Anti-Hla Donor-Specific Antibodies Are Associated to Infection and Not to the Engraftment Rate in Outpatient Haploidentical Hematopoietic Cell Transplantation.

Background: Recipients of a related haploidentical stem cell transplant (haplo-SCT) can have preformed antibodies to HLA donor's antigens. Objective: The aim of the study was to evaluate the engraftment rate and major clinical associations of anti-HLA donor-specific antibodies (DSA) at two mean fluorescence intensity (MFI) thresholds in recipients of an outpatient haplo-SCT. Methods: Seventy haplo-HCT recipients were analyzed. A virtual crossmatch was performed using the donor HLA typing and the recipient's anti-HLA DSA test results. Data for anti-HLA-A, -B, -C, and -DR were analyzed. Recipients with DSA ≥ 500 MFI were considered positive, and those with < 500 were considered negative; the same was adopted for MFI ≥ 1000. Results: Post-transplant infection was higher in recipients with DSA ≥ 500 MFI (84.6%, p = 0.041). First-year mortality was higher in DSA-positive patients ≥ 500 MFI, p = 0.004, and DSA ≥ 1000 MFI, p = 0.022, than in DSA-negative recipients. Graft failure in the first 100 days was not associated with DSA ≥ 500 or ≥ 1000 MFI. There was no difference in acute (a-GVHD) or chronic (c-GVHD) graft versus host disease between DSA-positive and negative patients. Conclusions: There was no association of anti-HLA DSA at MFI ≥ 500 and ≥ 1000 with graft failure, however, increased infection and 1st-year mortality were documented in related haplo-HCT at the MFI cutoffs studied.

The Influence of Nutritional Status at Diagnosis of Childhood B-Cell Acute Lymphoblastic Leukemia on Survival Rates: Data from a Hispanic Cohort.

The impact of nutritional status at diagnosis of childhood acute lymphoblastic leukemia (ALL) on survival rates was assessed in a Hispanic cohort. Children <16 years with newly diagnosed ALL-B from 2011 to 2019 were studied. Overweight and obesity were classified by body mass index (BMI) and Z-score according to WHO and CDC criteria. BMI, weight percentiles for age and Z-Score were assessed using the WHO Anthro (0-5 years) and AnthroPlus (5-19 years) programs. Cox model was used to estimate risk factors for relapse and death; differences between groups were assessed with Student's T test for parametric and Mann-Whitney U test for non-parametric variables. Disease-free survival (DFS) and overall survival (OS) were determined by the Kaplan-Meier method, calculating time, status, cumulative survival and standard error with a 95% confidence interval. Equal data distribution was estimated with the log-rank test. One-hundred and seventy-two B-ALL children were studied. The overweight-obese group had a non-significant lower DFS (CDC: 54% vs. 60%, p = 0.80; WHO: 57% vs. 64%, p = 0.89) and OS rate (CDC:76% vs. 82%, p = 0.38; WHO:65% vs. 81%, p = 0.13). An association between nutritional status determined by CDC and WHO criteria at diagnosis of B-cell ALL and survival rates was not documented.

Assessing the performance of a plateletpheresis unit at a tertiary-care academic medical center in Mexico: A 6-year experience.

BACKGROUND: Optimization of platelet (PLT) apheresis collection is a priority to satisfy the increasing demand of hemato-oncology patients. We assessed the performance of a plateletpheresis unit supporting hematology patients. STUDY DESIGN AND METHODS: This descriptive retrospective study included 561 plateletpheresis collections from 2013 to 2018. For data analysis, descriptive statistics and receiver operating characteristic (ROC) curve were used. A 5-item satisfaction questionnaire was analyzed. RESULTS: Ninety percent of the donors were males. The median plateletpheresis time was 89 minutes; its success rate was 92.5%; median donor PLT count was 232 × 109 /L, women median PLT count was 247 × 109 /L vs 231x109 /L in men (P = .017). Seventy-seven percent donors were candidates for a double product and 24.5% were processed; 20.8% of these donors had a weight ≤75 and 79.2% >75 kg, P = .003, and 6.6% were women and 93.4% men, P = .161. Thirty-six of donors had ≥250 × 109 /L and 16.8% was processed as a triple product. ROC analysis showed that with donor PLT counts ≥200 × 109 /L the sensitivity for obtaining double products was 0.981 and specificity 0.714, with an area under the curve (AUC) = 0.877. The adverse effect rate was 4.3%. Of the potential donors, 6.3% were rejected. The cost of processing single or double products was 430 USD. Comfort and time spent during plateletpheresis were areas for improvement. CONCLUSION: Platelet count and donor weight predicted PLT yield and obtaining double products. Women had higher PLT counts, but no significant difference was found between donor gender and processed products. Assessment of the apheresis unit can help to improve its performance.

