Essential thrombocythemia associated with recurrent abortions and fetal growth retardation

High Rate of Obstetric Complications in Patients With Essential Thrombocythemia

Background Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm characterized by persistently elevated platelet count without a clear secondary cause. Although most patients with ET are between 55 and 60 years of age, it has been estimated that 20% of women with ET are diagnosed during reproductive ages. Miscarriage is the most frequent complication of ET that has been hypothesized to be caused by microcirculatory disturbances and placental microinfarction. Furthermore, pregnant patients with ET are at increased risk of other pregnancy complications such as preterm delivery and intrauterine growth restriction. Methods This study was planned to evaluate pregnancy outcomes and predictors of obstetric complications in pregnant women with essential thrombocythemia (ET). The data of 21 patients with ET were analyzed retrospectively between 2016 and 2020. Age, parity, history of miscarriage, presence of Janus kinase 2 (JAK2) mutation, history of thrombotic events, treatment of thrombocytosis during pregnancy, and obstetrical outcomes including miscarriage were compared. Results Patients with ET had a significantly higher rate of history of two or more previous miscarriages. Miscarriage and obstetric complications in pregnant women with ET were found to be significantly higher than in the control group. Patients with ET with obstetric complications or miscarriage more frequently had a platelet count of >1000 × 103/μL. Acetylsalicylic acid (ASA) prevented miscarriages, but not obstetric complications, in patients with ET. Conclusion ET increases miscarriage and obstetric complications in pregnancy. Treatment with ASA may reduce pregnancy losses, but not obstetric complications.

Philadelphia chromosome-negative myeloproliferative neoplasms in younger adults: A critical discussion of unmet medical needs, with a focus on pregnancy

Myeloproliferative neoplasms (MPN) are traditionally regarded as a disease of older adults, though a not negligible fraction of cases occurs at a younger age, including women of childbearing potential. MPN in younger patients, indeed, offer several challenges for the clinical hematologist, that goes from difficulties in reaching a timely and accurate diagnosis to a peculiar thrombotic risk, with a relatively high incidence of thromboses in unusual sites (as the splanchnic veins or the cerebral ones). Moreover, the issue of pregnancy is recently gaining more attention as maternal age is rising and molecular screening are widely implemented, leading to a better recognition of these cases, both before and during pregnancy. In the present work we aim at discussing four clinical topic that we identified as areas of uncertainty or true unmet medical needs in the management of younger patients with MPN, with a particular focus on the topic of pregnancy. For each of these topics, we critically reviewed the available evidence that support treatment decisions, though acknowledging that recommendations in this field are mostly based on expert opinion or derived from guidelines of other clinical conditions that share with MPN a high vascular risk, as antiphospholipid syndrome. Taking into consideration both the lack of evidence-based data and the clinical heterogeneity of MPN, we support an individualized strategy of counseling and management for both young patients and for expectant mother with MPN.

Placental pathology in cancer during pregnancy and after cancer treatment exposure

Cancer during pregnancy has been associated with (pathologically) small for gestational age offspring, especially after exposure to chemotherapy in utero. These infants are most likely growth restricted, but sonographic results are often lacking. In view of the paucity of data on underlying pathophysiological mechanisms, the objective was to summarize all studies investigating placental pathology related to cancer(treatment). A systematic search in PubMed/Medline, Embase (OVID) and SCOPUS was conducted to retrieve all studies about placental pathology in cancer during pregnancy or after cancer treatment, published until August 2020. The literature search yielded 5784 unique publications, of which 111 were eligible for inclusion. Among them, three groups of placental pathology were distinguished. First, various histopathologic changes including maternal vascular malperfusion have been reported in pregnancies complicated by cancer and after cancer treatment exposure, which were not specific to type of cancer(treatment). Second, cancer(treatment) has been associated with placental cellular pathology including increased oxidative damage and apoptosis, impaired angiogenesis and genotoxicity. Finally, involvement of the placenta by cancer cells has been described, involving both the intervillous space and rarely villous invasion, with such fetuses are at risk of having metastases. In conclusion, growth restriction is often observed in pregnancies complicated by cancer and its cause can be multifactorial. Placental histopathologic changes, cellular pathology and genotoxicity caused by the cancer(treatment) may each play a role.

Contemporary management of patients with BCR-ABL1-negative myeloproliferative neoplasms during pregnancy

INTRODUCTION

The management of pregnancy during the course of BCR-ABL1-negative myeloproliferative neoplasms (MPN) is an increasingly relevant problem. This is mostly due to earlier and better diagnosis of MPN together with the trend in modern society toward delaying pregnancy until later life. Areas Covered: The present review aims to provide an overview of the available literature data concerning outcome of pregnancy in MPN. Possible therapeutic modalities are discussed and a management algorithm is suggested. Expert Commentary: Most data are available for women with essential thrombocythemia and we present 793 published pregnancies. Live birth rate is 68.5% with 31.5% miscarriages. Spontaneous abortion is the most frequent complication with 26.5%, followed by stillbirth with 4.8%. Maternal complications are relatively low with 1.8% major thrombotic and 2.4% major bleeding events. In polycythemia vera the situation is clinically more complex and roughly 150 pregnancy reports are available. There is very limited information in primary myelofibrosis with less than 20 reported pregnancies. With active management including control of blood counts, aspirin, low molecular weight heparin and in higher risk cases interferon alpha pregnancy in MPN is manageable with a success rate not far below the normal situation with 80%.

