Lactate dehydrogenase as a hematopoietic stem cell mobilization biomarker in autologous transplantation

ABSTRACT Introduction: Pre-apheresis peripheral blood CD34+ cell count (PBCD34+) is the most important predictor of good cell mobilization before hematopoietic stem cell transplantation, albeit flow cytometry is not always immediately available. Identification of surrogate markers can be useful. The CD34+ cells proliferate after mobilization, resulting in elevated lactate dehydrogenase (LDH) activity and correlating with the PBCD34+ count. Objective: To determine the LDH cut-off value at which adequate CD34+ cell mobilization is achieved and its diagnostic yield. Materials and methods: A total of 103 patients who received an autologous stem cell transplantation (ASCT) between January 2015 and January 2020 were included. Demographic and laboratory characteristics were obtained, including complete blood count, pre-apheresis PBCD34+ and LDH levels. Receiver operating characteristic (ROC) curves were performed to identify the optimal serum LDH activity cut-off points for ≥ 2 and ≥ 4 × 106 cells/kg post-mobilization CD34+ count and their diagnostic yield. Results: A post-mobilization serum LDH cut-off value of 462 U/L yielded a sensitivity (Se) = 86.8% (positive predictive value [PPV] = 72.7%), a pre- and post-mobilization serum LDH difference cut-off value of 387 U/L, an Se = 45.7% (PPV = 97%) and an LDH ratio of 2.46, with an Se = 47.1% (PPV = 97%) for an optimal mobilization count (CD34+ ≥ 4 × 106). Conclusion: The LDH measurement represents a fast and affordable way to predict PBCD34+ mobilization in cases where flow cytometry is not immediately available. According to the LDH diagnostic yield, it could be used as a surrogate marker in transplant centers, supporting the CD34+ count, which remains the gold standard.

Low-dose rituximab in steroid-refractory chronic graft-versus-host disease.

BACKGROUND: Chronic graft-versus-host disease (cGvHD) is a major complication that puts patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) at risk of death or infection. Currently, there is no gold standard for the first-line treatment of patients who do not respond to steroids, and there are several therapeutic options being evaluated in clinical trials for this disease to be used even in the first-line treatment for GvHD. There is evidence of the benefit of rituximab, an anti-CD20 antibody, at a standard dose of 375 mg/m2 weekly in the treatment of steroid-refractory chronic graft-versus disease (SR-cGvHD). OBJECTIVE: To demonstrate the safety and efficacy of low-dose rituximab in a middle-income center in northeastern Mexico STUDY DESIGN: We report the experience of 26 patients with chronic graft-versus-graft disease who received low-dose rituximab (100 mg weekly for 4 weeks). We utilized the advances in the National Institutes of Health (NIH) criteria for diagnosis, scoring, trial design, and assessment of treatment response. RESULTS: We obtained a 5-year overall survival of 23.6%, including four patients with complete response. The 1-year event-free survival was 70% for patients with rituximab. During the treatment, there were 3 hospitalizations, and the causes were: immune thrombocytopenia, a parapneumonic effusion, and a cerebral vascular event. The median length of hospital stay was twelve days. CONCLUSION: A low dose of rituximab is an available and cost-effective option for patients with steroid-refractory cGvHD.

Acute Leukemia Relapse after Hematopoietic Stem Cell Transplantation: The Good, the Bad, and the Ugly of Isolated Extramedullary Relapse in a Latin American Population.