Mobilization kinetics of CD34+ hematopoietic stem cells stimulated by G-CSF and cyclophosphamide in patients with multiple sclerosis who receive an autotransplant.

BACKGROUND AIMS: Autologous hematopoietic stem cell transplantation (AHSCT) is an alternative for multiple sclerosis (MS) patients who do not respond to conventional treatment. Mobilization kinetics of CD34+ cells in MS patients has not been studied. METHODS: Patients with MS mobilized with granulocyte colony-stimulating factor (G-CSF) and cyclophosphamide (Cy) were prospectively studied. Three counts of CD34+ cells were done in peripheral blood: at baseline before mobilization, at the start, and immediately at the end of apheresis. Complete blood counts were performed at the times of CD34+ cell counting. Standard statistical descriptive analysis of MS patients' salient features was performed, and after log 10 transformation of the data, Pearson test was performed to assess correlation between variables and CD34+ cell count. In addition, multiple linear regression of relevant data was carried out for multivariate analysis. RESULTS: Data of 51 consecutive MS patients with median age of 48 (31-64) years were analyzed. The CD34+ cell count increased 26-fold after mobilization. During large volume leukapheresis (LVL), the number of CD34+ cells in peripheral blood increased from 51.29 CD34+/µL at the start to 62.3 CD34+/µL at the end. A negative correlation between CD34+ cell count after leukapheresis and age (r = -0.32, P = 0.02) was observed. Neither the CD34+ baseline count nor sex correlated with the CD34+ count in peripheral blood immediately at the end of apheresis. CONCLUSIONS: Mobilization with G-CSF and Cy in MS patients resulted in effective CD34+ hematoprogenitors release from the bone marrow and in intra-apheresis recruitment.

Early changes in IL-21, IL-22, CCL2, and CCL4 serum cytokines after outpatient autologous transplantation for multiple sclerosis: A proof of concept study.

Changes in serum cytokines after autologous hematopoietic stem cell transplantation (AHSCT) in multiple sclerosis (MS) patients were documented. Thirty-six consecutive MS patients who had their Expanded Disability Status Scale (EDSS) scored before AHSCT were prospectively enrolled. Cyclophosphamide (Cy) was infused at 200 mg/kg in two administrations given 10 days apart: the first dose for mobilization, the second as the conditioning regimen. Patients were mobilized with 10 µg/kg/day subcutaneous G-CSF. Serum was collected 14 days before and 14 after AHSCT. IL-6, IL-9, IL-10, IL 17-A, IL-21, IL-22, IL-23, TNF-A, CCL2, CCL3, and CCL4 were measured by magnetic bead-based immunoassay. t Test and Wilcoxon test were used to compare cytokine levels before and after AHSCT. There were 28 women and 8 men with a median age of 46 (15-62) years, median duration of MS was 9.5 (1-32) years, and EDSS score was 5.7 (1.5-8.0). Patients had a decrement of pro-inflammatory IL-21 and IL-22 (p = .003 and p = .028) and an increment of anti-inflammatory CCL2 and CCL4 (p < .001 and p = .039) after AHSCT. Decrease of IL-21 and IL-22 coupled with an increment of CCL2 and CCL4 could reflect the immunomodulatory effect of auto-HSCT and be an early indicator of its efficacy.

