Effect of active prenatal management on pregnancy outcome in sickle cell disease in an African setting

Plasminogen activator inhibitor-2 and impaired fibrinolysis in pregnancy and sickle cell anemia

PURPOSE

This is the first study that aimed to determine antigen levels in plasma and genotypes of PAI-2 in pregnant and non-pregnant homozygous sickle cell anemia (SCA) patients.

METHODS

The study subjects were all Bahraini females in the reproductive age group. The study population included 31 pregnant homozygous SS (SCA) patients. Three control groups were also studied to evaluate the effect of pregnancy and SCA on PAI-2 levels and fibrinolysis: (1) 31 healthy non-pregnant volunteers; (2) 31 cases of normal pregnancy; and (3) 20 non-pregnant SCA patients. Pregnancies were screened in the second (TM2) and third (TM3) trimesters. Global coagulation, fibrinolysis rate (euglobulin clot lysis time, ECLT), PAI-2 antigen (ELISA), and PAI-2 Ser(413)/Cys polymorphism (restriction fragment length polymorphism analysis) were determined.

RESULTS

Feto-maternal complications were documented in both pregnancy groups. PAI-2 antigen levels were undetectable in the non-pregnant groups, but was quantifiable in both pregnant groups. Impaired fibrinolysis rate and rising PAI-2 levels with progression of pregnancy were observed in both healthy and SCA subjects. These changes were more prominent in SCA, although the rise in ECLT was less steep and PAI-2 antigen levels were not significantly different compared to normal pregnancy in the third trimester. No correlation was observed between PAI-2 genotypes and plasma antigen levels. Also, no significant difference in feto-maternal complications was found in normal (n = 25) versus SCA pregnant patients (n = 30).

CONCLUSIONS

These observations suggest that with progression of pregnancy, increasing PAI-2 levels contribute to the hypercoagulable state, particularly in SCA patients.

A Comprehensive Review of Pregnancy in Sickle Cell Disease

Sickle cell hemoglobinopathies encompass a range of qualitative and quantitative hemoglobin disorders that are inherited genetically. This group of disorders includes sickle cell beta thalassemia, sickle cell trait, and sickle cell disease (SCD). Globally, SCD is the most common disorder. Even epidemiological data suggests the majority of diseases, as well as traits, are concentrated in Sub-Saharan Africa, North-East Africa, the Middle East, and India. The physiological changes in pregnancy predispose to an increased risk of catastrophic events like a vaso-occlusive crisis, thromboembolic events, and their related sequelae, leading eventually to villous infarction, necrosis, and fibrosis leading to compromising uteroplacental circulation. Conversely, the mother may exhibit exacerbated symptoms of gestational hypertension, placental abruption, preterm labor, and venous thromboembolism. Although this disease is manageable, it has the potential to adversely impact maternal and child health on a national level. The chances of severe complications in the pregnant state affecting both mother and fetus attract due attention of health services towards redefining and researching this disease and its management frequently. The literature review on the following situation advocates the general treatment to be observed under the headings of preconceptual care, strengthened antenatal care, strict intranatal care, and compliant post-natal care. Preconceptually, genetic screening of couples, with education on the adverse effects of the disease, comes as the first line of management. Newer facilities like preimplantation genetic diagnosis and celocentesis may even allow for early diagnosis as well as help patients who do not wish to terminate the pregnancy by selective transfer of unaffected embryos. This may be combined with an extensive evaluation of the psychosocial aspect and socioeconomic status of couples who administer vaccines as prophylaxis for preventable diseases. Strengthening antenatal care is associated with routine blood investigations for every registered antenatal patient with adequate awareness about the conditions that precipitate the crisis. All patients should be prophylactically treated with appropriate doses of aspirin, iron, folic acid, and multivitamins. Radiological examinations by ultrasonography may be used to monitor placenta previa, abruption, or preterm labor. Later in pregnancy, it should be recommended to perform biophysical profiling and assessment of umbilical artery flow. Intranatal care deals with strict-term institutional delivery of all sickle cell-diseased mothers with a preference for vaginal delivery. Post-natal care requires a precise assessment of blood loss during labor to initiate transfusion therapy as soon as needed. Exclusive breastfeeding, with the importance of early initiation of it, must be emphasized. Screening of neonates as quickly as possible must be done for hemoglobinopathies. Through this review, authors are trying to make aware of the complications that can be faced during pregnancy in SCD patients, its prevention, and its treatment according to various new guidelines and research available.

