Lymphocyte subsets and soluble forms of MIC-A and MIC-B are prognostic factors in non-Hodgkin lymphoma patients

MIC-A and MIC-B are the natural ligands for NKG2D, an activator receptor expressed in NK cells. Soluble isoforms of MIC-A and MIC-B (sMICA, sMICB) have been identified in different malignancies, affecting NK cells' cytotoxicity. The study was performed to determine the levels of sMICA, sMICB, the expression of MIC-A, and MIC-B on tumor tissues, and lymphocyte subpopulations (CD4 + , CD8 + , NK, NKT, Tγδ cells, B cells, monocytes) in 94 patients with non-Hodgkin's lymphoma (NHL) and 72 healthy donors.The most frequent lymphoma was diffuse large B cell lymphoma (48%). Patients with NHL had decreased numbers of CD4 T cells, CD8 T cells, B cells, monocytes, NK cells, type 1 dendritic cells, γδ T cells, and increased iNKT cells. Patients showed higher levels of sMIC-A and similar serum levels of sMIC-B.Survival was poorer in patients having higher LDH values and lower numbers of CD4 T cells, type 1 dendritic cells, gamma-delta T cells, and high levels of sMIC-A.In conclusion, high levels of sMIC and decreased numbers in circulating lymphocyte subsets are related to poor outcomes in NHL.

Significant increase in MIC-A and MIC-B and soluble MIC-A and MIC-B in canine lymphomas

Non-Hodkin's lymphoma (NHL) is the most frequent hematologic malignancy in humans and dogs. NKG2D is one of the most critical receptors on NK cells, recognizing their natural ligands on malignant cells such as A and B major histocompatibility complex-related proteins (MIC-A and MIC-B). Soluble molecules (sMIC-A and sMIC-B) can interfere with immune synapsis between NK cells and tumor cells, impeding NK cytotoxicity. The main objectives of this study were to analyze, in dogs with diffuse large B cell lymphoma, NK cell lymphoma, and reactive lymphadenopathies, the role of NK cells, their activating receptors NKG2D and NKp46, and their ligands MIC-A and MIC-B, as well as soluble molecules sMIC-A and sMIC-B. Thirty-six dogs with a possible diagnosis of NHL and eight healthy dogs were studied. NHL was diagnosed in 28 (78 %) dogs; in the other 8 (22 %), reactive lymphadenopathies were present. Most of the lymphomas corresponded to B cell NHL (82 %). The most predominant subtype was diffuse large B cell lymphoma (21, 71.5 %), followed by five cases (18 %) that were Non-B Non-T lymphomas (presumably NK cell lymphomas) and other B cell lymphomas (3, 10.5%). There were no cases of T cell NHL. MIC-A was positive in 7 of 27 (26 %) cases of NHL, and MIC-B in 20 of 27 (74 %) NHL. In non-malignant lymphadenopathies, three (37.5 %) dogs were positive for MIC-A, and five (62.5 %) expressed MIC-B. Dogs with lymphoma had higher numbers of NK cells than eight healthy dogs. In 15 dogs (12 cases with NHL and three cases with reactive adenopathies) and eight controls, there were no differences in the number of NK cells expressing NKP46 and NKG2D. NHL dogs had higher values of sMIC-A and sMIC-B. B-cell and NK cell lymphomas correspond to 86 % and 14 % of all canine lymphomas. MIC-A, MIC-B, and sMIC-A and sMIC-B were increased in canine lymphomas.

Rates of Influenza and Pneumococcal Vaccination and Correlation With Survival in Multiple Myeloma Patients

BACKGROUND

Infections are a common reason for hospitalization and death in multiple myeloma (MM). Although pneumococcal vaccination (PV) and influenza vaccination (FV) are recommended for MM patients, data on vaccination status and outcomes are limited in MM.

MATERIALS AND METHODS

We utilized data from the global, prospective, observational INSIGHT MM study to analyze FV and PV rates and associated outcomes of patients with MM enrolled 2016-2019.

RESULTS

Of the 4307 patients enrolled, 2543 and 2500 had study-entry data on FV and PV status. Overall vaccination rates were low (FV 39.6%, PV 30.2%) and varied by region. On separate multivariable analyses of overall survival (OS) by Cox model, FV in the prior 2 years and PV in the prior 5 years impacted OS (vs. no vaccination; FV: HR, 0.73; 95% CI, 0.60-0.90; P = .003; PV: HR, 0.51; 95% CI, 0.42-0.63; P < .0001) when adjusted for age, region, performance status, disease stage, cytogenetics at diagnosis, MM symptoms, disease status, time since diagnosis, and prior transplant. Proportions of deaths due to infections were lower among vaccinated versus non-vaccinated patients (FV: 9.8% vs. 15.3%, P = .142; PV: 9.9% vs. 18.0%, P = .032). Patients with FV had generally lower health resource utilization (HRU) versus patients without FV; patients with PV had higher or similar HRU versus patients without PV.

CONCLUSION

Vaccination is important in MM and should be encouraged. Vaccination status should be recorded in prospective clinical trials as it may affect survival. This trial was registered at www.

CLINICALTRIALS

gov as #NCT02761187.

Chronic Lymphocytic Leukemia in the SARS-CoV-2 Pandemic

Purpose of Review

Chronic lymphocytic leukemia (CLL) is the most frequent lymphoproliferative disease in the elderly of the western world. Immune defective responses and treatment can worsen the immune system’s competence of CLL patients. Consequently, they may present a higher incidence of recurrent severe infections, second malignancies, and reduced efficacy of vaccines. The outbreak of COVID-19 is an ongoing pandemic, and patients with comorbidities experience more severe forms of the disease. Hematological malignancies are associated with higher case fatality rates (CFRs) than other cancers. Knowledge about COVID-19 incidence, clinical course, and immune response to the infection and vaccination in CLL may contribute to design strategies that improve the outcomes of patients in the future.

Recent Findings

The prevalence of SARS-CoV-2 positivity in CLL is not significantly higher than seen in the general population. CFRs for CLL patients are 16.5-fold more elevated than the median reported worldwide and even higher in older patients, those who require hospitalization have significant comorbidities or need oxygen therapy. CLL status decreases the anti-SARS-CoV-2 positivity after infection or vaccination by around 40%, and the spike-specific antibody titers are 74-fold lower than healthy age-matched controls. The response rate to COVID-19 vaccines is even worse in patients with active CLL-directed therapies like BTKi, BCL-2 antagonists, or anti-CD20 monoclonal antibodies.

Summary

CLL patients are at a greater risk of death from COVID-19. Inherent immunosuppression of CLL and immune deficiencies caused by treatment significantly decrease the ability to produce natural or vaccine-induced anti-SARS-CoV-2 immune responses.

Analysis of the quality of anticoagulation with vitamin K antagonists in three clinical scenarios in Mexico

INTRODUCTION

Vitamin K antagonists (VKA) are a therapeutic alternative in patients with venous thromboembolic disease; however, numerous factors affect their pharmacology.

OBJECTIVE

To evaluate the quality of VKA anticoagulation at three different time periods in Mexico.

METHODS

Prospective study, nested in patient cohorts at three different clinical scenarios between 2013 and 2019. Outpatients with indication for treatment with VKAs for at least 12 months were included. Patients were managed according to the criteria of the treating physician.

