Use of therapeutic plasma exchange in heparin-induced thrombocytopenia: A population-based study.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is characterized by anti-heparin/platelet factor 4 immune complexes, which are removed by therapeutic plasma exchange (TPE). Our main objective was to study TPE outcomes in HIT using a large administrative claims database. STUDY DESIGN AND METHODS: We used the National Inpatient Sample (NIS) to identify hospital discharges of adult patients (≥18) with a primary or secondary diagnosis of HIT. Cases were classified into two groups based on TPE use. The primary outcome was in-hospital mortality. Secondary outcomes were thrombotic events, major bleeding, hospital length of stay (LOS), and charges. Multivariable regression analysis, controlling for age and medical comorbidities, was used to examine the association of TPE with study outcomes. RESULTS: A HIT diagnosis was made in 22 165 discharges, of which 90 (0.4%) received TPE. Corresponding national estimates are 106 435 and 439, respectively. TPE was not associated with decreased in-hospital mortality (OR = 1.72; 95%CI: 0.93-3.17, P = .085). However, TPE was associated with a higher likelihood of major bleeding (OR = 2.35; 95%CI: 1.40-3.68, P = .0009), primarily driven by gastrointestinal bleeding (OR = 2.21; 95%CI: 1.17-4.17, P = .015). TPE was also associated with higher hospital LOS (20.5 vs 10 day, P < .0001) and charges (USD 211181 vs USD 81654, P < .0001). CONCLUSION: TPE's association with increased bleeding and a prolonged hospital course indicates that it is being used in HIT cases with a severe clinical phenotype. Future studies are needed to better characterize the HIT phenotype that will most benefit from TPE.

Mortality in patients with systemic lupus erythematosus in Colombia: a case series.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease associated with high mortality rates. This study aimed to describe the main causes of death in a case series of SLE patients attended in a single center in Colombia. METHODS: We conducted a retrospective review and analysis of records of SLE patients who died between January 2011 and June 2017. We extracted the main causes of death and described variables associated with this outcome as well as variables associated with the disease and its treatment. RESULTS: From a total of 1776 patients with SLE, we identified 49 fatal cases (89.8% women, n = 44). The average age at death was 40.6 years (SD 17.4), and patients had a median of 4.5 years (IQR 2-8) of disease duration. The main findings included lymphopenia in 44 patients (89.9%), biopsy-confirmed lupus nephritis (LN)-types IV and VI-in 38 (77.6%), catastrophic antiphospholipid syndrome (CAPS) in 8 (16.3%), and persistent hypocomplementemia (C3 and C4) in 8 (16.3%). The median SLE disease activity index (SLEDAI-2K) score at the time of death was 19 (IQR 11-39). The main cause of death was SLE activity and lupus-induced damage in 22 (44.9%) patients. CONCLUSION: The main causes of death included SLE activity refractory to immunosuppressive treatment, and nosocomial bacterial infections. The patients who died had persistently high SLEDAI scores, types IV and VI LN, associated antiphospholipid syndrome, and persistent hypocomplementemia, requiring severe immunosuppression and prolonged hospitalization.

Effects of Baseline Thrombocytopenia and Platelet Decrease Following Renal Replacement Therapy Initiation in Patients With Severe Acute Kidney Injury.

OBJECTIVES: Thrombocytopenia is common in critically ill patients with severe acute kidney injury and may be worsened by the use of renal replacement therapy. In this study, we evaluate the effects of renal replacement therapy on subsequent platelet values, the prognostic significance of a decrease in platelets, and potential risk factors for platelet decreases. DESIGN: Post hoc analysis of the Acute Renal Failure Trial Network Study. SETTING: The Acute Renal Failure Trial Network study was a multicenter, prospective, randomized, parallel-group trial of two strategies for renal replacement therapy in critically ill patients with acute kidney injury conducted between November 2003 and July 2007 at 27 Veterans Affairs and university-affiliated medical centers. SUBJECTS: The Acute Renal Failure Trial Network study evaluated 1,124 patients with severe acute kidney injury requiring renal replacement therapy. INTERVENTIONS: Predictor variables were thrombocytopenia at initiation of renal replacement therapy and platelet decrease following renal replacement therapy initiation. MEASUREMENTS AND MAIN RESULTS: Outcomes were mortality at 28 days, 60 days, and 1 year, renal recovery, renal replacement therapy free days, ICU-free days, and hospital-free days. Baseline thrombocytopenia in patients requiring renal replacement therapy was associated with increased mortality and was also associated with lower rates of renal recovery. A decrease in platelet values following renal replacement therapy initiation was associated with increased mortality. Continuous renal replacement therapy was not an independent predictor of worsening thrombocytopenia compared with those treated with intermittent hemodialysis. CONCLUSIONS: Baseline thrombocytopenia and platelet decrease following renal replacement therapy initiation were associated with increased mortality, and baseline thrombocytopenia was associated with decreased rates of renal recovery. Continuous renal replacement therapy did not decrease platelets compared with hemodialysis.

