Sex and age as prognostic factors in essential thrombocythemia.

BACKGROUND. The major causes of morbidity and mortality in essential thrombocythemia (ET) are bleeding and thrombotic accidents, but a prognostic pattern for these complications has not yet been discovered. MATERIALS AND METHODS. In this study we report data from a large cohort of patients with thrombocytosis, distinguished for sex and age, in order to define their thrombotic risk. The prevalence of vascular complications recognized in 86 patients with essential thrombocythemia was studied. In addition, 91 patients with polycythemia vera (PV), 20 with myelofibrosis (MF) and 63 with secondary thrombocytosis (ST) were evaluated. RESULTS. 6.3% of ET subjects younger than 40 (4.6% of males and 7.0% of females), 11.8% of patients between 40 and 65 years old (14.9% of males and 9% of females), and 16.8% of subjects over 65 (14.6% of males and 17.8% of females) showed thrombotic accidents. In the PV and MF groups thromboses occurred more frequently than in the ET groups for all ages and for both sexes. On the contrary, ST subjects showed fewer thromboses than ET patients, but their incidence rose with patient age; moreover the prevalence of males in this group was limited. In ET patients, particularly in females, the incidence of thrombosis was low under 40 years of age, but rapidly increased later. CONCLUSIONS. ET females over 40 must be followed with particular attention in order to prevent thrombotic complications.     

Polycythemia vera and essential thrombocythemia: 2012 update on diagnosis, risk stratification, and management

DISEASE OVERVIEW: Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms primarily characterized by erythrocytosis and thrombocytosis, respectively. Other disease features include leukocytosis, splenomegaly, thrombohemorrhagic complications, vasomotor disturbances, pruritus, and a small risk of disease progression into acute myeloid leukemia or myelofibrosis. DIAGNOSIS: Almost all patients with PV harbor a JAK2 mutation. When PV is suspected, the presence of a JAK2 mutation confirms the diagnosis and its absence, combined with normal or increased serum erythropoietin level, excludes the diagnosis. Differential diagnosis of ET had to include chronic myelogenous leukemia and prefibrotic myelofibrosis. A JAK2 mutation is found in approximately 60% of patients with ET. RISK STRATIFICATION: Current risk stratification in PV and ET is designed to estimate the likelihood of thrombotic complications: high-risk is defined by the presence of age >60 years or presence of thrombosis history; low-risk is defined by the absence of both of these two risk factors. Presence of extreme thrombocytosis (platelet count >1,000 × 10(9)/L) might be associated with acquired von Willebrand syndrome (AvWS) and, therefore, risk of bleeding. Risk factors for shortened survival in both PV and ET include advanced age, leukocytosis, and history of thrombosis. RISK-ADAPTED THERAPY: Survival is near-normal in ET and reasonably long in PV. The 10-year risk of leukemic/fibrotic transformation is <1%/1% in ET and <3%/10% in PV. In contrast, the risk of thrombosis exceeds 20%. The main goal of therapy is therefore to prevent thrombohemorrhagic complications and this is effectively and safely accomplished by the use of low-dose aspirin (PV and ET), phlebotomy (PV) and hydroxyurea (high risk PV and ET). Treatment with busulfan or interferon-α is usually effective in hydroxyurea failures. Screening for clinically significant AvWS is recommended before administrating aspirin in the presence of extreme thrombocytosis.     

Thrombotic complications of polycythemia vera

Abstract

Background: Polycythemia vera (PV) is an uncommon clonal disorder of stem cells. The literature regarding the thrombotic complications of this disorder in the developing countries is scarce. The present study was undertaken retrospectively to look at the association of thrombotic complications of PV with various patient characteristics.

Materials and methods: All the patients diagnosed to have PV from January 1986 to December 2005 according to Polycythemia Vera Study Group criteria were included. Their clinical characteristics, laboratory parameters, clinical complications such as thrombosis and myelofibrosis, treatment modalities, malignancies and deaths, if any were noted. The various characteristics of patients who had developed thrombosis were compared statistically with those of patients without thrombosis.

Results: Out of the 9550 patients seen during this period, 32 patients fulfilled the inclusion criteria. The median age at the time of diagnosis was 56·5 years. Eight patients developed thrombotic complications; out of which four had arterial and four had venous thrombosis. There was no statistically significant difference in the mean hemoglobin, white cell count (WBC), platelet count and RBC mass in patients with thrombosis as compared to patients without thrombosis. These parameters were also not statistically significant when patients with arterial thrombosis were compared with patients with venous thrombosis.

