Sickle cell disease

Multiparametric Cardiac Magnetic Resonance Assessment in Sickle Beta Thalassemia

Cardiac involvement in sickle beta thalassemia (Sβ-thal) patients has been poorly investigated. We aimed to evaluate cardiac function and myocardial iron overload by cardiovascular magnetic resonance (CMR) in patients with Sβ-thal. One-hundred and eleven Sβ-thal patients consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) network were studied and compared with 46 sickle cell anemia (SCA) patients and with 111 gender- and age- matched healthy volunteers. Cine images were acquired to quantify biventricular function. Myocardial iron overload (MIO) was assessed by the T2* technique, while macroscopic myocardial fibrosis was evaluated by the late gadolinium enhancement (LGE) technique. In Sβ-thal and SCA patients, the morphological and functional CMR parameters were not significantly different, except for the left atrial area and left ventricular (LV) stroke volume, indexed by body surface area (p = 0.023 and p = 0.048, respectively), which were significantly higher in SCA patients. No significant differences between the two groups were found in terms of myocardial iron overload and macroscopic myocardial fibrosis. When compared to healthy subjects, Sβ-thal patients showed significantly higher bi-atrial and biventricular parameters, except for LV ejection fraction, which was significantly lower. The CMR analysis confirmed that Sβ-thal and SCA patients are phenotypically similar. Since Sβ-thal patients showed markedly different morphological and functional indices from healthy subjects, it would be useful to identify Sβ-thal/SCA-specific bi-atrial and biventricular reference values.

"The project did not come to us with a solution": Perspectives of research teams on implementing a study about electronic health record-embedded individualized pain plans for emergency department treatment of vaso-occlusive episodes in adults with sickle cell disease

BACKGROUND

This study aimed to capture the implementation process of the ALIGN Study, (An individualized Pain Plan with Patient and Provider Access for Emergency Department care of Sickle Cell Disease). ALIGN aimed to embed Individualized Pain Plans in the electronic health record (E-IPP) and provide access to the plan for both adult patients with sickle cell disease (SCD) and emergency department providers when a person with SCD comes to the emergency department in vaso-occlusive crises.

METHODS

Semi-structured interviews were conducted with research teams from the 8 participating sites from the ALIGN study. Seventeen participants (principal investigators and study coordinators) shared their perspectives about the implementation of ALIGN in their sites. Data were analyzed in three phases using open coding steps adapted from grounded theory and qualitative content analysis.

RESULTS

A total of seven overarching themes were identified: (1) the E-IPP structure (location and upkeep) and collaboration with the informatics team, (2) the role of ED champion, (3) the role of research coordinators, (4) research team communication, and communication between research team and clinical team, (5) challenges with the study protocol, (6) provider feedback: addressing over-utilizers, patient mistrust, and the positive feedback about the intervention, and (7) COVID-19 and its effects on study implementation.

CONCLUSIONS

Findings from this study contribute to learning how to implement E-IPPs for adult patients with SCD in ED. The study findings highlight the importance of early engagement with different team members, a champion from the emergency department, study coordinators with different skills and enhancement of communication and trust among team members. Further recommendations are outlined for hospitals aiming to implement E-IPP for patients with SCD in ED.

Immunological Efficacy of Pneumococcal Vaccination Including the 13-Valent Pneumococcal Conjugate Vaccine in Adult Patients With Sickle Cell Disease: Results of the Randomized DREVAC Controlled Trial

BACKGROUND

Patients with sickle cell disease (SCD) are at high risk for invasive pneumococcal diseases. The immunological efficacy of 13-valent conjugate pneumococcal vaccine (PCV13) followed by a 23-valent polysaccharide vaccine (PPSV23) is poorly documented in adults with SCD.

