Lesson learned in pediatric haploidentical transplantation in a low-resource environment: delivering melphalan IV and using low dose radiation reduce graft failure.

Objectives: Primary graft failure (pGF) after hematopoietic stem-cell transplant is associated with considerable morbidity and mortality. The incidence in haplo-HSCT has been reported to be between 0% and 30%. In 2018, we identified a pGF incidence of 35% in our pediatric haplo-HSCT recipients with hematologic malignancies, which motivated us to enact changes to the conditioning regimen.Methods: We performed a single-center prospective, pre-post study of consecutive patients under 16 years with hematologic malignancies, from January 2015 to December 2022 who received a haplo-HSCT. Twenty-six pediatric patients received a haplo-HSCT before September 2018 (G1) and 36 patients after (G2). The main conditioning regimen for G1 was myeloablative with Flu/Cy/Bu, and for G2 the main regimen was reduced intensity Flu/Cy/Mel/TBI2.Results: Nine patients (35%) in G1 had primary graft failure, while in G2 there were no patients with pGF. The median follow-up for G1 was 15.9 months, and for G2 was 24.8 months, with an estimated overall survival at 12 months of 63% (95% CI 47-76) versus 85% (95% CI 73-93), and at 24 months of 47% (95% CI 31-64) versus 70% (95% CI 54-82) respectively (p = .007).Conclusion: After September 2018 conditioning regimen modifications were implemented with the objective of reducing primary failure, consisting mainly of switching from busulfan to melphalan as the alkylating agent of choice, and adding, when clinically possible TBI. Primary failure has been significantly reduced in our institution since then.

Treatment of Ph-Negative Acute Lymphoblastic Leukemia in Adolescents and Young Adults with an Affordable Outpatient Pediatric Regimen.

BACKGROUND: B-cell acute lymphoblastic leukemia is frequent in Hispanic adolescents and young adults. Outcomes of implementation of pediatric-inspired regimens in low-and middle-income countries are not well known. METHODS: In this study we treated 94 adolescents and young adults with a local BFM regimen designed to be affordable with the use of native L-asparaginase and mitoxantrone administered in an outpatient fashion, and the of BCR/ABL and measurable residual disease (MRD) determined by high sensitivity flow cytometry for risk stratification. RESULTS: Induction mortality was 11%; 25% of patients had to abandon treatment or be transferred to another health system. Two-year overall (OS) and event free survival (EFS) were 61.5% and 49.8%, MRD-negative patients had a 24-month OS of 85.6% vs. 69.6% (p = .024) and EFS of 76% vs. 45.5% (p = .004). Patients older than 40 years and those who abandoned treatment had worse EFS. Overall drug costs in our regimen were 52% lower than those of CALGB10403. CONCLUSION: The treatment of AYAs with ALL with an outpatient focus was implemented successfully at a reduced cost. Genetic risk assessment, treatment abandonment and lack of access to novel therapies remain major barriers for improving outcomes.

The 1,000th Transplant for Multiple Sclerosis and Other Autoimmune Disorders at the HSCT-México Program: A Myriad of Experiences and Knowledge.

After gaining experience conducting both auto and allografts in persons with hematological diseases in the HSCT programs in Puebla and Monterrey, México, this study outlines subsequent program autografting patients with autoimmune conditions. The first transplant in multiple sclerosis was conducted in Puebla on July 5, 2006. From 2015 we increased activity autografting persons with autoimmune conditions in the two campuses of the HSCT-México program: Puebla and Monterrey. By December 6, 2020, patient number 1,000 in the program was autografted. In our experience, a significant reduction in the expanded disability status scale score was achieved in all of the three phenotypes of the disease (from a median of 5.1 to 4.5 points), whereas the response rate (defined as a decrease of at least 0.5 of EDSS score regardless of baseline EDSS, or unchanged EDSS) was 83, 78, and 73% after 12 months in the relapsing-remitting, primary-progressive and secondary-progressive forms of multiple sclerosis, respectively. In addition to analyzing the viability, safety, and efficacy of our method, this study contributes new knowledge to the field of both stem cell transplantation and multiple sclerosis.

Concordant acute myeloblastic leukemia in identical twins treated with allogeneic transplantation from a younger HLA-identical sibling following a single apheresis procedure.

A concordant leukemia is that which occurs in a pair of monozygotic twins; a similar genetic background suggests an in utero monoclonal origin. We present the case of a pair of monozygotic infants with concordant acute myeloid leukemia who underwent a peripheral blood hematopoietic stem-cell transplant (HSCT) from a single, younger human leukocyte antigen-identical sibling donor, using a fractioned graft collected during only one apheresis procedure. Twin A relapsed at +456 and received a second haploidentical HSCT from his father, twin B has been in complete remission since the first HSCT. Both children are in complete remission and with negative minimal residual disease at +900 (after second transplant) and +1488, respectively.

Determine safety of outpatient chemotherapy and autotransplants using refrigerated, non-frozen grafts in persons with multiple sclerosis.