RESULTS

Patient general characteristics were similar between groups, except for the VKA indication. The results of 4,148 patients and 38,548 INR assessments were analyzed. The times in therapeutic range during the three phases of the study and pooled data were significantly higher for the anticoagulation clinic. Only the number of patient visits was significantly associated with the results, unlike age, gender, and type of VKA.

CONCLUSIONS

VKAs are widely used, but it is difficult for therapeutic goals to be achieved, especially in non-specialized clinical services. Creation of anticoagulation clinics is an urgent need for the Mexican health system.

Abo Blood Group, Atherothrombotic Comorbidities, and COVID-19: A Case-Control Study of their Association in the Mexican Population

Background

COVID-19 has been associated with negative results in patients with A blood group and with a better evolution in O blood group individuals.

Aim

Because the evidence regarding ABO blood groups and COVID was empirically not that clear in our country, we tested the association regarding COVID-19 and blood groups.

Material and Methods

Adult patients were enrolled in this prospective, case-control, observational multicenter study. Patients with a confirmed diagnosis of COVID-19 were assigned to one of three groups based on the clinical presentation of the infection. Age, gender, ABO and Rh blood groups, body mass index, history of diabetes mellitus or high blood pressure, and smoking were recorded directly or from their clinical charts. ABO blood group was obtained from 5,000 blood donors (50% each gender). Atherothrombotic variables were compared with a nation-wide data collection.

Results

A total of 2,416 patients with COVID-19 were included (women:39.6%; men:60.4%). There were no significant differences between cases and controls in terms of age. O blood group was the most frequently found in healthy donors and COVID-19 patients, but this blood group was significantly higher in COVID-19 patients vs. healthy donors. ABO blood group was not associated with the final health status in COVID-19 patients. Obesity, diabetes mellitus, hypertension and smoking were significantly more frequent among COVID-19 patients.

Conclusion

The proposed protective effect of the O blood group in COVID-19 patients could not be reproduced in the Mexican population while some atherothrombotic risk factors had a significant effect on the clinical evolution.

Ixazomib-lenalidomide-dexamethasone in routine clinical practice: effectiveness in relapsed/refractory multiple myeloma

Aim: To evaluate the effectiveness and safety of ixazomib-lenalidomide-dexamethasone (IRd) in relapsed/refractory multiple myeloma in routine clinical practice. Patients & methods: Patient-level data from the global, observational INSIGHT MM and the Czech Registry of Monoclonal Gammopathies were integrated and analyzed. Results: At data cut-off, 263 patients from 13 countries were included. Median time from diagnosis to start of IRd was 35.8 months; median duration of follow-up was 14.8 months. Overall response rate was 73%, median progression-free survival, 21.2 months and time-to-next therapy, 33.0 months. Ixazomib/lenalidomide dose reductions were required in 17%/36% of patients; 32%/30% of patients discontinued ixazomib/lenalidomide due to adverse events. Conclusion: The effectiveness and safety of IRd in routine clinical practice are comparable to those reported in TOURMALINE-MM1. Clinical trial registration: NCT02761187 (ClinicalTrials.gov).

Clinical relevance of NKT cells and soluble MIC-A in Hodgkin lymphoma

Previous studies demonstrated that the majority of Hodgkin lymphoma (HL) patients achieve response after treatment, while 5% become refractory. Studies analyzing the role of lymphocyte subsets in peripheral blood are limited. This investigation sought to evaluate peripheral blood lymphocyte subsets and soluble MHC class I chain-related proteins A and B (sMIC-A/B) and their correlation with survival in patients with newly diagnosed HL. The study recruited 36 patients and 72 healthy donors. HL patients showed a decrease in CD4, B, monocytes, NK, and NKT cells; and an increase in γ-δ T cells and soluble MIC-A serum levels. Higher values of s-MIC-A  >100 ng/mL and NKT cells >40 µL correlated with poor overall survival (OS). In conclusion, in HL peripheral blood CD4 T and B cells, monocytes, NK, and NKT cells were decreased, while s-MIC-A and γ-δ T cells increased. Higher values of s-MIC-A and NKT cells correlated with poor survival.

FLT3-ITD and CD135 Over-Expression are Frequent Findings of Poor Survival in Adult Patients with Acute Leukemias

BACKGROUND

Fms-like tyrosine kinase 3 (FLT3) expression and mutation have been considered a poor prognostic factor in acute myeloid leukemia (AML). FLT3-ITD mutation is present in 30% of adult patients with AML and 2-5% in childhood acute lymphoblastic leukemia (ALL). The impact of these mutations on the prognosis of ALL patients, has not yet been established. Moreover, a limited number of publications regarding the level of expression of the FLT3 receptor (CD135) in both leukemias exist. This study aimed to analyze the clinical outcomes associated to the presence of FLT3-ITD mutation and the expression of CD135.

METHODS

82 adult patients with newly diagnosed acute leukemia (39 with AML and 43 with ALL) were included. Flow cytometry and RT-PCR were done to analyze the expression of CD135 and the presence of FLT3 ITD mutation, respectively.

RESULTS

FLT3-ITD was present in 14 (36%) of AML and 15 (35%) of ALL patients. Disease free survival (DFS) and overall survival (OS) were lower in ALL patients having a CD135 expression >3000 cells/μL. There was a trend for poor OS in AML patients expressing FLT3 ITD. OS was worse in AML patients with high expression of CD135.

CONCLUSION

A higher (35%) frequency of FLT3-ITD was found in adult ALL patients. The presence of FLT3-ITD was associated with a trend of poor OS in AML cases, and overexpression of CD135 was correlated with poor DFS in ALL cases and poor OS in both acute leukemias.

γδ T Cells Number, CD200, and Flt3 Expression Is Associated with Higher Progression Free Survival in Patients with Chronic Myeloid Leukemia

BACKGROUND

Tumor immunoedition involves alterations in cells of immune system, which may play an important role in the immunosurveillance of patients with cancer diseases.

AIM OF THE STUDY

To determine the association between the number of immune cells and the expression of surface markers in leukemic cells of patients with de novo CML who achieved molecular response.

METHODS

A longitudinal study was conducted in 31 patients with de novo CML. Peripheral blood samples were obtained at diagnosis for quantification of immune cells and tumor cells expressing CD200, CD135, GpP, and Bcl-2. Results were compared with a group of 60 healthy donors. Lymphocyte subsets were analyzed during a 48 month follow-up period and molecular response to treatment was assessed simultaneously by QT-PCR. The group of patients with deep molecular response was compared with de novo CML patients; the cut-off value of cell count was determined by ROC analysis. Kaplan-Meier and Cox proportional hazard model were used to determine the significant association between the number of cells and progression-free survival.

RESULTS

Differences in number of CD4, CD4Tregs, NK, γδT, monocytes, and pDC's, tumor-cells expressing CD200⁺, CD135⁺, GpP⁺, and Bcl-2⁺ were observed between patients and healthy donors. The number of γδT lymphocytes, CD200⁺, and CD135⁺ cells were associated with longer progression-free survival (p = 0.0112, p = 0.0012 and p = 0.0201 respectively).

