Evaluation of Thalassaemia Screening Tests in the Antenatal and Non-Antenatal Populations in Singapore

INTRODUCTION

Haemoglobinopathy testing is performed for carrier screening and evaluation of microcytic anaemia. We evaluated the effectiveness of thalassaemia screening tests at our institution and suggest ways of improving the testing algorithm.

MATERIALS AND METHODS

A total of 10,084 non-antenatal and 11,364 antenatal samples with alkaline gel electrophoresis (AGE), capillary electrophoresis (CE), haemoglobin H (HbH) inclusion test, mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) were retrospectively reviewed. A subgroup of 187 samples with genetic testing was correlated with HbH inclusions and MCH/ MCV. The effect of iron deficiency on percentage hemoglobin A2 (HbA2) was studied.

RESULTS

HbH inclusion test showed low sensitivity of 21.43% for α-thalassaemia mutations but higher sensitivity of 78.95% for ^--SEA deletion. By receiver operating characteristic (ROC) analysis, MCH ≤28 pg or MCV ≤80 fl for non-antenatal samples and MCH ≤27 pg or MCV ≤81 fl for antenatal samples had >98% sensitivity for HbH inclusions. Above these thresholds, the probability that HbH inclusions would be absent was <99% (negative predictive value [NPV] >99%). MCH ≥28 pg had 100% sensitivity (95% CI 95.63%-100%) for α-thalassaemia mutations and 97.68% calculated NPV in the antenatal population. Detection of haemoglobin variants by CE correlated highly with AGE (99.89% sensitivity, 100% specificity). Severe iron deficiency reduced HbA2 in hemoglobin (P <0.001) and α-thalassaemia (P = 0.0035), but not in β-thalassaemia.

CONCLUSION

MCH/MCV thresholds have adequate sensitivity for α-thalassaemia in the antenatal population, and genotyping plays an important role as HbH inclusion test shows low sensitivity. CE without AGE, may be used as initial screening for haemoglobin variants. Our study provides contemporary data to guide thalassaemia screening algorithms in Singapore.

Multiple Placental Infarcts in a Pregnant Woman with Essential Thrombocythemia

Myeloproliferative neoplasms (MPNs), including polycythemia vera, essential thrombocythemia (ET), and primary myelofibrosis, mainly occur in older patients, but have also been reported in younger patients. A "second peak" occurs in female patients in their thirties, particularly in ET; thus, the management of pregnancy is often discussed. We herein present the case of a 33-year-old woman with a high platelet count and multiple placental infarcts during delivery who was subsequently diagnosed with ET. Although there are no worldwide guidelines for the management of MPNs in pregnancy, the risk of thrombosis is markedly increased in these patients, and antithrombotic therapy should be considered.

[Diagnostics and treatment of iron deficiency in pregnancy]

Iron deficiency and iron deficiency anaemia are frequent complications to pregnancy and especially iron deficiency is underdiagnosed because of scarce symptoms. Due to the increased need for iron and the variation in iron storage in healthy pregnant women, iron supplementation should be individualised based on the level of haemoglobin and ferritin. First choice of treatment is oral iron supplementation, unless there is a failure of treatment, a known condition with malabsorption, or severe iron deficiency anaemia very close to due date. In these cases, intravenous iron may be considered.

Microangiopathic Hemolytic Anemia in Pregnancy

Thrombotic microangiopathies (TMAs) are associated with microangiopathic hemolytic anemia and thrombocytopenia, resulting in microvascular thrombosis and end-organ damage. In pregnancy, this may be the result of pregnancy-related TMAs such as preeclampsia; hemolysis, elevated liver enzymes, and low platelets; or pregnancy-associated TMAs, specifically thrombotic thrombocytopenic purpura (TTP) or complement-mediated hemolytic uremic syndrome (CM HUS). TTP and CM HUS are rare disorders, and their diagnosis may be missed, no less because features at presentation may be misdiagnosed as a pregnancy-related TMA, such as hypertension, proteinuria, fetal growth restriction, or in utero fetal death. The mainstay of treatment for pregnancy-associated TMAs is plasma exchange. Presentation is likely in the third trimester for TTP and postpartum for CM HUS. However, both conditions can present in any trimester, unlike pregnancy-related TMAs which rarely present before the second trimester, commonly in the third trimester. Delivery is the mainstay of treatment for pregnancy-related TMAs. More recently, it has become clear that pregnancy may be a trigger for late-onset congenital TTP, as well as immune-mediated TTP, diagnosed by ADAMTS13 analysis. Complement inhibitor therapy is the treatment of choice for CM HUS cases. However, their diagnosis is by exclusion, but complement inhibitor therapy reduces the risk of end-stage renal failure. Subsequent pregnancies can be supported for TTP and CM HUS.