METHODS

This was a randomized open-labeled phase 2 study of the immunogenicity of PCV13 at week 0, followed by PPSV23 at week 4, compared with PPSV23 alone at week 4 in adult patients with SCD. The proportion of responders (4-fold increase in serotype-specific immunoglobulin [Ig] G antibodies) to ≥10 shared serotypes was assessed at week 8. Secondary end points were (1) geometric mean titers, (2) responders to 0-1, 2-5, 6-9, or 10-12 serotypes, (3) pneumococcal opsonophagocytic activity, and (4) response durability at weeks 24 and 96.

RESULTS

In total, 128 patients were randomized in the PCV13/PPSV23 (n = 63) or PPSV23-alone groups (n = 65). At week 8, 24.56% and 8.20% of patients from the PCV13/PPSV23 and PPSV23 groups, respectively, reached the primary end point (P = .02). These numbers were 36.2% and 8.7% for opsonophagocytic activity responders (P = .002). A combined PCV13/PPSV23 strategy improved the breadth of responses to 0-1, 2-5, 6-9, or 10-12 serotypes with 15.8%, 35%, 24.6%, and 24.6% versus 52.5%, 31%, 8%, and 8% in the PPSV23 group. At week 96, geometric mean titers were significantly higher in the PCV13/PPSV23 than in the PPSV23-alone group for 5 serotypes (4, 14, 19A, 19F, 23F).

CONCLUSIONS

A PCV13/PPSV23 regimen improved the breadth and magnitude of antibody responses against a large range of pneumococcal serotypes in adults with SCD. The sustainability of the immune response requires recall strategies.Clinical Trial Registration: NCT02274415.

Emotional distress among parent caregivers of adolescents with sickle cell disease: Association with patients and caregivers variables

Evidence suggests that impairment in caregiver wellbeing can alter the quality of care in children with sickle cell disease. We examined 121 parent caregivers of adolescents with sickle cell disease for emotional distress and disruptions to caregiver lifestyle and interests. Participants were predominantly mothers 92(76%) with mean age, 43.59 ( SD = 6.39) years. Four in every ten caregivers had emotional distress, and this was predicted by frequent hospital attendance and disruptions in caregiver lifestyle, relationships, and interests. Psychosocial support to promote resilience and adaptive coping-styles to deal with the stress from unforeseen crises, frequent hospital visits, and lifestyle disruptions are indicated to improve caregiver wellbeing.

Magnesium for treating sickle cell disease

BACKGROUND

Sickle cell disease is an autosomal recessive inherited haemoglobinopathy which causes painful vaso-occlusive crises due to sickle red blood cell dehydration. Vaso-occlusive crises are common painful events responsible for a variety of clinical complications; overall mortality is increased and life expectancy decreased compared to the general population. Experimental studies suggest that intravenous magnesium has proven to be well-tolerated in individuals hospitalised for the immediate relief of acute (sudden onset) painful crisis and has the potential to decrease the length of hospital stay. Some in vitro studies and open studies of long-term oral magnesium showed promising effect on pain relief but failed to show its efficacy. The studies show that oral magnesium therapy may prevent sickle red blood cell dehydration and prevent recurrent painful episodes. There is a need to access evidence for the impact of oral and intravenous magnesium effect on frequency of pain, length of hospital stay and quality of life. This is an updated version of the review.

OBJECTIVES

To evaluate the effects of short-term intravenous magnesium on the length of hospital stay and quality of life in children and adults with sickle cell disease. To determine the effects of long-term oral magnesium therapy on the frequency of painful crises and the quality of life in children and adults with sickle cell disease.

SEARCH METHODS

We searched the Cochrane Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books.Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 03 February 2019.Date of last search of other resources (clinical trials registries): 04 April 2019.

SELECTION CRITERIA

We searched for published and unpublished randomized controlled studies of oral or intravenous magnesium compared to placebo or no magnesium.

DATA COLLECTION AND ANALYSIS

Authors independently assessed the study quality and extracted the data using standard Cochrane methodologies.

