Suzane Dal Bó

The expression of CD56 antigen is associated with poor prognosis in patients with acute myeloid leukemia

Background The expression of CD56 is considered a bad prognostic factor for overall survival, lower rates or short complete remission and extramedullary invasion but the results are controversial. The importance of validating new prognostic parameters in acute leukemias was the reason to investigate the CD56 expression in blast cells of patients with acute myeloid leukemia. Methods A cohort of 48 patients treated at Hospital de Clinicas de Porto Alegre and diagnosed with acute myeloid leukemia as classified by the French-American-British group (FAB) criteria using cell morphology, cytochemistry and flow cytometry were evaluated. Results Eight cases (16.7%) were CD56 positive without correlation to age or gender. The highest incidence of CD56 positivity was in FAB subtypes M4 and M5. The death rate during induction was not significantly different between patients with and without CD56 expression (62.5% vs. 27.5%; p-value = 0.097). However, patients that expressed CD56 had significantly lower overall survival than those who did not (mean 4.0 months vs. 14.5 months; p-value = 0.03). Conclusions The data suggest that expression of CD56 in acute myeloid leukemia may be indicative of poor prognosis because it is associated with a shorter overall survival. The death rate during induction was not significantly different despite an apparent difference in proportions between groups.

Importância clínica e laboratorial do volume plaquetário médio

Os indices plaquetarios fornecidos pelos analisadores hematologicos sao provavelmente os parâmetros mais ignorados pela maioria dos laboratorios clinicos, em virtude da dificuldade de sua padronizacao. Desses indices, o volume plaquetario medio (VPM) vem merecendo destaque por sua grande utilidade, nao so em casos de trombose e hemostasia, mas tambem em uma serie de patologias, como diabetes, doencas da tireoide, doencas vasculares, entre outras. O VPM e um parâmetro plaquetario fornecido no hemograma que nao gera custos adicionais para o laboratorio. Junto com a contagem de plaquetas, ele e um sensivel indicador de desordens plaquetarias in vivo, mas pode ser tecnicamente dificil de analisa-lo in vitro por causa dos interferentes pre-analiticos, como tempo de armazenamento da amostra e artefatos gerados pelos anticoagulantes. Neste artigo descrevemos as principais metodologias e seus interferentes na determinacao da contagem plaquetaria e do VPM, destacando a importância do laboratorio de analises clinicas em validar esse parâmetro, proporcionando sua utilizacao no diagnostico de desordens hematologicas e de outras patologias.

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.

Detection of minimal residual disease by flow cytometry for patients with multiple myeloma submitted to autologous hematopoietic stem cell transplantation.

The treatment strategy in multiple myeloma (MM) is to get complete remission followed by high-dose chemotherapy and autologous Hematopoietic Stem Cell Transplantation (HSCT). Neoplastic Plasma Cells (NPCs) are CD45−/dim, CD38+high, CD138+, CD19−, and  CD56+high in most cases. The description of this immunophenotype is of major importance as it leads to the correct identification of minimal residual disease (MRD). Samples from 44 Patients were analyzed prospectively in this study. We analyzed if the presence of MRD at three months after HSCT was predictive of relapse or death. There were 40 evaluable patients of whom 16/40 patients had MRD at three moths after HSCT and there were none in cytological relapse. The mean overall survival (OS) was 34 months and disease-free survival (RFS) was 28 months after HSCT. There was no significant difference in the log rank analysis comparing OS and the presence of MRD (P = 0,611) and RFS (P = 0,3106). Here, we demonstrate that three color flow cytometry (FCM) is more sensitive for MDR evaluation than cytological analyzes. However, based in our data we can not affirm that MRD is a good predictor of MM relapse or death. In conclusion, our results could be attributed to a short followup, small sample size, and over most to the inability of a three-color FCM to detect the NPC population.

Reference interval determination of hemoglobin fractions in umbilical cord and placental blood by capillary electrophoresis.

INTRODUCTION Umbilical cord and placental blood (UCPB) is a rich source of hematopoietic stem cells widely used to treat diseases that did not have effective treatments until recently. Umbilical cord and placental blood banks (UCPBBs) are needed to be created to store UCPB. UCPB is collected immediately after birth, processed, and frozen until infusion. Detection of abnormal hemoglobins is one of UCPB screening tests available. The objective of the present study was to determine the reference interval for HbA, HbF, and HbA2 in UCPB using capillary electrophoresis. Methods: Observational retrospective study of UCPB samples undergoing hemoglobin electrophoresis was performed between April 2012 and May 2013. We analyzed 273 UCPB samples. All cords met the criteria of BrasilCORD. RESULTS We found 19.9% (10.5–36.7%) for HbA, 80.1% (62.7–89.4%) for HbF, and 0.1% (0.0–0.6%) for HbA2. Data were expressed as median (P2.5–P97.5). CONCLUSION Establishing specific reference intervals is the best option for most tests because such ranges reflect the status of the population in which the tests will be applied. The use of appropriate reference intervals ensures that clinical labs provide reliable information, thus enabling clinicians to correctly interpret results and choose the best approach for the target population.

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.