Cíntia Machado

Platelet function and the von Willebrand factor antigen in the hepatosplenic form of schistosomiasis mansoni.

Forty-five individuals with hepatosplenic schistosomiasis mansoni were studied with the aim of measuring levels of von Willebrand factor antigen (vWF:Ag), detecting abnormalities in platelet morphology and aggregation, and identifying changes to surface antigens. Haemograms, platelet aggregation tests, flow cytometry investigations of CD41/CD42b antibody and vWF:Ag assays were performed. Mean platelet counts were low (77,522/mm3) and 82.2% of patients presented thrombocytopenia. An inverse relationship between spleen size and platelet count was seen. Macroplatelets were found in 57.1% of patients, indicating good bone-marrow response, but were insufficient to compensate for the decrease in platelets due to splenomegaly. Decreased or absent platelet aggregation was seen in 50% of patients, probably due to low platelet counts. Markers for GPIIb/IIIa were normal in more than 90% of patients, not supporting the increased capture and destruction of platelets in the spleen that is hypothesized to occur with cirrhosis. Similar to cirrhosis, vWF:Ag levels were high or very high in 70.5% of patients. High levels of vWF:Ag were associated with platelet counts <100,000/mm3, larger spleen diameter and oesophageal varices. In conclusion, hepatosplenic schistosomiasis leads to a lower platelet count due to pooling in the spleen and, consequently, impaired aggregation, but not to increased capture and destruction of platelets in the spleen. High vWF:Ag levels probably promote stabilization of platelet microaggregates and prevent minor manifestations of thrombocytopenia such as petechiae, ecchymosis and gingival bleeding.

Hidroxiuréia em pacientes com síndromes falciformes acompanhados no Hospital Hemope, Recife, Brasil

The use of hydroxyurea increases concentrations of fetal hemoglobin (Hb F) in sickle cell disease patients. It has been used in adults and in trials with children with the aim of preventing events such as episodes of pain or stokes. The objective of this study was to analyze the efficacy and side effects of Hydroxyurea in children with ages ranging from 5 to 17 years and also in young adults with SS or Sβ0 hemoglobinopathies. The patients were treated in the outpatient clinic of the Hemope Hospital. Young patients were treated with hydroxyurea at 10 mg/kg/day which was increased by 5 mg/kg/day at 8-week intervals until reaching a maximum dose of 25 mg/kg/day. For adults, the treatment started at 500 mg/day and increased until a dose of 1000 mg/day was reached. Total Hb F levels and the Mean Corpuscular Volume rose with hydroxyurea therapy and there was a reduction of events involving pain as well as the necessity of hospitalization among the pediatric patients. With the over 18year-old patients, a better clinical state was noticed together with a rise in hemoglobin levels and a reduction in the reticulocyte, leukocyte and platelet counts. No signs or symptoms in respect to drug toxicity were evidenced in either group. The use of hydroxyurea seems to be safe and effective in both children and young adults with sickle cell disease. The drug also improves theO uso de hidroxiureia promove a elevacao dos niveis de hemoglobina fetal (Hb F) em pacientes portadores de sindromes falciformes (SF) e o medicamento vem sendo estudado em varios grupos de pacientes, incluindo adultos e criancas. O presente trabalho analisou a eficacia e tolerabilidade do uso de hidroxiureia em criancas na faixa etaria entre 5 e 17 anos de idade e em adultos jovens acima de 18 anos, portadores de hemoglobinopatia SS ou Sb0 que foram acompanhados regularmente no ambulatorio do Hospital Hemope. Os pacientes pediatricos foram tratados com dose inicial de hidroxiureia de 10 mg/kg/dia, a qual era aumentada em 5 mg/kg por dia em intervalos de oito semanas, ate a dose maxima de 25 mg/kg/dia. Para os adultos, o tratamento foi iniciado com 500 mg/dia de hidroxiureia ate a dose maxima de 1g/dia. Foi observada reducao do numero de crises algicas assim como do numero de internacoes hospitalares, elevacao do nivel de Hb F e do Volume Corpuscular Medio, no grupo pediatrico. Entre os pacientes maiores de 18 anos, tambem se observou melhora clinica e significância estatistica com aumento dos valores da hemoglobina e reducao dos valores de reticulocitos, leucocitos e plaquetas. Nao foram observados sinais ou sintomas sugestivos de toxicidade medicamentosa em ambos os grupos. O uso de hidroxiureia em todos os pacientes parece ser seguro e eficaz e assegura melhora da qualidade de vida e beneficios a seus familiares. Ademais, as doses preconizadas de hidroxiureia aparentemente nao foram mielotoxicas, nao tendo sido necessaria a suspensao do tratamento em nenhum dos pacientes.