Pregnancy outcome in homozygous sickle cell disease: observations from the Jamaican Birth Cohort

OBJECTIVE

To document pregnancy outcome in homozygous sickle cell (SS) disease and in age-matched controls with a normal haemoglobin genotype followed from birth for up to 45 years.

METHODS

A total of 100 000 consecutive non-operative deliveries screened for sickle cell disease at the main Government maternity hospital in Kingston, Jamaica between 1973 and 1981 detected 311 (149 female) babies with SS disease who were matched by age and gender with 250 (129 female) controls with an AA haemoglobin phenotype. These individuals have been followed from birth with prospective assessment of menarche and detailed documentation of all pregnancies.

RESULTS

There were 177 pregnancies in 71 SS patients and 226 pregnancies in 74 AA controls. Mothers with SS disease had more spontaneous abortions (adjusted relative risk [aRR] 3.2, 95% CI 1.6-6.1), fewer live births (aRR 0.7, 95% CI 0.6-0.9) and their offspring were more likely to have a gestational age <37 weeks (aRR 2.1, 95% CI 1.1-3.7) and low birthweight <2.5 kg (aRR 3.0, 95% CI 1.6-5.3). They were more prone to acute chest syndrome (aRR 13.7, 95% CI 4.1-45.5), urinary tract infection (aRR 12.8, 95% CI 1.3-125.9), pre-eclampsia/eclampsia (aRR 3.1, 95% CI 1.1-8.8), retained placenta (aRR 10.1, 95% CI 1.1-90.3), sepsis (Fisher's Exact test 0.04) and pregnancy-related deaths (Fisher's Exact test 0.02). Four of five deaths were attributable to acute chest syndrome. There was no genotypic difference in pregnancy-induced hypertension or postpartum haemorrhage.

CONCLUSION

Pregnancy in SS disease carries risks for both mother and child. The variable characteristics of pregnancy-related deaths complicate their prevention.

TWEETABLE ABSTRACT

Pregnancy in SS disease compared with controls showed increased abortions and stillbirths, fewer live births and maternal deaths in 7% patients.

Quality assessment of evidence-based clinical practice guidelines for the management of pregnant women with sickle cell disease using the AGREE II instrument: a systematic review

BACKGROUND

The management of pregnant women with sickle cell disease (SCD) poses a major challenge for maternal healthcare services owing to the potential for complications associated with morbidity and mortality. Trustworthy evidence-based clinical practice guidelines (CPGs) have a major impact on the positive outcomes of appropriate healthcare. The objective of this study was to critically appraise the quality of recent CPGs for SCD in pregnant women.

METHODS

Clinical questions were identified and the relevant CPG and bibliographic databases were searched and screened for eligible CPGs. Each CPG was appraised by four independent appraisers using the AGREE II Instrument. Inter-rater analysis was conducted.

RESULTS

Four eligible CPGs were appraised: American College of Obstetricians and Gynecologists (ACOG), National Heart, Lung, and Blood Institute (NHLBI), National Institute of Health and Care Excellence (NICE), and Royal College of Obstetricians and Gynaecologists (RCOG). Among them, the overall assessments of three CPGs (NICE, RCOG, NHLBI) scored greater than 70%; these findings were consistent with the high scores in the six domains of AGREE II, including:[1] scope and purpose,[2] stakeholder involvement,[3] rigor of development,[4] clarity of presentation,[5] applicability, and [6] editorial independence domains. Domain [3] scored (90%, 73%, 71%), domain [5] (90%, 46%, 47%), and domain [6] (71%, 77%, 52%) for NICE, RCOG, and NHLBI, respectively. Overall, the clinical recommendations were not significantly different between the included CPGs.