Clinical characteristics, predictors of immune reconstitution inflammatory syndrome and long-term prognosis in patients with Kaposi sarcoma.

OBJECTIVE: To investigate the predictive factors for the development of Kaposi sarcoma-related immune reconstitution inflammatory syndrome (KS-IRIS) and long-term prognosis in patients starting combined antiretroviral therapy (cART). METHODS: We studied a retrospective-cohort of consecutive antiretroviral-naïve patients with KS initiating cART from January 2005 to December 2011 and followed through June 2013. KS-IRIS was defined as ≥2 of the following: abrupt increase in number of KS lesions, appearance or exacerbation of lung-opacities or lymphedema, concomitantly with an increase in CD4+ cell-count ≥50 cells/mm3 and a decrease of >1 log in viral-load once started cART. We compared individuals who met KS-IRIS criteria with those that did not and described the long-term follow-up. RESULTS: We included 89 patients, 88 males; 35 (39%) developed KS-IRIS at a median of 10 weeks (IQR 4-16). KS-IRIS patients had more pulmonary-involvement (60% vs. 16.6% of patients; p < 0.0001), eight died attributed to pulmonary-KS. Thrombocytopenia <100,000/mm3 at follow-up occurred in 36% of KS-IRIS vs. 4% in non-KS-IRIS patients (p = 0.0002), 45% KS-IRIS patients with thrombocytopenia died, non without KS-IRIS. Chemotherapy (bleomicyn-vincristine) was more frequently prescribed in KS-IRIS patients (88.6% vs. 29.6%) with no differences in outcome; 80% of all patients achieve KS complete remission, 52% of them never received chemotherapy. No difference between groups in the long-term follow-up (mean 52.4 ± 27.4 months) was found, only one patient developed a secondary malignancy (1.12%). CONCLUSIONS: Lung-involvement was predictive of IRIS development. Thrombocytopenia in KS-IRIS patients at week 12 follow-up after cART initiation was associated with high mortality. Over a third of patients with KS achieve remission without chemotherapy. Individuals that survive the initial period of KS-IRIS adhere to cART had a good long-term prognosis.

Active haematological manifestations of systemic lupus erythematosus lupus are associated with a high rate of in-hospital mortality.

The aim of this study was to estimate the impact of the haematological manifestations of systemic lupus erythematosus (SLE) on mortality in hospitalized patients. For that purpose a case-control study of hospitalized patients in a medical referral centre from January 2009 to December 2014 was performed. For analysis, patients hospitalized for any haematological activity of SLE ( n = 103) were compared with patients hospitalized for other manifestations of SLE activity or complications of treatment ( n = 206). Taking as a variable outcome hospital death, an analysis of potential associated factors was performed. The most common haematological manifestation was thrombocytopenia (63.1%), followed by haemolytic anaemia (30%) and neutropenia (25.2%). In the group of haematological manifestations, 17 (16.5%) deaths were observed compared to 10 (4.8%) deaths in the control group ( P < 0.001). The causes of death were similar in both groups. In the analysis of the variables, it was found that only haematological manifestations were associated with intra-hospital death (odds ratio 3.87, 95% confidence interval 1.8-88, P < 0.001). Our study suggests that apparently any manifestation of haematological activity of SLE is associated with poor prognosis and contributes to increased hospital mortality.

Heparin-induced thrombocytopenia testing is over-utilized in cirrhosis & correlates with poor clinical outcomes.