Pregnancy complications predict thrombotic events in young women with essential thrombocythemia

Although Philadelphia-negative myeloproliferative neoplasms (MPNs) occur typically in middle to advanced age, any age group may be affected, posing a challenge for their management during pregnancy when they occur in young females. There is a high incidence of thromboembolic events and pregnancy complications in patients with myeloproliferative neoplasms, and a possible relationship between these complications is a matter of concern. The aim of this article was to correlate thrombosis and pregnancy outcome in 158 females with ET experiencing 237 pregnancies. Seven patients had a thrombotic event before their first pregnancy, one of them ended (14.3%) in a miscarriage. Among the 151 patients with no history of thrombosis before they became pregnant, 40 (26.5%) had a miscarriage (P = NS). Eighteen patients (11.4%) developed major thrombotic complications (12 splanchnic vein, 1 cerebral vein, 2 coronary syndromes, and 3 strokes) after at least one pregnancy (4 uneventful and 14 complicated). The occurrence of thrombosis was significantly more frequent (P < 0.001) in patients with a history of pregnancy complications (28%) than in those experiencing a normal pregnancy and delivery (3.7%). Pregnancy complications in women with ET are associated with a higher risk of subsequent thromboses, so pregnant women with this neoplasm who miscarry need to be carefully monitored.

A systematic review of the fetal safety of interferon alpha

BACKGROUND

Interferon alpha (IFN) is an effective treatment for a variety of conditions including essential thrombocythemia (ET), chronic myelocytic leukemia, Hepatitis B and C. Because these conditions also occur in women of childbearing age who may become pregnant, information regarding the safety of this medication in pregnancy is essential. This systematic review attempts to summarize all published data on outcome of pregnancies exposed to IFN alpha, trying to differentiate between disease effect and drug effect.

METHODS

Reports on the use of IFN alpha in human pregnancy and reports on essential thrombocythemia (ET) without use of any medication in pregnancy were identified by a systematic search of the medical literature. We were able to locate only case reports of IFN alpha exposure in pregnancy, of whom 40 out of 63 were diagnosed with ET. We also collected randomly 71 cases (more cases were available in the literature) that were diagnosed with ET due to different etiologies, but who had not received any medication in pregnancy.

RESULTS

Among the 63 IFN alpha exposures in pregnancy, the mean maternal age was 30±6 years and the mean full term babies' weight was 3096±463 g. Mean gestational age at delivery was 37±3 weeks. There were 55 single and 4 twin pregnancies. No cases of major malformations or stillbirths were reported. There was one case of spontaneous abortion and 13 preterm deliveries (20% of all exposed cases). Among the 71 cases with untreated ET in pregnancy of different etiologies, 46 (65%) had early (within the first 12 weeks of pregnancy) or late (13-20 weeks of gestation) pregnancy loss. There were also 3 cases (4%) of stillbirth and 4 cases (5.6%) of preterm delivery. Only 18 women (25%) delivered healthy term babies.

CONCLUSIONS

The results of our systematic review suggest that IFN-α does not significantly increase the risk of major malformation, miscarriage, stillbirth or preterm delivery above general population rates. It is also possible that IFN-α may have a protective effect against pregnancy loss in cases of ET.

Outcome of 122 pregnancies in essential thrombocythemia patients: A report from the Italian registry

Pregnancy is a high-risk event in women with essential thrombocythemia (ET). This observational study evaluated pregnancy outcome in ET patients focusing on the potential impact of aspirin (ASA) or interferon alpha (IFN) treatment during pregnancy. We retrospectively analyzed 122 pregnancies in 92 women consecutively observed in the last 10 years in 17 centers of the Italian thrombocythemia registry (RIT). The live birth rate was 75.4% (92/122 pregnancies). The risk of spontaneous abortion was 2.5-fold higher than in the control population (P < 0.01). ASA did not affect the live birth rate (71/93, 76.3% vs. 21/29, 72.4%, P = 0.67). However, IFN treatment during pregnancy was associated with a better outcome than was management without IFN (live births 19/20, 95% vs. 73/102, 71.6%, P = 0.025), and this finding was supported by multivariate analysis (OR: 0.10; 95% CI: 0.013-0.846, P = 0.034). The JAK2 V617F mutation was associated with a poorer outcome (fetal losses JAK2 V617F positive 9/25, 36% vs. wild type 2/24, 8.3%, P = 0.037), and this association was still significant after multivariate analysis (OR: 6.19; 95% CI: 1.17-32.61; P = 0.038). No outcome concordance between first and second pregnancies was found (P = 0.30). Maternal complications occurred in 8% of cases. In this retrospective study, in consecutively observed pregnant ET patients, IFN treatment was associated with a higher live birth rate, while ASA treatment was not. In addition, the JAK2 V617F mutation was confirmed to be an adverse prognostic factor.

Management of Philadelphia negative chronic myeloproliferative disorders in pregnancy

The management of pregnancy in Philadelphia negative chronic myeloproliferative disorders (CMPDs) is an increasingly frequent problem. In the literature, most pregnancies are reported for women with essential thrombocythemia (ET) with about 400 pregnancies in about 200 women. In ET, first trimester abortion is the most frequent complication occurring in about one third of pregnancies. Interestingly, the incidence of maternal complications is relatively low with 3% for major thromboembolic and 2% for major bleeding events. The presence of the Jak2 mutation seems to be an independent predictor of pregnancy complications. Pregnancies in ET should be stratified according to underlying risk factors in low, high and highest risk pregnancies. Women with low risk pregnancies are treated with low-dose aspirin, whereas women with high and higher risk pregnancies may benefit from low-dose aspirin plus interferon alpha +/- low molecular weight heparin throughout pregnancy and at least for six weeks post-partum. In polycythemia vera (PV) there is only very few information on pregnancy outcome with 36 pregnancies reported in the literature. According to these data pregnancy in PV is per se a high risk situation. Accordingly, all women with PV should be treated with low-dose aspirin. Some pregnant PV patients may benefit from a more intensive therapy including interferon alpha +/- low molecular weight heparin throughout pregnancy and at least for six weeks post-partum.