Sexual Dimorphism in Children and Adolescents With Acute Lymphoblastic Leukemia: Influence on Incidence and Survival.

Acute lymphoblastic leukemia (ALL) incidence and poor prognosis are higher in male individuals. There is a lack of studies assessing the influence of sex in ALL. We documented this influence in a homogenous cohort. Three hundred three ALL Hispanic patients 1 to 20 years of age diagnosed over 10 years at a university hospital were evaluated. Patients were divided by sex and stratified by age. Survival rates were assessed by the Kaplan-Meier method, and the Cox model was used for univariate and multivariate analysis. The median age for female individuals was 6 years versus 9 years for male individuals (P=0.002). In the whole cohort, there was a male preponderance (P=0.025), with a 1.3 male-to-female ratio. For male individuals, the 5-year relapse-free survival was 46%; for female individuals, it reached 58.7%, (P=0.009). Male individuals 1-9 years of age had a lower 5-year relapse-free survival than female individuals, 51.5% versus 66.7% (95% confidence interval, 65.35-68.01; P=0.020); this was not the case for overall survival (P=0.660). The male-to-female ratio in the 10 to 15 years' group was 1.59, and 2.35 in the 16 to 20 years' group. Incidence and relapse of ALL were higher in male individuals. A skewed distribution in the 10 to 20 years' age group disproportionately affected male individuals, suggesting a hormonal influence.

Diagnoses, Outcomes, and Chronicity Predictors of Patients with Secondary Immune Thrombocytopenia: Ten-Year Data from a Hematology Referral Center.

BACKGROUND: Secondary immune thrombocytopenia (ITP) is a heterogeneous and unpredictable disease associated with various underlying conditions. OBJECTIVE: The objective of the study was to investigate clinical evolution and chronicity predictors in secondary ITP. METHODS: Patients treated at an academic medical center during 2008-2019 were stratified by age as children <16 years and adults <16 years. Responses to steroids, intravenous immunoglobulin G (IVIG), rituximab, and eltrombopag were classified as response (R) and complete response (CR). Risk factors for chronic ITP were determined by multiple regression with uni- and multi-variate analysis. RESULTS: Eighty-three patients were included, 37 children and 46 adults. The most frequent associated conditions were infections 53%, systemic lupus erythematosus (SLE) 24%, thyroid disease 9.6%, and Evans syndrome 3.6%. Response to first-line treatment in the whole cohort was 94%; CR 45.7%; and R 50.6%. Initial response to steroids alone was 91.3% (n = 21/23), rituximab plus high-dose dexamethasone (HDD) 93.3% (n = 14/15); children receiving IVIG alone 100% (n=12/12); and eltrombopag in adults 100% (n = 3/3). Relapse was documented in 19.4% of children and 34% of adults, at a median time of 15 and 2 months, respectively; 30.4% of adults (15.2% from the miscellaneous group, 10.9% SLE-associated, and 4.3% infection-associated) and 18.9% of children followed a chronic course; age ≥10 years and platelets ≥20 × 109/L were risk factors for chronic ITP in children. CONCLUSION: Evolution was heterogeneous: a better and more sustained response was documented in the infections group compared to SLE or the miscellaneous group.

IMPACT OF HLA-DPB1 MATCHING ON CLINICAL OUTCOMES AFTER HAPLOIDENTICAL-RELATED HEMATOPOIETIC STEM CELL TRANSPLANTATION.