Conclusions: PV is an uncommon disorder when compared with other hematological disorders in northern India. There was no relationship between the development of thrombotic complications and hemoglobin, RBC mass or platelet count. Twenty patients received hydroxyurea with a median follow-up of 57 months, none developed acute leukemia.     

Hemorrhagic and thrombotic complications in polycythemia vera. A clinical study

This study reviewed the clinical and hematologic characteristics of 161 patients with polycythemia vera treated with myelosuppressive agents, with or without antiaggregating platelet therapy, in order to determine the features associated with a risk of hemorrhagic or thrombotic complications. At presentation, 7 patients (4.3%) showed hemorrhages and 36 (22%) complained of thrombotic events. None of the evaluated clinical and hematologic parameters was significantly related to hemorrhagic or thrombotic presentation. During the clinical course, four of 107 patients (3.7%) experienced hemorrhagic complications and 34/107 patients (28%) complained of occlusive events, which accounted for 30% of total deaths. Among the clinical and hematologic presenting features, only age over 60 yrs could be identified as an unfavorable prognostic factor for the occurrence of thromboembolic episodes. Marked thrombocytosis, a high packed cell volume (PCV) and the thrombotic onset were not significantly related to the thrombotic risk. Platelet count and PCV at the time of the occlusive episode did not correlate with the clinical event; however, inadequate control of the proliferative disease seemed to increase the thrombotic tendency. Antiaggregating drugs, although unable to avoid thrombosis in our experience, might be safely associated with the myelosuppressive therapy, particularly in selected patients.     

Platelet hyperaggregability and thrombosis in patients with thrombocythemia

The relation between platelet hyperaggregability and thrombosis was assessed in 28 patients with thrombocythemia due to myeloproliferative diseases and 11 with reactive thrombocytosis. None of the patients with reactive thrombocytosis had thrombotic or hemorrhagic complications, but thrombosis was noted in seven patients and bleeding in two patients with thrombocythemia. Nineteen were asymptomatic. In patients with thrombosis, bleeding time, platelet glass retention, and clot retraction were normal, but evidence of platelet hyperaggregability was present in all but one. Serial studies on six patients revealed a close association between platelet hyperaggregability and ischemic attacks. Neither patient with bleeding complications had evidence of platelet hyperaggregability, although poor platelet function was found in one. Platelet function in asymptomatic patients can be classified as hyperactive, hypoactive, or normal.     

Vascular complications of essential thrombocythaemia: a link to cardiovascular risk factors

Essential thrombocythaemia (ET) is a myeloproliferative disorder characterized by absolute thrombocytosis and increased incidence of thrombosis and haemorrhage. We report higher morbidity in patients with ET due to arterial ischaemic complications when cardiovascular risk factors are present. In this retrospective analysis of 46 patients, arterial complications occurred in 20/46 patients (43.4%); patients with cardiovascular risk factors, especially cigarette smoking, had more than twice as many arterial complications than patients without risk factors (62.5% v 22.7%, P <0.05). Neither age, gender nor degree of thrombocytosis were linked to the number of complications. In contrast, we observed no association between cardiovascular risk factors and venous thrombosis or haemorrhagic complications of ET.     

Incidence and clinical risk factors for bleeding and thrombotic complications in myeloproliferative disorders