INTRODUCTION: Heparin-induced thrombocytopenia (HIT) is a serious complication seen in hospitalized, medically-ill patients. Evaluation for HIT using a commercially-available ELISA-based test has become increasingly common; however, it does have a high false positive rate. Implications of HIT testing in patients with cirrhosis have not yet been reported. MATERIAL AND METHODS: We conducted a single-institution, retrospective review of all patients with cirrhosis admitted over a 29-month period. The student's t-test and the χ2 test were used for comparisons. We performed a stratified survival analysis using Kaplan-Meier and log rank testing. RESULTS: A total of 1,305 patients had a HIT Ab sent during the study period. Of these patients, 106 had cirrhosis and were included in the study. Eighteen (17%) of the patients with cirrhosis were HIT Ab positive and four of the eighteen had a positive Serotonin Release Assay (SRA) confirmatory test. No difference was found in platelet nadir, thrombotic rate, length of stay, and patient survival between patients with positive HIT Ab and negative HIT Ab testing. No consistent treatment was used among patients who were HIT Ab positive, despite hematology service consultation. Patients who were HIT Ab negative were more likely to have undergone liver transplantation compared to those who were positive (27 vs. 5.5%, respectively; p = 0.048). CONCLUSION: Our data suggest that HIT Ab testing is over-used in patients with cirrhosis and is poorly predictive of outcomes. With a poor positive predictive value, HIT testing may add unnecessary complexity to an already complicated patient population.

Altered immunophenotypic features of peripheral blood platelets in myelodysplastic syndromes.

BACKGROUND: Multiparameter flow cytometric analysis of bone marrow and peripheral blood cells has proven to be of help in the diagnostic workup of myelodysplastic syndromes. However, the usefulness of flow cytometry for the detection of megakaryocytic and platelet dysplasia has not yet been investigated. The aim of this pilot study was to evaluate by flow cytometry the diagnostic and prognostic value of platelet dysplasia in myelodysplastic syndromes. DESIGN AND METHODS: We investigated the pattern of expression of distinct surface glycoproteins on peripheral blood platelets from a series of 44 myelodysplastic syndrome patients, 20 healthy subjects and 19 patients with platelet alterations associated to disease conditions other than myelodysplastic syndromes. Quantitative expression of CD31, CD34, CD36, CD41a, CD41b, CD42a, CD42b and CD61 glycoproteins together with the PAC-1, CD62-P, fibrinogen and CD63 platelet activation-associated markers and platelet light scatter properties were systematically evaluated. RESULTS: Overall, flow cytometry identified multiple immunophenotypic abnormalities on platelets of myelodysplastic syndrome patients, including altered light scatter characteristics, over-and under expression of specific platelet glycoproteins and asynchronous expression of CD34; decreased expression of CD36 (n = 5), CD42a (n = 1) and CD61 (n = 2), together with reactivity for CD34 (n = 1) were only observed among myelodysplastic syndrome cases, while other alterations were also found in other platelet disorders. Based on the overall platelet alterations detected for each patient, an immunophenotypic score was built which identified a subgroup of myelodysplastic syndrome patients with a high rate of moderate to severe alterations (score>1.5; n = 16) who more frequently showed thrombocytopenia, megakaryocytic dysplasia and high-risk disease, together with a shorter overall survival. CONCLUSIONS: Our results show the presence of altered phenotypes by flow cytometry on platelets from around half of the myelodysplastic syndrome patients studied. If confirmed in larger series of patients, these findings may help refine the diagnostic and prognostic assessment of this group of disorders.

Thrombocytopenia in cardiac surgery: diagnostic and prognostic importance.

OBJECTIVE: Patients undergo to cardiac surgery have more probability to develop thrombocytopenia. The heparin induced thrombocytopenia happens in 5% of the patients. The aim from this study was to evaluate the clinical importance from the severe thrombocytopenia in postoperative cardiac surgical patients. METHODS: It was included cardiac surgical patients with platelets < 150000 cel/mm³ during firsts 24 h from postoperative. All patients underwent evaluation for four Ts score (thrombocytopenia, use preview of heparin, thrombosis and platelets decreased not related to heparin). In order to a four Ts score e" 6 was considered as suggestive of heparin induced thrombocytopenia type II. The mortality rate in intensive care (ICU) and hospital, length of stay, healthy state and incidence from thrombosis were compared in patients with score > 6 (group 1) and < 6 (group 2). RESULTS: It was include 120 patients who met the inclusions criterions. There was no difference between the groups in related to age, gender, time of cardiopulmonary bypass and surgery. However, the incidence of thrombosis was higher in group 1 (23% vs. 0%, P<0.0001), as well as the greater score is related to higher hospital mortality rate. CONCLUSION: The score > 6, in postoperative cardiac surgical patients, it is associated to higher incidence of thrombosis as well as the greater score is related to higher hospital mortality rate.