Hematopoietic stem cell transplantation (HSCT) is an effective therapy for acute leukemia (AL). Relapse represents the main cause of mortality. Isolated extramedullary relapse (iEMR) is atypical and has been related to better outcomes. Here we describe the clinical characteristics and outcomes of AL relapse after HSCT in our study population and analyze the impacts of different types of relapse on survival outcomes. This retrospective, multicenter study included 124 patients age ≥15 years with AL who underwent HSCT between 2004 and 2019. At diagnosis, 66.1% of the patients had lymphocytic AL, 19.7% presented with high-risk features, and 18.5% had extramedullary disease (EMD). At HSCT, 83.1% of the patients were in complete remission (CR), and 44.8% had negative measurable residual disease (MRD). The vast majority of donors were related (96%), including 48.4% HLA-matched and 47.6% haploidentical. Myeloablative conditioning was provided to 80.6% of patients. The median overall survival (OS) was 15 months (95% confidence interval [CI] 9.9 to 20.1 months). Factors associated with improved OS were adolescent and young adult (AYA) patient (P = .035), first or second CR (P = .026), and chronic graft-versus-host disease (GVHD) (P < .001). Acute GVHD grade III-IV (P = .009) was associated with increased mortality. The median relapse-free survival was 13 months (95% CI, 7.17 to 18.8 months); early disease status (P = .017) and chronic GVHD (P < .001) had protective roles. Sixty-eight patients (55%) relapsed after HSCT, with a median time to relapse of 6 months (95% CI, 3.6 to 8.4 months). iEMR was reported in 16 patients (23.5%). The most commonly involved extramedullary sites were the central nervous system and skin. Compared to patients with bone marrow relapse, all patients with iEMR had a diagnosis of acute lymphoid leukemia (P = .008), and 93.8% belonged to the AYA group; regarding pre-HSCT characteristics, iEMR patients had higher rates of negative MRD (P = .06) and a history of EMD (P = .009). Seventy-seven percent of relapsed patients received additional treatment with curative intent. The median OS after relapse (OSr) was 4 months (95% CI, 2.6 to 5.4 months). Factors related to increased OSr included lymphoid phenotype (P = .03), iEMR (P = .0042), late relapse (≥6 months) (P = .014), receipt of systemic therapy including second HSCT (P < .001), and response to therapy (P < .001). Rates of relapse and iEMR were higher than those previously reported in other studies. Advanced disease, reduced-intensity conditioning, and a diminished graft-versus-leukemia effect were factors influencing these findings. At relapse, presenting with iEMR after 6 months and receiving intensive therapy with adequate response were associated with better outcomes. Our results strongly suggest that a personalized approach to treating patients with HSCT is needed to counterbalance specific adverse factors and can positively impact clinical outcomes.

Orbital myeloid sarcoma treated with low-dose venetoclax and a potent cytochrome P450 inhibitor.

CASE REPORT: We report the first case of orbital myeloid sarcoma that was successfully treated with a standard venetoclax dose of 25%. A 38-year-old man with acute myeloid leukemia (AML) post-haplo-hematopoietic stem cell transplantation (HSCT) presented with a nine-month history of progressive right proptosis and a visual acuity deficit. The patient was treated with venetoclax (100 mg orally on days 1-28), cytarabine (40 mg subcutaneously, days 1-10), and itraconazole (100 mg twice daily orally on days 1-28). MANAGEMENT AND OUTCOME: The present case report shows that using cytochrome P450 (CYP) inhibitors is a helpful strategy to reduce the cost of expensive treatments. DISCUSSION: There are limited data on the use of CYP inhibitors as a strategy to reduce the costs of expensive drugs (i.e. venetoclax). This approach has some advantages over standard dose venetoclax (400 mg/day) such as significantly reduced costs (which is relevant for patients in low-income countries). In this case, we used itraconazole-a potent CYP3A4 inhibitor-which can theoretically reduce the dose to 100 mg/day without losing serum therapeutic concentrations.

Lactate dehydrogenase as a hematopoietic stem cell mobilization biomarker in autologous transplantation.

INTRODUCTION: Pre-apheresis peripheral blood CD34+ cell count (PBCD34+) is the most important predictor of good cell mobilization before hematopoietic stem cell transplantation, albeit flow cytometry is not always immediately available. Identification of surrogate markers can be useful. The CD34+ cells proliferate after mobilization, resulting in elevated lactate dehydrogenase (LDH) activity and correlating with the PBCD34+ count. OBJECTIVE: To determine the LDH cut-off value at which adequate CD34+ cell mobilization is achieved and its diagnostic yield. MATERIALS AND METHODS: A total of 103 patients who received an autologous stem cell transplantation (ASCT) between January 2015 and January 2020 were included. Demographic and laboratory characteristics were obtained, including complete blood count, pre-apheresis PBCD34+ and LDH levels. Receiver operating characteristic (ROC) curves were performed to identify the optimal serum LDH activity cut-off points for ≥ 2 and ≥ 4 × 106 cells/kg post-mobilization CD34+ count and their diagnostic yield. RESULTS: A post-mobilization serum LDH cut-off value of 462 U/L yielded a sensitivity (Se) = 86.8% (positive predictive value [PPV] = 72.7%), a pre- and post-mobilization serum LDH difference cut-off value of 387 U/L, an Se = 45.7% (PPV = 97%) and an LDH ratio of 2.46, with an Se = 47.1% (PPV = 97%) for an optimal mobilization count (CD34+ ≥ 4 × 106). CONCLUSION: The LDH measurement represents a fast and affordable way to predict PBCD34+ mobilization in cases where flow cytometry is not immediately available. According to the LDH diagnostic yield, it could be used as a surrogate marker in transplant centers, supporting the CD34+ count, which remains the gold standard.