Summary Bleeding and thrombosis are frequent complications in myeloproliferative disorders (MPD) and are associated with severe organ damage and a high mortality. Elevated platelet count, elevated hematocrit, and patient age are regarded as risk factors for bleeding and thromboembolic events in MPD, although the significance of these parameters was not confirmed by clinical studies. We retrospectively analyzed vascular complications in 260 patients with MPD and tried to identify parameters predictive for bleeding and thromboembolic events. Our cohort consisted of 115 patients with chronic myeloid leukemia (CML), 84 patients with polycythemia vera (PV), 26 with essential thrombocythemia (ET), 25 with osteomyelofibrosis (OMF), and 10 patients with unclassifiable MPD. During a median follow-up period of 31 months, 126 patients with chronic MPD suffered bleeding or thrombotic events. Bleeding was observed in 57% of patients with OMF, 23% with PV, 20% with chronic phase CML, and 16% with ET. Thrombotic events were most common in patients with PV (36% of patients), followed by ET, OMF, and chronic phase CML (20%, 17%, and 6% of patients, respectively). Recurrent thrombotic episodes frequently occurred in patients with PV and ET, whereas patients with OMF often had more than one bleeding event. Thirty patients died of thrombohemorrhagic complications during follow-up. Multivariate analysis, including all patients with chronic MPD, revealed that elevated red blood cell count, higher hemoglobin level, and increased percentage of segmented neutrophils at the time of diagnosis were associated with thrombosis, whereas patients with bleeding complications were characterized by low red cell count, lower hemoglobin, and a lower percentage of segmented neutrophils. However, when analyzed by MPD subgroup, none of these parameters retained a predictive value for bleeding or thrombotic events. Moreover, elevated platelet count and patient age were not risk factors for bleeding complications. Thrombotic events were less frequent in patients below the age of 40, and were increased in patients aged 70 and above. However, this was primarily due to the high percentage of elderly patients in subgroups mainly affected by thrombosis (PV and ET). In most MPD subgroups, the rate of bleeding and thrombosis was highest just before and during the first months after diagnosis, and declined thereafter. Thrombohemorrhagic complications were less frequent after phlebotomy in PV and after therapy with alkylating agents in CML. The institution of cytoreductive therapy soon after the diagnosis was made may explain the reduced incidence of complications later in the disease. We conclude that morbidity and mortality from thrombohemorrhagic complications are high in myeloproliferative disorders. Subgroup and stage of the disease and previous complications are helpful in estimating the risk of a bleeding or thrombotic event. Conventional cytoreductive therapy may result in a reduction of these complications.     

Aetiology and clinical significance of thrombocytosis: analysis of 732 patients with an elevated platelet count

OBJECTIVE: To determine the aetiology and clinical significance of an elevated platelet count (thrombocytosis) in a large cohort of patients. DESIGN: A retrospective review of the medical records was performed on all patients, who had at least one platelet count > or = 500 x 10(9) L-1. SETTING: Departments of Medicine and Surgery, University of Ulm, Germany. SUBJECTS: A total of 732 patients with thrombocytosis. MAIN OUTCOME MEASURES: Classification of thrombocytosis and thromboembolic complications, and evaluation of laboratory parameters distinguishing between primary and secondary thrombocytosis. RESULTS: Of the total of 732 patients, 89 (12.3%) had primary and 643 (87.7%) had secondary thrombocytosis. Essential thrombocythaemia was observed in 40 of 89 patients (45%) with primary thrombocytosis. The most frequent causes of secondary thrombocytosis were tissue damage (42%), infection (24%), malignancy (13%) and chronic inflammation (10%). Primary thrombocytosis was significantly associated with a higher platelet count and an increased incidence of both arterial and venous thromboembolic complications. In secondary thrombocytosis, thromboembolic events were restricted to the venous system and occurred only in the presence of other risk factors. Mean values of leucocyte count, haematocrit, erythrocyte sedimentation rate, fibrinogen, serum potassium and lactate dehydrogenase were significantly different in primary and secondary thrombocytosis. CONCLUSIONS: The finding of an elevated platelet count on routine blood examination has diagnostic, prognostic and therapeutic implications. It is of clinical importance to distinguish between primary and secondary thrombocytosis, as thrombotic complications occur more frequently in primary thrombocytosis. Unless additional risk factors are present, secondary thrombocytosis is not associated with a significant risk for thromboembolic events.     

An increased prevalence of fibromyalgia in iron deficiency anemia and thalassemia minor and associated factors

In this study, we evaluated the prevalence of fibromyalgia (FM) in iron deficiency anemia (IDA) and thalassemia minor (TM) patients and associated factors. In addition, we investigated the prevalence of IDA in outpatients with fibromyalgia, and its effect on clinical findings. The study included 205 IDA, 40 TM patients and 100 healthy controls. FM was diagnosed according to 1990 ACR criteria. Whole blood count, biochemical tests, and serum iron parameters were determined. Pain, fatigue, and FM Impact Questionnaire (FIQ) functional item scores were assessed in FM subjects. In addition, the prevalence of IDA in FM patients diagnosed at the Rheumatology Outpatient Clinic was determined. The prevalences of FM in IDA (17.6%) and TM (20%) groups were higher than in controls (6%; p values 0.006 and 0.025, respectively). When IDA patients with FM were compared to those without FM, it was seen that a higher percentage were females, married, and a higher percentage had history of pica (all p values < 0.05). Serum hemoglobin and iron parameters did not differ between IDA patients with and without FM. IDA was detected in 48 (24.5%) of 196 FM patients. FM patients without IDA had higher sleep disturbance scores (p = 0.012) and longer duration of FM (p = 0.045). FM was a common finding in patients with IDA and TM. FM was associated with female sex and history of pica in IDA patients, and not associated with serum hemoglobin and selected iron parameters. The presence of FM in TM had no association with any of the above-mentioned parameters.     

