Analysis of baseline characteristics, disease burden and long-term follow-up of 167 patients with Paroxysmal Nocturnal Hemoglobinuria at a single center in Brazil.

Paroxysmal nocturnal hemoglobinuria (PNH) can occur as a hemolytic form or small PNH clone found in a patient with bone marrow failure. METHODS: Describe Brazilian retrospective PNH cohort and identify the impact of disease burden on long-term follow-up. RESULTS: 167 patients, mean age at diagnosis 28.4 (7.1-71.2 years), four years mean interval between onset of cytopenia/aplasia diagnosis and PNH clone detection. Patients were divided into 15 Classic PNH, 55 Hemolytic PNH with bone marrow hypoplasia (PNH/AA), and 97 Subclinical PNH (sc-PNH). Hypocellular bone marrow was found in 89.2%; 55 had hemoglobinuria and 22 thrombosis during monitoring. WBC PNH clone correlated with RBC PNH clone, LDH and cytopenia. Subclinical patients had lower median lower RBC clone (2.0% vs 24.0% vs 57.8%) and WBC clone (11.7% vs 58.8% vs 81.2%) than PNH/AA and Classic PNH, respectively. PNH granulocyte clone was 89.1% in thrombotic patients. Ten-year overall survival 80.4% and mortality in transplanted patients 9.6%. Sepsis was mortality cause in subclinical PNH (16/18, 88.8%), and thrombosis in hemolytic PNH (11/13, 84.6%). CONCLUSION: Large PNH clones and LDH burden were associated with increased hemolysis and thrombosis risks, while young patients were associated with small PNH clones and subclinical form of the disease. Knowledge of the patient profile, the low risk associated with HSCT, and the use of long-term IST may be instrumental in the clinical management of PNH in restricted-resources countries.

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.

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.

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.

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

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.

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...

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

BACKGROUND: Paroxysmal nocturnal hemoglobinuria is an acquired chronic hemolytic anemia, 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 paroxysmal nocturnal hemoglobinuria (10), paroxysmal nocturnal hemoglobinuria with aplastic anemia (39), and paroxysmal nocturnal hemoglobinuria with subclinical features and aplastic 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 nocturnal hemoglobinuria cases from a single center in Brazil. Flow cytometry showed that a larger clone was associated with classical symptoms and increased risk of thrombosis, even in patients with bone marrow failure, whereas a smaller clone was associated with bone marrow aplasia.

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.

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. .

Immune reconstitution in patients with Fanconi anemia after allogeneic bone marrow transplantation.

BACKGROUND AIMS: Fanconi anemia is an autosomal recessive or X-linked genetic disorder characterized by bone marrow (BM) failure/aplasia. Failure of hematopoiesis results in depletion of the BM stem cell reservoir, which leads to severe anemia, neutropenia and thrombocytopenia, frequently requiring therapeutic interventions, including hematopoietic stem cell transplantation (HSCT). Successful BM transplantation (BMT) requires reconstitution of normal immunity. METHODS: In the present study, we performed a detailed analysis of the distribution of peripheral blood subsets of T, B and natural killer (NK) lymphocytes in 23 patients with Fanconi anemia before and after BMT on days +30, +60, +100, +180, +270 and +360. In parallel, we evaluated the effect of related versus unrelated donor marrow as well as the presence of graft-versus-host disease (GVHD). RESULTS: After transplantation, we found different kinetics of recovery for the distinct major subsets of lymphocytes. NK cells were the first to recover, followed by cytotoxic CD8(+) T cells and B cells, and finally CD4(+) helper T cells. Early lymphocyte recovery was at the expense of memory cells, potentially derived from the graft, whereas recent thymic emigrant (CD31(+) CD45RA(+)) and naive CD4(+) or CD8(+) T cells rose only at 6 months after HSCT, in the presence of immunosuppressive GVHD prophylactic agents. Only slight differences were observed in the early recovery of cytotoxic CD8(+) T cells among those cases receiving a graft from a related donor versus an unrelated donor. Patients with GVHD displayed a markedly delayed recovery of NK cells and B cells as well as of regulatory T cells and both early thymic emigrant and total CD4(+) T cells. CONCLUSIONS: Our results support the utility of post-transplant monitoring of a peripheral blood lymphocyte subset for improved follow-up of patients with Fanconi anemia undergoing BMT.

Bone marrow stem cell transplantation and coronary artery bypass grafting surgery for chronic ischemic myocardiopathy.

We studied 12 consecutive patients with chronic ischemic myocardiopathy treated with bone marrow adult stem cell (ASC) transplantation and coronary artery bypass grafting (CABG). The aim of the study was to evaluate functional class (New York Heart Association), wall motion score index (WMSI), and ejection fraction by echocardiography and to evaluate myocardial perfusion by single-photon emission computed tomography (SPECT). Follow-up evaluations were performed at 3, 6, and 12 months. The results revealed functional class improvement until 12 months, a progressive increase in the ejection fraction of 15% to 20% in the first 6 months, and a progressive increase in the WMSI by 35% to 45% in 12 months. Evaluation of the WMSI in the stem cell and CABG areas separately revealed a similar improvement in the first 3 months and a better progression in the CABG area. SPECT images revealed perfusion improvements in ischemic areas and no difference in fibrous tissue areas. These preliminary results show the safety of the method and its reproducibility. When performed concomitantly with CABG, bone marrow ASC transplantation may improve functional class, ejection fraction, WMSI, and myocardial perfusion. This study will be completed with all patients followed up for 12 months and compared with a control group.