CONCLUSION

A γδT lymphocyte count <63 cel/uL, CD200⁺ <997 cel/uL, and CD135⁺ <23 317 cel/uL at diagnosis is associated with the maintenance of deep molecular response at 48 months in patients with de novo CML.

Multiple myeloma treatment patterns and clinical outcomes in the Latin America Haemato-Oncology (HOLA) Observational Study, 2008-2016

Limited data are available regarding contemporary multiple myeloma (MM) treatment practices in Latin America. In this retrospective cohort study, medical records were reviewed for a multinational cohort of 1103 Latin American MM patients (median age, 61 years) diagnosed in 2008–2015 who initiated first‐line therapy (LOT1). Of these patients, 33·9% underwent autologous stem cell transplantation (ASCT). During follow‐up, 501 (45·4%) and 129 (11·7%) patients initiated second‐ (LOT2) and third‐line therapy (LOT3), respectively. In the LOT1 setting, from 2008 to 2015, there was a decrease in the use of thalidomide‐based therapy, from 66·7% to 42·6%, and chemotherapy from, 20·2% to 5·9%, whereas use of bortezomib‐based therapy or bortezomib + thalidomide increased from 10·7% to 45·5%. Bortezomib‐based therapy and bortezomib + thalidomide were more commonly used in ASCT patients and in private clinics. In non‐ASCT and ASCT patients, median progression‐free survival (PFS) was 15·0 and 31·1 months following LOT1 and 10·9 and 9·5 months following LOT2, respectively. PFS was generally longer in patients treated with bortezomib‐based or thalidomide‐based therapy versus chemotherapy. These data shed light on recent trends in the management of MM in Latin America. Slower uptake of newer therapies in public clinics and poor PFS among patients with relapsed MM point to areas of unmet therapeutic need in Latin America.

Pathophysiology of Alloimmunization

Introduction

Alloimmunization is caused by exposure to erythrocytes from a donor that expresses blood group antigens other than those of the recipient and is related to processes that alter the balance of the immune system. Knowing the pathophysiology of alloimmunization process is essential to understand clinical complications associated with this process.

Patients and Methods

From October 2016 to April 2017, irregular antibody screening was performed in 1,434 polytransfused (compatible with the ABO and D system) patients by means of agglutination techniques using erythrocytes of a known phenotype of 44 patients with a positive alloantibody screening. Non-alloimmunized (control) subjects were matched for age, gender, pathology, and treatment group with alloimmunized patients. The subsets of B, T, and Treg lymphocytes were determined by flow cytometry.

Results

The results of screening for alloantibodies in patients by specificity of antibodies were as follows: nonspecific (30%), followed by anti-Di^a (13%), anti-e (9%), anti-S (9%), anti-I (7%), anti-K (7%), and anti-P (7%). A lower percentage of CD4+ T lymphocytes and an increase of CD8+ T lymphocytes were observed in alloimmunized patients, as well as a low CD4/CD8 ratio (0.7 vs. 1.6, p = 0.003), a higher percentage of B lymphocytes versus the control group (30 vs. 20%, p = 0.003), and a decrease of Treg CD4+ lymphocytes versus the control group (3 vs. 12 cells/μL, p = 0.043). These observations suggest that alloimmunized patients have important alterations in the number of some lymphocyte subsets that can be translated into clinical immune dysregulation.

Conclusion

A decreased CD4/CD8 ratio, increased B lymphocytes, and Treg lymphocyte deficiency are the most significant changes observed in alloimmunized patients.

Post-treatment improvement of NK cell numbers predicts better survival in myeloma patients treated with thalidomide-based regimens

Multiple myeloma (MM) is a disease characterized by antitumoral immune dysfunction. The objective of the present study was to determine lymphocyte subsets (B, T, NK, NKT, iNKT, dendritic cells, and regulatory T cells) in 68 newly diagnosed patients and 113 healthy donors. Lymphocyte subsets were studied in the same patients 6 months after treatment. Pre-treatment values of CD4+ T cells, NK cells, type 2 dendritic cells, and B cells in MM patients were lower than in healthy donors. Forty patients (59%) received MPT treatment and 28 (41%) thal-dex. Patients with no response to treatment, exhibited a decrease in CD4+ T cells and NK cells, as well as an increase in Treg cell numbers. Median DFS and OS was lower in patients not achieving response, in patients having low numbers of NK cells, and higher values of LDH. The number of CD4 T cells, NK, DC2, and B cells at diagnosis is lower in patients with MM. Non-responder patients had lower CD4 and NK, but higher Treg cell values. Patients in which response is not achieved, and those holding lower values of NK cells and higher levels of LDH, have poor DFS and OS.

INSIGHT MM: a large, global, prospective, non-interventional, real-world study of patients with multiple myeloma

With the introduction of new drugs with different mechanisms of action, multiple myeloma (MM) patients' outcomes have improved. However, the efficacy seen in clinical trials is often not seen in real-world settings and data on the effectiveness of MM therapies are needed. INSIGHT MM is a prospective, global, non-interventional, observational study that is enrolling approximately 4200 patients with newly diagnosed or relapsed/refractory MM, making it the largest study of its kind to date. The study aims to describe contemporary, real-world patterns of patient characteristics, clinical disease presentation, therapies chosen, clinical outcomes (response, treatment duration, time-to-next-therapy, progression-free and overall survival), safety, healthcare resource utilization and quality of life. One interim analysis has been conducted to date; current accrual is approximately 3094 patients. Trial registration number: NCT02761187.

INSIGHT MM: a large, global, prospective, non-interventional, real-world study of patients with multiple myeloma

With the introduction of new drugs with different mechanisms of action, multiple myeloma (MM) patients’ outcomes have improved. However, the efficacy seen in clinical trials is often not seen in real-world settings and data on the effectiveness of MM therapies are needed. INSIGHT MM is a prospective, global, non-interventional, observational study that is enrolling approximately 4200 patients with newly diagnosed or relapsed/refractory MM, making it the largest study of its kind to date. The study aims to describe contemporary, real-world patterns of patient characteristics, clinical disease presentation, therapies chosen, clinical outcomes (response, treatment duration, time-to-next-therapy, progression-free and overall survival), safety, healthcare resource utilization and quality of life. One interim analysis has been conducted to date; current accrual is approximately 3094 patients.

Trial registration number: NCT02761187

Maternal obesity associated with increase in natural killer T cells and CD8+ regulatory T cells in cord blood units

BACKGROUND

One of the major limitations of umbilical cord blood (UCB) as hematopoietic stem cell source is its restricted cell number. In mothers who are candidates for stem cell donation, there are variables that affect the quantity and quality of UCB units. The aim of this study was to determine if obstetric, maternal, and fetal factors modify the number of lymphocyte subsets in UCB units.

STUDY DESIGN AND METHODS

This was a prospective, observational study. In UCB units, the numbers of CD34, NK, NKT, iNKT, Type 1 dendritic cells (DCs), Type 2 DCs, T γδ, T CD4+, T CD8+ lymphocytes, CD4+CD25+FoxP3+, and CD8+CD25+FoxP3+ T regulatory (Treg) cells were quantified by flow cytometry.