Trombocitopenia em cirurgia cardíaca: importância diagnóstica e prognóstica / Thrombocytopenia in cardiac surgery: diagnostic and prognostic importance

OBJETIVO: Pacientes submetidos à cirurgia cardíaca estão mais propensos a desenvolver plaquetopenia. A trombocitopenia induzida por heparina acomete cerca de 5% dos pacientes. O objetivo foi avaliar a importância clínica da trombocitopenia grave em pacientes no pós-operatório de cirurgia cardíaca. MÉTODOS: Estudo prospectivo observacional que incluiu os pacientes de cirurgia cardíaca com plaquetas <150.000 cel/mm³, durante as primeiras 24 h do pós-operatório. Todos os pacientes foram submetidos a avaliação pelo escore dos quatro "Ts" (trombocitopenia, uso de heparina prévia, trombose e queda de plaquetas não relacionada à heparina) e considerado como suspeita de trombocitopenia induzida pela heparina tipo II um escore > 6. A mortalidade na Unidade de Terapia Intensiva (UTI) e hospitalar, o tempo de internação, os escores de gravidade e a incidência de tromboses foram comparados em pacientes com escore e" 6 (grupo 1) e < 6 (grupo 2). RESULTADOS: Foram incluídos 120 pacientes divididos nos dois grupos, não havendo diferença entre os mesmos com relação a idade, prevalência do sexo, tempo de circulação extracorpórea e de cirurgia. Contudo, a incidência de trombose foi mais elevada nos pacientes do grupo 1 (23% vs. 0%, P<0,0001), assim como quanto maior o escore maior a mortalidade hospitalar (P<0,001). CONCLUSÕES: O escore > 6, em pacientes no pós-operatório de cirurgia cardíaca, está associado a maior incidência de trombose, assim como o maior escore está relacionado à elevada mortalidade hospitalar.

OBJECTIVE: Patients undergo to cardiac surgery have more probability to develop thrombocytopenia. The heparin induced thrombocytopenia happens in 5% of the patients. The aim from this study was to evaluate the clinical importance from the severe thrombocytopenia in postoperative cardiac surgical patients. METHODS: It was included cardiac surgical patients with platelets < 150000 cel/mm³ during firsts 24 h from postoperative. All patients underwent evaluation for four Ts score (thrombocytopenia, use preview of heparin, thrombosis and platelets decreased not related to heparin). In order to a four Ts score e" 6 was considered as suggestive of heparin induced thrombocytopenia type II. The mortality rate in intensive care (ICU) and hospital, length of stay, healthy state and incidence from thrombosis were compared in patients with score > 6 (group 1) and < 6 (group 2). RESULTS: It was include 120 patients who met the inclusions criterions. There was no difference between the groups in related to age, gender, time of cardiopulmonary bypass and surgery. However, the incidence of thrombosis was higher in group 1 (23% vs. 0%, P<0.0001), as well as the greater score is related to higher hospital mortality rate. CONCLUSION: The score > 6, in postoperative cardiac surgical patients, it is associated to higher incidence of thrombosis as well as the greater score is related to higher hospital mortality rate.

Importance of multi-lineage hematologic involvement and hypoalbuminemia at diagnosis in patients with "risk-organ" multi-system Langerhans cell histiocytosis.