Integrated point-of-care testing (POCT) of HIV, syphilis, malaria and anaemia in antenatal clinics in western Kenya: A longitudinal implementation study

Background

In sub-Saharan Africa, HIV, syphilis, malaria and anaemia are leading preventable causes of adverse pregnancy outcomes. In Kenya, policy states women should be tested for all four conditions (malaria only if febrile) at first antenatal care (ANC) visit. In practice, while HIV screening is conducted, coverage of screening for the others is suboptimal and early pregnancy management of illnesses is compromised. This is particularly evident at rural dispensaries that lack laboratories and have parallel programmes for HIV, reproductive health and malaria, resulting in fractured and inadequate care for women.

Methods

A longitudinal eight-month implementation study integrating point-of-care diagnostic tests for the four conditions into routine ANC was conducted in seven purposively selected dispensaries in western Kenya. Testing proficiency of healthcare workers was observed at initial training and at three monthly intervals thereafter. Adoption of testing was compared using ANC register data 8.5 months before and eight months during the intervention. Fidelity to clinical management guidelines was determined by client exit interviews with success defined as ≥90% adherence.

Findings

For first ANC visits at baseline (n = 529), testing rates were unavailable for malaria, low for syphilis (4.3%) and anaemia (27.8%), and near universal for HIV (99%). During intervention, over 95% of first attendees (n = 586) completed four tests and of those tested positive, 70.6% received penicillin or erythromycin for syphilis, 65.5% and 48.3% received cotrimoxazole and antiretrovirals respectively for HIV, and 76.4% received artemether/lumefantrine, quinine or dihydroartemisinin–piperaquine correctly for malaria. Iron and folic supplements were given to nearly 90% of women but often at incorrect doses.

Conclusions

Integrating point-of-care testing into ANC at dispensaries with established HIV testing programmes resulted in a significant increase in testing rates, without disturbing HIV testing rates. While more cases were detected and treated, treatment fidelity still requires strengthening and an integrated monitoring and evaluation system needs to be established.

Validation of the quantitative point-of-care CareStart biosensor for assessment of G6PD activity in venous blood

INTRODUCTION

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy in the human population affecting an estimated 8% of the world population, especially those living in areas of past and present malaria endemicity. Decreased G6PD enzymatic activity is associated with drug-induced hemolysis and increased risk of severe neonatal hyperbilirubinemia leading to brain damage. The G6PD gene is on the X chromosome therefore mutations cause enzymatic deficiency in hemizygote males and homozygote females while the majority of heterozygous females have an intermediate activity (between 30-80% of normal) with a large distribution into the range of deficiency and normality. Current G6PD qualitative tests are unable to diagnose G6PD intermediate activities which could hinder wide use of 8-aminoquinolines for Plasmodium vivax elimination. The aim of the study was to assess the diagnostic performances of the new Carestart G6PD quantitative biosensor.

METHODS

A total of 150 samples of venous blood with G6PD deficient, intermediate and normal phenotypes were collected among healthy volunteers living along the north-western Thailand-Myanmar border. Samples were analyzed by complete blood count, by gold standard spectrophotometric assay using Trinity kits and by the latest model of Carestart G6PD biosensor which analyzes both G6PD and hemoglobin.

RESULTS

Bland-Altman comparison of the CareStart normalized G6PD values to that of the gold standard assay showed a strong bias in values resulting in poor area under-the-curve values for both 30% and 80% thresholds. Performing a receiver operator curve identified threshold values for the CareStart product equivalent to the 30% and 80% gold standard values with good sensitivity and specificity values, 100% and 92% (for 30% G6PD activity) and 92% and 94% (for 80% activity) respectively.