Annual Clinical Updates in Hematological Malignancies: a continuing medical education series: polycythemia vera and essential thrombocythemia: 2011 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW: Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms primarily characterized by erythrocytosis and thrombocytosis, respectively. Other disease features include leukocytosis, splenomegaly, thrombohemorrhagic complications, vasomotor disturbances, pruritus, and a small risk of disease progression into acute leukemia or myelofibrosis. DIAGNOSIS: Diagnosis is based on JAK2 mutation status (PV and ET), serum erythropoietin (Epo) level (PV), and bone marrow histopathology (ET). The presence of a JAK2 mutation and subnormal serum Epo level confirm a diagnosis of PV. Differential diagnosis in ET should include chronic myelogenous leukemia and prefibrotic myelofibrosis. RISK STRATIFICATION: Current risk stratification in PV and ET is designed to estimate the likelihood of thrombotic complications: high-risk-age > 60 years or presence of thrombosis history; low-risk-absence of both of these two risk factors. Presence of extreme thrombocytosis (platelet count > 1,000 x 10?/L) might be associated with acquired von Willebrand syndrome (AvWS) and, therefore, risk of bleeding. Risk factors for shortened survival in both PV and ET include age > 60 years, leukocytosis, history of thrombosis, and anemia. RISK-ADAPTED THERAPY: Survival is near-normal in ET and reasonably long in PV. The 10-year risk of leukemic/fibrotic transformation is < 1%/1% in ET and < 5%/10% in PV. In contrast, the risk of thrombosis exceeds 20%. The main goal of therapy is therefore to prevent thrombohemorrhagic complications and this is effectively and safely accomplished by the use of low-dose aspirin (PV and ET), phlebotomy (PV), and hydroxyurea (high risk PV and ET). Treatment with busulfan or interferon-a is usually effective in hydroxyurea failures.     

Risk of thrombosis in patients with malignancy and heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a common immunological drug reaction. After exposure to heparin, some patients develop heparin dependent antibodies with no evidence of thrombosis, while others are at risk of thrombocytopenia, thrombosis, limb loss, and death. We conducted a retrospective chart review on all patients serologically positive for HIT by HPIA ELISA in a single tertiary-care hospital, to determine whether patients with malignancy had an increased risk of thrombotic complications. Medical records of 55 patients who tested positive for HIT and met clinical criteria for HIT were analyzed. All patients had been treated with unfractionated heparin. Malignancy was diagnosed in 11 patients, either at surgery or post-mortem examination. A higher rate of venous thrombosis and pulmonary embolism was observed in patients with HIT and malignant disease when compared to patients with no underlying malignancy (odds ratio 13.6, 95% CI 2.9-63.8).     

Heparin-induced thrombocytopenia with thrombosis: Incidence,analysis of risk factors,and clinical outcomes in 108 consecutive patients treated at a single institution