MAIN RESULTS

We included five randomized placebo-controlled studies with a total of 386 participants (aged three to 53 years). Of these, two shorter parallel studies (n = 306) compared intravenous magnesium sulphate to placebo (normal saline) for admission to hospital due to a vaso-occlusive crisis, for which we were able to analyse data. The quality of evidence was moderate for studies in this comparison, mainly due to limitations due to risk of bias and imprecision. Two of the three longer-term studies comparing oral magnesium pidolate to placebo had a cross-over design. The third was a parallel factorial study which compared hydroxyurea and oral magnesium to each other and to placebo over a longer period of time; we only present the comparison of oral magnesium to placebo from this study. The quality of evidence was very low with uncertainty of the estimation.The eight-hourly dose levels in the two studies of intravenous magnesium were different; one used 100 mg/kg while the second used 40 mg/kg. Only one of these studies (n = 104) reported the mean daily pain score while hospitalised (a non-significant difference between groups, moderate quality evidence). The second study (n = 202) reported a number of child- and parent-reported quality of life scores. None of the scores showed any difference between treatment groups (low quality evidence). Data from one study (n = 106) showed no difference in length of stay in hospital between groups (low quality evidence). Both studies reported on adverse events, but not defined by severity as we had planned. One study showed significantly more participants receiving intravenous magnesium experienced warmth at infusion site compared to placebo; there were no differences between groups for other adverse events (low quality evidence).Three studies (n = 80) compared oral magnesium pidolate to placebo. None of them reported data which we were able to analyse. One study (n = 24) reported on the number of painful days and stated there was no difference between two groups (low quality evidence). None of the studies reported on quality of life or length of hospital stay. Two studies (n = 68) reported there were no differences in levels of magnesium in either plasma or red blood cells (moderate quality evidence). Two studies (n = 56) reported adverse events. One reported episodes of mild diarrhoea and headache, all of which resolved without stopping treatment. The second study reported adverse events as gastrointestinal disorders, headache or migraine, upper respiratory infections and rash; which were all evenly distributed across treatment groups (moderate quality evidence).

AUTHORS' CONCLUSIONS

Moderate to low quality evidence showed neither intravenous magnesium and oral magnesium therapy has an effect on reducing painful crisis, length of hospital stay and changing quality of life in treating sickle cell disease. Therefore, no definitive conclusions can be made regarding its clinical benefit. Further randomized controlled studies, perhaps multicentre, are necessary to establish whether intravenous and oral magnesium therapies have any effect on improving the health of people with sickle cell disease.

Specifying sickle cell disease interventions: a study protocol of the Sickle Cell Disease Implementation Consortium (SCDIC)

BACKGROUND

Sickle cell disease (SCD) is an inherited blood disorder that results in a lifetime of anemia, severe pain, and end-organ damage that can lead to premature mortality. While the SCD field has made major medical advances, much needs to be done to improve the quality of care for people with SCD. This study capitalizes on the Sickle Cell Disease Implementation Consortium (SCDIC), a consortium of eight academic sites aiming to test implementation strategies that could lead to more accelerated application of the NHLBI guidelines for treating SCD. This report documents the process to support the consortium by specifying the interventions being developed.

METHODS

This study consists of three steps. The Principal Investigator of each site and two site representatives who are knowledgeable of the intervention (e.g., study coordinator or the person delivering the intervention) will answer an online survey aiming to capture components of the interventions. This survey will be completed by the site representatives three times during the study: during the development of the interventions, after one year of the interventions being implemented, and at the end of this study (after 2 years). A site visit and semi-structured interview (Step 2) in the first year of the process will capture the context of the sites. Step 3 comprises of the development of a framework with the details of the multi-component SCDIC interventions at the sites.

DISCUSSION

The outcome of this study, a framework of the SCDIC, will enable accurate replication and extension of published research, facilitating the translation of SCD studies to diverse populations and settings and allowing for theory testing of the effects of the intervention components across studies in different contexts and for different populations.

TRIAL REGISTRATION

ClinicalTrial.Gov (# NCT03380351 ). Registered December 21, 2017.