Prognostic importance of CD56 expression in intermediate risk acute myeloid leukaemia

Recently, we showed that clinical outcomes of Brazilian acute myeloid leukaemia (AML) patients were significantly inferior to those in the USA and Europe. Excluding well-recognized differences between developed and developing countries, heterogeneity in outcome still exists in patients with the same cytogenetic risk (Lima et al, 2015). Therefore, it would be interesting to identify supplementary biological markers that yield non-redundant biological information for further prognostic refinement of AML patients. In this context, aberrant expression of CD56 antigen (also termed NCAM1) in leukaemic blasts has been frequently associated with inferior outcome in patients with AML, particularly those with t (8;21) (Iriyama et al, 2013) and t(15;17) abnormalities (Montesinos et al, 2011). Nevertheless, knowledge regarding its prognostic value in other subtypes of AML remains limited. Here, we evaluated clinical outcomes of non-selected patients with AML (non-acute promyelocytic leukaemia) according to CD56 expression. Our data suggest that aberrant expression of this antigen may predict inferior outcome in patients with intermediate outcome. One hundred and forty-one newly diagnosed AML patients were included between August 2008 and April 2015, with last follow-up in May 2015. Patients were classified according to morphological, immunophenotypic and cytogenetic findings. Treatment protocol was previously described (Lima et al, 2015). The local Research Ethics Board approved the study. To determine CD56 antigen expression, immunophenotypic analysis was accomplished using diagnostic bone-marrow samples and standard flow-cytometry methods. Patients were designated ‘CD56-positive’ when ≥20% of leukaemic cells expressed CD56 antigen (Bene et al, 1995). Fisher’s exact test or Chi-square test, as appropriate, was used to compare categorical variables. Wilcoxon rank-sum test was used to compare continuous variables. Overall survival (OS) and disease-free survival (DFS) were calculated using the Kaplan–Meier method. OS was defined as the time from the initiation of induction therapy to death from any cause; those alive or lost to follow-up were censored at the date last known alive. DFS was defined as the time from complete remission to disease relapse, development of secondary malignancy, or death from any cause, whichever occurred first. Patients who were alive without disease relapse or secondary malignancy were censored at the time last seen alive and disease-free. The log-rank test was used for comparisons of Kaplan–Meier curves. Univariate and multivariate proportional hazards regression analysis was performed for potential prognostic factors for OS and DFS (Table I). Potential prognostic factors examined in multivariate regression analysis were CD56 expression, cytogenetic risk stratification, age at diagnosis and leucocyte counts. Proportional hazards assumption for each variable of interest was tested. Linearity assumption for all continuous variables was examined using restricted cubic spline estimates of the relationship between the continuous variable and log relative hazard/risk. All P-values were two sided with a significance level of 0 05. All calculations were performed using Stata Statistic/Data Analysis version 12 (Stata Corporation, College Station, TX, USA) and R 2.10.1 (The CRAN project, www.r-project.org) software.

Mannose-binding lectin 2 (MBL2) gene polymorphisms do not influence frequency of infections in chronic lymphocytic leukemia patients

Background Infectious complications represent the main cause of morbidity and mortality in chronic lymphocytic leukemia. It has been reported that polymorphisms of the mannose-binding lectin 2 (MBL2) genes are correlated with MBL protein serum levels and, consequently, are associated with the development of infectious diseases. Objective The purpose of this study was to investigate the possible association between MBL2 gene polymorphisms and risk of infection in chronic lymphocytic leukemia patients. Methods Peripheral blood samples from 116 chronic lymphocytic leukemia patients were collected; after genomic DNA extraction, real time polymerase chain reaction was used to determine the polymorphisms of the promoter region and exon 1 of the MBL2 gene. Results A high frequency of Binet stage A (p-value = 0.005) and absence of splenomegaly (p-value = 0.002) were observed in patients with no infection; however, variant alleles/ genotypes and haplotypes of this gene had no impact on the risk of infection. Conclusion To the authors’ knowledge, this is the first study describing the association between MBL2 polymorphisms and infectious disease in chronic lymphocytic leukemia. Although it was not possible to demonstrate any influence of MBL2 polymorphisms as a genetic modulator of infection in chronic lymphocytic leukemia, the authors believe that the present data are clinically relevant and provide the basis for future studies.

Importância e vantagem da citometria de fluxo frente aos testes de triagem no diagnóstico da hemoglobinúria paroxística noturna

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disease of the hematopoietic stem cell caused by a somatic mutation in the PIG-A gene, resulting in the inability of erythrocytes, granulocytes and platelets to protect themselves against complement system mediated lysis. Thus, PNH screening tests (Hams test and CD55 e CD59 proteins investigation through gel column agglutination) were evaluated using flow cytometry, a test useful to detect and measure the PNH clone. Initially, 63 patients evaluated using the Hams test between January 2003 and December 2004 from the Hemope Foundation were selected. From these, 15 cases were positive for PNH. The inclusion criterion for cytometry evaluation was a positive Hams test. Thus, four patients were included in the study group. Furthermore, two cases with clinical symptoms of the disease but with negative results for PNH were included in this group. Negative results were explained by the gel test being performed after blood transfusion, giving a suspicion of false negative results. These six cases were submitted to flow cytometry with all cases proving to be positive for the disease as the PNH clone was confirmed, to different degrees, in both erythrocytes and granulocytes. The flow cytometry results proved the limitation of screening tests as well as showing the importance of cytometry in the identification of the intense variations of clone guaranteeing precise diagnosis in previously transfused patients.