Intracranial hemorrhage and hydrops in the fetus of a mother with thrombocytosis: implications for possible pathogenetic factors and therapy

We report a case of prenatally diagnosed intracranial hemorrhage and hydrops in the fetus of a mother with a past history of surgical and medical treatment for gastric lymphoma and having high platelet counts thereafter. To the best of our knowledge, such a complication of maternal thrombocythemia has not been described in the literature. In our opinion, the possible pathophysiology of the disease is based on placental insufficiency due to infarctions and related fetal platelet dysfunction, leading to intracranial hemorrhage with subsequent hydrops fetalis. The trigger in this event appears to be trauma to the maternal abdomen. Certain measures for high-risk mothers such as avoidance of trauma to the abdomen and platelet-lowering medications like interferon-alpha may be useful for preventing such fetal complications.

Hematological malignancy and pregnancy: a single-institution experience of 21 cases

The incidence of hematological malignancies during pregnancy is low, and treatment in this setting is problematic. This study observed 21 pregnancies in 18 patients with hematological malignancies. Patients' ages were between 19 and 43 (median 25) years. Two pregnancies ended with spontaneous abortion, one pregnancy ended with in utero death, three therapeutic abortions were carried out, and 15 infants were born alive but three of them died later. The median birth weight was 2.47 kg. Twelve babies survived to a median age of 36 (range 4-117) months. Eight babies were exposed to chemotherapy during the in utero period. One baby was exposed to chemotherapy during all the trimesters and was born prematurely and later died because of intracranial bleeding. Four babies were exposed to chemotherapy during the first trimester, one of them had low birth weight and floating thumb malformation, two of them had only low birth weight, and one was born healthy, but died at 3 months of age as a result of severe gastroenteritis. Two babies were exposed to chemotherapy during the second and third trimesters; one of them had low birth weight, and the other pregnancy ended in in utero death. One infant was exposed to chemotherapy during the third trimester and was born at term, but died because of pulmonary hemorrhage. We concluded that chemotherapy during all trimesters of pregnancy carries a significant risk for an unfavorable outcome.

Pregnancy and its management in the Philadelphia negative myeloproliferative diseases

The myeloproliferative diseases (MPDs) present several therapeutic challenges in patients of childbearing potential. The most extensive literature exists for patients with essential thrombocythaemia, with over 200 pregnancies reported in retrospective case series. Yet there is conflicting data in relation to predicting pregnancy outcome and optimal management strategy. Pregnancy is less frequently reported for polycythaemia vera and myelofibrosis. There is a need for collaboration to further our knowledge in this field. Here, the literature is reviewed in detail and experience of different therapeutic strategies in pregnancy discussed. There is increasing understanding about the pathogenesis of placental dysfunction in inherited thrombophilia and antiphospholipid antibody syndrome pregnancy outcomes in these conditions parallel those reported for MPDs. Furthermore several large studies have influenced pregnancy management in these conditions and, whilst not directly applicable to MPDs, this data have potential to inform treatment protocols. This data are reviewed and a personal management strategy for pregnancy in MPD proposed.

Platelet-derived soluble factors induce human extravillous trophoblast migration and differentiation: platelets are a possible regulator of trophoblast infiltration into maternal spiral arteries

In early pregnancy, human extravillous trophoblasts (EVTs) invade and remodel maternal arteries. We have previously demonstrated that CCR1 is expressed on perivascular/endovascular trophoblasts and that CCR1 ligands promote EVT migration. In this study, we examined the physiologic roles of platelet-derived chemoattractants on EVT invasion. By immunohistochemistry, maternal platelets were localized among endovascular trophoblasts within the lumen of spiral arteries. Extracellular matrices (ECMs) were also detected among endovascular trophoblasts and platelets, suggesting that the platelets in these arteries were activated by ECMs. In vitro, platelets attached to EVTs isolated from human villous explant cultures and expressed P-selectin on the cell surface. Platelets significantly enhanced migration of EVTs without affecting proliferation of EVTs or secretion of MMP-2 or MMP-9. The invasion-enhancing effect of platelet-derived culture medium on EVTs was neutralized by anti-CCR1 antibody. Heat treatment completely abrogated the invasion-promoting effects of platelet-derived culture medium, but charcoal stripping did not. Platelets also induced endovascular trophoblast-like morphologic changes and integrin alpha1 expression in EVTs during 48-hour culture. These findings suggest that maternal platelets activated in the spiral arteries can regulate trophoblastic vascular infiltration and differentiation by releasing various soluble factors.