CONCLUSION

The Carestart G6PD biosensor represents a significant improvement for quantitative diagnosis of G6PD deficiency over previous versions. Further improvements and validation studies are required to assess its utility for informing radical cure decisions in malaria endemic settings.

Molecular prenatal diagnosis of alpha and beta thalassemia in pregnant Hakka women in southern China

BACKGROUND

To date, there has been no systematic study of DNA-based prenatal diagnosis of thalassemia in pregnant Hakka women in southern China.

METHODS

A total of 279 pregnant Hakka women with confirmed cases of thalassemia who had been treated at the Meizhou People's Hospital in China's Guangdong Province from January 2014 to December 2016 were here enrolled. Genomic DNA was extracted from peripheral blood of couples and villus, amniotic fluid, or fetal cord blood. DNA-based diagnosis was performed on the tissues of fetuses whose parents had tested positive for α- and β-globin gene mutations were found using polymerase chain reaction (PCR) and flow-through hybridization technique. Follow-up visits were performed 6 months after the fetuses were born. Prenatal diagnosis was performed on 279 fetuses in at-risk pregnancies.

RESULTS

Here, 211 α-thalassemia fetuses were confirmed, including 41 (19.43%) that tested positive for Bart's hydrops syndrome and 15 (7.11%) for Hb H disease. There were 103 (48.81%) heterozygotes. β-thalassemia was confirmed in 68 fetuses, including 23 (33.82%) with severe thalassemia and 27 (39.71%) heterozygotes. Another 12 cases were confirmed with α+β-thalassemia, including three cases of severe β-thalassemia. DNA-based testing prenatal diagnosis of thalassemia was found to be highly reliable.

CONCLUSIONS

Our findings provide key information for clinical genetic counseling of prenatal diagnosis for major thalassemia in pregnant Hakka women in southern China.

Iron deficiency in gynecology and obstetrics: clinical implications and management

Iron deficiency is the commonest cause of anemia during pregnancy; however, its prevalence is highly determined by nutritional and socioeconomic status. Oral iron is the frontline therapy, but is often poorly tolerated. Awareness of the available intravenous formulations is essential for management. Before delivery, risk factors such as multiparity and heavy uterine bleeding increase the prevalence of iron deficiency and should be motivation for early diagnosis and treatment. Neonates born with iron deficiency have a statistically significant increment in both cognitive and behavioral abnormalities that persist after repletion, highlighting the need for heightened awareness of the diagnosis. A smartphone application providing information on nutrition and treatment is provided. New formulations of intravenous iron with carbohydrate cores, which bind elemental iron more tightly, minimize the release of labile free iron to allow complete replacement doses of intravenous iron in 15 to 60 minutes, facilitating and simplifying care.

Thrombocytopenia in pregnancy

Thrombocytopenia develops in 5% to 10% of women during pregnancy or in the immediate postpartum period. A low platelet count is often an incidental feature, but it might also provide a biomarker of a coexisting systemic or gestational disorder and a potential reason for a maternal intervention or treatment that might pose harm to the fetus. This chapter reflects our approach to these issues with an emphasis on advances made over the past 5 to 10 years in understanding and managing the more common causes of thrombocytopenia in pregnancy. Recent trends in the management of immune thrombocytopenia translate into more women contemplating pregnancy while on treatment with thrombopoietin receptor agonists, rituximab, or mycophenylate, which pose known or unknown risks to the fetus. New criteria to diagnose preeclampsia, judicious reliance on measurement of ADAMTS13 to make management decisions in suspected thrombotic thrombocytopenic purpura, new evidence supporting the efficacy and safety of anticomplement therapy for atypical hemolytic uremic syndrome during pregnancy, and implications of thrombotic microangiopathies for subsequent pregnancies are evolving rapidly. The goals of the chapter are to help the hematology consultant work through the differential diagnosis of thrombocytopenia in pregnancy based on trimester of presentation, severity of thrombocytopenia, and coincident clinical and laboratory manifestations, and to provide guidance for dealing with some of the more common and difficult diagnostic and management decisions.