Effects of vaccines in patients with sickle cell disease: a systematic review protocol

INTRODUCTION

Sickle cell disease (SCD) is an inherited haematological disorder caused by a single point mutation (Glub6Val) that promotes polymerisation of haemoglobin S and sickling of erythrocytes. Inflammation, haemolysis, microvascular obstruction and organ damage characterise the highly variable clinical expression of SCD. People with SCD are at increased risk of severe infections, hence the need for vaccination against common disease-causing organisms in this population. We aim to review the evidence on the efficacy and safety of vaccines in people with SCD.

METHODS AND ANALYSIS

The present systematic review will examine the current data as indexed in PubMed, CENTRAL, EMBASE and EBSCOHost. We will consult Strategic Advisory Group of Experts practice statements, conference abstracts, reference lists of relevant articles, WHO ICTRP trial registry and experts in the field. Two authors will independently screen search outputs, select studies, extract data and assess risk of bias; resolving discrepancies by discussion and consensus between the two authors or arbitration by a third author when necessary. We will perform a meta-analysis for clinically homogenous studies. Evidence from clinically diverse studies will be aggregated using narrative synthesis of the findings. In either case, we will use the GRADE approach to assess the strength of the available evidence.

ETHICS AND DISSEMINATION

The study draws on data that are readily available in the public domain, hence no formal ethical review and approval is required. The findings of this review will be disseminated through conference presentations and a publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42018084051.

Folate supplementation in people with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a group of disorders that affects haemoglobin, which causes distorted sickle- or crescent-shaped red blood cells. It is characterized by anaemia, increased susceptibility to infections and episodes of pain. The disease is acquired by inheriting abnormal genes from both parents, the combination giving rise to different forms of the disease. Due to increased erythropoiesis in people with SCD, it is hypothesized that they are at an increased risk for folate deficiency. For this reason, children and adults with SCD, particularly those with sickle cell anaemia, commonly take 1 mg of folic acid orally every day on the premise that this will replace depleted folate stores and reduce the symptoms of anaemia. It is thus important to evaluate the role of folate supplementation in treating SCD.

OBJECTIVES

To analyse the efficacy and possible adverse effects of folate supplementation (folate occurring naturally in foods, provided as fortified foods or additional supplements such as tablets) in people with SCD.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also conducted additional searches in both electronic databases and clinical trial registries.Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 17 November 2017.

SELECTION CRITERIA

Randomised, placebo-controlled trials of folate supplementation for SCD.

DATA COLLECTION AND ANALYSIS

Four review authors assessed We used the standard Cochrane-defined methodological procedures.Four review authors independently assessed the eligibility and risk of bias of the included trials and extracted and analysed the data included in the review. The quality of the evidence was assessed using GRADE.