Pregnancy in essential thrombocythaemia: experience with 40 pregnancies

In this study, the course of 40 pregnancies in 16 women with essential thrombocythaemia (ET) was analysed retrospectively. Of the pregnancies, 45% were complicated, 55% uncomplicated, and 62% resulted in live birth. The most common complication was spontaneous abortion during the first trimester seen in 33% of all pregnancies and comprising 72% of all complications. Two intrauterine foetal deaths occurred at weeks 22 and 28. Three pregnancies were complicated by eclampsia or pre-eclampsia. Nine of 16 women with 29 pregnancies had at least one complicated pregnancy. In seven of 16 women, all 11 pregnancies were uneventful. The non-pregnancy-related symptoms of ET or the platelet count before conception or during pregnancy did not correlate with the risk of pregnancy complications. Treatment with low-dose acetylsalicylic acid (ASA) alone during pregnancy or platelet-lowering drugs before or during pregnancy reduced the risk of complications.

Interferon alfa treatment for pregnant women affected by essential thrombocythemia: case reports and a review

OBJECTIVES

In the past essential thrombocythemia was considered a disease of the elderly. At present, the number of young people suffering from this disease is growing, with a slightly higher frequency in females. We investigated the effects of interferon alfa therapy in these patients.

STUDY DESIGN

We describe 9 pregnancies in 4 women affected by essential thrombocythemia.

RESULTS

Four pregnancies were carried out without interferon alfa therapy, and resulted in 2 intrauterine deaths, 1 spontaneous abortion, and 1 neonatal death. Interferon alfa was given during another 5 pregnancies; among them, 2 ended in preterm deliveries with normal infants, and 3 in full-term deliveries. The literature is reviewed.

CONCLUSION

Our cases and published series suggest that fetal outcome is improved by therapy, and that interferon alfa may be the best therapeutic option.

Thrombocythaemia and pregnancy

The diagnosis of essential thrombocythaemia (ET) is considered when all causes of reactive (secondary) thrombocytosis have been excluded in a patient with a persistent thrombocytosis. Among the chronic myeloproliferative disorders, ET has the highest proportion of young as well as female patients affected. As such, the optimal management of ET during pregnancy becomes an important issue. Although ET is not a contraindication to childbearing, the risks to both the fetus and mother are increased, and would-be-parents should be counselled regarding these. Obstetric complications occurring at higher than expected rates include spontaneous abortion in the first-trimester. Maternal complications, both haemorrhagic and thrombotic, are reported relatively infrequently. It is generally difficult to make specific management recommendations because of the relative rarity of the association between ET and pregnancy, which has precluded adequately powered controlled trials. In this communication, we review our own experience as well as that of other investigators on the subject matter and provide management guidelines that are based on best available information.

Sticky platelet syndrome and thrombocythemia

Platelets are intimately involved in the pathogenesis of thromboembolic disorders, especially arterial forms of thrombosis. Although most arterial thromboses develop on the basis of endothelial injuries, some do not. In these instances "hyperactive" platelets could be the cause. Hyperaggregable platelets have been described in association with a number of acquired disease entities whereby the cause-and-effect relationship is unclear. In contrast, the sticky platelet syndrome is a congenital, autosomal dominant disorder, characterized by hyperaggregable platelets in response to ADP, epinephrine, or both. Patients usually seek treatment for transient or permanent arterial vascular occlusions. These are often precipitated by stressful events. Treatment with low-dose aspirin (81 mg/day) reverses clinical symptoms and hyperaggregability in the laboratory.

The role of blood component removal in essential and reactive thrombocytosis

An elevated platelet count is now a common finding in both hospitalized and ambulatory patients with the advent of automated complete blood cell counters. Clinicians may be called upon to make a distinction between a reactive process and a primary hematologic disorder as the cause of a thrombocytosis and to determine whether treatment is indicated. Essential thrombocythemia and other myeloproliferative disorders may present with marked increases in the platelet counts and may be associated with thrombohemorrhagic complications. Reactive thrombocytosis can be caused by iron deficiency and a variety of inflammatory conditions, infections, malignancy, bleeding or hemolysis, splenectomy, and drugs. Acute therapy for all of these disorders has included blood component removal, specifically plateletpheresis. The role of plateletpheresis in current management of thrombocytosis is considered, based on current knowledge of pathophysiology and a review of the literature.

Current opinion in essential thrombocythemia: pathogenesis, diagnosis, and management

A working diagnosis of essential thrombocythemia (ET) is made in the presence of nonreactive thrombocytosis and after the exclusion of another chronic myeloid disorder that may mimic ET in its presentation. Clinically, ET is characterized by vasomotor symptoms, thrombohemorrhagic complications, recurrent fetal loss, and transformation of the disease into either myelofibrosis with myeloid metaplasia or acute myeloid leukemia. Median survival in the majority of patients is close to that of an age-adjusted normal population, and current therapy has not been shown to either retard or hasten leukemic transformation, which is reported to occur in 1% to 20% of patients. The use of hydroxyurea in high-risk patients with ET has reduced the incidence of thrombosis, and recent studies have suggested the value of keeping the platelet count below 400 x 10(9)/L in such cases. The incidence of thrombosis in low-risk patients may not be high enough to warrant the use of cytoreductive therapy. Although effective in controlling vasomotor symptoms, aspirin therapy has not been shown to influence the risk of either recurrent thrombosis or first-trimester miscarriage in ET. Recent laboratory studies have suggested that hematopoiesis in ET may not always be clonal. Similarly, there is substantial heterogeneity in both megakaryocyte/platelet surface expression of the thrombopoietin receptor (c-Mpl) and bone marrow microvessel density. Clinicopathologic correlates to these biologic parameters are currently being defined.

A single institutional experience with 43 pregnancies in essential thrombocythemia

OBJECTIVES

We describe the periconception circumstances and outcome of 43 consecutive pregnancies in an unselected group of young women with essential thrombocythemia (ET).