RESULTS

Fifty-four UCB units were included; the donors' mean weight was 75 kg (range, 52 to 102 kg) and they had a mean body mass index (BMI) of 30 kg/m(2) (range 22 to 40 kg/m(2) ), of which 12 (22%) had a normal BMI, 14 (26%) were overweight, and 28 (52%) were obese. The mean number of CD34+ cells was 4.45 × 10(6) (range, 0.7 × 10(6) to 20.5 × 10(6) ). The number of NKT, CD3+, CD4+, CD8+, and CD8+CD25+FoxP3+ Treg cells was significantly higher in overweight or obese mothers; CD34+ cells were decreased in the same group. The number of iNKT and CD34+ cells was decreased in newborns weighing above the average.

CONCLUSIONS

Maternal factors such as BMI, and fetal factors such as weight at birth, should be added to the selection criteria of UCB donors.

[CD200 protein, bad prognostic in patients with multiple myeloma]

BACKGROUND

Multiple myeloma (MM) is a monoclonal gammopathy characterized by abnormal proliferation of malignant plasma cells. The median overall survival rate has changed from 2-3 to 5-6 or more years with the introduction of novel agents. Recently CD200 protein has been described as an immunosuppressive protein that confers a poor prognostic factor in several neoplastic diseases, including MM. The purpose of our study was to determine CD200 protein in plasma cells of newly diagnosed patients with MM and in CD3+ lymphocytes of healthy donors.

METHODS

35 newly diagnosed MM patients and 25 healthy donors were studied. For flow cytometry tests, a FacsCalibur device and CellQuestPro software were used. Monoclonal antibodies for CD38 (PeCyC5), CD138 (APC), and CD200 (PE) were used. The statistical analysis was performed with SPSS 19v. Mann-Whitney U test, Kaplan-Meier survival curves with Log-Rank tests were done when indicated.

RESULTS

The frequencies of anemia, hypercalcemia, increased in LDH, serum creatinine and b2-microglobulin were 68%, 34%, 20%, 22% and 45% respectively. The treatment consisted in MPT 20 (57%), Thal-Dex 8 (23%), and VAD 7 (20%). Five patients (14%) achieved complete response, 17 (49%) partial response, and 13 (37%) minor response or failure to treatment.

CONCLUSION

CD200 is a poor prognostic factor for overall survival in multiple myeloma patients. Bone marrow CD3 lymphocytes from MM patients express CD200 protein in higher proportion than healthy donors.

Peri-infusional adverse reactions to rituximab in patients with non-Hodgkin's lymphoma

BACKGROUND AND AIMS

Rituximab is effective in the treatment of B-cell lymphoid malignances and some autoimmune diseases. Most patients receiving the first infusion of rituximab experience symptoms that decrease with subsequent infusions. It is assumed that the first dose of rituximab should be infused slowly during a 6-h period and during 4-h periods subsequently. The aim of the study was to evaluate the frequency and severity of adverse reactions to rituximab in patients with non-Hodgkin's lymphoma.

METHODS

This was an intensive pharmacovigilance prospective, observational, open labeled, multicenter cohort study conducted in 12 hospitals. Adults requiring treatment with rituximab (375 mg/m(2) body surface area) alone or with chemotherapy were included. Adverse reactions were graded according to the National Cancer Institute scale, whereas causality was established using the Naranjo algorithm. Infusions were classified as fast (0-90 min) and slow (>91 min). Fast infusions were used to analyze the associated adverse reactions.

RESULTS

We included 550 adult patients. Total infusion episodes were 1,749 and 52 adverse reactions were reported in 22 patients (4%). Thirty-one of 52 adverse reactions occurred during the first infusion. The risk of adverse reactions was lower with the fast infusions (10/52 adverse reactions [19.23%]). All adverse effects were mild. Twenty-three adverse effects were possibly related to rituximab.

CONCLUSIONS

Rituximab can be infused at a fast rate without an increase in adverse reactions. Peri-infusional adverse reactions are similar to those described for other populations but the incidence rate is lower. Rituximab has a favorable safety profile in patients with non-Hodgkin's lymphoma.

Silent Ischemic Heart Disease in a Patient with Necrotizing Glomerulonephritis due to Wegener's Granulomatosis

OBJECTIVE: Wegener's granulomatosis (WG) is a necrotizing vasculitis that mainly affects the respiratory tract and kidneys, but can also affect other systems such as the eye, joints, skin, muscles, nerves, and gastrointestinal tract. Cardiac involvement is traditionally believed to be rare. We report a patient with silent myocardial infarction (MI) and review previously reported cases showing this association. METHODS: A Medline database search of cases published between January 1978 and July 2008 both in English and Spanish, reporting silent MI complicating WG, was conducted. RESULTS: We describe a typical patient with WG who had both respiratory and renal involvement and died unexpectedly following a silent MI after a period of clinical improvement induced by treatment with prednisone and cyclophosphamide. We report necropsy findings and the association with 5 additional cases of WG with silent MI reported in the literature. CONCLUSIONS: Clinicians should be aware of potential cardiac involvement due to WG. Careful evaluation of each patient, with or without cardiac symptoms, using ECG, echocardiogram, and myocardial enzymes is prudent.

[Hematopoietic cells raising with plerixafor in non-Hodgkin lymphoma]

BACKGROUND

bone marrow autologous transplantation (BMAT) has proven benefits in patients treated for non-Hodgkin's lymphoma (NHL). Plerixafor is an inhibitor of CXCR4 receptor. The aim was to report the raise of hematopoietic cells with plerixafor in patients with NHL.

CLINICAL CASES

patient 1 with follicular NHL, GI, intermediate FLIPI, CD20+, CD45+, BCL-2+, who reached complete response after three chemotherapy regimes. Mobilization failed after use of filgrastim (G-CSF) alone and G-CSF + cyclophosphamide. A new attempt was made with G-CSF + plerixafor (G-CSF, 10 μg/kg for 7 days + plerixafor, 240 μg/kg in days 4 to 7). Patient 2 with follicular NHL and CD20+ reached complete remission with MINE after therapeutic failure with other regimes, but develops severe marrow toxicity. Mobilization was supported with G-CSF 10 μg/kg/d + plerixafor in days 4 and 5. In case one, proper cell counts where obtained after three aphaeresis. In the second case, two harvests add of 2.7 × 106/kg were obtained.

CONCLUSIONS

plerixafor raised the hematopoietic stem cells in peripheral blood and improves mobilization of proper cell population.

[Prevalence of bacterial infections and patterns of bacterial susceptibility among patients with fever, neutropenia, and hematological neoplasias]

Chemotherapy induces immunosuppression which is associated with a significant increase in the frequency and severity of infections. Neutropenia is the most important factor in determining susceptibility to bacterial infections. Our aim was to establish the prevalence of bacterial infections and bacterial susceptibility patterns in patients with fever, neutropenia and hematological neoplasias. Cultures were obtained prior empirical antimicrobial treatment. Susceptibility tests to antibiotics were performed for all microorganisms considered pathogens. Descriptive statistics were used for each variable. Differences between proportions were estimated by means of χ2 or Fisher's exact test. We included 85 patients.Primary bacteremia was the most frequent cause of fever (52%). Microorganisms most frequently isolated were:S. epidermidis (54.2%), E. coli (12.5%), S. aureus (8.3%). In susceptibility tests 88.5% of S. epidermidis strains were resistant to oxaciline (MIC > 8 μ/ml); E. coli was resistant to ceftazidime (50%) and trimethroprim/sulfamethoxazole (83%).In conclusion, gram-positive microorganisms are predominant in patients with fever and neutropenia followed by gram-negatives like E. coli. Predominance of gram-positives microorganism forces us to reconsider our current prophylactic and therapeutic antimicrobials regimens used in these patients.