AIM: To perform a risk factor analysis in patients with "risk organ" multi-system Langerhans cell histiocytosis at diagnosis. METHODS: From 1987 to 2007, 77 patients were analyzed. A univariate analysis of the variables, age <2 years, lungs, spleen and hepatic involvement, presence of >or=2 risk involved organs, hypoalbuminemia and the presence of isolated anemia, anemia with thrombocytopenia with or without leukopenia at diagnosis was performed. Statistically significant variables were combined and entered into a multivariate analysis. RESULTS: Fifty-six and 66 evaluable patients had hematologic and hepatic involvement at diagnosis, respectively. Among the hematologic patients, the subgroup of anemia with thrombocytopenia with or without leukopenia showed a significantly lower 5-year survival than the subgroup of isolated anemia (0.19 vs. 0.87, respectively; P=0.0001). Of all the patients, those with hypoalbuminemia had a 5-year survival of 0.16 compared with those with normal albumin levels, who had a 5-year survival of 0.65 (P<0.0001). In multivariate analysis, only anemia with thrombocytopenia with or without leukopenia and hypoalbuminemia were the independent risk factors (relative risk 3.77; confidence interval, 1.7-8.4; P<0.0011 and relative risk 2.59; confidence interval, 1.24-5.4; P<0.0112). CONCLUSIONS: Anemia with thrombocytopenia with or without leukopenia and hypoalbuminemia, were associated with worse prognosis in multi-system Langerhans cell histiocytosis. Other therapeutic strategies should be considered at diagnosis or early during the initial treatment for this high risk subgroup of patients.

Disease activity, damage and survival in Mexican patients with acute severe systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a clinical syndrome of varying severity. Although the survival and prognosis of SLE have steadily improved, there is a group of patients who present an acute fatal outcome despite aggressive therapy. We designed this study to evaluate the factors associated with mortality in patients with acute severe SLE. During 2004-06, 41 Mexican SLE patients that could not be managed in the out-patient clinic and with acute severe major organ system involvement [nephritis, severe thrombocytopenia (platelet count below 20 000 per microL) acute neuropsychiatric pulmonary, gastrointestinal or cardiac disease and generalized vasculitis] were studied. During the first admission, disease activity (SLE Disease Activity Index (SLEDAI), SLE Activity Measured), damage [SLE International Collaborating Clinics (SLICC)], and therapy were assessed. Survival using Kaplan-Meier curves, odd ratios with 95% confidence interval and logistic regression analysis were used to determine risk factors for mortality. Ninety percent were female with a mean age of 29 +/- 19 years and mean disease duration of 21 +/- 9 months. The principal causes of first admission were renal (27%), SNC (22%) and cardiopulmonary (15%). After a mean follow-up of 9.7 +/- 6 months, 16 (39%) patients died. Deceased patients had significantly higher SLEDAI (P = 0.004), and SLICC (P = 0.03) scores. The manifestations associated with mortality were renal disease activity (odds ratio, OR 4.6, confidence interval, CI 95% 1.0-20.6), infections (OR 3.2 CI 95% 2.0-5.3) and thrombocytopenia (OR 4.0, CI 95% 1.0-15.9). The survival at 9.7 months was 72, 62 and 50% in patients with an SLEDAI score of 3-10, 11-20 and > or =21, respectively. The SLEDAI score, the presence of damage and infection were associated with death in patients with acute severe SLE.

[Maternal and perinatal surgical complications in low platelet count for HELLP syndrome in severe preeclampsia-eclampsia in intensive care]. / Complicaciones quirúrgicas maternas y perinatales en pacientes con plaquetopenia por síndrome de HELLP, en preeclampsia severa-eclampsia en terapia intensiva.

The preeclampsia is the first cause of maternal morbility, with increase in the obstetric complications when it is associated to HELLP syndrome, for the low platelets that even involves to the neonate. This study was carried out in the patients accepted in the intensive Adults Cares Unit in the period of one year, surgical complications and the perinatal results were determined in women with low platelet count for HELLP syndrome in preeclampsia-eclampsia. Three groups were formed according to the platelets account and then were analyzed using chi square to determine association among these groups of patients, as well as mean and standard deviation (M +/- DE) to describe results. Forty patients were studied with low platelets by HELLP syndrome in preeclampsia-eclampsia, where the distribution for the group with platelets < 50,000 were 12 patients (30%), in the group among 51,000-100,000 of 18 cases (45%), and of 101,000-150,000 were of 10 cases (25%). The mean of gestas was of 2.3 +/- 1.2, more frequent delivery was for cesarean section in 39 cases (97.5%) and a single case for vaginal via (2.5%), a maternal death was presented (8.3%). The surgical reintervention was observed with more frequency in the group of < 50,000 platelets, the most frequent cause in these reinterventions was the hipovolemic shock. Also in this group the perinatal mortality was presented in 3 cases (25%) and the asphyxia at the birth with Apgar < 6 was presented in 5 cases (41.7%). A bigger morbility was observed inversely proportional to the account platelets, being the renal failure the cause most frequent of this morbility in the three groups. The low platelets account contribute in a direct way in the obstetric complications, since there are more surgical reinterventions, with bled in the transsurgical and increase in the days of intrahospitalary stay. Also with smaller account platelet, there are bigger prematural index, asphyxia and perinatal mortality in the newborn of mothers with HELLP syndrome.