PATIENTS AND METHODS

We retrospectively studied 74 consecutive cases of young women with ET seen at our institution, among whom 43 pregnancies occurred in 20 patients.

RESULTS

Of the 43 pregnancies, 22 (51%) were successful (21 term and 1 preterm live births) and 21 (49%) ended in miscarriages (1 ectopic pregnancy, 2 elective abortions, 16 first-trimester spontaneous abortions, 1 stillbirth at 22 wk, and 1 abruptio placentae at 33 wk). Management of ET at the time of conception included either no specific therapy (16 cases) or the use of aspirin alone (24 cases), a cytoreductive agent (2 cases), or heparin (1 case). There were no significant differences with respect to platelet count or the effect of treatment with aspirin, either at the time of conception or during the first trimester, among cases of successful pregnancies (22), all miscarriages (21), or first-trimester spontaneous abortions (16). The findings were similar when the analysis was restricted to only first-time pregnancies. In patients with multiple pregnancies, the outcome of a subsequent pregnancy was not predicted by the outcome of the first. In general, in successful cases the last two trimesters were mostly uneventful, with healthy offspring being reported in all cases.

CONCLUSIONS

Pregnant patients with ET have an increased risk of first-trimester abortion which is not predictable by preconception platelet count or aspirin therapy. In addition, our experience does not support the use of prophylactic platelet apheresis during delivery.

Administration of interferon-alpha during pregnancy: effects on fetus

Interferon-alpha (IF alpha) is used for the treatment of myeloproliferative diseases and chronic viral illnesses. Because the agent has antiproliferative activity, its effects on a fetus are a concern. We encountered a 40-year-old Japanese woman who inadvertently received IF alpha during pregnancy for the treatment of HCV hepatitis. The patient received 5 million units of IF alpha 2 to 4 times per week (total dose of 315 million units) between 13 and 33 weeks gestation. The patient delivered a normally formed healthy male infant, weighing 2,252 g at 37 weeks of gestation. The infant at 20-month-old exhibited normal growth and neurological development when last examined. Literatures were reviewed to determine the effects of IF alpha on the fetus. There have been 27 infants born to 26 mothers, including the present case, who were exposed to IF alpha in utero. Six women (23%) were administered IF alpha inadvertently during pregnancy. Four women (15%) gave birth prematurely. Although 6 infants (22%) were affected by intrauterine growth retardation (IUGR), there were no IF alpha-related malformed infants. These results suggested that an inadvertent administration of IF alpha during pregnancy may occur, but in that case IF alpha may not induce congenital malformations. These findings may encourage such women to continue pregnancy.

Management of essential thrombocythaemia during pregnancy

Essential thrombocythaemia is a rare myeloproliferative disorder that often presents with haemorrhagic or thrombotic complications. It may be detected incidentally in an asymptomatic younger adult and there are only a few case reports of essential thrombocythaemia in pregnant women. The risks posed by essential thrombocythaemia during pregnancy and its optimal management are uncertain. To determine if there is increased incidence of obstetric complications seen in women who have essential thrombocythaemia, we collected a large case series from a number of tertiary obstetric units in Australia and New Zealand. There were 30 pregnancies in 12 women who had essential thrombocythaemia. There were 17 live births (57%), 7 stillbirths (23%), 5 miscarriages (17%) and 1 ectopic (3%). Five pregnancies were complicated by placental abruption. When the outcomes of those women who received treatment with aspirin or interferon were compared to those that did not receive any treatment, there was a trend towards a higher livebirth rate (79% v. 38%, p = 0.06). Seven women were treated with aspirin and 5 had successful outcomes with no fetal complications. Four women were treated with alpha-interferon which reduced their platelet counts and all had successful outcomes with no fetal complication. These findings suggest that there is a high incidence of miscarriage, stillbirth and abruption in women with essential thrombocythaemia. Their pregnancies should be carefully monitored. Treatment with low dose aspirin and/or the use of alpha-interferon may be associated with an improved pregnancy outcome.

Essential thrombocythemia in young adults: major thrombotic complications and complications during pregnancy--a follow-up study in 68 patients

OBJECTIVES

Although essential thrombocythemia (ET) is usually primarily considered a disorder of middle age, it has been observed in children and young adults. However, the real risk for thrombosis in these patients has not been clearly established.

DESIGN

Prospective analysis of consecutive patients younger than 40 at the time of the diagnosis of ET and followed in our department between 1980 and 1998.

SUBJECTS

Sixty-eight patients (28 males and 40 females, median follow-up 99.14 months) affected by ET diagnosed in agreement with the Polycythemia Vera Study Group criteria.

INTERVENTIONS

Asymptomatic ET patients were not treated. In contrast, patients with associated atherosclerotic risk factors, microvascular disturbances, or a previous major arterial thrombosis were given acetyl salicylic acid (ASA 100 mg/day). Only patients with major thrombotic complications and a platelet count > 1,000 x 10(9)/L received cytoreductive therapy.

OUTCOME MEASURES

(1) to evaluate thrombotic complications in young patients with ET, (2) to relate thrombotic risk to the presence of general atherosclerotic risk factors, and (3) to adopt treatment, and (4) to report the outcome of the pregnancies monitored in our population.