Graft versus host disease is associated with overproduction of TNFα and not with interleukin 17 (169.14)

Allogeneic transplantation of hematopoietic cells (HCT) is a therapy used to treat a number of malignant and nonmalignant diseases, including acute and chronic leukemia, myelomas, lymphomas, aplastic anemia, solid tumors and severe immunodeficiencies. Unfortunately, a main complication of this treatment is the development of graft versus host disease (GVHD). GVHD is characterized by events caused by the reaction of immunocompetent cells from the graft against host tissues, developing an inflammatory reaction. In this work we studied 6 patients undergoing HCT, and one patient undergoing syngeneic transplantation of hematopoietic stem cells; 6 healthy donors were included as controls. In contrast to studies in mice showing that proinflammatory cytokine Th17 correlated with the occurrence and severity of GVHD, we did not observe overproduction of IL-17 in any patient that developed GVHD, in comparison to IL-17 production in controls and before transplantation. Furthermore, patients whose lymphocytes did not respond to polyclonal activators were of poor prognosis, correlating with graft loss, infections by opportunistic microorganisms and relapse. Remarkably, patients with GVHD showed exacerbated TNFα production, which correlated with the occurrence and severity of GVHD. These data show the importance of the TNFα and its contribution to the widespread damage experienced by patients who develop GVHD, and the importance of the use of specific immunosuppression of TNFα.

In vitro growth of hematopoietic progenitors and stromal bone marrow cells from patients with multiple myeloma

In the present study we have determined the content of hematopoietic and stromal progenitors in multiple myeloma (MM) bone marrow, and assessed their in vitro growth. Marrow cells were obtained from 17 MM patients at the time of diagnosis, and from 6 hematologically normal subjects. When mononuclear cells (MNC) from MM marrow were cultured, reduced numbers of hematopoietic progenitors were detected and their growth in long-term cultures was deficient, as compared to cultures of normal cells. When cell fractions enriched for CD34(+) Lin(-) cells were obtained, the levels of hematopoietic progenitors from MM marrow were within the normal range, and so was their growth kinetics in liquid suspension cultures. The levels of fibroblast progenitors in MM were not statistically different from those in normal marrow; however, their proliferation potential was significantly reduced. Conditioned media from MM-derived MNC and stroma cells contained factors that inhibited normal progenitor cell growth. Our observations suggest that hematopoietic progenitors in MM marrow are intrinsically normal; however, their growth in LTMC may be hampered by the presence of abnormal accessory and stroma cells. These results suggest that besides its role in the generation of osteolytic lesions and the expansion of the myeloma clone, the marrow microenvironment in MM may have a negative effect on hematopoiesis.

[Long-term response to rituximab in a patient with acquired hemophilia]

A 28 year-old female without history of previous disease. In the seventh month of her first pregnancy she developed hemorrhagic tendency that worsened in the early postpartum period. Activated partial thromboplastin time was 110 sec (control=35.8 sec) with negative tests for lupus anticoagulant. Factor VIII was <1% and a factor VIII inhibitor titer was 84 Bethesda Units/mL (BU). Initial therapy included methylprednisolone, prednisone, and cyclophosphamide. After two weeks of treatment, clinical conditions of the patient improved slightly and she was discharged. Outpatient therapy included azathioprine, and prednisone for a period of 22 months but in-hospital management was several times required. We initiated rituximab 375 mg/m2/week/4 weeks. A clinical improvement and increased levels of factors VIII and XI were observed 10 weeks later and factor VIII inhibitor decreased to undetectable levels. After a 82-month follow-up period (since the first rituximab infusion), she is asymptomatic and factor VIII and factor XI plasma levels are 70% and 94%, respectively FVIII inhibitor level is still undetectable. Rituximab seems an alternative for the treatment of acquired hemophilia refractory to standard treatment.

Role of CD4+CD25+highFoxp3+CD62L+ regulatory T cells and invariant NKT cells in human allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for some hematological diseases; however, graft-versus-host disease (GVHD) is still one of the most important and deleterious complications. Regulatory T cells and iNKT cells can decrease the incidence and severity of GVHD, while preserving the graft-versus-tumor response. In order to analyze the relationship between the transfused dose of these cells, the presence of GVHD and survival, 15 normal donors and 15 patients with hematological diseases who underwent allogeneic HSCT from HLA-identical siblings were studied. The mobilization and infused doses of valpha24-vbeta11(iNKT cells) lymphocytes and CD4+CD25+FoxP3+, CD4+CD25+FoxP3+CD62L+, regulatory T cells were analyzed. All patients were conditioned with busulfan and cyclophosphamide and received cyclosporine and methotrexate as GVHD prophylaxis. iNKT and FoxP3 cells were mobilized after G-CSF administration. Acute GVHD was present in 9 of 15 (60%) and cGVHD in 7 of 13 (54%) patients. Patients who received a dose <0.6 x 10(6)/kg of iNKT cells and >4 x 10(6)/kg of FoxP3 had better disease-free survival and overall survival. Individuals transfused with >1.1 x 10(6)/kg of FoxP3+ CD62L+ Treg cells had better overall survival. In conclusion, iNKT and Treg cells are mobilized with G-CSF in healthy donors and the dose of iNKT cells and FoxP3 and CD62L+ regulatory T cells is of clinical importance in human HSCT.

Potent, transient inhibition of BCR-ABL with dasatinib 100 mg daily achieves rapid and durable cytogenetic responses and high transformation-free survival rates in chronic phase chronic myeloid leukemia patients with resistance, suboptimal response or intolerance to imatinib

BACKGROUND

Dasatinib 100 mg once daily achieves intermittent BCR-ABL kinase inhibition and is approved for chronic-phase chronic myeloid leukemia patients resistant or intolerant to imatinib. To better assess durability of response to and tolerability of dasatinib, data from a 2-year minimum follow-up for a dose-optimization study in chronic-phase chronic myeloid leukemia are reported here.

DESIGN AND METHODS

In a phase 3 study, 670 chronic-phase chronic myeloid leukemia patients with resistance, intolerance, or suboptimal response to imatinib were randomized to dasatinib 100 mg once-daily, 50 mg twice-daily, 140 mg once-daily, or 70 mg twice-daily.

RESULTS

Data from a 2-year minimum follow-up demonstrate that dasatinib 100 mg once daily achieves major cytogenetic response and complete cytogenetic response rates comparable to those in the other treatment arms, and reduces the frequency of key side effects. Comparable 2-year progression-free survival and overall survival rates were observed (80% and 91%, respectively, for 100 mg once daily, and 75%-76% and 88%-94%, respectively, in other arms). Complete cytogenetic responses were achieved rapidly, typically by 6 months. In patients treated with dasatinib 100 mg once daily for 6 months without complete cytogenetic response, the likelihood of achieving such a response by 2 years was 50% for patients who had achieved a partial cytogenetic response, and only 8% or less for patients with minor, minimal, or no cytogenetic response. Less than 3% of patients suffered disease transformation to accelerated or blast phase.