Heparin-induced thrombocytopenia with thrombosis (HITT) can lead to serious morbidity and may be potentially fatal. We reviewed our experience with this entity over a 4-year period, to determine the following: 1) incidence and type of thrombosis in patients with heparin-induced thrombocytopenia (HIT), 2) clinical consequences of thrombosis, i.e., amputation, cerebrovascular accidents and death, 3) risk factors associated with development of thrombosis, and 4) impact of therapy on clinical outcomes in patients with HITT. Between 1991–1994, 108 patients were diagnosed to have HIT by heparin-induced platelet aggregation test. Thirty-two (29%) of these developed thrombotic complications, of which 20 were venous, 8 arterial, and 4 both. Five of the 32 died, 3 underwent amputations, and 3 had cerebrovascular accidents. The patients who developed thrombotic complications, when compared to those with HIT alone, were older (68.7 ± 11.5 vs. 63.3 ± 16 years, P = .05), had more severe thrombocytopenia (platelet count 46,300 ± 30,400/mm³ vs. 62,500 ± 34,400/mm³, P = .02), and developed it earlier (6.0 ± 2.9 vs. 7.4 ± 3.1 days, P = .03). Multivariate analysis showed that severity of thrombocytopenia and early fall in platelet count were independent risk factors for development of thrombotic complications. We did not find an association between development of thrombosis and clinical events (myocardial infarction, cardiac procedures or surgery, noncardiac surgery, and sepsis) that occurred immediately prior to onset of thrombocytopenia. Heparin was stopped in all 32 patients with HITT. Six received no additional therapy, and one received a single dose of aspirin. Three of these 7 died. The other 25 received anticoagulant or multiagent therapy, with 2 deaths. The death rate was lower in those who were treated with anticoagulant or multiagent therapy (P = .05). We conclude that: 1) Thrombotic complications occur in about 29% of hospitalized patients who develop HIT. 2) Early, severe fall in platelet count in elderly patients receiving heparin appears to be associated with development of thrombotic complications. 3) Our data do not show an association between development of thrombotic complications and clinical events immediately preceding the diagnosis of HIT. 4) In addition to discontinuation of heparin, anticoagulant or thrombolytic therapy should be considered in patients with HITT. Am. J. Hematol. 56:12–16, 1997. © 1997 Wiley-Liss, Inc.     

Risk factors of long-term incidences of thrombosis, myelofibrosis and evolution into malignance in polycythemia vera: a single center experience from China

To find out risk factors of incidences of long-term complications of thrombosis, myelofibrosis with myeloid metaplasia (MMM) and evolution into malignance in Chinese PV patients, we evaluated 320 PV patients referred to our center from April 1984 to June 2005 by Kaplan–Meier estimation and Cox proportional hazards models. A total of 250 events of thrombosis were observed in 138 (43.13%) patients. Advanced age, prior thrombosis and hemoglobin out of control were statistically significant risk factors of incidences of thrombotic events. A total of 43 patients progressed into MMM at a median time of 84 (7–240) months, higher white blood cell (WBC) count, splenomegaly, receiving alkylating agent and hydroxycarbamide were associated with the progression into MMM. During the follow-up time, 11 and 2 patients died of fatal complications of thrombosis and acute myeloid leukaemia (AML), respectively. These results suggest that advanced age, prior thrombosis and hemoglobin out of control contributed to relatively high incidence of thromboembolism; higher WBC count, splenomegaly, receiving alkylating agent and hydroxycarbamide were risk factors of evolution to MMM. The main poor factors that influenced the survival of Chinese PV patients were incidences of thromboembolism and evolution into AML.     

The expression pattern of c-mpl in megakaryocytes correlates with thrombotic risk in essential thrombocythemia

Using immunohistochemistry, we investigated the expression of c-mpl in bone marrow megakaryocytes of 88 patients with essential thrombocythemia (ET), 6 patients with secondary thrombocytosis (ST), and 20 patients with lymphoma (controls). Considering both the pattern of expression and the staining intensity, we identified a uniform and a heterogeneous pattern of c-mpl expression. The uniform pattern was found in all the controls, all the patients with ST, and 28 of the patients with ET, with a strong staining intensity observed in most megakaryocytes (> 80%). In contrast, c-mpl expression was heterogeneous in 60 patients with ET, 18 of whom (30%) presented with thrombosis at diagnosis, a significant difference from patients with a uniform c-mpl pattern (2 of 28; 7%; P =.026). In particular, the overrepresentation of thrombotic complications in patients with a heterogeneous c-mpl expression pattern was found mainly among patients with a significant percentage (10% to 40%) of weakly stained or c-mpl-negative megakaryocytes (heterogeneous-weak pattern; 13 of 30; 43%; P =.002). Accordingly, this pattern was associated with a 6.1-fold increased risk of thrombosis compared with that of patients with a uniform c-mpl pattern. In conclusion, the presence of a heterogeneous pattern of c-mpl distribution in bone marrow megakaryocytes could be a useful diagnostic criterion in the differential diagnosis of thrombocytosis. Furthermore, detection of a significant percentage of weakly stained or c-mpl-negative megakaryocytes can identify patients with a higher risk of thrombosis.     