BACKGROUND: The impact of HLA-DPB1 compatibility and its role as a transplantation antigen in haploidentical-related hematopoietic stem cell transplant (haplo-R-HSCT) have not been established, and a negative effect on survival has been suggested. OBJECTIVE: The objective of the determine was to study the frequency and clinical effects of incompatibility at the HLA-DPB1 locus in the haplo-R-HSCT setting. METHODS: Clinical records and electronic files of 91 patients with a hematological disease who underwent haplo-HSCT from January 2009 to October 2017 in a university medical center were scrutinized. Overall survival (OS) was estimated by the Kaplan-Meier method; the cumulative incidence of transplant-related mortality (TRM) and relapse rates was determined. Acute graft-versus-host disease was assessed by binary logistic regression. Cox regression model with a 95% confidence interval was used to examine the association between the different variables and their effect on OS. RESULTS: Of the 91 donor-recipient pairs, 24 (26.37%) shared complete DPB1 identity, 60 (65.93%) had a mismatch at one allele, and 7 (7.70%) were mismatched at two alleles. Twenty-four different HLA-DPB1 alleles were found; the most frequent were DPB1*04:01 (34.1%) and DPB1*04:02 (27.5%). Two-year OS, the cumulative incidence of TRM and relapse was 51.3 ± 6.8%, 28 ± 6% and 60 ± 7.8% for all haplo-related transplants, respectively, with no statistical difference between HLA-DPB1 matched and partially matched patients. In Cox regression analysis, no risk factors associated with OS, TRM, or relapses were identified. CONCLUSION: HLA-DPB1 mismatching in the haplo-R-HSCT setting did not influence transplant outcomes and was clinically tolerable. A high degree of homozygosity was found.

Real-world outcomes of treatment for acute lymphoblastic leukemia during adolescence in a financially restricted environment: Results at a single center in Latin America.

OBJECTIVE: There is a paucity of the studies of adolescents with acute lymphoblastic leukemia (ALL). This is more noticeable in low- and middle-income countries. The international 5-year event-free survival (EFS) and overall survival (OS) for this age group is around 80%, with pediatric-inspired protocols offering better results. METHODS: A retrospective analysis of adolescents aged 16-20 diagnosed with ALL during the period 2004-2015 treated with a high-risk pediatric protocol at an academic center from a middle-income country was performed. Five-year OS and EFS were estimated by the Kaplan-Meier analysis. Hazard ratios of relapse and death were estimated by the Cox regression model. RESULTS: Five-year EFS and OS for 57 adolescents were 23.3% and 48.9%, respectively. From the 41 patients who achieved complete remission, 24 (58.5%) relapsed. Bone marrow and central nervous system were the most frequent sites of relapse. Hazard ratio of treatment failure and death for patients with organomegaly at diagnosis was 2.026 and 2.970, respectively. Treatment-related toxicity developed in 31 (54.4%) patients and febrile neutropenia was the most frequent in 14 (24.6%) cases. Twelve patients (21.1%) had poor adherence to treatment. CONCLUSIONS: High relapse rate and low 5-year EFS compared with international standards, was documented. Use of intensified pediatric regimens, adherence to proven effective medications, improved supportive care, and prevention of abandonment are necessary to improve survival rates in these patients.

Assessment of immune reconstitution status in recipients of a successful hematopoietic stem cell transplant from peripheral blood after reduced intensity conditioning.

OBJECTIVE: To document immune reconstitution status after hematopoietic stem cell transplantation (HSCT) for malignant hematologic diseases. METHODS: Hematology patients who received a reduced intensity conditioning (RIC) were followed after successful allogeneic or autologous HSCT. Patients had at least 100days post-transplant. T, B and NK cells in peripheral blood (PB), and CD34+, CD133+ progenitor cells in bone marrow (BM) and peripheral blood (PB) were determined by flow cytometry. RESULTS: Twenty-seven HSCT recipients, 19 allogeneic and 8 autologous, were studied at a median 155 (100-721) days post-transplant. In the whole group the median value of CD34+ cells was 1.03% in the bone marrow and 0.04% in PB, whereas values for CD133+ cells were 0.39% and 0.13%, respectively, without statistical differences between autologous and allogeneic recipients. Significantly more B cells (CD3-/CD56-/CD19+) were found in the autologous compared to the allogeneic group, 12.6 vs. 5.01, p=0.04. An increased number of CD8+ lymphocytes with a 0.63 CD4:CD8 relationship was documented in PB. CONCLUSION: In clinically recovered autologous and allogeneic HSCT recipients BM and PB CD34+/CD133+ hematoprogenitor homeostasis is maintained within normal ranges, with better B-cell reconstitution in the autologous group.