RESULTS

Fifteen patients had major thrombosis, 11 of which were the presenting features of ET. No rethrombosis has been observed. Only one patient with thrombotic complications was under efficient treatment. Atherosclerotic risk factors are more common in patients with major arterial thrombosis than in asymptomatic subjects. Thirteen normal babies were delivered out of 16 pregnancies, 6 of the pregnant women were on ASA therapy.

CONCLUSIONS

Most thrombosis in young ET patients occurred at the time of the diagnosis, and venous thrombotic events represent one-third of total thrombosis. Cardiovascular risk factors seem to be concurrent stimuli for arterial thrombosis in ET. The thrombotic complication rate was 2.6/100 patients/year ASA reduces microvascular disturbances, thrombosis, and rethrombosis and possibly reduces obstetric complications in women with ET.

Acute coronary occlusion and in-stent thrombosis in a patient with essential thrombocythemia

We describe a case of essential thrombocythemia in a 34-year-old male who presented with acute anterior wall myocardial infarction and a platelet count of 2,100,000/mm3. Primary percutaneous coronary angioplasty and stenting were performed. Postangioplasty course was complicated by stent thrombosis requiring repeat coronary angioplasty and persistent femoral arterial bleeding that was treated with surgical exploration and repair. The patient was subsequently treated with platelet pheresis, acetylsalicylic acid, ticlopidine, hydroxyurea, and anagrelide without further complications.

Fertility, pregnancy and the management of myeloproliferative disorders

The management of pregnant patients with chronic myeloproliferative disorders (MPD) is a difficult problem. Patients with essential thrombocythaemia (ET), and, less frequently, those with chronic myeloid leukaemia (CML) or polycythaemia vera (PV), present at a childbearing age. Pregnancy itself does not appear to affect adversely the natural course and prognosis of the MPD. However, fertility might be reduced, and an adverse outcome of pregnancy due to thrombotic or bleeding complications is a matter of concern. It ET, first-trimester abortion is the most frequent complication but increased perinatal mortality and premature delivery are also observed. Placental infarction due to thrombosis seems to be the most consistent event. Maternal thrombotic or haemorrhagic complications are rare but are more common than seen in normal pregnancy. The outcome of pregnancy seems to be positively influenced by aspirin, at least in some cases. The value of cytoreduction and/or heparin prophylaxis has not been established but may have a role in selected cases. In CML, the potential adverse effects of hyperleukocytosis, and sometimes thrombocytosis, generally make myelosuppressive treatment essential. In PV, the number of reported pregnancies is low. Maintaining the PCV below 0.45 is of the utmost importance relating to the outcome of pregnancy. Although cytoreductive drugs should generally be avoided, if possible, until at least after the first trimester of pregnancy, interferon-alpha seems to be the drug of choice when myelosuppression is indicated. In summary, the available information about pregnancy occurring during the course of an MPD indicates that successful management of pregnancy is possible. However, optimal management of these patients is poorly defined and agreed protocols are not available. In view of these problems, it is timely to consider the establishment of a national or European registry to monitor prospectively the management offered to pregnant women found to have an MPD.

Multivessel coronary thrombosis treated with abciximab (ReoPro) in a patient with essential thrombocythemia

A 50-year-old man was admitted with acute inferior and anterior myocardial infarction. The patient was diagnosed with essential thrombocythemia (ET) based on the findings of marked thrombocytosis of 1,113 x 10(3)/mm3, splenomegaly, and numerous clumping megakaryocytes on bone marrow biopsy. Emergent coronary angiography revealed extensive multivessel thrombosis involving the left main coronary artery and completely occluding the proximal right coronary artery. In addition to standard therapy with aspirin, heparin, and primary angioplasty of the right coronary artery, the patient received additional antiplatelet therapy with ticlopidine, hydroxyurea, and the platelet glycoprotein IIb/IIIa receptor-inhibiting monoclonal antibody drug abciximab (ReoPro). Serial coronary angiograms 1 and 5 days following the infarction showed progressive thrombus resolution. The pathophysiologic mechanisms and therapeutic challenges of ET-associated coronary thrombosis are discussed in this report.

Spontaneous remission during two pregnancies in a patient with essential thrombocythaemia

A woman with untreated essential thrombocythaemia (ET) exhibited spontaneous normalization of her elevated platelet count during two pregnancies. After delivery the platelet count increased rapidly to the same high level as before. Low platelet adhesion as well as adrenalin- and collagen-induced platelet aggregation, present before pregnancy, increased to normal values during pregnancy. Furthermore, no erythropoietin-independent colony growth was observed during pregnancy, while such colonies were clearly demonstrated when the patient was assayed after pregnancy. This is the second case in the literature demonstrating that remission of ET can occur without treatment during pregnancy.

Essential thrombocythemia during pregnancy

Essential thrombocythemia is a myeloproliferative disorder characterized by a persistent increase in the platelet count. The disease occurs more often in late middle age, but reports confirm the possibility of earlier occurrence. When the disease affects women during pregnancy, an adverse pregnancy outcome is possible: abortion, intrauterine fetal death, abruptio placentae, intrauterine growth retardation, and premature delivery. The possibility of thrombosis formation in this disease encouraged many physicians to use various treatments aimed at lowering the platelet count. Treatments used during pregnancy include acetylsalicylic acid, dipyridamole, heparin, and plateletpheresis. This article describes pregnancy outcomes and reviews the suggested treatments.

