Mariela Granero Farias

Assessment of immature platelet fraction and immature reticulocyte fraction as predictors of engraftment after hematopoietic stem cell transplantation

Engraftment is a critical milestone of the hematopoietic stem cell transplantation (HSCT) process. The immature platelet fraction (IPF) and immature reticulocyte fraction (IRF) are considered early indicators of bone marrow recovery. The objective of this study was to assess these parameters as predictors of HSCT engraftment.

Flow Cytometry in Detection of Fetal Red Blood Cells and Maternal F Cells to Identify Fetomaternal Hemorrhage

ABSTRACT Accurate detection and quantitation of fetomaternal hemorrhage (FMH) is critical to the obstetric management of rhesus D alloimmunization in Rh-negative pregnant women. The flow cytometry is based on the detection of fetal red blood cells using a monoclonal anti-HbF antibody, and is the method most indicated for this estimation. The objective of this study was to quantify fetal red blood cell levels of pregnant women using flow cytometry. We analyzed 101 peripheral blood samples from Rh-negative and Rh-positive women, whose mean age was 24 years (20–32 years), after vaginal delivery or cesarean section. Our study showed that 53% of pregnant women had fetal red blood cells levels <2.0 mL, 31% between 2.0–3.9 mL, 16% between 4.0–15.0 mL, and 1% >15.0 mL. Accurate quantitation of fetal red blood cells is necessary to determine the appropriate dose of anti-D (RHD) immunoglobulin to be administered to pregnant or postpartum women.

Determination of reference ranges for immature platelet and reticulocyte fractions and reticulocyte hemoglobin equivalent

Introduction The immature platelet and immature reticulocyte fractions represent the ratios of platelets and reticulocytes recently released into the circulation and thus with higher RNA content. They are considered early indicators of bone marrow recovery. Objective The aim of this study was to determine the reference ranges for the immature platelet and reticulocyte fractions of hematologically normal individuals in a university hospital. Methods Venous blood samples collected in ethylenediaminetetraacetic acid K3 were analyzed using a Sysmex XE-5000™ analyzer. Individuals with platelet and reticulocyte counts within the reference ranges, and a blood count within the laboratorys screening criteria were included. Individuals with clinical conditions that could affect hematological results were excluded. The immature platelet fraction, high, medium and low fluorescence reticulocyte fractions and reticulocyte hemoglobin equivalent were evaluated. The reference ranges were determined according to the recommendations of the International Federation of Clinical Chemistry. Results One hundred and thirty-two outpatients were evaluated. The mean age was 44 years (range: 13–80 years), 72 (54.5%) were women treated in a university hospital. The mean platelet count was 250.8 × 109/L and the mean reticulocyte count was 0.052 × 109/L. The following reference ranges were obtained: immature reticulocyte fraction 1.6–12.1%, the high, medium and low fluorescence reticulocyte fractions were 0.0–1.7%, 1.6–11.0% and 87.9–98.4%, respectively, the reticulocyte hemoglobin equivalent was 30.0–37.6% and immature platelet fraction was 0.8–5.6%. There was a statistically significant difference (p-value = 0.006) between genders in respect to the immature platelet fraction with 0.8–4.7% for females and 0.7–6.1% for males. The immature reticulocyte fraction was directly correlated with the reticulocyte count. Conclusion Determining the reference range is critical to the introduction of a new parameter. The reference ranges obtained herein corroborate those reported in previous publications and will contribute to the clinical and laboratory application of the indices.

Análise morfológica, imunofenotípica e molecular na identificação da leucemia megacariocítica aguda (LMA-M7)

Abstract Acute megakaryocytic leukemia (AML-M7) is a rare subtype ofacute myeloid leukemia (AML), which has recently beenincorporated in the FAB (French-American-British) classification.It represents from 3 to 5% of AML cases, is frequently associatedto myelofibrosis and is a subtype with poor prognosis. Thediagnosis of AML-M7 is initially based on the morphologiccharacteristics of leukemic cells. Bone marrow aspirates or biopsyshows a population of pleomorphic and basophilic cells whichmay present cytoplasmatic blebs. Morphologic and cytochemicalcriteria are not enough for a correct diagnosis. It is necessary todifferentiate acute megakaryocytic leukemia with other subtypesof acute myeloid leukemia mainly in cases in which blast cells areundifferentiated, as are the cases of AML-M0, AML-M1 and ofacute lymphoid leukemia, subtypes L1 and L2. The use ofimmunopherotypic techniques is essential for a differentialdiagnosis showing a population of leukemia cells with the absenceof most surface lymphoid and myeloid markers, yet relevant forthe antigen of the megakaryocytic expression: CD41a (complexglycoproteic IIb/IIIa), CD42b (glycoprotein Ib) and/or CD61(glycoprotein IIIa), there by providing the for correct classificationin 98% of the cases. Chromosomal abnormalities identified bycytogenetic techniques and molecular analysis are important fordetermining the prognosis and definition of the therapheutic regi-me Rev. bras. hematol. hemoter. 2007;