CONCLUSIONS

Three evidence-based CPGs presented superior methodological quality. NICE demonstrated the highest quality followed by RCOG and NHLBI and all three CPGs were recommended for use in practice.

"Dual-gene" malaria-resistance: Therapeutically-rational exchange (T-REX) of group-O sickle trait and group-O C-traittrait red blood cells can be evaluated in Benin and Nigeria

BACKGROUND

Using indicators of disease severity, clinicians can predict which Plasmodium falciparum (Pf) malaria patients being treated with artesunate or quinine are likely to die despite these drugs. Effective "rescue adjuncts" are needed when drugs alone are inadequate. "Therapeutically-rational exchange" (T-REX) of special malaria-resistant red blood cells (RBCs) has been proposed to optimize adjunctive exchange transfusion.

METHODS

Studies were reviewed that (1) quantified how group-O status and "sickle-trait" (HbAS) and "C-trait" (HbAC) hemoglobins affect Pf mortality, risk of thrombosis, or birth outcomes for women with pregnancy associated malaria (PAM), (2) reported prevalences of "dual-gene" malaria-resistant RBCs, or (3) reflected the level of exchange-transfusion and malaria-related expertise in Benin and Nigeria.

RESULTS

Data show that the malaria- and thrombosis-resistance of RBCs depend on specific genes and the patient's clinical status and medical history. In malaria-endemic Benin and Nigeria, prevalences of "dual-gene" malaria-resistant group-O HbAS and group-O HbAC RBCs are substantial, and both malaria- and exchange-related expertise are outstanding.

CONCLUSIONS

T-REX of "dual-gene" malaria-resistant RBCs is feasible in Benin and Nigeria and warrants evaluation as a rescue adjunct for 3 subsets of Pf-malaria patients. For therapeutic use, group-O HbAS RBCs are likely to be more effective than non-O HbAS RBCs for Pf-infected patients who (1) have a history of thrombosis or (2) are taking birth-control hormones while group-O HbAC RBCs may substantially improve birth outcomes for women with PAM. Studies suggest it is prudent to assume - until proven otherwise - that T-REX of "dual-gene" malaria-resistant RBCs can improve ("personalize") rescue of these patient subsets.

Transfusion practices in the care of pregnant women with sickle cell disease in Ouagadougou

OBJECTIVE

To study the contribution of blood transfusion management in the improvement of maternal and perinatal outcomes in pregnant women with sickle cell disease in Ouagadougou.

METHODS

A cross-sectional retrospective study with data collected from February 2012 to January 2014 was used. Patients were differentiated into three groups: patients with at least one exchange transfusion, patients who received blood transfusion, and patients who did not receive any transfusion. Data were collected from patients' patient care documents.

RESULTS

One hundred and sixty-four patients were included, of whom 53 were in the first group, 32 in the second group, and 79 in the third group. Maternal complications in the last trimester of pregnancy were significantly less important (P=0.000) in the first group (58.5%) than in the second (78.5%) and third group (91.1%). The same trend was observed for postpartum maternal mortality (5.7%; 12.5%; 12.6%; P=0.009). Fetal complications such as preterm birth and early neonatal death were lower in the first group (15.1%; 1.8%) than in the second (40.6%; 23.1%) and third group (32.9%; 7.6%).

CONCLUSION

Prophylactic blood transfusion is an important part of the management of pregnant patients with sickle cell disease.