CONCLUSIONS

Intermittent kinase inhibition can achieve rapid and durable responses, indistinguishable from those achieved with more continuous inhibition.

The C677T polymorphism of the methylenetetrahydrofolate reductase gene is associated with idiopathic ischemic stroke in the young Mexican-Mestizo population

BACKGROUND AND PURPOSE

Previous studies have demonstrated that a common polymorphism in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) is associated with an increased risk for stroke. However, this relation remains controversial. Our aim was to investigate the possible association between the C677T polymorphism in the MTHFR gene and idiopathic ischemic stroke in the young Mexican-Mestizo population.

METHODS

One hundred seventy-eight patients <45 years with idiopathic ischemic stroke and 183 controls were tested for the C677T polymorphism in the MTHFR gene. Causes of primary thrombophilia as well as classical risk factors for atherothrombotic disease were also evaluated.

RESULTS

There was a significant difference in the genotype distribution between patients and controls (p = 0.01), but the allele frequency was similar in both groups (p = 0.09). The univariate analysis identified the T allele as a risk factor for ischemic stroke (TT and CT carriers), as compared with homozygous for C allele (p = 0.01). Hypertension and smoking prevalences were significantly higher in the group of patients. Also the T allele was significantly associated with large-vessel ischemic stroke. The postoral methionine load homocysteine levels were higher in patients with ischemic stroke versus controls (p < 0.001). There was a low prevalence of primary thrombophilia markers.

CONCLUSIONS

The T allele from the C677T polymorphism of the MTHFR gene represents an independent risk factor for idiopathic ischemic stroke at young age in the Mexican-Mestizo population. Also, hypertension and smoking were independent risk factors in our study population. Primary thrombophilic risk factors were not associated with ischemic stroke in our population.

Allogeneic Hematopoietic Stem Cell Transplantation with Non-Myeloablative Conditioning in Patients with Acute Myelogenous Leukemia Eligible for Conventional Allografting: A Prospective Study

Using a non-myeloablative stem cell trasplantation (NST) program, 25 allografts were prospectively given to 24 patients with acute myelogenous leukemia (AML) eligible for conventional allografting; 2 individuals had secondary forms of AML. The median age of the patients was 35 years, with a range of 12 to 56. All patients engrafted; median time to achieve an absolute neutrophil count > 0.5 x 10(9)/1 was 12 days (range 0-26), whereas the median time to a platelet count > 20 x 10(9)/1 was 13 days (range 0-26). Patients developed mixed chimerism 15 to 100 (median 30) days after the allograft. The follow-up periods range between 33 and 2670 days (median 450). The median post-transplant overall survival of the patients has not been reached and is above 89 months, whereas the 683 days both overall and progression-free survival is 66%. In 14 grafts (56%) acute GVHD ensued; in 12 cases grades I-II and in 2 cases grade IV which was fatal in both. In 9/19 patients (47%) limited chronic GVHD developed. In 22 cases (88%), the procedure could be completed fully on an outpatient basis. The 100-day and the transplant-related mortality were both 8%. NST appears to be an effective additional therapeutic option for patients with AML in remission and a matched donor available.

Intermittent target inhibition with dasatinib 100 mg once daily preserves efficacy and improves tolerability in imatinib-resistant and -intolerant chronic-phase chronic myeloid leukemia

PURPOSE

Dasatinib is a BCR-ABL inhibitor, 325-fold more potent than imatinib against unmutated BCR-ABL in vitro. Phase II studies have demonstrated efficacy and safety with dasatinib 70 mg twice daily in chronic-phase (CP) chronic myelogenous leukemia (CML) after imatinib treatment failure. In phase I, responses occurred with once-daily administration despite only intermittent BCR-ABL inhibition. Once-daily treatment resulted in less toxicity, suggesting that toxicity results from continuous inhibition of unintended targets. Here, a dose- and schedule-optimization study is reported.

PATIENTS AND METHODS

In this open-label phase III trial, 670 patients with imatinib-resistant or -intolerant CP-CML were randomly assigned 1:1:1:1 between four dasatinib treatment groups: 100 mg once daily, 50 mg twice daily, 140 mg once daily, or 70 mg twice daily.

RESULTS

With minimum follow-up of 6 months (median treatment duration, 8 months; range, < 1 to 15 months), marked and comparable hematologic (complete, 86% to 92%) and cytogenetic (major, 54% to 59%; complete, 41% to 45%) response rates were observed across the four groups. Time to and duration of cytogenetic response were similar, as was progression-free survival (8% to 11% of patients experienced disease progression or died). Compared with the approved 70-mg twice-daily regimen, dasatinib 100 mg once daily resulted in significantly lower rates of pleural effusion (all grades, 7% v 16%; P = .024) and grade 3 to 4 thrombocytopenia (22% v 37%; P = .004), and fewer patients required dose interruption (51% v 68%), reduction (30% v 55%), or discontinuation (16% v 23%).

CONCLUSION

Dasatinib 100 mg once daily retains the efficacy of 70 mg twice daily with less toxicity. Intermittent target inhibition with tyrosine kinase inhibitors may preserve efficacy and reduce adverse events.

[Factor VIII activity among young Mexican patients with acute myocardial infarction]

BACKGROUND

Atherothrombotic disease is the leading cause of death worldwide. Most casualties are due to acute myocardial infarction (AMI). Patients younger than 45 years account for 5-10% of AMI cases. These patients generally do not display typical atherothrombotic risk factors.

METHODS

Our cross-sectional study included adult patients under 45; men and women with AMI were included. A control group of healthy individuals matched for age, sex, and blood group was included to determine the role of several atherothrombotic risk factors on AMI. One hundred and sixty patients were included, the control group was comprised by 77 males (m) and 83 females (f)

RESULTS

Our results indicate that 25% of patients (23 m and 18 f) had increased FVIII compared with 8.8% of control subjects. Mean FVIII activity for patients and controls was 134 mg/dl (95%CI=114) vs. 118 mg/dl (95%CI=128-140), respectively (p=0.001). Prevalence of elevated FVIII was higher than the one found for hypertension or diabetes mellitus. HDL cholesterol was higher among patients than controls. Quantitative variables associated with AMI were high FVIII activity, blood monocyte count and HDL cholesterol.

CONCLUSIONS

Classical atherothrombotic risk factors do not fully explain AMI events in the young. High levels of FVIII activity is a moderate but common risk factor in young people suffering AMI.

Activated Protein C Resistance and Factor V Leiden in Mexico

A common cause of hereditary thrombophilia is activated protein C resistance (APCR), and most cases result from factor V Leiden mutation. An APCR phenotype without association with factor V Leiden has been described. This transversal, observational, nonrandomized study evaluated these 2 phenomena in healthy indigenous and mestizo Mexican subjects (n = 4345), including 600 Mexican natives. No indigenous subjects had APCR, but 82 mestizo subjects did. After retesting, 50 subjects had a negative test. The remaining 32 subjects had factor V Leiden, giving a 0.85% prevalence of factor V Leiden in the mestizo Mexican population. Only 31% of APCR carriers had factor V Leiden. These results show a very low prevalence of APCR and factor V Leiden in Mexico. Except for factor V Leiden, there are no other mutations in the factor V gene responsible for the APCR phenotype. Acquired APCR is nearly twice as prevalent as the inherited variant.

