Minimal residual disease assessment in acute lymphoblastic leukemia by 4-color flow cytometry: Recommendations from the MRD Working Group of the Brazilian Society of Bone Marrow Transplantation

Abstract Introduction: The minimal residual disease (MRD) status plays a crucial role in the treatment of acute lymphoblastic leukemia (ALL) and is currently used in most therapeutic protocols to guide the appropriate therapeutic decision. Therefore, it is imperative that laboratories offer accurate and reliable results through well standardized technical processes by establishing rigorous operating procedures. Method: Our goal is to propose a monoclonal antibody (MoAb) panel for MRD detection in ALL and provide recommendations intended for flow cytometry laboratories that work on 4-color flow cytometry platforms. Results and conclusion: The document includes pre-analytical and analytical procedures, quality control assurance, technical procedures, as well as the information that needs to be included in the reports for clinicians.

Evaluation of criteria of manual blood smear review following automated complete blood counts in a large university hospital

Abstract Background: There is great interest in reducing the number of automated complete blood counts requiring manual blood smear reviews without sacrificing the quality of patient care. This study was aimed at evaluating and establishing appropriate screening criteria for manual blood smear reviews to improve the performance in a hematology laboratory. Method: A total of 1977 consecutive samples from the daily workload were used to evaluate four sets of screening criteria for manual blood smear reviews to identify samples with positive smear findings. Three sets of screening criteria were arbitrarily proposed in this study: Group 1 (narrow ranges), Group 2 (intermediate ranges), and Group 3 (wide limits) and one set (Group 4) was adapted from the International Society for Laboratory Hematology. All samples were run on Sysmex hematology analyzers and were investigated using manual blood smear reviews. Diagnostic accuracy and agreement were performed for each set of screening criteria, including an investigation of microscopic review rate and efficiency. Results: The microscopic review rates for Groups 1, 2, 3 and 4 were 73.85%, 54.52%, 46.33% and 46.38%, respectively; the false-negative rates were 0.50%, 1.97%, 2.73% and 3.95%, respectively. The efficiency and negative predictive values of Group 3 were 73.04% and 4.91%, respectively. Conclusions: Group 3 had the best relationship between safety (false-negative rate: ≤3%) and efficiency to estimate the limits of automation in performing complete blood counts. This study strengthens the importance of establishing screening criteria for manual blood smear reviews, which account for the different contexts in which hematological determinations are performed. Each laboratory should optimize the screening criteria for manual blood smear reviews in order to maximize their efficiency and safety.

Proposal for the standardization of flow cytometry protocols to detect minimal residual disease in acute lymphoblastic leukemia

Minimal residual disease is the most powerful predictor of outcome in acute leukemia and is useful in therapeutic stratification for acute lymphoblastic leukemia protocols. Nowadays, the most reliable methods for studying minimal residual disease in acute lymphoblastic leukemia are multiparametric flow cytometry and polymerase chain reaction. Both provide similar results at a minimal residual disease level of 0.01% of normal cells, that is, detection of one leukemic cell in up to 10,000 normal nucleated cells. Currently, therapeutic protocols establish the minimal residual disease threshold value at the most informative time points according to the appropriate methodology employed. The expertise of the laboratory in a cancer center or a cooperative group could be the most important factor in determining which method should be used. In Brazil, multiparametric flow cytometry laboratories are available in most leukemia treatment centers, but multiparametric flow cytometry processes must be standardized for minimal residual disease investigations in order to offer reliable and reproducible results that ensure quality in the clinical application of the method. The Minimal Residual Disease Working Group of the Brazilian Society of Bone Marrow Transplantation (SBTMO) was created with that aim. This paper presents recommendations for the detection of minimal residual disease in acute lymphoblastic leukemia based on the literature and expertise of the laboratories who participated in this consensus, including pre-analytical and analytical methods. This paper also recommends that both multiparametric flow cytometry and polymerase chain reaction are complementary methods, and so more laboratories with expertise in immunoglobulin/T cell receptor (Ig/TCR) gene assays are necessary in Brazil.