Could CD64 expression be used as a predictor of positive culture results in children with febrile neutropenia

Background Early recognition of infectious processes in neutropenic patients is hampered by the fact that these processes may have dissimilar and non-specific clinical presentations. CD64 is a neutrophil surface marker that is not expressed in non-sensitized neutrophils. When the neutrophil is exposed to tumor necrosis factor-alpha it is activated and is measured via the CD64 index. Methods This paper evaluated the relationship between the index value of CD64 on the first day of febrile neutropenia and a positive blood culture. The correlations with white blood count, C-reactive protein and erythrocyte sedimentation rate were also evaluated. This case–control, prospective, diagnostic study included 64 episodes of neutropenia. Case group (n = 14) comprised positive blood cultures, and the control group (n = 50), negative blood cultures. Results The median rates of CD64 were 2.1 (σ ± 3.9) in the case group and 1.76 (σ ± 5.02) in the control group. There was no correlation between the value of the CD64 index and blood cultures. The CD64 index was also not correlated with C-reactive protein positivity. Furthermore, the CD64 index was not able to predict blood culture positivity. The sensitivity was 64.3%, the specificity was 42%, the positive predictive value was 23.7% and the negative predictive value was 80%. For C-reactive protein, the sensitivity, specificity, positive predictive value, and negative predictive value were 71.4%, 32%, 22.7%, and 80%, respectively. Conclusion The CD64 index is not suitable for predicting the positivity of blood cultures in this specific population of patients with febrile neutropenia.

Leucemia mielomonocítica juvenil: relato de caso

A leucemia mielomonocitica juvenil (LMMJ) e uma doenca rara, que representa de 2%a 3% de todas as leucemias pediatricas. E uma doenca clonal de celulas da linhagem mieloide, que apresenta caracteristicas de mieloproliferacao e de displasia. Os sinais e os sintomas sao resultantes da infiltracao de celulas monociticas malignas em orgaos nao hematopoeticos. Os sintomas mais comuns sao febre, tosse, infeccao, fraqueza, palidez, linfadenopatia, hepatoesplenomegalia, lesoes cutâneas e manifestacoes hemorragicas. Como a LMMJ exibe um curso clinico muito agressivo e responde pobremente a quimioterapia, o transplante de celulas-tronco hematopoeticas e a unica modalidade terapeutica curativa. Neste estudo, relatamos o caso de um paciente do sexo masculino, com um ano e dez meses de idade, que compareceu na emergencia do Hospital de Clinicas de Porto Alegre por apresentar febre, com diagnostico previo de mononucleose feito em outra Instituicao. A apresentacao clinica, em conjunto com os achados laboratoriais, permitiu o diagnostico correto. O paciente foi tratado com quimioterapia e submetido a transplante de celulas-tronco hematopoeticas.

Flow cytometry to identify bone-marrow relapse in blastic plasmacytoid dendritic cell neoplasm: a case report

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare acute leukemia subtype characterized by clonal expansion of dendritic-lineage cells.1 These cells are identified immunophenotypically by weak CD45 expression and coexpression of the CD4 and CD56 antigens in the absence of other lineage-specific markers.2,3 Previously known as blastic natural killer (NK)-cell lymphoma or CD4+/CD56+ hematodermic neoplasm, it is currently classified by the World Health Organization (WHO) as a distinct entity, under the acute myeloid leukemia (AML) and related precursor neoplasm group.4 Few studies have assessed the incidence of BPDCN in the general population. The limited existing data suggest an extremely low overall incidence, representing 0.44% of all hematological malignancies3,5 and 0.7% of cutaneous

Quantification of peripheral blood CD34+ cells prior to stem cell harvesting by leukapheresis: a single center experience