Rituximab therapy for chronic and refractory immune thrombocytopenic purpura: a long-term follow-up analysis

The aim of this study was to evaluate the long-term response to rituximab in patients with chronic and refractory immune thrombocytopenic purpura (ITP). Adults with ITP fail to respond to conventional therapies in almost 30% of cases, developing a refractory disease. Rituximab has been successfully used in these patients. We used rituximab at 375 mg/m², IV, weekly for a total of four doses in 18 adult patients. Complete remission (CR) was considered if the platelet count was >100 × 10⁹/l, partial remission (PR) if platelets were >50 × 10⁹/l, minimal response (MR) if the platelet count was >30 × 10⁹/l and <50 × 10⁹/l, and no response if platelet count remained unchanged. Response was classified as sustained (SR) when it was stable for a minimum of 6 months. Median age was 43.5 years (range, 17 to 70). Median platelet count at baseline was 12.5 × 10⁹/l (range, 3.0 to 26.3). CR was achieved in five patients (28%), PR in five (28%), MR in four (22%), and two patients were classified as therapeutic failures (11%). Two additional patients were lost to follow-up. The median time between rituximab therapy and response was 14 weeks (range, 4 to 32). SR was achieved in 12 patients (67%). There were no severe adverse events during rituximab therapy. During follow-up (median, 26 months; range, 12 to 59), no other immunosuppressive drugs were used. In conclusion, rituximab therapy is effective and safe in adult patients with chronic and refractory ITP. Overall response rate achieved is high, long term, and with no risk of adverse events.

Autologous peripheral blood stem cell transplantation in multiple myeloma using oral versus I.V. melphalan

Autologous peripheral blood stem cell transplantation is the therapy of choice for the treatment of multiple myeloma (MM) patients younger than 70 years old. Between August 1993 and November 2004, 54 patients with MM were autografted after conditioning with high-dose oral melphalan 140 mg/m(2) in combination with etoposide and carmustine (28 patients) or with high-dose melphalan 200 mg/m(2) I.V. (26 patients). The oral and IV melphalan groups were comparable. There were no significant differences in disease-free survival (DFS) and overall survival (OS) between the groups; however, in patients transplanted in remission, OS and DFS were better in the I.V. melphalan group. Four good-prognostic factors were identified: interval between diagnosis and transplant <18 months, number of prior chemotherapy lines < or =2, remission status (complete or partial), and the use of I.V. melphalan. In conclusion, I.V. melphalan is the therapy of choice for conditioning patients with MM who are in remission.

In vitro functional alterations in the hematopoietic system of adult patients with acute lymphoblastic leukemia

In previous studies, we have demonstrated that progenitor cell-enriched marrow cell populations from patients with myeloid leukemia - including both acute (AML) and chronic (CML) - show severe functional alterations when cultured in stroma-free liquid cultures supplemented with stimulatory cytokines. In trying to expand our characterization of the biology of leukemic cells, in the present study we have used a similar approach and analyzed the in vitro growth of equivalent cell populations from patients with acute lymphoblastic leukemia (ALL). ALL marrow cell populations -enriched for hematopoietic progenitors by means of a negative selection procedure- were assessed for their proliferation and expansion potentials, in liquid cultures supplemented with a mixture of early- and late-acting recombinant stimulatory cytokines, throughout a 25-day culture period. ALL cells, although capable of responding to the stimulatory signals provided by hematopoietic stimulators, showed deficient proliferation potentials (reduced capacity to generate more nucleated cells), as compared with their normal counterparts. The capacity to generate myeloid and erythroid progenitors was also significantly reduced in ALL cultures. Interestingly, the functional alterations observed in ALL cultures (i.e., deficient proliferation and expansion potentials) were more pronounced in those from Ph+ patients than in those from Ph- patients. This study indicates that bone marrow cell populations - enriched for hematopoietic progenitor cells - from ALL patients possess deficient proliferation and expansion potentials in vitro, and that such functional alterations are more severe when cells are derived from Ph+ patients, as compared to their Ph- counterparts.

[Ultrastructural study of platelets patients with paroxysmal nocturnal hemoglobinuria]

INTRODUCTION

Paroxysmal nocturnal hemoglobinuria (PNH) is a hemolytic anemia characterized by intravascular hemolysis, cytopenias and venous thrombosis. Previous studies in patients with PNH have shown platelet abnormalities; however, their association with the clinical development of the sickness has not still been determined.

MATERIAL AND METHODS

In this study, we compared the morphology and distribution pattern of actin, myosin, tubulin and p-selectin in resting and activated platelets from 22 PNH patients and healthy donors by transmission electron microscopy and immunofluorescence.

RESULTS

The PNH platelet ultrastructure of resting and activated with different agonists (ADP, collagen and thrombin) showed morphological changes which suggested the presence of circulating platelets. The developed structures during the adhesion process (filopodia and lamellipodia formation), as well as the pattern distribution of actin, myosin, tubulin and p-selectin in PNH platelets were not modified in relation to control platelets.

CONCLUSION

Morphological changes in resting platelets were related with p-selectin expression suggesting its determination as thrombosis indicator.

The early referral for reduced-intensity stem cell transplantation in patients with Ph1 (+) chronic myelogenous leukemia in chronic phase in the imatinib era: results of the Latin American Cooperative Oncohematology Group (LACOHG) prospective, multicenter study

Using a reduced-intensity stem cell transplantation (RIST) schedule, 24 patients with Philadelphia (Ph1) (+) chronic myelogenous leukemia (CML) in first chronic phase (CP) were prospectively allografted in four Latin American countries: México, Brazil, Colombia and Venezuela, using HLA-identical siblings as donors. The median age of the patients was 41 years (range 10-71 years); there were eight females. Patients received a median of 4.4 x 10(6)/kg CD34 cells. The median time to achieve above 0.5 x 10(9)/l granulocytes was 12 days, range 0-41 days, and the median time to achieve above 20 x 10(9)/l platelets was also 12 days, range 0-45 days. In all, 22 patients are alive 81-830 (median 497) days after RIST. The 830-day probability of survival is 92%, and the median survival has not been reached, being beyond 830 days. A total of 11 patients (46%) developed acute graft-versus-host disease (GVHD), and seven of 23 (30%) developed chronic GVHD. Two patients died 43 and 210 days after RIST, one as a result of sepsis and the other of chronic GVHD. The 100-day mortality was 4.4%, and transplant-related mortality was 8%. RIST for patients with CML in CP appears to be an adequate therapeutic option.