Primary thrombocythemia and pregnancy: treatment and outcome in fifteen cases

Pregnancy in patients with primary thrombocythemia (PT) is reported to be often complicated by recurrent abortion and fetal growth retardation. Fifteen pregnancies in nine patients with PT are reported. Nine pregnancies had a good outcome, with the birth of a healthy infant. There were two spontaneous abortions and three intrauterine deaths. One pregnancy was electively terminated after extensive thrombosis in the splanchnic district requiring surgical entero-resection. In five pregnancies the mother received no treatment; in ten pregnancies acetylsalicylic acid (ASA) was prescribed to the mother as soon as she was found pregnant, subcutaneous heparin was added from the middle trimester in seven cases. In patients treated with ASA and subcutaneous heparin pregnancies had a good outcome. Administration of ASA and heparin during pregnancy appears to improve the outcome in patients with PT and can prevent severe maternal complications, but requires close monitoring.

Essential thrombocythemia and pregnancy

A review of the literature disclosed 106 pregnancies (preg.) in 57 women with essential thrombocythemia (ET). The success rate (baby alive) was 57% (60 live births/106 preg.), the rate of miscarriage 43% (46 miscarriages/106 preg.). The most frequent complication was spontaneous abortion during the first trimester in 36% (38 abortions/106 preg.). Other complications such as intrauterine death and stillbirth after the 28th week, which occurred in 5% (7/106), premature delivery in 8% (8/106), pre-eclampsia in 4% (4/106), and fetal growth retardation in 4% (4/106) were rarer events. Placental infarction due to thrombosis seems to be the most consistent pathological event as far as the fetus is concerned. Maternal hemorrhage occurred in 4% (3 minor and 1 major bleeding) and only 2 minor maternal thrombotic episodes have been observed. Interestingly, a decline in platelet count has been observed in 14 women and was associated with a successful preg, in 13/14 cases (93%). Aspirin (ASS) was the most frequently used drug in 47 of 93 recorded cases (51%). In 16 evaluable women treated with ASS the live birth rate was higher (12/16 preg., 75%) than for 21 untreated women (9/21 preg., 43%). In 5 cases interferon alpha (IFN) has been used successfully. In summary, 57% of women with ET had a live birth, maternal complications happened in 6%. Promising treatment modalities might be ASS and IFN. However, no definitive answer can be given on the ideal management for women with ET during pregnancy. A European register should be set up.

Successful treatment of essential thrombocythaemia and recurrent abortion with alpha interferon

A 27-year-old woman with essential thrombocythaemia (ET) had three miscarriages. She was treated with alpha interferon which was continued after she became pregnant again. The platelet count remained well controlled and at term she delivered a healthy baby with normal blood counts. The case demonstrates the effectiveness of IFN in preventing recurrent miscarriage associated with ET and the safety of IFN with respect to fertility and fetal development.

Splenic thrombosis complicating pregnancy in patients with poor obstetrical outcome. A report of four cases

The association of pregnancy and splenic vein thrombosis is rare. The authors describe four patients who had acute painful splenomegaly in association with pregnancy. All patients had a slightly elevated platelet count in the nonpregnant state and had at least one spontaneous abortion. One patient had transient neurologic symptoms, and two others had a history of gastric ulcer. The splenic thrombosis occurred in the 9th (in two cases) and in the 13th week of gestation (in two cases), and 1 week after abortion (in two cases). Three patients underwent splenectomy and one refused it. All patients had persistent thrombocythemia after the splenectomy. In three patients the platelet count reversibly dropped at least 50% during pregnancy. Of their 19 pregnancies, one resulted in normal birth, one in preterm birth, two in therapeutic abortion, and 15 in spontaneous abortion. Data presented suggest that the latent form or early stage of a myeloproliferative disorder may contribute to both splenic and placental thrombosis.

Megakaryocyte and erythroid colony formation in essential thrombocythaemia and reactive thrombocytosis: diagnostic value and correlation to complications

Megakaryocyte and erythroid colony formation in vitro by progenitors from the bone marrow and/or blood was studied in 61 patients with essential thrombocythaemia (ET) and 22 patients with reactive thrombocytosis (RT) using the methyl cellulose assay. 47 (77%) of the patients with ET showed megakaryocyte and/or erythroid spontaneous colony formation while 14 (23%) patients did not have any kind of spontaneous colonies. Spontaneous megakaryocyte colony formation was seen in 42 (69%) of the patients and 36 (59%) ET patients showed spontaneous erythroid growth. 31 patients had both types of spontaneous colonies. 11 patients showed only spontaneous megakaryocyte colony formation, and five patients only spontaneous erythroid growth. None of the patients with RT or of the normal controls showed either type of spontaneous growth. Neither the presence of spontaneous megakaryocyte colony formation nor the number of spontaneous colonies correlated with the platelet count. Patients with spontaneous megakaryocyte growth had significantly more often thromboembolic or haemorrhagic problems than those without spontaneous colony formation. In conclusion, it was found that a great majority of patients with ET but none of those with RT grow spontaneous megakaryocyte and/or erythroid colonies. Spontaneous colony formation is strong evidence for a myeloproliferative disorder. The presence of spontaneous colony growth is associated with an increased risk of thromboembolic or haemorrhagic complications regardless of the platelet count, particularly among young patients.

Essential thrombocythemia in pregnancy: platelet count and pregnancy outcome

We report our experience of 4 successful pregnancies (including a pair of twins) in 3 women who have essential thrombocythemia (ET). All of the patients had a significant fall in platelet count (> 20% of non-pregnant state) during the course of the pregnancy. A review of the literature and our own experience suggests that the degree of platelet count reduction may be correlated with pregnancy outcome. Close monitoring of the platelet count is useful in the management of these cases.