Implementation of multidisciplinary care reduces maternal mortality in women with sickle cell disease living in low-resource setting

Sickle cell disease (SCD) is associated with adverse pregnancy outcome. In women with SCD living in low-resource settings, pregnancy is associated with significantly increased maternal and perinatal mortality rates. We tested the hypothesis that implementing a multidisciplinary obstetric and hematology care team in a low-resource setting would significantly reduce maternal and perinatal mortality rates. We conducted a before-and-after study, at the Korle-Bu Teaching Hospital in Accra, Ghana, to evaluate the effect of a multidisciplinary obstetric-hematology care team for women with SCD in a combined SCD-Obstetric Clinic. The pre-intervention period was assessed through a retrospective chart review to identify every death and the post-intervention period was assessed prospectively. Interventions consisted of joint obstetrician and hematologist outpatient and acute inpatient reviews, close maternal and fetal surveillance, and simple protocols for management of acute chest syndrome and acute pain episodes. Primary outcomes included maternal and perinatal mortality rates before and after the study period. A total of 158 and 90 pregnant women with SCD were evaluated in the pre- and post- intervention periods, respectively. The maternal mortality rate decreased from 10 791 per 100 000 live births at pre-intervention to 1176 per 100 000 at post-intervention, representing a risk reduction of 89.1% (P = 0.007). Perinatal mortality decreased from 60.8 per 1000 total births at pre-intervention to 23.0 per 1000 at post-intervention, representing a risk reduction of 62.2% (P = 0.20). A multidisciplinary obstetric and hematology team approach can dramatically reduce maternal and perinatal mortality in a low-resource setting.

Family, Community, and Health System Considerations for Reducing the Burden of Pediatric Sickle Cell Disease in Uganda Through Newborn Screening

Sickle cell disease (SCD) is associated with high mortality for children under 5 years of age in sub-Saharan Africa. Newborn sickle screening program and enhanced capacity for SCD treatment are under development to reduce disease burden in Uganda and elsewhere in the region. Based on an international stakeholder meeting and a family-directed conference on SCD in Kampala in 2015, and interviews with parents, multinational experts, and other key informants, we describe health care, community, and family perspectives in support of these initiatives. Key stakeholder meetings, discussions, and interviews were held to understand perspectives of public health and multinational leadership, patients and families, as well as national progress, resource needs, medical and social barriers to program success, and resources leveraged from HIV/AIDS. Partnering with program leadership, professionals, patients and families, multinational stakeholders, and leveraging resources from existing programs are needed for building successful programs in Uganda and elsewhere in sub-Saharan Africa.

Global, regional, and national levels and causes of maternal mortality during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

The fifth Millennium Development Goal (MDG 5) established the goal of a 75% reduction in the maternal mortality ratio (MMR; number of maternal deaths per 100,000 livebirths) between 1990 and 2015. We aimed to measure levels and track trends in maternal mortality, the key causes contributing to maternal death, and timing of maternal death with respect to delivery.

METHODS

We used robust statistical methods including the Cause of Death Ensemble model (CODEm) to analyse a database of data for 7065 site-years and estimate the number of maternal deaths from all causes in 188 countries between 1990 and 2013. We estimated the number of pregnancy-related deaths caused by HIV on the basis of a systematic review of the relative risk of dying during pregnancy for HIV-positive women compared with HIV-negative women. We also estimated the fraction of these deaths aggravated by pregnancy on the basis of a systematic review. To estimate the numbers of maternal deaths due to nine different causes, we identified 61 sources from a systematic review and 943 site-years of vital registration data. We also did a systematic review of reports about the timing of maternal death, identifying 142 sources to use in our analysis. We developed estimates for each country for 1990-2013 using Bayesian meta-regression. We estimated 95% uncertainty intervals (UIs) for all values.

FINDINGS

292,982 (95% UI 261,017-327,792) maternal deaths occurred in 2013, compared with 376,034 (343,483-407,574) in 1990. The global annual rate of change in the MMR was -0·3% (-1·1 to 0·6) from 1990 to 2003, and -2·7% (-3·9 to -1·5) from 2003 to 2013, with evidence of continued acceleration. MMRs reduced consistently in south, east, and southeast Asia between 1990 and 2013, but maternal deaths increased in much of sub-Saharan Africa during the 1990s. 2070 (1290-2866) maternal deaths were related to HIV in 2013, 0·4% (0·2-0·6) of the global total. MMR was highest in the oldest age groups in both 1990 and 2013. In 2013, most deaths occurred intrapartum or postpartum. Causes varied by region and between 1990 and 2013. We recorded substantial variation in the MMR by country in 2013, from 956·8 (685·1-1262·8) in South Sudan to 2·4 (1·6-3·6) in Iceland.