Eltrombopag and high-dose dexamethasone as frontline treatment of newly diagnosed immune thrombocytopenia in adults.

Immune thrombocytopenia (ITP) results from platelet destruction and production suppression. Eltrombopag belongs to a new class of thrombopoietin-mimetic drugs that raise platelet counts in ITP patients. We performed a single-arm study to assess the response to a single course of dexamethasone (40 mg by mouth, days 1-4) in combination with eltrombopag (50 mg, days 5-32) in 12 adults with newly diagnosed ITP in an outpatient setting. Median follow-up was 12.5 months. After therapy (day 33), 100% of patients achieved at least ≥30 × 10(9)/L platelets. Four patients relapsed. Complete response at 6 months (platelets ≥100 × 10(9)/L) was achieved in 50% of patients and response at 6 months (platelets ≥30 <100 × 10(9)/L) was achieved in another 25%; relapse-free survival was 66.7% at 12 months (median response duration of 8.3 months). In conclusion, eltrombopag/dexamethasone is a feasible frontline therapy for ITP. This trial is registered at www.clinicaltrials.gov as NCT01652599.

[Comparison of the effectiveness of hematopoietic cell mobilization with chemotherapy and filgrastim versus filgrastim alone for autologous transplant in patients with lymphoma.] / Comparación de la efectividad de la movilización de células hematopoyéticas con quimioterapia y filgrastim, o con filgrastim solo, para autotrasplante en pacientes con linfoma.

INTRODUCTION: Autologous hematopoietic stem cell transplantation is the treatment of choice for high-risk Hodgkin's lymphoma and non-Hodgkin's lymphoma. OBJECTIVE: Compare the capacity to mobilize CD34+ cells for autologous hematopoietic stem cell transplantation using schemes with chemotherapy and without chemotherapy plus filgrastim in patients diagnosed with Hodgkin's lymphoma or non-Hodgkin's lymphoma. MATERIAL AND METHODS: The clinical records of patients with Hodgkin's lymphoma or non-Hodgkin's lymphoma who received an autologous hematopoietic stem cell transplant were analyzed retrospectively. Filgrastim alone or in combination with chemotherapy was used as mobilization scheme. Cell harvesting was classified as adequate when > 2 × 106 cells/kg were collected. RESULTS: Forty-seven patients (Hodgkin's lymphoma, 24; non-Hodgkin's lymphoma, 23) were included. Comparing groups of Hodgkin's lymphoma mobilized with chemotherapy (15 patients) and without chemotherapy (nine patients), one apheresis procedure was sufficient in 73 and 44% of patients, respectively (p = 0.04), the average of CD34 + cells/kg collected was 11 x 106 and 3 x 106, respectively (p = 0.017), and the collection was adequate in 100 and 55.6% of cases, respectively (p = 0.014). Comparing the groups of non-Hodgkin's lymphoma mobilized with chemotherapy (six patients) and without chemotherapy (17 patients), one apheresis procedure was sufficient in 33 and 65% of patients, respectively (p = 0.26), the average of CD34+ cells/kg was 3.56 x 106 and 3.41 x 106, respectively (p = 0.47), and collection was adequate in 66.6 and 59% of cases, respectively (p = 0.37). CONCLUSION: In Hodgkin's lymphoma patients, mobilization schemes with chemotherapy were more effective considering the number of cells collected, the number of apheresis required, and the percentage of successful cell collections. In non-Hodgkin's lymphoma patients, there were no significant differences between the two groups.

Increased bacterial infections after transfusion of leukoreduced non-irradiated blood products in recipients of allogeneic stem cell transplants after reduced-intensity conditioning.