Idiopathic thrombocythemia and pregnancy; a case report

A 28-year-old women with idiopathic thrombocytosis was treated with melphalan before pregnancy, which resulted in a normal platelet count. During pregnancy 80 mg acetylsalicyclic acid was given daily to prevent microcirculatory thrombotic complications. Fetal outcome was normal.

Primary thrombocythaemia in pregnancy

Nine pregnancies in six patients with primary thrombocythaemia are reported. Eight pregnancies resulted in the delivery of normal infants. One pregnancy ended in spontaneous abortion at 7 weeks gestation. One pregnancy was complicated by superficial thrombophlebitis and a postpartum haemorrhage. We suggest that pregnancy in patients with primary thrombocythaemia can have a favourable outcome, but requires close monitoring. Administration of aspirin during pregnancy may be of benefit.

Essential thrombocythemia in young adults

Essential thrombocythemia is typically a disorder of adults in the sixth or seventh decade of life and is characterized by frequent thrombohemorrhagic complications. In young patients, the optimal management of complications is controversial. We studied 56 young adults (33 female and 23 male patients) with a diagnosis of essential thrombocythemia. The mean duration of follow-up was 4.68 years. The mean platelet count at diagnosis was 1,328,000/mm3. Platelet aggregation studies in 21 patients demonstrated hypoaggregation to epinephrine; spontaneous platelet aggregation was present in 4. At diagnosis, 39 patients were asymptomatic, and thrombocytosis was discovered incidentally. Throughout follow-up (up to 20 years), 24 patients remained asymptomatic. Thrombotic complications developed in 24 patients; they were life-threatening in only 3. The most common vaso-occlusive symptoms were migraine headache (in 12 patients) and erythromelalgia (in 3). Minor hemorrhagic complications occurred in six patients, and none was life-threatening. Serious complications (one cerebral and two myocardial infarctions) occurred in three patients, all of whom recovered. Two deaths occurred, neither of which was attributable to essential thrombocythemia. The treatment regimens used were chemotherapy in 9 patients, antiaggregating agents in 7, radioactive phosphorus in 1, the newer platelet-lowering agent anagrelide in 10, and only observation in 29. No treatment-related acute leukemias developed. This series of young patients with essential thrombocythemia, the largest to date, demonstrates a low incidence of life-threatening complications and a favorable long-term prognosis. Therapeutic recommendations should remain conservative, and potential leukemogens should be avoided unless serious complications develop. Anagrelide may be useful in young patients with thrombocythemia who are symptomatic.

The clinical spectrum of thrombocytosis and thrombocythemia

Platelet production is the result of a highly ordered maturation of a developmental hierarchy of megakaryocytic progenitor cells regulated by a variety of cytokines. GM-CSF, II-3 and II-6 have a stimulatory effect and several cytokines (TGF-beta, platelet released glycoprotein, platelet factor 4 and interferons) have inhibitory effects down regulating platelet production perhaps as part of an autocrine control loop. Excess platelet production can be clinically characterized as pseudothrombocytosis, thrombocytosis or thrombocythemia; the clinical features and criteria for each are defined. The term thrombocytosis infers its reactive nature and, in the absence of arterial disease or prolonged immobility, it poses little risk regardless of platelet numbers. By contrast, in thrombocythemia, whether primary or associated with other myeloproliferative lesions, significant thrombohemorrhagic events occur. The natural history, rationale, and approach to platelet reduction and control of clinical sequela are reviewed. Clinical therapeutic options include a new agent, Anagrelide.

Hemostatic complications in young patients with essential thrombocythemia

PURPOSE

The purpose of this study was to determine the incidence of hemostastic complications in young patients with essential thrombocythemia (ET).

PATIENTS AND METHODS

The clinical course of 44 patients under the age of 45 with the diagnosis of ET was reviewed in a retrospective manner. Patients were collected from three medical centers in the United States and Italy: the Brigham and Women's Hospital and the Harvard Community Health Plan, Boston, Massachusetts, and the Ospedali Riuniti di Bergamo, Bergamo, Italy.

RESULTS

The overall incidence of hemorrhage or thrombosis, or both, in this group of patients was 39% (17 of 44), with serious complications occurring in 23% (10 of 44). Two patients died of thrombotic events. Neither the presence of symptoms at diagnosis nor any single laboratory parameter proved predictive of clinical sequelae. Treatment with antiplatelet drugs or platelet-lowering agents was not protective.

CONCLUSION

We conclude that ET in young patients may result in serious and life-threatening hemostatic problems and consequently that young age is not a favorable prognostic factor in this disease.

Clinical manifestations of essential thrombocythemia in young adults

Essential thrombocythemia (ET) is a myeloproliferative disorder characterized by isolated overproduction of platelets, thrombohemorrhagic complications, and a median age of 50-60. When it occurs in younger patients, the incidence of complications has been reported to be quite low, with a good long-term prognosis. We report a retrospective review of 13 patients with ET between the ages of 22 and 35 in which 11 were symptomatic at diagnosis, with only one remaining asymptomatic during follow-up. Three patients presented with potentially life-threatening complications (two myocardial infarctions, one stroke), although no deaths were observed. The majority of the nonlife-threatening complications were vaso-occlusive in nature, including erythromelalgia and transient neurologic symptoms. We conclude that ET in young adults is not always a benign disease and that potentially life-threatening complications are not rare. The optimum approach to treatment in this or any other age group remains uncertain.