Peripheral blood mobilization of different lymphocyte and dendritic cell subsets with the use of intermediate doses of G-CSF in patients with non-Hodgkin's lymphoma and multiple myeloma

Between June 2003 and November 2004, we collected mobilized peripheral blood units from 29 patients with non-Hodgkin's lymphoma and multiple myeloma for autologous peripheral blood stem cell transplantation. They received granulocyte colony-stimulating factor (G-CSF) (16 micro g/kg/day) for a total of 5 days. Immediately before and 3 h after the fourth and fifth dose of G-CSF, we performed flow cytometry analysis to quantify: T cells (CD3+CD4+, CD3+CD8+), B cells (CD19+), NK cells (CD3-CD16+CD56+), NKT cells (CD3+CD16+CD56+), type 1 dendritic cells (DC1) (lin-HLA-DR+CD11c+), type 2 dendritic cells (DC2) (lin-HLA-DR+CD123+), regulatory T cells (Tregs) (CD4+CD25+), and activated T cells (CD3+HLA-DR+). All cell subsets were mobilized after G-CSF treatment with the exception of B, NK, and NKT lymphocytes. The median number of Treg cells before and after G-CSF was statistically different (29+/-14.9x10(6)/l vs 70.1+/-46.1x10(6)/l, P<0.02). DCs were mobilized significantly with a 5.9-fold increase in DC2 (15.1+/-30.3x10(6)/l vs 89.8+/-81.0x10(6)/l, P<0.02) and a 2.6-fold increase for DC1 (41+/-42.5x10(6)/l vs 109.5+/-58.0x10(6)/l, P<0.04). Patients received a mean of 3.1+/-1.2x10(7)/kg NK cells, 1.3+/-0.9x10(7)/kg NKT cells, 0.41+/-0.29x10(7)/kg DC1, 0.2+/-0.22x10(7)/kg DC2, and 1.8+/-1.9x10(7)/kg Tregs. In conclusion, intermediate doses of G-CSF induce mobilization of different lymphocyte subsets, with the exception of B, NK, and NKT cells. The mobilization of certain suppressive populations (DC2 and Treg) could be in theory deleterious, at least in patients with cancer.

Functional integrity in vitro of hematopoietic progenitor cells from patients with chronic myeloid leukemia that have achieved hematological remission after different therapeutic procedures

In this study, we have assessed the in vitro growth of hematopoietic progenitor cells (HPC) from chronic myeloid leukemia (CML) patients that have recovered after different treatments. Bone marrow cells were obtained from 33 CML patients, including patients at diagnosis, before treatment (n=12), and patients that have achieved hematological remission (and in most cases a major cytogenetic response) after different therapeutic procedures (n=21), including patients treated with Interferon-alpha (IFN; n=5), imatinib mesylate (IMATINIB; n=8) and patients that received an allogeneic hematopoietic cell transplant (HCT; n=8). Marrow cells were enriched for CD34(+) cells and cultured in a serum- and stroma-free liquid culture system, supplemented with a combination of 8 recombinant cytokines. Normal samples were studied as controls. HPC from CML patients before therapy showed deficient proliferation and expansion potentials in culture (140-fold increase in nucleated cell number and 1.3-fold increase in colony-forming cell number) as compared to normal progenitors (1200-fold increase in nucleated cell number and 25-fold increase in colony-forming cell number). In contrast, HPC from patients treated with IMATINIB showed growth potentials similar to those of normal progenitors. Progenitors from patients after HCT also showed significant proliferation and expansion capacities. Interestingly, progenitors from IFN-treated patients showed proliferation and expansion kinetics similar to those of cells from untreated patients. These results indicate that, although treatment of CML patients with IFN, IMATINIB or HCT resulted in complete hematological remission (and a major cytogenetic response), only patients treated with IMATINIB and, to a lesser extent, with HCT showed a full hematopoietic recovery, as determined by the in vitro growth of HPC in our culture system.

Allografting in patients with severe, refractory aplastic anemia using peripheral blood stem cells and a fludarabine-based conditioning regimen: the Mexican experience

We studied the effectiveness of a fludarabine/cyclophosphamide-based conditioning regimen without anti-thymocyte globulin in 23 aplastic anemia patients who had no response to previous conventional pharmacologic treatment. Patients received oral busulphan 4 mg/kg/day/2 days, IV cyclophosphamide 350 mg/m(2)/day/3 days, and fludarabine 30 mg/m(2)/day/3 days. For GVHD prophylaxis, patients received MTX 5 mg/m(2) days +1, +3, +6, and +11 and oral cyclosporin A (CyA) 5 mg/kg/day, starting on day -1. Peripheral blood stem cell products were used with a median dose of 5.5 x 10(6) CD34(+)/kg. The patients were followed for an average of 25 months. By a median of day +11, an ANC > 0.5 x 10(9)/L was reached; and by day +12, the platelet count had reached >20,000 x 10(9)/L. Acute grade I-II GVHD occurred in 4 patients, whereas limited chronic GVHD presented in 6 cases. Twenty-one patients (91.3%) achieved engraftment. Two patients failed to engraft, and 4 developed late rejection; 2 of these individuals died, 2 have survived with high transfusion requirements, whereas 2 received a second peripheral blood stem cell infusion and achieved sustained engraftment. Currently 21 (91%) of the 23 patients are alive, whereas 19 of 21 (90%) remain in complete remission. The average cost was about USD 15,000 for this kind of reduced-intensity allotransplant. Reduced-intensity stem cell transplantation represents an affordable alternative to traditional more cytotoxic conditioning for severe aplastic anemia (SAA) patients. Long-term effects however, remain to be evaluated.

Clinical relevance of NK, NKT, and dendritic cell dose in patients receiving G-CSF-mobilized peripheral blood allogeneic stem cell transplantation

To analyze the relationship between the cellular composition of peripheral blood allografts and clinical outcome, we performed a prospective study in 45 adult patients who underwent allogeneic peripheral blood hematopoietic stem cell transplantation (HSCT) from a histocompatibility leukocyte antigen identical sibling donor for different hematological malignancies. The dose of CD34+, CD3+, CD4+, CD8+, and CD19+ lymphocytes, natural killer (NK) cells, natural killer T (NKT) cells, type 1 and type 2 dendritic cells (DC1 and DC2), as well as regulatory T (Treg) lymphocytes was analyzed. All patients were conditioned with busulphan and cyclophosphamide (BuCy2) +/- VP-16 and received a short course of methotrexate and cyclosporin-A as graft-versus-host disease (GVHD) prophylaxis. Acute GVHD (aGVHD) was present in 9 of 43 (21%) patients, and chronic GVHD (cGVHD) developed in 18 of 39 (46%) patients. There was a significantly higher incidence of aGVHD in patients receiving more than 6x10(6)/kg CD34+ cells. In univariate analysis, variables associated with better survival were as follows: a dose of less than 1.5x10(7)/kg NKT cells and less than 1.7x10(6)/kg DC2 for disease-free survival (DFS), and a dose of less than 3x10(7)/kg NK cells, less than 1.5x10(7)/kg NKT cells, less than 3x10(6)/kg DC1, and less than 1.7x10(6)/kg DC2 for overall survival (OS). In the Cox regression analysis, the dose of NKT cells was the only variable associated with better DFS, while the doses of NK, NKT, and CD34+ cells (less than 8x10(6)/kg) were associated with better OS. In conclusion, different circulating cell populations, other than CD34+ cells, are also of relevance in predicting the clinical outcome after allogeneic peripheral blood HSCT.