BACKGROUND: Persons with multiple sclerosis are increasingly treated with intermediate- or high-dose chemotherapy and a hematopoietic cell autotransplant. This is often done in an inpatient setting using frozen blood cell grafts. OBJECTIVE: Determine if chemotherapy and a hematopoietic cell autotransplant can be safely done in an outpatient setting using refrigerated, non-frozen grafts. METHODS: We developed an autotransplant protocol actionable in an outpatient setting using a refrigerated, non-frozen blood graft collected after giving cyclophosphamide, 50 mg/kg/d × 2 days and filgrastim, 10 µg/kg/d. A second identical course was given 9 days later followed by infusion of blood cells stored at 4°C for 1-4 days. The co-primary outcomes were rates of granulocyte and platelet recovery and therapy-related mortality. RESULTS: We treated 426 consecutive subjects. Median age was 47 years (range, 21-68 years). A total of 145 (34%) were male. Median graft refrigeration time was 1 day (range, 1-4 days). Median interval to granulocytes >0.5 × 10E + 9/L was 8 days (range, 2-12) and to platelets >20 × 10E + 9/L, 8 days (range, 1-12). Only 15 subjects (4%) were hospitalized, predominately for iatrogenic pneumothorax (N = 5) and neutropenic fever (N = 4). There was only 1 early death from infection. CONCLUSION: Intermediate-dose chemotherapy and a hematopoietic cell autotransplant can be safely done in an outpatient setting using, refrigerated, non-frozen grafts.

Acute Leukemia Characteristics are Different Around the World: the Mexican Perspective.

BACKGROUND: The incidence of acute leukemia (AL) has increased. Its prognosis is variable and depends on several baseline characteristics with a highly heterogeneous presentation. In Mexico, large-scale descriptive studies have not yet been published; the objective of this study was to analyze the initial basic characteristics of patients diagnosed with AL in our population. PATIENTS AND METHODS: In this multicenter, retrospective study, 1018 patients ≥ 16 years of age and diagnosed with AL between 2009 and 2014, were included. We described age, gender, complete blood count, and AL subtype according to flow cytometry analysis. RESULTS: Acute lymphoblastic leukemia (ALL) was as common as acute myeloid leukemia (AML) (51% vs. 49%). The median age was 31 years. Only 9.6% of patients with ALL were positive for the Philadelphia chromosome. No gender differences were observed. The median age at presentation of AML was 43 years. Acute promyelocytic leukemia was the most frequent AML subtype (38.3%), with a median age of 37 years. CONCLUSION: ALL is equally as frequent as AML in patients ≥16 years of age. Philadelphia-positive prevalence is less frequent than that reported in literature. AML cases occur in a younger age in comparison with other countries. There is a higher rate of acute promyelocytic leukemia among our patients compared with other non-Latin American populations. This study is the largest ever performed in Mexico regarding descriptive AL data.

Haploidentical peripheral blood stem cell transplantation with posttransplant cyclophosphamide in children and adolescents with hematological malignancies.

BACKGROUND: Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) using posttransplant cyclophosphamide (Cy) for graft versus host disease (GVHD) prophylaxis has emerged as an alternative transplant strategy for patients without related donors, especially in the setting of limited resources in which T-cell ex vivo depletion is not affordable. Experience with this transplant modality in children and adolescents is limited. PROCEDURE: We report a retrospective analysis of 25 consecutive outpatients under 21 years of age with high-risk hematological malignancies, who received a haplo-HSCT using posttransplant Cy as GVHD prophylaxis. RESULTS: Twenty-three (92%) of the 25 patients engrafted, and 20 (95%) of 21 evaluable subjects achieved full donor chimerism by day +30. One-year estimated overall survival and event-free survival were 50% and 33%, respectively. The cumulative incidence rate of severe acute GVHD was 19%, and 15% of patients developed chronic GVHD. CONCLUSIONS: Haplo-HSCT with posttransplant Cy is a feasible therapeutic option for children and adolescents with high-risk hematological malignancies in a limited resource setting.

Angioimmunoblastic T-cell lymphoma: a diagnostic challenge.

Angioimmunoblastic T-cell lymphoma (AITL) accounts for 15-20% of all peripheral T-cell lymphomas. It is a rare subtype of CD4 T-cell peripheral lymphoma that affects aged individuals, causing B symptoms, generalized lymphadenopathy and hepatosplenomegaly. Its pathogenesis is still unclear, but in some cases it has been associated with infection, allergic reaction or drug exposure. The majority of patients are diagnosed in an advanced stage and anthracycline based regimen is considered the first-line therapy. Skin involvement is not well characterized, occurring in up to 50% of patients and presenting as nonspecific rash, macules, papules, petechiae, purpura, nodules and urticaria. We present the illustrative case of a 55-year-old woman with an AITL who presented prominent skin findings, arthritis, lymphadenopathy and hypereosinophilia. Skin biopsy reported a T-cell lymphoma and the diagnosis of AITL was confirmed by an axillary lymph node biopsy, which was also positive for Epstein-Barr virus. Chemotherapy with CHOP-21 and thalidomide was given, accomplishing complete remission after six cycles.