Blood components transfused to hematopoietic stem cell transplant (HSCT) recipients are irradiated to prevent transfusion-associated graft-versus-host disease (TA-GVHD). The effect of transfusing non-irradiated blood products in HSCT outcome, including incidence of transplant complications, bacterial infections, acute and chronic GVHD presentation, and characteristics, has not been documented. Clinical records as well as blood bank and electronic databases of HSCT patients grafted after reduced-intensity conditioning who received irradiated versus non-irradiated blood products, after blood irradiation became unavailable at our center, were scrutinized for transplant outcome, clinical evolution, engraftment characteristics including days to neutrophil and platelet recovery, acute and chronic GVHD, rate and type of infections, and additional transplant-related comorbidities. All transfused blood products were leukoreduced. A total of 156 HSCT recipients was studied, 73 received irradiated and 83 non-irradiated blood components. Bacterial infections were significantly more frequent in patients transfused with non-irradiated blood products, P = .04. Clinically relevant increased rates of fever and neutropenia and mucositis were also documented in these patients. No cases of TA-GVHD occurred. Classical GVHD developed in 37 patients (50.7%) who received irradiated blood products and 36 (43.9%) who received non-irradiated blood products, P = .42. Acute GVHD developed in 28 patients (38.4%) in the blood-irradiated and 33 patients (39.8%) in the non-irradiation group, P = .87. The 2-year GVHD-free survival rate was 40% in the irradiated versus 40.6% in the non-irradiation group, P = .071. Increased bacterial infections were found in HSCT recipients transfused with non-irradiated blood products, which ideally must always be irradiated.

Assessing the Efficacy of Mitoxantrone and Doxorubicin as Frontline Anthracyclines During Induction Therapy of Newly Diagnosed Acute Promyelocytic Leukemia.

BACKGROUND: Therapeutic advances in acute promyelocytic leukemia (APL) have transformed it into today's most curable form of leukemia. However, recommended agents, including arsenic trioxide, idarubicin, or daunorubicin, are not easily available in low-middle-income countries, where outcomes remain suboptimal. We aimed to assess the efficacy and safety of more accessible anthracyclines. METHODS: We conducted a retrospective cohort study including sixty-one patients diagnosed with APL over a 15-year period. Patients received low-dose all-trans retinoic acid (ATRA, 25 mg/m2) with mitoxantrone or doxorubicin as an induction to remission therapy. Groups were compared using the χ2 and Student's t-tests. Kaplan-Meier analysis was used for survival analyses. RESULTS: Thirty (49.18%) patients received mitoxantrone, and 31 (50.82%) received doxorubicin. The median follow-up was 24.6 months (1-146). Twenty-eight (93.3%) patients achieved complete remission (CR) in the mitoxantrone group and 28 (87.1%) in the doxorubicin group (p=0.103), and the median time to CR was 40 and 31 days, respectively. Mitoxantrone had a 6.7% early mortality rate and a 16.7% relapse rate compared with doxorubicin (3.2% and 32.3%, respectively). No differences were found in survival (p = 0.795), hospitalization days (p = 0.261), or adverse events (p = 0.554). CONCLUSIONS: Using mitoxantrone or doxorubicin as induction therapy in newly diagnosed APL is a safe and adequate alternative with comparable outcomes to first-line agents in scenarios where the latter might not be readily available, such as in low-middle-income countries.

Acute maternal cytomegalovirus infection is associated with significantly decreased numbers of CD34+ cells in umbilical cord blood.

OBJECTIVE AND BACKGROUND: There is little information regarding the serologic status of umbilical cord blood (UCB) donors. Cytomegalovirus (CMV) is the most frequent agent transmitted by blood products and studies have reported that CMV can inhibit myelopoiesis, however, its effects on the cellular content of UCB have not been documented. STUDY DESIGN AND METHODS: We investigated, retrospectively, the prevalence of serological evidence of infection in 857 women donating their UCB at a public university hospital and studied the influence of acute CMV exposure on UCB content of CD34+ cells. The biological characteristics of UCB from serology positive-donors were compared with those of women with negative tests. RESULTS: We found that 51 of 857 (6%) UCB units were positive for infectious disease markers; anti-CMV IgM was the most prevalent marker, 43 of 51 (86%) of cases with infectious markers. UCB collected from anti-CMV IgM-positive donors more frequently met rejection criteria for use as a transplanation product. The CD34+ cell count was the most often affected, 2.48×10(6) in anti-CMV IgM-positive donors compared to 1.48×10(6) in unaffecetd donors( p=0.006). The probability of a UCB meeting a CD34+ cell content≥2×10(6) was significantly lower in units from IgM anti-CMV+ women compared to unaffecetd donors [Odds ratio (OR)=0.428 (95% CI 0.182-0.632; p=0.015]; the total nucleated cell count (TNC) was lower but not statistically significant [p=0.068]. CONCLUSION: UCB donated by anti-CMV IgM-positive women has a high probability of not meeting the criteria required for cryopreservation for future use as a transplantation product, because of the low number of CD34+ cells.