Current challenges in the management of essential thrombocythemia

Essential thrombocythemia (ET), an uncommon blood cancer, is one of the classic myeloproliferative neoplasms, a category that also includes polycythemia vera and primary myelofibrosis. All 3 diseases are clonal hematopoietic stem cell disorders. Since 2005, when scientists discovered a molecular aberration driving clonal hematopoiesis in polycythemia vera, our understanding of the genomic underpinnings of these conditions has increased rapidly. Over the last decades, primary prevention of thrombotic and hemorrhagic complications has improved the lives of patients with ET, and the ability to characterize the disease by the presence or absence of molecular mutations has lent precision to our prognostic models. This review outlines a modern approach to the diagnosis and treatment of ET. It highlights the 2016 World Health Organization standards for differentiating the disease from primary myelofibrosis, which is key for an accurate prognosis. It also describes the current risk stratification models and discusses the vascular and hemorrhagic risks that affect patients with this chronic condition, including younger individuals and pregnant women. Finally, it outlines a simple-to-follow treatment algorithm that is based on an understanding of the vascular risks and provides a foundation for discussing treatment choices with patients.

Personalized thromboprophylaxis using a risk score for the management of pregnancies with high risk of thrombosis: a prospective clinical study

Essentials Pregnancy is a risk factor for thrombosis. Management of thrombosis risk in pregnancy remains a challenge. Prophylaxis needs to be personalized. Our score may be a helpful tool for the management of pregnancies at high risk of thrombosis.

SUMMARY

Background Patients with thrombophilia and/or a history of venous thromboembolism (VTE) are at risk of thrombosis during pregnancy. A risk score for pregnancies with an increased risk of VTE was previously described by our group (Lyon VTE score). Objectives The aim of this prospective study was to assess the efficacy and safety of our score-based prophylaxis strategy in 542 pregnancies managed between 2005 and 2015 in Lyon University Hospitals. Patients/Methods Of 445 patients included in the study, 36 had several pregnancies during the study period. Among these 445 patients, 279 had a personal history of VTE (62.7%), 299 patients (67.2%) had a thrombophilia marker, and 131 (29.4%) thrombophilic women had a personal history of VTE. During pregnancy, patients were assigned to one of three prophylaxis strategies according to the risk scoring system. Results In the antepartum period, low molecular weight heparin (LMWH) prophylaxis was prescribed to 64.5% of patients at high risk of VTE. Among them, 34.4% were treated in the third trimester only, and 30.1% were treated throughout pregnancy. During the postpartum period, all patients received LMWH for at least 6 weeks. Two antepartum-related VTEs (0.37%; one with a score of < 3 and the other with a score of > 6) and four postpartum-related VTEs (0.73%; three with scores of 3-5 and one with a score of > 6) occurred. No case of pulmonary embolism was observed during the study period. The rate of bleeding was 0.37%. No serious bleeding requiring transfusions or surgery occurred during the study period. Conclusion The use of a risk score may provide a rational decision process to implement safe and effective antepartum thromboprophylaxis in pregnant women at high risk of VTE.

ANESTHETIC MANAGEMENT OF DELIVERY IN PATIENTS WITH COMPLEMENT-ASSOCIATED DISORDERS. CLINICAL OBSERVATION OF A PREGNANT WOMAN WITH PAROXYSMAL NOCTURNAL HEMOGLOBINURIA

There was a case in MRRIOG (Moscow Regional Research Institute of Obstetrics and Gynecology) in 2015 when pregnant patient with paroxysmal nocturnal hemoglobinuria(PNH) has successfully passed through a delivery process. This paper analyzes the medical history, clinical, laboratory and instrumental examination, particularly anesthesia tactics for the patients with complement-associated diseases during delivery. The presented clinical case demonstrates the need for and the importance of early diagnosis of PNH in pregnant women. Of course, women with PNH are one of the most complex contingent ofpregnant women, threatened by the development of obstetric and anesthetic complications, and it requires constant monitoring of clinical and laboratory parameters of their condition, the joint hematologist, obstetri- cian and anesthesiologist observationand delivery in hospitals of III and IV levels.