INTERPRETATION

Global rates of change suggest that only 16 countries will achieve the MDG 5 target by 2015. Accelerated reductions since the Millennium Declaration in 2000 coincide with increased development assistance for maternal, newborn, and child health. Setting of targets and associated interventions for after 2015 will need careful consideration of regions that are making slow progress, such as west and central Africa.

FUNDING

Bill & Melinda Gates Foundation.

Clinical complications in pregnant women with sickle cell disease: prospective study of factors predicting maternal death or near miss

OBJECTIVE

To evaluate complications in pregnant women with sickle cell disease, especially those leading to maternal death or near miss (severe obstetric complications).

METHODS

A prospective cohort of 104 pregnant women registered in the Blood Center of Belo Horizonte (Hemominas Foundation) was followed up at high-risk prenatal units. They belonged to Group I (51 hemoglobin SS and three hemoglobin S/β(0)-thalassemia) or Group II (49 hemoglobin SC and one hemoglobin S/β(+)-thalassemia). Both groups had similar median ages. Predictive factors for 'near miss' or maternal death with p-value≤0.25 in the univariate analysis were included in a multivariate logistic model (significance set for p-value≤0.05).

RESULTS

Group I had more frequent episodes of vaso-occlusive crises, more transfusions in the antepartum and postpartum, and higher percentage of preterm deliveries than Group II. Infections and painful crises during the postpartum period were similar in both the groups. The mortality rate was 4.8%: three deaths in Group I and two in Group II. One-third of the women in both the groups experienced near miss. The most frequent event was pneumonia/acute chest syndrome. Alpha-thalassemia co-inheritance and β-gene haplotypes were not associated with near miss or maternal death. In multivariate analysis predictors of near miss or death were parity above one and baseline red blood cell macrocytosis. In Group I, baseline hypoxemia (saturation<94%) was also predictive of near miss or death.

CONCLUSION

One-third of pregnant women had near miss and 4.8% died. Both hemoglobin SS and SC pregnant women shared the same risk of death or of severe complications, especially pulmonary events.

Current management of sickle cell disease in pregnancy

Life expectancy in sickle cell disease (SCD) has increased substantially and thus women with SCD are almost universally reaching child-bearing age. Studies on potential complications during pregnancy have generated mixed data; however, it is generally accepted that women with SCD are at higher risk for adverse pregnancy outcomes and maternal mortality. It is therefore critical that their care be provided by a team that includes a hematologist and a maternal-fetal medicine specialist. Despite the published risks, women with SCD are capable of successful pregnancy outcomes with proper education and well-coordinated multidisciplinary care. Further investigation is needed to standardize management.

Gestational age assessment in malaria pregnancy cohorts: a prospective ultrasound demonstration project in Malawi

Background

Malaria during pregnancy is associated with an increased risk for low birth weight (<2500 grams). Distinguishing infants that are born premature (< 37 weeks) from those that are growth-restricted (less than the 10th percentile at birth) requires accurate assessment of gestational age. Where ultrasound is accessible, sonographic confirmation of gestational age is more accurate than menstrual dating. The goal was to pilot the feasibility and utility of adding ultrasound to an observational pregnancy malaria cohort.

Methods

In July 2009, research staff (three mid-level clinical providers, one nurse) from The Blantyre Malaria Project underwent an intensive one-week ultrasound training to perform foetal biometry. Following an additional four months of practice and remote image review, subjects from an ongoing cohort were recruited for ultrasound to determine gestational age. Gestational age at delivery established by ultrasound was compared with postnatal gestational age assessment (Ballard examination).