Thrombocytopenia and thromboembolism in pediatric systemic lupus erythematosus.

To define in children with systemic lupus erythematosus (SLE) the incidence, outcome, and association of thrombocytopenia with other SLE manifestations, specifically thromboembolic events (TEs), we retrospectively reviewed 106 pediatric patients with SLE diagnosed between 1992 and 2001. Thrombocytopenia was found in 50%, which was of a moderate or severe degree in 34%. The thrombocytopenia was sustained in 29% of all patients. Twelve patients were diagnosed with autoimmune thrombocytopenic purpura 2 to 69 months before the diagnosis of SLE. Of them, 10 children required treatment, and three patients underwent splenectomy. TEs occurred in 10.4% of the total cohort of 106. Lupus anticoagulant, but not anticardiolipin antibodies and sustained thrombocytopenia, were associated with a higher risk for TEs.

Trombocitopenia con trombosis inducida por heparina / Thrombocytopenia with thrombosis induced by heparine

Heparin induced thrombocytopenia with thrombosis (HITTS) is a syndrome with broad spectrum of clinical features that has been diagnosed with more frequency, Up to 5 per cent of patients exposed to heparin develop some type of manifestations. The etiology is probably related with the development of antibodies against a complex between heparin and platelet factor 4. The mortality is close to 25 per cent in patients who develop the thrombotic spectrum of the syndrome. This is a review about HITTS and the new alternatives for anticoagulation in experimentation today.

Síndrome de Wiskott Aldrich / The Wiskott-Aldrich syndrome

Introducción. El síndrome de Wiskott-Aldrich es un padecimiento recesivo ligado al cromosoma X, caracterizado por la triada de eccema, trombocitopenia e inmunodeficiencia variable, generalmente letal por la tendencia a infecciones graves. Caso clínico. Se describe el caso de lactante masculino de seis meses de edad quien manifestó inicialmente eccema a los 20 días de vida y cinco meses después se hicieron aparentes infecciones y petequias corroborándose trombocitopenia. Conclusiones. Tener presente esta posibilidad en el paciente varón con eccema, trombositopenia y tendencia a infecciones ya que se tiene la opción terepéutica del transplante de médula ósea

Thrombocytopenia and leptospirosis

O proposito do presente trabalho e colaborar para o estudo da patogenia da plaquetopenia que ocorre na Leptospirose. A pesquisa foi feita de maneira prospectiva e o grupo de casos foi constituido por 30 pacientes internados com hipotese diagnostica de Leptospirose na Clinica de Doencas Infecciosas e Parasitarias do Hospital das Clinicas da Faculdade de Medicina de Sao Paulo. Investigou-se a possibilidade de haver consumo de plaquetas por coagulacao intra vascular disseminada, ou a possibilidade de destruicao periferica de plaquetas por anticorpos e, se poderia haver inibicao da producao de plaquetas em nivel medular. Para a investigacao desejada foram utilizados os seguintes exames: contagem de plaquetas, tempo de protrombina, tempo de recalcificacao, tempo de trombina, tempo de tromboplastia parcial ativada, dosagem do fibrinogenio, dosagem do fator V, dosagem do fator VIII, dosagem dos produtos de degradacao da fibrina, dosagem da antitrombina III, mielograma e pesquisa de anticorpos antiplaquetas. Foram ainda estudados o hemograma, a dosagem de ureia, a dosagem de creatinina, a dosagem das enzimas hepaticas (aspartatoaminotransferase, alaninaaminotransferase, desidrogenase lactica, gamaglutamiltranspeptidade e fosfatase alcalina), e a dosagem das bilirrubinas. A analise dos dados obtidos no presente trabalho