Prognostic utility of spontaneous erythroid colony formation and JAK2 mutational analysis for thrombotic events in essential thrombocythaemia

Background: Thrombotic events in essential thrombocythaemia (ET) are difficult to predict with current risk stratification based on age and prior history of thrombosis. Aims: We aimed to assess the predictive value of the JAK2 V617F mutation (JAK2) and spontaneous erythroid colony (SEC) growth for the development of thrombotic events post diagnosis in patients with ET. Methods: Consecutive patients with ET were retrospectively identified, and clinical and laboratory correlates were evaluated. Thrombotic events were categorized according to their occurrence at or prior to diagnosis (prior thrombosis), and any time post diagnosis of ET (subsequent thrombosis). JAK2 analysis was performed by allele‐specific PCR on whole blood or bone marrow. Results: A total of 62 patients was identified, median age 63 years; 67% (41/61) JAK2‐positive and 47% (25/53) SEC‐positive. Median follow‐up was 33 months (range, 1 to 137). JAK2‐positive patients showed a trend to increased prior thrombosis (27% vs 5%, P= 0.08), and a significant increase in the development of subsequent thrombosis (5‐year event rate 31% vs 6%, P= 0.04), which persisted when stratified for a history of prior thrombosis (P= 0.04). Survival was not affected by JAK2 status. The SEC assay predicted an increased rate of baseline thrombosis (16% vs 0%, P= 0.04), but was not found to be predictive of any subsequent thrombotic events. Conclusions: Patients with ET who are JAK2‐positive by whole blood allele‐specific PCR appear to be at increased risk of thrombotic complications, which is independent of a prior history of thrombosis.     

Hereditary thrombocytosis caused by MPLSer505Asn is associated with a high thrombotic risk, splenomegaly and progression to bone marrow fibrosis

Background

The MPL^Ser505Asn mutation has been reported to be a cause of hereditary thrombocythemia. Recently, we detected this mutation in a large proportion of children with familial thrombocythemia, suggesting that in Italy the incidence of MPL^Ser505Asn mutation could be underestimated.

Design and Methods

We extended the search for this mutation to all patients with essential thrombocythemia who had a positive family history for thrombocytosis or essential thrombocythemia. We identified eight Italian families positive for the MPL^Ser505Asn mutation. Clinical and hematologic data were available for members of seven families, including 21 patients with a proven mutation and 20 relatives with thrombocytosis.

Results

Fifteen major thrombotic episodes, nine of which were fatal, were recorded among 41 patients. The thrombotic manifestation was stroke in four cases, myocardial infarction in seven cases, fetal loss in two cases, deep vein thrombosis of the leg in one case and Budd Chiari syndrome in one case. Almost all patients over 20 years old had splenomegaly and bone marrow fibrosis, while these were rarely observed in patients under 20 years old, suggesting that these manifestations are associated with aging. Finally, the life expectancy of family members with thrombocytosis was significantly shorter than that of members without thrombocytosis (P=0.003).

Conclusions

Patients with familial thrombocytosis caused by a MPL^Ser505Asn mutation have a high risk of thrombosis and, with aging, develop splenomegaly and bone marrow fibrosis, significantly affecting their life expectancy.     

Hemostatic gene polymorphisms and the prevalence of thrombotic complications in polycythemia vera and essential thrombocythemia.

Patients with polycythemia vera and essential thrombocythemia are at risk for thrombotic and bleeding complications. Currently, no diagnostic test can predict thrombohemorrhagic complications. In a prospective study of 86 patients with polycythemia vera (43 patients) or essential thrombocythemia (43 patients), we examined the possible role of polymorphisms of platelet adhesion receptors [glycoprotein (GP) Ibalpha, GPIa, GPIIIa) and clotting factor II (prothrombin's G20210A mutation) and clotting factor V (Leiden mutation) in determining the risk of thrombotic or bleeding complications. Except for an association between vasomotor symptoms and prothrombin mutation (P < 0.001), no significant correlation between polymorphism of clotting factors and thrombohemorrhagic complications was identified. When the entire patient cohort was considered, the polymorphisms of platelet adhesion receptors were not associated with the risk for thrombotic or bleeding complications. However, among patients with polycythemia vera, the presence of the PlA2 allele of GPIIIa was associated with an increased risk of arterial thrombosis. In view of previous studies linking the presence of the PlA2 allele of GPIIIa to a higher risk for coronary artery thrombosis, our data have physiologic relevance. However, they need to be confirmed in a larger study.     