Paroxysmal nocturnal hemoglobinuria clone in 103 Brazilian patients: diagnosis and classification

Background: Paroxysmal nocturnal hemoglobinuria is an acquired chronic hemolytic ane- mia, which often manifests as peripheral blood cytopenias and thrombosis. Objective: The aim of this study is to describe a Brazilian population of paroxysmal nocturnal hemoglobinuria patients. Methods: One hundred and three paroxysmal nocturnal hemoglobinuria cases were retrospectively reviewed and the clinical presentation, thrombosis, survival, and clone size were assessed. Diagnosis was established by flow cytometry. Results: Fifty-two male and 51 female patients with a median age of 24.1 years (5.5-62 years) were studied. Clinical symptoms included hemoglobinuria (18.4%), infection (46.6%) and thrombosis (16.5%), and 80.6% had pancytopenia. Patients were classified as classic parox- ysmal nocturnal hemoglobinuria (10), paroxysmal nocturnal hemoglobinuria with aplastic anemia (39), and paroxysmal nocturnal hemoglobinuria with subclinical features and aplas- tic anemia (54). There were significant differences in terms of median age, size of clone, clinical symptoms, and peripheral blood cell counts between the three subcategories. The clone size in erythrocytes and granulocytes were respectively 0.04% (range: 0-18%) and 7.3% (range: 0.3-68.7%) in patients with subclinical features and aplastic anemia, 15.8% (range: 0-99.7%) and 63.0% (range: 1.7-99.8%) in patients with aplastic anemia alone, and 82.2% (range: 0-99.85%) and 98.0% (81.3-100.0%) in Classic disease. Statistical differences were identified for platelets (p-value = 0.001), lactate dehydrogenase (p-value = 0.002) and the clone size (p-value < 0.001) in patients who suffered thrombotic events compared to those who did not. Overall survival was 81.7%, with patients with subclinical features and aplastic anemia having lower overall survival (76.5%). Conclusion: This retrospective review of 103 patients over an 11-year period represents the largest collection of paroxysmal...

Are the review criteria for automated complete blood counts of the International Society of Laboratory Hematology suitable for all hematology laboratories?

OBJECTIVE: to verify whether the review criteria for automated blood counts suggested by the International Consensus Group for Hematology Review of the International Society for Laboratory Hematology are suitable for the Hematology Laboratory of Hospital de Clinicas, Universidade Federal do Paraná. METHODS: initially, the review criteria of the International Society for Laboratory Hematology were adapted due to limitations in the Institution's electronic hospital records and interfacing systems. The adapted review criteria were tested using 1977 samples. After this first assessment, an additional 180 inpatient samples were analyzed to evaluate the screening criteria of the review criteria in conjunction with positive smear findings established by the institution. The performance of the review criteria was verified by determining false positive, false negative, true positive and true negative rates, sensitivity, specificity, positive predictive value, negative predictive value, microscopic review rate and efficiency. RESULTS: initial analysis showed false negatives = 6.73%, false positives = 23.27%, microscopic review rate = 46.03% and efficiency = 70.0%. An evaluation of the screening criteria adapted from the review criteria together with the positive smear findings of the institution showed false negatives = 15.5%, false positives = 10.5%, microscopic review rate = 37.3% and efficiency = 73.8%. In both situations the safety limit (false negative <5%) recommended by the review criteria was exceeded. CONCLUSIONS: the review criteria adapted from the International Society for Laboratory Hematology are neither suitable nor safe for use in the hematology laboratory of the Hospital de Clinicas. This implies a need to develop and validate institution-specific review criteria in order to decrease false negative results to an acceptable and safe rate for patients. .

Expressão dos marcadores mielóides e prognóstico das leucemias / myeloid markers expression and prognosis of acute lymphoid leukemia

Objetivos: avaliar os marcadores mielóides positivos como fator de risco para a sobrevida livre de doença e mortalidade em crianças com leucemia linfóide aguda. Casuística e métodos: d=foram revisados 84 prontuários de crianças com leucemia linfóide aguda do Hospital Pequeno Princípe de Curitiva, PR ...

Análise imunofenotípica de subpopulações linfocitárias do sangue periférico na esclerose sistêmica / Immunophenotypic analysis of lymphocyte subpopulations in the blood of systemic sclerosis patients