Results

One hundred and seventy-eight women were enrolled. The majority of images were of good quality (94.3%, 509/540) although a learning curve was apparent with 17.5% (24/135) images of unacceptable quality in the first 25% of scans. Ultrasound was used to date 13% of the pregnancies when menstrual dates were unknown and changed the estimated gestational age for an additional 25%. There was poor agreement between the gestational age at delivery as established by the ultrasound protocol compared to that determined by the Ballard examination (bias 0.8 weeks, limits of agreement -3.5 weeks to 5.1 weeks). The distribution of gestational ages by Ballard suggested a clustering of gestational age around the mean with 87% of the values falling between 39 and 41 weeks. The distribution of gestational age by ultrasound confirmed menstrual dates was more typical. Using ultrasound confirmed dates as the gold standard, 78.5% of preterm infants were misclassified as term and 26.8% of small-for gestational age infants misclassified as appropriately grown by Ballard.

Conclusion

Ultrasound should be strongly considered in prospective malaria studies with obstetric endpoints to confirm gestational age and avoid misclassification of infants as premature or growth-restricted. The use of ultrasound does require a significant investment of time to maintain quality image acquisition.

Sickle cell disease in pregnancy: trend and pregnancy outcomes at a tertiary hospital in Tanzania

SCD in pregnancy is associated with increased adverse fetal and maternal outcomes. In Tanzania where the frequency of sickle cell trait is 13% there has been scanty data on SCD in pregnancy. With progressive improvement in childhood survival the burden of SCD in pregnancy will increase. We analyzed all deliveries at Muhimbili National Hospital (MNH) from 1999 to 2011. Fetal and maternal outcomes of SCD deliveries were compared with non-SCD. Data were analyzed using IBM SPSS statistics version 19. Chi square and Fisher Exact tests were used to compare proportions and the independent t-test for continuous data. To predict risks of adverse effects, odds ratios were determined using multivariate logistic regression. A p-value<0.05 was considered significant. In total, 157,473 deliveries occurred at MNH during the study period, of which 149 were SCD (incidence of 95 SCD per 100,000 deliveries). The incidence of SCD had increased from 76 per 100,000 deliveries in the 1999–2002 period to over 100 per 100, 000 deliveries in recent years. The mean maternal age at delivery was lower in SCD (24.0±5.5 years) than in non-SCD deliveries (26.2±6.0 years), p<0.001. Compared with non-SCD (2.9±0.7 Kg), SCD deliveries had less mean birth-weight (2.6±0.6 Kg), p<0.001. SCD were more likely than non-SCD to deliver low APGAR score at 5 minutes (34.5% Vs 15.0%, OR = 3.0, 95%CI: 2.1–4.2), stillbirths (25.7% Vs 7.5%, OR = 4.0, 95%CI: 2.8–5.8). There was excessive risk of maternal deaths in SCD compared to non-SCD (11.4% Vs 0.4%, OR = 29, 95%CI: 17.3–48.1). The leading cause of deaths in SCD was infections in wholly 82% in contrast to only 32% in non-SCD. In conclusion SCD in pregnancy is an emerging problem at MNH with increased adverse fetal outcomes and excessive maternal mortality mainly due to infections.

Misconceptions about sickle cell disease (SCD) among lay people in Benin

OBJECTIVE

The aim of this study was to determine the accuracy of people's ideas in Benin about the common affliction of sickle cell disease (SCD).

METHODS

A questionnaire asking for the degree of agreement with 111 statements about SCD was given in 2011 to 6 physicians (the gold standard) and 178 lay people living in Cotonou, Benin. A misconception was defined as a statistically significant (p<0.001) deviation of at least 2.5 points on the 0-10 response scale of the lay people's mean response from that of the physicians.

RESULTS

Lay people tended not to be sufficiently aware that SCD is a hereditary illness, that a genetic test can detect the gene, that having it does not automatically lead to illness, that SCD may induce severe kidney, lung, heart, or cerebrovascular disorders, and that SCD cannot be cured by traditional healers. These misconceptions were greater among those who knew they had SCD or carried the gene than among those who knew they did not.