Thrombosis in antithrombin-III-deficient persons. Report of a large kindred and literature review.

PURPOSE: To estimate the prevalence of objectively proven thrombotic complications in antithrombin-III-deficient persons. STUDY DESIGN: Cross-sectional study and a critical review of the literature. DATA SOURCES AND EXTRACTION: The prevalence of thrombosis in antithrombin III-deficient and -nondeficient family members of a large kindred was estimated by history, review of diagnostic tests, and examination for venous reflux by Doppler ultrasonography, as an indicator of previous venous thrombosis. A MEDLINE search and literature review of the published English- and French-language literature from 1966 to 1990 that described antithrombin-III-deficient families was done, and the following information was obtained: the prevalence of thrombosis in deficient and nondeficient family members, the presence or absence of risk factors for thrombosis (surgery, pregnancy, the postpartum state, use of oral contraceptives, immobilization, metastatic cancer, major trauma) at the time of the thrombotic event, and age of onset of the first episode of thrombosis. The validity of the studies was assessed according to predetermined criteria. RESULTS: Sixty-seven research subjects were evaluated. Six of 31 (19.4%) antithrombin-III-deficient subjects compared with none of 36 (0%) nondeficient subjects had had one or more thrombotic events. The initial episode in five of six subjects had occurred in association with risk factors for thrombosis. The literature search indicated that the pooled prevalence of symptomatic venous thrombosis among the deficient subjects was 51%, but objective testing was done in only 17% of these subjects at the time of presentation. CONCLUSION: Based on the data from this antithrombin-III-deficient kindred, lifelong anticoagulant prophylaxis does not appear to be warranted in asymptomatic carriers, and prophylaxis could be limited to periods of high risk for thrombosis.     

Platelet count and platelet parameters in hemoglobin E carriers.

Hemoglobinopathies are an important inherited disorder with a high prevalence in Thailand. Of several hemoglobinopathies, hemoglobin E (Hb) disorder (beta 26, GAG-AAG, Glu-Lys) is the most common. Coagulation disorders in these patients have also been proposed. Even though thrombotic risks in the patients with hemoglobin disorders from standpoints of platelet dysfunction and coagulation factors are controversial, they are in favor of thrombosis due to thrombocytosis. A study was performed in 57 healthy subjects to evaluate platelet count and platelet parameters in hemoglobin E carriers compared to values in healthy subjects. Classified by standard hemoglobin electrophoresis, there were 46 healthy subjects and 11 hemoglobin E carriers. There are no significant differences in platelet count and platelet parameters between the two groups (p > 0.05). Although there are reports that indicate the change in the quality of platelet in hemoglobin E disorders, no quantitative disorder was detected. There was no trend toward increased platelet count in the HbE carriers.     

Thrombosis and hemorrhage in the critically ill cirrhotic patients: five years retrospective prevalence study

Background. Cirrhotic patients present a complex interaction between deficient synthetic liver function, hemodynamic abnormalities and superimposed conditions that alter coagulation system. This alters both coagulation and fibrinolytic processes,increasing bleeding and thrombosis risks. Particularly, critically ill cirrhotic patients represent a diagnostic challenge since they have multiple comorbidities making the thrombotic and bleeding risks unpredictable. The prevalence of bleeding and thrombosis in this subset of patients remains poorly described. The main aim of this article is to describe the prevalence of thrombotic and hemorrhagic complications in cirrhotic patients admitted between 2007 and 2012 at Médica Sur Clinic and Foundation ICU.Material and methods. We performed a five years retrospective study including every cirrhotic patient admitted to ICU between January 2007 and December 2012.Results. The incidence of hemorrhage was 48.5%, the overall incidence of thrombotic complications was 13.66%. Variceal bleeding was the most prevalent hemorrhagic event and portal vein thrombosis the most common thrombotic event. Factors associated with presenting a bleeding episode included kidney injury, infection an thrombosis. Factors associated with increased thrombotic risk included ascitis,infection and bleeding.Conclusion. Critically ill cirrhotic patients have an high risk for both thrombotic and bleeding episodes. The association between the presence of bleeding and thrombotic events was statistically significant.