Pregnancies with factor V deficiency: a case report and review of the literature

CASE REPORT

A 30-year-old Japanese nulliparous woman visited for pregnancy at 33 weeks with a massive ovarian tumor located in the pouch of Douglas. By preoperative screening, her prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged, and her FV activity was significantly decreased to 4.8%. After prophylactic FFP 20 ml/kg was administered and her FV factor was 19.3%, cesarean delivery was performed, and her perioperative course was uneventful. One year later, she underwent a dilatation and evacuation because of a missed abortion, although prophylactic FFP was not administered. During a third pregnancy, after prophylactic FFP 20 ml/kg was administered and FV activity increased to 21.1%, elective cesarean delivery was performed, and her postoperative course was uneventful.

CONCLUSION

For surgical therapy or delivery, the goal of therapy is to maintain FV activity above 20%. It is particularly useful to administer prophylactic FFP.

Congenital and acquired bleeding disorders in pregnancy

Obstetrical hematology represents challenges not only for the patient, but also for her progeny. In particular, bleeding disorders, both congenital and acquired, not only present problems both for delivery and in the immediate postpartum period, but also may have significant implications for the fetus and neonate. Women with congenital bleeding disorders or who are carriers of X-linked or autosomal disorders should be counseled prior to conception so that pregnancy can be safely undertaken with careful preparation. A treatment plan should be set up by a specialized care team that includes the hematologist, obstetrician, and anesthesiologist; the patient should be followed closely during pregnancy, through delivery, and in the immediate postpartum period. Acquired disorders of hemostasis that occur with pregnancy may present particular diagnostic difficulties and require rapid diagnosis and management.

Inherited thrombophilia: a double-edged sword

Inherited thrombophilia is a blood coagulation disorder that increases the risk for venous thromboembolism (VTE). During the last decades, the practice of testing has evolved from testing selected populations, leading to high perceived risks, to broad testing for various conditions that included VTE, arterial thrombosis, and pregnancy complications. Because results of such tests usually do not guide treatment decisions, not testing patients with VTE for inherited thrombophilia is on the "Choosing Wisely" list endorsed by multiple specialty societies, including ASH. Inherited thrombophilia can be regarded a double-edged sword, as despite the rationale not to test, it is still being performed frequently. Another way of seeing inherited thrombophilia as a double-edged sword lies in its 2-sided association with reproduction, both in men and in women. Current areas of research are whether women with inherited thrombophilia and pregnancy complications benefit from anticoagulant therapy with regard to improving the chance of a successful pregnancy. Potential effects of inherited thrombophilia, most notably factor V Leiden, on improved embryo implantation in women and sperm counts in men are intriguing, but are currently poorly understood.

Pregnancy complicated with agranulocytosis

RATIONALE

Pregnancy is a complicated physiological process. Physiological leukocytosis often takes place and it is primarily related to the increased circulation of neutrophils, especially during the last trimester of pregnancy. Noncongenital agranulocytosis during pregnancy is rare and reported only occasionally, while in most of the cases, the agranulocytosis has already occurred prior to pregnancy or induced by identified factors such as antibiotics, antithyroid agents, or cytotoxic agents. Gestation-induced agranulocytosis has not been reported, so we present a case of gestation-induced agranulocytosis in this article.

PATIENTS CONCERN

In this case, we present a Chinese woman (aged 25) in her 38th week of the first gestation who had the complication of agranulocytosis. No abnormality was detected in regular examinations before pregnancy and in the first trimester. Since the last trimester of pregnancy, the patient began to suffer from agranulocytosis and intermittent fever, the maximum being temperature 38.8°C. At admission, the neutrophil granulocytes were 0.17 × 10 L and the bone marrow biopsy showed that agranulocytosis was detected, but the levels of red blood cell and megalokaryocyte were normal. In addition, antinuclear antibodies were detected at a dilution of 1:40, but anti-dsDNA, antiphospholipid antibody, and neutrophil granulocyte antibody were negative.

DIAGNOSES

The patient was empirically treated as having pneumonia.

INTERVENTIONS

We tried to use granulocyte colony-stimulating factor, γ-globulin, glucocorticoids, antibiotics, and antifungi agents to treat the patient, but her symptoms were not alleviated until the patient had a cesarean section.

OUTCOMES

After 24 hours of cesarean section, the temperature and neutrophil granulocyte returned to normal. After a year of follow-up, we found that the patient and the baby were healthy.

LESSONS

Agranulocytosis during pregnancy seems to be associated with immunosuppression induced by immunoregulations and termination of pregnancy may be effective for refractory pregnancy complicated with agranulocytosis, but further studies are needed to confirm this.