CONCLUSION

Major efforts are needed to overcome the educational and cultural barriers to accurate understanding of how to prevent and treat SCD among lay people in Benin, especially among those at greatest risk.

Excess risk of maternal death from sickle cell disease in Jamaica: 1998-2007

Background

Decreases in direct maternal deaths in Jamaica have been negated by growing indirect deaths. With sickle cell disease (SCD) a consistent underlying cause, we describe the epidemiology of maternal deaths in this population.

Methods

Demographic, service delivery and cause specific mortality rates were compared among women with (n = 42) and without SCD (n = 376), and between SCD women who died in 1998–2002 and 2003–7.

Results

Women with SCD had fewer viable pregnancies (p: 0.02) despite greater access to high risk antenatal care (p: 0.001), and more often died in an intensive care unit (p: 0.002). In the most recent period (2003–7) SCD women achieved more pregnancies (median 2 vs. 3; p: 0.009), made more antenatal visits (mean 3.3 vs. 7.3; p: 0.01) and were more often admitted antenatally (p:<0.0001). The maternal mortality ratio for SCD decedents was 7–11 times higher than the general population, with 41% of deaths attributable to their disorder. Cause specific mortality was higher for cardiovascular complications, gestational hypertension and haemorrhage. Respiratory failure was the leading immediate cause of death.

Conclusions

Women with SCD experience a significant excess risk of dying in pregnancy and childbirth [MMR: (SCD) 719/100,000, (non SCD) 78/100,000]. MDG5 cannot be realised without improving care for women with SCD. Tertiary services (e.g. ventilator support) are needed at regional centres to improve outcomes in this and other high risk populations. Universal SCD screening in pregnancy in populations of African and Mediterranean descent is needed as are guidelines for managing SCD pregnancies and educating families with SCD.

Malaria in pregnancy: the difficulties in measuring birthweight

Recommendations for interventions to control malaria in pregnancy are often based on studies using birthweight as the primary endpoint. Differences in birthweight may be attributable partly to methodological difficulties. We performed a structured search of the literature using ‘malaria’, ‘pregnancy’ and ‘birth weight’ as search terms. Of the clinical trials reporting birthweight, only 33% (14/43) gave information about the timing of the measurement and details on the scales used. Seventy seven per cent explained how gestational age was estimated. We propose a standardised method for the measurement and reporting of birthweight in future studies.

The incidence of malaria and the comparison of hematological and biochemical indices of Plasmodium falciparum-parasitemic and aparasitemic sickle cell disease (SCD) patients

Hemolytic anemia is common in sickle cell disease (SCD), but the course and extent differ, depending on genetic, epigenetic, and environmental factors. In the malaria-endemic tropical environment, some vulnerable subjects would be infected and the impact of infection would vary. Therefore, this study was to find malaria incidence and the associated changes in some laboratory indices in 330 SCD subjects. Following blood smear preparation for falciparum detection, hematological and biochemical indices were measured for a comparison of parasitemic and age-matched, genotype-matched, and sex-matched nonparasitemics. For sixty-nine parasitemics, constituting about 21% of all subjects studied, and sixty-six matched nonparasitemics, hematological indices (hemoglobin, white-cell count, red-cell count, mean cellular volume, reticulocyte count, and HbF) as well as biochemical indices (LDH, total bilirubin, AST, and ALT) were determined. For all quantities, except the reticulocyte count (12.3% ± 12.4% for parasitemics and 23.6% ± 17.7% for nonparasitemics), no statistically significant differences were observed. Classification of both cohorts according to their genotypes showed some intergenotypic differences for hemoglobin and WBC counts. Mathematical modeling of the reticulocyte counts shows the distribution in the parasitemics followed an exponential pattern, while the nonparasitemic showed a polynomial distribution, with each model characterized by an equation of best fit. The study has shown about 21% incidence of parasitemia. All differences in the indices can be seen as normal variations, unattributable to the malaria infection. However, the lower reticulocyte count in the parasitemic is a reflection of lowered erythropoietic activity because of the infection.