A esclerose sistêmica (ES) é uma doença inflamatória crônica do tecido conjuntivo, de etiologia desconhecida, caracterizada por fibrose e dano microvascular dos órgãos afetados. Há várias evidências de que a ativação do sistema imune participa de maneira expressiva na sua patogênese. Objetivo: Analisar numericamente as subpopulações linfocitárias no sangue periférico de pacientes com ES e sua possível relação com fatores clínicos e laboratoriais. Métodos: Foram analisadas as subpopulações linfocitárias de 42 pacientes com ES e 28 controle normais, através de citometria de fluxo utilizando os antígenos linfocitários: CD2, CD3, CD4, CD8, CD19, CD25, CD45RA, CD56, CD71, HLA-DR, TCRalfa/beta e TCRgama/delta. Resultados: Nos pacientes com ES comparados com o grupo-controle, foram encontrados valores porcentuais normais para os linfócitos T CD2+, CD3+, CD3+CD4+, CD3+CD8+, CD25+, CD4+CD45RA+, CD8+CD45RA+, CD71+ e para a relação CD4+/CD8+. Em contraste, os linfócitos T CD3+TCRgama/delta+ monstram-se com porcentuais diminuídos nos pacientes com ES difusa, de longa duração, com envolvimento pulmonar caracterizado por doença pulmonar restritiva, envolvimento muscular e presença de anticorpo anti-Scl-70. Os pacientes com a forma difusa de ES apresentaram, tanto na fase recente como na tardia, aumento na porcentagem de linfócitos T CD4+ e CD8+ expressando moléculas de ativação HLA-DR. Na fase tardia da doença, não importando a forma clínica, foi encontrado aumento na porcentagem de linfócitos T CD4+CD45RA+. Os pacientes com ES limitada e fase recente mostraram diminuição na porcentagem dos linfócitos B CD19+. Os pacientes com doença difusa e fase tardia apresentaram diminuição na porcentagem dos linfócitos NK CD56+. Conclusões: Estes resultados sugerem que as alterações dos linfócitos T, B e NK possam estar envolvidos no processo de desencadeamento e/ou perpetuação da ES, havendo a possibilidade de ter utilidade prognóstica em alguns grupos de pacientes

Síndrome de Imerslund-Gräsbek: relato de dois casos / Imerslund-Gräsbeck syndrome: report of two cases

Introdução: A síndrome de Imerslund-Gräsbeck é uma entidade rara, de transmissão autossônica recessiva, caracterizada por anemia megaloblástica e proteinúria assintomática, que se manifesta, geralmente, nos dois primeiros anos de vida. Objetivo: Enfatizar aos pediatras gerais a importância do diagnóstico precoce desta entidade, em vista da alta morbidade causada pela ausência da terapia correta, além da necessidade de realização de triagem e aconselhamento genético dos familiares assintomáticos. Métodos: Os autores descrevem 2 casos de pacientes dos sexos masculino e feminino, com 8 e 10 anos de idade respectivamente, com história de anemia e múltiplas transfusões desde os primeiros anos de vida, que evoluíram para pancitopenia em idade escolar, havendo suspeita de anemia aplástica ou anemia de Fanconi e encaminhamento ao Serviço de Transplante de Medula Óssea - HC-UFPR. Resultados: Presença de pancitopenia com medula óssea megaloblástica em ambos os casos. Parciais de urina demonstraram proteinúria em ambos os casos. Parciais de urina demonstraram proteinúria de 24 horas de 3 e 5,8 g/dl em cada caso. Os estudos citogenéticos foram normais. O tratamento com viitamina B12 intramuscular após o diagnóstico foi efetivo, com resolução do quadro clínico em ambos os casos. Conlcusão: A presença de anemia megaloblástica na infância deve ser sempre acompanhada da investigação de proteinúria, com vistas à caracterização desta entidade rara, porém de diagnóstico simples e tratamento eficaz

Valores normais e variaçöes fisiológicas de leucócitos no sangue periférico / Normal values and physiological variations of the leucocytes in peripheral blood

O número total de leucócitos e as células correspondentes, principalmente os neutrófilos, sofrem influência de inúmeros fatores como idade, sexo, raça, exercício, stress, variaçäo temporal, ciclo menstrual, gravidez, anticoncepcionais e fumo. Além destas variáveis, na análise comparativa deste dado biológico com valores normais da literatura devem ser ainda considerados os métodos de coleta, os métodos laboratoriais e a individualidade de cada paciente

Valores normais de leucócitos em populaçäo adulta de Curitiba / Normal values of leucocytes in adult population of Curitiba, Brazil

O número de leucócitos e a contagem diferencial de leucócitos foram realizados em 258 homens e 106 mulheres, adultos, clinicamente normais e laboratorialmente sem depleçäo de ferro. Foi utilizado o Coulter Counter Modelo "S" e contadas 100 células na diferencial de leucócitos. Os resultados expressos em células/micron-l foram: número de leucócitos 6531 (3611 a 9451), neutrófilos 3707 (1507 a 5907), segmentados 3489 (1349 a 5629) em homens e número de leucócitos 6607 (2867 a 10347), neutrófilos 3734 (1214 a 6254), segmentados 3458 (1116 a 5800) em mulheres. Em ambos os sexos: bastonetes (0 a 678), linfócitos (798 a 3306), monócitos (80 a 858), eosinófilos (0 a 552) e basófilos (0 a 124). Näo houve diferença estatisticamente significante entre os sexos. Os resultados säo concordantes com os valores mais baixos encontrados na literatura