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.

Diagnosis and treatment of acute lymphoblastic leukemia in Latin America.

OBJECTIVE: to discuss the status and challenges associated with the management of acute lymphoblastic leukemia (ALL) in Latin America. METHODS: This review summarizes various insights gained from information regarding diagnostic approaches and treatment strategies in adult patients with ALL in Latin American Countries. RESULTS: Information regarding ALL in Latin America is scarce; however, many efforts have been made to overcomes these barriers. Nevertheless, major obstacles to successful treatment in Latin America and LMIC remain poor adherence, abandonment of treatment, and lack of supportive therapy and new therapeutic agents. CONCLUSION: Further improvements in survival should be pursued by developing more Latin American registries, forming cooperative groups, developing educational models to facilitate earlier diagnosis and prevention of complications, better support therapy and management of infections, and adapting treatment strategies.

Outpatient allogeneic hematopoietic stem-cell transplantation: a review.

Hematopoietic stem-cell transplantation (HSCT) is usually performed in well-equipped units inside a hospital. The cost of this in-hospital transplant is usually very high; therefore, this procedure is more difficult to perform in low- and middle-income countries. Autologous outpatient HSCT is now a common procedure; however, outpatient allogeneic transplants are more complicated. Only a few centers in the world have incorporated outpatient HSCT. This transplant requires special adaptation, like a day hospital, careful selection of patients, oral medications, and the patient must live relatively close to the hospital. The results until now suggest that this outpatient transplant is factible and similar to inpatient HSCT. The objective was to review and describe the different methods and results following an outpatient allogeneic-HSCT strategy.

Venetoclax-based combinations for acute myeloid leukemia: optimizing their use in Latin-America.

Objectives: Venetoclax combinations are a new standard for patients with acute myeloid leukemia (AML). We aimed to evaluate the safety and efficacy of these combinations in a period of accelerated approval in Latin-America.Methods: This observational study evaluated adults with acute myeloid leukemia who received venetoclax-based therapy in 11 public or private centers in Mexico and Peru for both newly diagnosed or relapsed and refractory AML.Results: Fifty patients were included; 28 with newly diagnosed (ND) AML and 22 with relapsed/refractory (RR) disease. ND patients were older (64 vs. 40 years; p < 0.001) with a lower functional capacity (ECOG ≥2 64.3% vs 9%; p < 0.001). Venetoclax was frequently combined with azacytidine (60%) and prophylactic azoles (82%) with a median maximum dose of 200 mg (range, 100-600 mg). Hematologic toxicities were common. Complete response rates including patients with incomplete hematopoietic recovery were 78.6% in ND and 45.5% in RR patients, with a median overall survival of 9.6 (95% CI 3.7-15.5) and 8 months (95% CI 4.8-11.2).Discussion: Our study showed a preferred use of venetoclax plus azacytidine over cyatrabine. Patients in the first-line setting were similar to those in the landmark studies, while most patients with relapsed disease had received prior intensive therapies. Responses were favorable, with a median survival in agreement to other reports, albeit shorter than that observed in the randomized phase-3 trials.Conclusion: Venetoclax-based therapy in AML was effective despite dose reductions and prophylactic antifungals in two middle-income countries outside of a clinical trial setting.

Desensitization to Brentuximab Vedotin after anaphylaxis in refractory Hodgkin's lymphoma.