Cord blood banking activities at a university hospital in northeast Mexico: an 8-year experience.

BACKGROUND: Umbilical cord blood (UCB) represents an alternative source of stem cells for transplantation for the treatment of hematologic malignancies and genetic disorders. There is scarce information detailing cord blood bank (CBB) collection and transplantation activities from developing countries. We documented our experience at a public university hospital in northeast Mexico. STUDY DESIGN AND METHODS: We carried out a retrospective and descriptive analysis of our CBB activity during an 8-year period from May 2002 to September 2010. Collection, processing, and cryopreservation of CB were carried out following standard operating procedures. The minimum volume and total nucleated cell (TNC) content for cryopreservation were 80 mL and 8.0 × 10(8) , respectively. RESULTS: A total of 1256 UCB units were collected; 428 (34%) were banked and 828 (66%) were discarded. The main reason for exclusion was biologic: low volume and/or low number of TNC accounted for 84% of the total discarded units. Cryopreserved cord blood units (CBUs) had a median volume of 113.8 mL (range, 80-213.2 mL) and 13.0 × 10(8) (range, 8 × 10(8) -36.6 × 10(8) ) TNCs. Cell viability was 99.3% (88-100%). The median CD34+ cell content was 4.0 × 10(6) (0.46 × 10(6) -19.38 × 10(6) ). Sixteen units have been released for transplantation, leading to a utilization rate of 3.7%. CONCLUSION: CBB demands considerable human and financial resources; it is then essential for centers at developing countries to share their experience, results, and databases to increase the probability of finding matching units for their patients. Efforts to create and maintain CBBs allow to offer this therapeutic option at an affordable cost.

A Method for the Elution of Anti-CD20 With an EDTA/Glycine Acid Solution for Accurate Immunophenotyping of B Lymphocytes Sensitized With Rituximab.

OBJECTIVES: To assess the efficacy of a method to circumvent CD20-positive antigen masking by rituximab for flow cytometry analysis of B-cell malignancies in hematology patients. METHODS: Mononuclear cells (MNCs) from 10 healthy individuals and 5 untreated patients with B-cell malignancies were sensitized with rituximab. Patients' diagnoses included chronic lymphocytic leukemia, hairy cell leukemia, and follicular lymphoma. MNCs were isolated by gradient density centrifugation. An EDTA/glycine acid (EGA) elution method was used to dissociate CD20-rituximab complexes; afterwards, CD20-positive immunoreactivity was assessed by flow cytometry. A saturation curve was built based on serial dilutions of rituximab. Median fluorescent intensities of CD20-positive signals were obtained before sensitization with rituximab and after its elution with EGA. RESULTS: CD20-positive signals were not detectable by flow cytometry after rituximab sensitization of B cells. CD20-sensitized vs CD20-unsensitized, CD20-sensitized vs CD20-eluted, and CD20-eluted vs CD20-negative control (NC) MNC populations exhibited statistical differences (P = .001), while CD20-sensitized vs CD20-NC populations did not (P = .499), confirming CD20 antigen masking by rituximab. CONCLUSIONS: Rituximab interfered with the flow cytometry protocol for CD20 determination on normal and neoplastic B cells. The EGA method efficiently eluted rituximab, allowing for accurate identification of CD20-positive B cells.