemia major (TM). There are limited data on the clinical profile and long-term outcome of patients who have had a GR. We undertook a retrospective analysis of patients who had a graft failure after allo-SCT for TM at our center. From October 1991 to June 2016, 55 of 506 patients (11%) transplanted for TM had a graft failure. An additional 7 patients with graft failure after allo-SCT done at other centers were referred to us for a second transplant. The median age was 8 years (range, 1 to 19), and there were 38 males (61.2%). Thirty-two patients (52.4%) were primary graft failures (15 with aplasia and 17 with autologous recovery) and 30 (47.6%) were secondary graft failures (5 with aplasia and 25 with autologous recovery). On conventional risk stratification 40 patients (64.5%) were class III. Seventeen patients (53.12%) with primary graft failure and 16 (53.3%) with secondary graft failure did not receive a second transplant. Twenty-nine patients (46%) with GR underwent a second allo-SCT. With the exception of 1 patient (first allo-SCT with an unrelated cord blood product), the donor for the second transplant was the same as the first transplant. Conditioning regimen for the second SCT was busulfan-based myeloablative (MAC) in 7 patients (24%), treosulfan-based MAC in 12 patients (41.3%), and the remaining received non-MAC regimens in view of pancytopenia and perceived inability to tolerate MAC. None of the patients conditioned with a treosulfan-based regimen had a GR, although 1 patient died with complications secondary to chronic graft-versus-host disease. Of the remaining 17 patients, 10 died after the second GR and 3 of regimen-related toxicity. Four are alive, of which 1 has recurrent TM and the rest are well and transfusion independent at 55, 80, and 204 months, respectively, from second transplant (all busulfan-based MAC). On a univariate analysis a nontreosulfan-based conditioning regimen and time from GR to second transplant of <1 year was significantly associated with an adverse impact. However, on a multivariate analysis only a nontreosulfan-based regimen was associated with a significant adverse impact on event-free survival (HR, 11.5; 95% CI, 1.13 to 116.4; P = .039). In conclusion, there has been a significant improvement in clinical outcomes in our experience with the use of a treosulfan-based reduced-toxicity MAC regimen for second allo-SCT for TM. It would be reasonable, where feasible, to defer the second transplant by a year after the first GR.

A stepwise α-thalassemia screening strategy in high-prevalence areas.

INTRODUCTION: Coinheritance of α-thalassemia influences the clinical and hematological phenotypes of ß-hemoglobinopathies (ß-thalassemia and sickle cell disease) and when present together in significant frequency within a population, a spectrum of clinical forms is observed. Precise molecular characterization of α-thalassemia is important in understanding their disease-modifying role in ß-hemoglobinopathies and for diagnostic purposes. PATIENTS AND METHODS: Because currently used approaches are labor/cost-intensive, time-consuming, error-prone in certain genotype combinations and not applicable for large epidemiological screening, we developed a systematic stepwise strategy to overcome these difficulties. We successfully applied this to characterize the α-globin gene status in 150 Omani cord blood samples with Hb Barts and 32 patients with HbH disease. RESULTS: We observed a good correlation between α-globin genotypes and level of Hb Bart's with the Hb Bart's levels significantly higher in both deletional and non-deletional α-globin genotypes. The most common α-globin genotype in HbH cases was α(TSaudi) α/α(TSaudi) α (n = 16; 50%) followed by -α(3.7) /-(MED) (n = 10; 31%). This approach detects also the α-globin gene triplication as exemplified by the study of a family where the ß-globin gene defect failed to explain the ß-thalassemia intermedia phenotype. CONCLUSION: Molecular characterization of α-thalassemia is complex due to high sequence homology between the duplicated α-globin genes and to the existence of a variety of gene rearrangements (small and large deletions of various sizes) and punctual substitutions (non-deletional alleles). The novelty of our strategy resides, not in the individual technical steps per se but in the reasoned sequential order of their use taking into consideration the hematological phenotype as well.

Improved clinical outcomes of high risk ß thalassemia major patients undergoing a HLA matched related allogeneic stem cell transplant with a treosulfan based conditioning regimen and peripheral blood stem cell grafts.

Improving clinical outcomes among high risk Class III ß thalassemia major patients (Class IIIHR) receiving an allogeneic SCT remains a challenge. From October, 2009 a treosulfan based regimen (TreoFluT) was used for all consecutive Class III patients (n = 50). The clinical outcomes were compared with the historical conventional busulfan (BuCy) based regimen (n = 139). Use of TreoFluT was associated with a significantly reduced incidence of sinusoidal obstruction syndrome (SOS) among Class IIIHR cases (78% to 30%; P = 0.000) and early TRM (46% to 13%; p = 0.005). There was also a trend towards better engraftment in the Class IIIHR subset (P = 0.055). However, the use of bone marrow (BM) as source of stem cells along with the TreoFluT regimen was associated with 50% early mixed chimerism which reduced to 8.5% with the use of a peripheral blood stem cell graft (PBSC). Use of a PBSC graft was not associated with a significant increase in the incidence of acute or chronic graft versus host disease (GVHD). The overall and event free survival was significantly better among the Class IIIHR subset with the use of TreoFluT Vs. BuCy (86.6 ± 7.3 Vs. 39.4 ± 6.8%; P = 0.002 and 77.8 ± 8.8 Vs. 32.4 ± 6.5%; P = 0.003 respectively). A TreoFluT conditioning regimen with a PBSC graft can significantly improve clinical outcomes of Class IIIHR patients.