INTRODUCTION: Brentuximab vedotin (BV) is a monoclonal antibody that targets CD30 antigen. It is indicated for the treatment of CD30 + lymphomas and classical Hodgkin lymphoma (HL), including advanced (stage III-IV) untreated disease, relapsed/refractory disease, and consolidation after autologous hematopoietic stem cell transplantation. In clinical trials the incidence of a hypersensitivity reaction is 1.2%. CASES REPORT: We present 3 cases of patients with refractory HL and anaphylaxis to the administration of BV ( Table 1). Symptoms are analyzed using a grading system described by Brown (2004) and a desensitization protocol was performed with a total dose of 100 mg of BV in 4 solution bags with an initial concentration of 1:1000 of total dose for cases of severe anaphylaxis, and desensitization of 3 solution bags with baseline concentration of 1: 100 for cases of moderate anaphylaxis. MANAGEMENT & OUTCOME: Intradermal skin tests were positive. Before desensitization, premedication with methylprednisolone and chlorphenamine was administered, as well as fluid therapy with 0.9% physiological solution at 100 cc/hour at induction stage, 250 cc/hour at maintenance stage, and increased to 500 cc/hour in case of hypersensitivity reaction. DISCUSSION: Drug desensitization in 12 or 16 steps allows tolerable administration of brentuximab vedotin after moderate to severe anaphylaxis. The favorable response to treatment of these patients may indicate that desensitization is a viable strategy for patients with relapsed or refractory HL.

Contributions to the American Society of Hematology Meeting From Low- and Middle-Income Countries: An In-Depth Analysis and Call to Action.

PURPOSE: Establishing research capacity in low- and middle-income countries (LMICs) is key for improving the outcomes of patients with hematologic diseases globally. Few studies have analyzed the contributions of LMICs to global hematology. The American Society of Hematology Meeting (ASH) is the largest international academic event where peer-reviewed contributions in our field are presented. METHODS: In this cross-sectional analysis, all abstracts accepted to ASH 2018 selected for a poster or oral presentation were reviewed. Those that had a contributing author from an LMIC were identified. The proportion of LMIC abstracts across categories was analyzed. Country of origin, high-income country participation, the presence of a conflict of interest (COI), and sponsorship were determined. RESULTS: From 4,871 abstracts reviewed, 506 had a contributing author from an LMIC (10.4%), with 277 (54.7%) contributions in partnership with a high-income country. LMIC-independent contributions corresponded to 19 of 1,026 oral abstracts (1.9%) and 209 of 3,845 posters (5.4%). Most abstracts from LMICs were clinical (n = 311; 61.5%) and multicentric in nature (n = 353; 69.8%). COI statements with the pharmaceutical industry were common (n = 214; 42.3%). Collaboration between LMICs was infrequent (n = 33; 6.5%). Upper-middle-income countries had 466 participations (81.5%), in comparison with 96 (16.8%) in low-middle-income and 10 (1.7%) in low-income countries. CONCLUSION: LMICs were responsible for a small fraction of abstracts at ASH18; low-income countries were practically absent. Almost half of accepted works represented a form of international collaboration, with clinical, multicenter studies predominating and COI disclosures a frequent and unexpected feature, reflecting the instrumental nature of LMIC participation and a lack of independent, robust, locally developed hematology research.

Outpatient Haploidentical Stem Cell Transplantation Using Post-Transplant Cyclophosphamide Is Safe and Feasible.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) feasibility has increased in the last decades because of haplo-HSCT, changes in chemotherapy schedules, and the possibility of an outpatient-based HSCT. The main barriers remain in low-middle income countries. There is a lack of information regarding haplo-HSCT with a myeloablative (MAC) regimen on an outpatient basis. OBJECTIVES: Our primary objective was to determine if outpatient haplo-HSCT was feasible. STUDY DESIGN: Single center, retrospective cohort, n=60 adult patients undergoing Haplo-HSCT. Descriptive statistical analysis, univariate and multivariate comparison. PATIENTS AND METHOD: We analyzed 60 adult patients transplanted with an intended haplo-HSCT on an outpatient basis from 2015 to 2019 in our unit. A multivariate analysis was performed on risk factors for hospitalization. RESULTS: Median age was 27 years (15-64). All patients underwent conditioning as outpatients, and none required hospitalization before day 0. Thirteen patients (21.6%) were followed completely in the outpatient clinic and 47 (78.3%) required hospitalization in a median of 3 days after infusion (range, 1-14). The median length of stay (LOS) was 8 days (IQR, 3-17). Fever secondary to cytokine release syndrome (CRS) was the most common reason for hospitalization occurring in 43/47 (91.5%), 4 were related to infection and 36 were related to CRS. In the univariate analysis, CRS, slower engraftment, and female sex were associated with the need for hospitalization. In the multivariate analysis, only CRS remained significant (OR 9.14 [95%CI, 1.58-56.46]). The 2-year overall survival (OS) was 41.7% for ambulatory transplant vs. 38% for those requiring hospitalization (P = 0.12). The 2-year event-free survival (EFS) was 33% for outpatient patients and 16.7% for those hospitalized (log-rank, P = 0.062). CONCLUSIONS: We demonstrated the feasibility and safety of carrying out an outpatient haplo-HSCT, potentially resulting in cost savings and perhaps a higher quality of life.