Background Due to laboratory logistic issues, our center has traditionally scheduled peripheral blood stem cell harvests based on timing from the start of mobilization. This has proved to be useful in some cases, but also resulted in many fruitless harvests due to poor mobilization. In order to improve the efficiency of collections and compare the effectiveness of peripheral blood CD34+ cells as a predictor with data from other reports, this study analyzed the implementation of this routine. Methods Peripheral blood and leukapheresis samples were quantified by flow cytometry and the association between these parameters was assessed. Results Sixty-six consecutive leukapheresis samples were collected from 34 patients after the collection of peripheral blood samples for CD34+ quantification. A moderate positive correlation was observed between peripheral blood CD34+ cell count and total CD34+ cell count/kg (r = 0.596; p-value < 0.001). A multivariable regression model also confirmed this association and allowed the estimation that for every increase in five CD34+ cells/μL in the peripheral blood, a mean increase of 0.38 × 106 CD34+ cells/kg could be predicted. Demographic characteristics, baseline comorbidities and mobilization regimen did not influence final CD34+ cell count in this sample. Conclusions As observed in other centers, quantification of peripheral blood CD34+ progenitor cells is a strong predictor of effectiveness to guide stem cell harvesting. Due to the results of this study, a modification in the peripheral blood stem cell harvesting logistics was implemented at our center in order to incorporate this routine.

Analysis of predictive factors of complete blood count for a high-yield hematopoietic stem cell apheresis collection -

Introduction: In medical practice, quantification of peripheral blood CD34+ cells is a method of choice to calculate apheresis yield. Nevertheless, other predictive factors have been evaluated. The objective of this study was to investigate the association between CD34+ cells and number of apheresis collections from patients undergoing autologous bone marrow transplantation based on complete blood count parameters. Methods: Retrospective analysis of 113 patients of the Department of Pediatric Oncology of Hospital de Clinicas de Porto Alegre (HCPA) who had autologous bone marrow transplantation between 2004 and 2011 and underwent mobilization with granulocyte-colony stimulating factor in combination or not with chemotherapy. The following parameters were assessed: Total leukocyte count, platelets, hemoglobin, absolute neutrophil count, lymphocytes, monocytes, and immature granulocytes (IG). Statistical tests were used for asymmetric variables. Results: The correlation between CD34+ × 106/kg and leukocyte count (rs = 0.082; P = 0.394), platelets (rs = 0.078; P = 0.418), hemoglobin level (rs = −0.05; P = 0.564), neutrophils (rs = 0.042; P = 0.665), lymphocytes (rs = 0.048; P = 0.619), and IG (rs = 0.165; P = 0.083) revealed no significant result. In relation to monocytes, there was a weak but significant correlation (rs = 0.255; P = 0.007). In addition, patients with leukocyte count higher than 30 × 109/L and monocyte count higher than 1.8 × 109/L had good collection yield. Conclusion: Although there was no significant association between CD34 × 106/kg and blood parameters, we found that leukocyte count higher than 30 × 109/L and monocyte count higher than 1.8 × 109/L may be predictive factors of efficient collection. However, these values cannot be considered absolute factors because patients with lower counts also had satisfactory collections.

Infiltração cutânea na leucemia megacariocítica aguda com expressão de CD56

Abstract AML-M7 is a rare subtype of acute myeloid leukemia (AML). It isfrequently associated with myelofibrosis and corresponds to a poorprognosis subtype. It rarely presents with infiltration atextramedullary sites. The bone marrow aspirate or biopsy identifiespleomorphic and basophilic cell populations that may present withcytoplasmatic projections. The use of immunophenotyping is essentialfor the diagnosis of AML-M7. The characteristic immunophenotypepresents a leukemic cell population without most lymphoid andmyeloid surface markers, but with an expression of themegakaryocytic antigens: CD41a (glycoprotein complex IIb/IIIa),CD42b (glycoprotein Ib) and/or CD61 (glycoprotein IIIa), or thefactor VIII-related antigen. The cytochemical stain Sudan Black isfrequently negative for megakaryocytic blasts; in this case, it waspositive in 40% of the analyzed cells. The presence of CD56, whoseaberrant expression in some myeloid leukemias indicates poorprognosis, might be associated with skin infiltration. Rev. bras.hematol. hemoter. 2007;