Comparison of Plasmodium falciparum growth in sickle cells in low oxygen environment and candle-jar

The first successful in vitro cultivation of Plasmodium falciparum in sickle cells in a gas mixture containing 3% oxygen, 4% carbon dioxide and 93% nitrogen has been reported recently, contradicting earlier claims that the parasite does not multiply continuously in sickle cell trait (HbAS) and sickle cell anemia (HbSS) erythrocytes at low oxygen tension. The present study extends that report by growing three P. falciparum strains in erythrocytes from four different sickle cell trait and four sickle cell anemia donors. Because P. falciparum is known to grow normally in sickle cells when incubated in a candle-jar estimated to contain 15-18% oxygen, we have also compared the growth at 3% oxygen with that in a candle-jar. For convenience, we also refer to the 3% oxygen and the candle-jar as low and high oxygen environment, respectively. The three P. falciparum strains were first grown continuously in low oxygen environment for at least 1 month in erythrocytes from one HbAS carrier. These stock cultures were then used to infect erythrocytes from additional three HbAS carriers and four HbSS patients. Results of the experiments showed that parasite growth and hemozoin production in HbAS erythrocytes in low oxygen environment were comparable to those obtained in the candle-jar. There was growth retardation in HbSS erythrocytes in low oxygen environment, but some of the parasites survived and eventually produced high parasitemia levels. Continuous cultivation of different P. falciparum strains in HbAS erythrocytes is necessary for investigation of possible molecular differences between malaria parasites in sickle cells and those in HbAA erythrocytes.

Sickle-cell disease

With the global scope of sickle-cell disease, knowledge of the countless clinical presentations and treatment of this disorder need to be familiar to generalists, haematologists, internists, and paediatricians alike. Additionally, an underlying grasp of sickle-cell pathophysiology, which has rapidly accrued new knowledge in areas related to erythrocyte and extra-erythrocyte events, is crucial to an understanding of the complexity of this molecular disease with protean manifestations. We highlight studies from past decades related to such translational research as the use of hydroxyurea in treatment, as well as the therapeutic promise of red-cell ion-channel blockers, and antiadhesion and anti-inflammatory therapy. The novel role of nitric oxide in sickle-cell pathophysiology and the range of its potential use in treatment are also reviewed. Understanding of disease as the result of a continuing interaction between basic scientists and clinical researchers is best exemplified by this entity.

Effect of a comprehensive clinical care program on disease course in severely ill children with sickle cell anemia in a sub-Saharan African setting

Clinical severity of sickle cell anemia (SS) in Africa may not be solely determined by genetic factors. This study evaluated the effects of intensive parental education and adequate clinical care on the course of SS in children in Benin. SS children referred to the National Teaching Hospital in Cotonou were included in the study. Teaching about SS was repeated frequently, emphasizing the importance of keeping clinic appointments, improving the nutrition of the affected children, and instituting antipneumococcal and antimalarial prophylaxis. Frequency and severity of SS-related events, changes in physical growth, frequency of malarial attacks, causes of transfusion, and causes of death were the principal variables assessed. 236 young children with repeated SS-related acute complications were studied from July 1, 1993, to December 31, 1999 (983 patient-years). A marked reduction in the frequency and severity of SS-related acute events was observed. Improvement in general status and physical growth was noted in 184 patients (78%); in addition, 22 of the remaining 52 patients showed similar improvement after remotivating the parents for compliance. There were 10 deaths, primarily in this cohort of 52 patients. Intensive sociomedical intervention can produce sustained clinical improvement in many severely ill SS children in sub-Saharan Africa.

Sickle cell disease in Africa

Africa is the main birthplace of sickle mutations; the number of newborns affected by sickle cell disease is estimated at 200,000 per year. However, because of low family income and public health funding and, to a lesser extent, because of local beliefs about sickle cell disease, overall treatment of patients is still poor and, in some places, inadequate. Efforts to adapt therapeutic options and overcome difficulties are presented and analyzed.