Outpatient low toxic regimen with bortezomib in relapsed/refractory acute lymphoblastic leukemia in pediatrics and AYA patients: Single-center Mexican experience.

Relapsed or refractory acute lymphoblastic leukemia represents a major challenge in low- and middle-income countries where new therapies are not easily accessible. Combinations of cost-effective drugs should be considered as a bridge for hematopoietic stem cell transplantation. We retrospectively analyzed pediatric and adolescent and young adult patients who received reinduction with a protocol based on l-asparaginase, doxorubicin, vincristine, dexamethasone, and bortezomib (BZ). Fifteen patients were included. Total complete response (CR) was achieved by nine of 15 patients (60%); five patients achieved CR with negative minimal residual disease, two achieved complete morphological response (CR), and two complete morphological response without platelet recovery. Eleven patients (73%) were not hospitalized and 10 (66%) did not require any blood component transfusions. There were no cases of serious toxicity or mortality. Nine patients (60%) underwent transplant. Five-year overall survival was 40%. This BZ-based protocol is effective and safe when administered as an outpatient regimen and feasible in a low resource setting.

Efficacy of three filgrastim-intended copies for hematopoietic stem cell mobilization in healthy adult and pediatric donors in Mexico.

INTRODUCTION: The use of filgrastim biosimilars for healthy adult and pediatric donor mobilization in hematopoietic stem cell transplantation has been met with increased safety and efficacy concerns in contrast to generic small molecule drugs. In Mexico, several filgrastim-intended copies (FIC) have been available and marketed since 2001, while no clinical comparability studies to evaluate their use in this setting have been published and thus are not considered to be true biosimilars. In this study, we report our experience using three different FIC products currently available (Filatil, Dextrifyl, and Biofilgran). METHODS: We retrospectively evaluated 118 related donors of all ages who received any brand 5 µg/kg subcutaneously twice daily for 4 days and were harvested in a single apheresis system on day 5. RESULTS: Donors had a median age of 38 years (range, 1-69). A successful harvest defined as ≥2 × 106 CD34+ cells/kg of recipient weight was achieved in 95.8% of cases, with a median CD34+ cell dose of 9.4 × 106 /kg (range 1-42.8). A single apheresis session was performed in 89.8% of cases. No significant difference in cell yield between each brand was observed. All pediatric donors had a successful harvest with similar results to adult donors. No immediate severe adverse effects were documented in any case. CONCLUSIONS: In conclusion, three FICs available in Mexico were efficacious and without immediate severe adverse effects, resulting in significant cost savings. Evaluation of immunogenicity and establishment of a pharmacovigilance program with the use of FICs is warranted.

Geographic Hematology: Some Observations in Mexico.

In 1963 Jean Bernard introduced the concept of "geographic hematology" and distinguished 2 branches, i.e., "ethnic hematology," which deals with differences between populations, and "environmental hematology," which considers factors such as food habits, infections, and others. Both of these branches have implications in the distribution of hematological diseases worldwide. In comparison with Caucasian populations, in Mexico a significantly higher prevalence of acute lymphoblastic, acute promyelocytic, and acute megakaryoblastic leukemias has been described. The rate of chronic myeloid leukemia seems to be as high as that reported in Caucasian populations, while other myeloproliferative neoplasias are significantly less frequent in Mexico. Significantly lower prevalences of hairy cell leukemia, chronic lymphocytic leukemia, multiple myeloma, and Waldenström's macroglobulinemia have been reported from Mexico. Regrettably, the influence of drug companies interested in selling their new and expensive drugs has resulted in both overdiagnosis of some diseases and overidentification of the refractory forms of some of these conditions to justify the use of unnecessary drugs.