Comparison of Two Diagnostic Scores of Disseminated Intravascular Coagulation in Pregnant Women Admitted to the ICU

Objective

To compare the validity of two previously published diagnostic scores of disseminated intravascular coagulation (DIC) in pregnant women admitted to ICU for an acute thrombotic or hemorrhagic complication of delivery and postpartum.

Methods

This was a population based retrospective study of 154 patients admitted to ICU for severe delivery and postpartum complications in a University Hospital. A recently published score (adapted to physiological changes of pregnancy and based on three components: platelet count, prothrombin time difference and fibrinogen) was compared to the International Society for Thrombosis and Hemostasis (ISTH) score (based on four components: platelet count, fibrinogen, prothrombin time, and fibrin related marker). Both scores were calculated at delivery, ICU admission (day 0), day 1 and day 2 during the postpartum ICU stay. The validity of both scores was assessed by comparison with the consensual and blinded analysis of two experts. The sensitivity, specificity, and area under the curve (AUC) of each score were calculated at each time and overall by generalized linear mixed model. The agreement between the two scores was evaluated by the Kappa coefficient.

Results

The new score had a sensitivity of 0.78, a specificity of 0.97 (p <0.01) and a global AUC of 96% while the ISTH score had a sensitivity of 0.31, a specificity of 0.99 and an AUC of 94% (p <0.01). The Kappa coefficient of correlation between both scores was 0.35. The lower sensitivity of the ISTH score was mainly explained by the lack of fibrinogen and fibrin-related peptides thresholds adapted to the physiological changes of coagulation induced by pregnancy.

Conclusion

The new DIC score seem highly discriminant in the subset of patients admitted to the ICU after delivery for an acute specific complication. The ISTH score is not recommended in pregnant women because of its poor sensitivity.

Management of aplastic anaemia in pregnancy in a resource poor centre

Aplastic anaemia occurring in pregnancy is a rare event with life threatening challenges for both mother and child. We present a successful fetomaternal outcome despite the challenges in the management of this rare condition in a tertiary but resource poor centre. This is case of a 37 year old Nigerian woman G6P0+5managed with repeated blood transfusions from 28 weeks of gestation for bone marrow biopsy confirmed aplastic anaemia following presentation with weakness and gingival bleeds. She had a cesarean section at 37 weeks for pre-eclampsia and oligohydraminous with good feto-maternal outcome. She was managed entirely with fresh whole blood and received 21 units. Aplastic Anaemia in Pregnancy is a rare event with poor feto maternal prognosis. Successful management is possible with good multi-disciplinary approach and availability of supportive comprehensive obstetric care.

Physiological macrocytosis of pregnancy

In a prospective study of 40 women, mean corpuscular volume (MCV) values in second and third trimesters were compared between women who were iron deficient and those who were iron replete. There was no difference in the two groups. Hence reduced MCV seen in iron deficiency anaemia cannot be relied upon as an effective marker in pregnancy due to physiological macrocytosis.

Iron deficiency anaemia

Anaemia affects roughly a third of the world's population; half the cases are due to iron deficiency. It is a major and global public health problem that affects maternal and child mortality, physical performance, and referral to health-care professionals. Children aged 0-5 years, women of childbearing age, and pregnant women are particularly at risk. Several chronic diseases are frequently associated with iron deficiency anaemia--notably chronic kidney disease, chronic heart failure, cancer, and inflammatory bowel disease. Measurement of serum ferritin, transferrin saturation, serum soluble transferrin receptors, and the serum soluble transferrin receptors-ferritin index are more accurate than classic red cell indices in the diagnosis of iron deficiency anaemia. In addition to the search for and treatment of the cause of iron deficiency, treatment strategies encompass prevention, including food fortification and iron supplementation. Oral iron is usually recommended as first-line therapy, but the most recent intravenous iron formulations, which have been available for nearly a decade, seem to replenish iron stores safely and effectively. Hepcidin has a key role in iron homoeostasis and could be a future diagnostic and therapeutic target. In this Seminar, we discuss the clinical presentation, epidemiology, pathophysiology, diagnosis, and acute management of iron deficiency anaemia, and outstanding research questions for treatment.