MAIN RESULTS

One trial, undertaken in 1983, was eligible for inclusion in the review. This was a double-blind placebo-controlled quasi-randomised triaI of supplementation of folic acid in people with SCD. A total of 117 children with homozygous sickle cell (SS) disease aged six months to four years of age participated over a one-year period (analysis was restricted to 115 children).Serum folate measures, obtained after trial entry at six and 12 months, were available in 80 of 115 (70%) participants. There were significant differences between the folic acid and placebo groups with regards to serum folate values above 18 µg/L and values below 5 µg/L (low-quality evidence). In the folic acid group, values above 18 µg/L were observed in 33 of 41 (81%) compared to six of 39 (15%) participants in the placebo (calcium lactate) group. Additionally, there were no participants in the folic acid group with serum folate levels below 5 µg/L, whereas in the placebo group, 15 of 39 (39%) participants had levels below this threshold. Haematological indices were measured in 100 of 115 (87%) participants at baseline and at one year. After adjusting for sex and age group, the investigators reported no significant differences between the trial groups with regards to total haemoglobin concentrations, either at baseline or at one year (low-quality evidence). It is important to note that none of the raw data for the outcomes listed above were available for analysis.The proportions of participants who experienced certain clinical events were analysed in all 115 participants, for which raw data were available. There were no statistically significant differences noted; however, the trial was not powered to investigate differences between the folic acid and placebo groups with regards to: minor infections, risk ratio (RR) 0.99 (95% confidence interval (CI) 0.85 to 1.15) (low-quality evidence); major infections, RR 0.89 (95% CI 0.47 to 1.66) (low-quality evidence); dactylitis, RR 0.67 (95% CI 0.35 to 1.27) (low-quality evidence); acute splenic sequestration, RR 1.07 (95% CI 0.44 to 2.57) (low-quality evidence); or episodes of pain, RR 1.16 (95% CI 0.70 to 1.92) (low-quality evidence). However, the investigators reported a higher proportion of repeat dactylitis episodes in the placebo group, with two or more attacks occurring in 10 of 56 participants compared to two of 59 in the folic acid group (P < 0.05).Growth, determined by height-for-age and weight-for-age, as well as height and growth velocity, was measured in 103 of the 115 participants (90%), for which raw data were not available. The investigators reported no significant differences in growth between the two groups.The trial had a high risk of bias with regards to random sequence generation and incomplete outcome data. There was an unclear risk of bias in relation to allocation concealment, outcome assessment, and selective reporting. Finally, There was a low risk of bias with regards to blinding of participants and personnel. Overall the quality of the evidence in the review was low.There were no trials identified for other eligible comparisons, namely: folate supplementation (fortified foods and physical supplementation with tablets) versus placebo; folate supplementation (naturally occurring in diet) versus placebo; folate supplementation (fortified foods and physical supplementation with tablets) versus folate supplementation (naturally occurring in diet).

AUTHORS' CONCLUSIONS

One doubIe-blind, placebo-controlled triaI on folic acid supplementation in children with SCD was included in the review. Overall, the trial presented mixed evidence on the review's outcomes. No trials in adults were identified. With the limited evidence provided, we conclude that, while it is possible that folic acid supplementation may increase serum folate levels, the effect of supplementation on anaemia and any symptoms of anaemia remains unclear.If further trials were conducted, these may add evidence regarding the efficacy of folate supplementation. Future trials should assess clinical outcomes such as folate concentration, haemoglobin concentration, adverse effects and benefits of the intervention, especially with regards to SCD-related morbidity. Such trials should include people with SCD of all ages and both sexes, in any setting. To investigate the effects of folate supplementation, trials should recruit more participants and be of longer duration, with long-term follow-up, than the trial currently included in this review. However, we do not envisage further trials of this intervention will be conducted, and hence the review will no longer be regularly updated.

Impact of aerobic exercises on selected inflammatory markers and immune system response among patients with sickle cell anemia in asymptomatic steady state

Background & objective

Sickle cell anemia (SCA) is well recognized as a chronic inflammatory disease. Despite progress in therapy, SCA remains a cause of significant morbidity and mortality. The relationship between exercise and immune function has been of great interest to the scientific community and the lay public. The aim of this study was to measure the impact of aerobic exercise training on the immunologic parameters and inflammatory cytokines of patients with sickle cell anemia (SCA) in asymptomatic steady state.

Material and methods

Sixty asymptomatic sickle cell anemia patients were involved in this study, their age ranged from 25– 40 years and were assigned to two sub-groups; group (A) received aerobic exercise training for 12 weeks, however group (B) received no training intervention for 12 weeks. Parameters of CD3, CD4 and CD8 were quantified, Leukocyte, differential counts, IL-6 and TNF-α were measured before and after 12 weeks, at the end of the study.

Results

The mean values of CD3, CD4 and CD8, leukocyte, monocytes counts, IL-6 and TNF-α were significantly decreased in group (A), while group (B) showed non-significant changes in these parameters. Also; there were significant differences between mean levels of the investigated parameters in group (A) and group (B) after treatment.

Conclusion

The current study provides evidence that aerobic exercise training improves inflammatory markers and immune system in patients with sickle cell anemia (SCA) in asymptomatic steady state.

Magnesium for treating sickle cell disease

BACKGROUND

Sickle cell disease is an autosomal recessive inherited haemoglobinopathy which causes painful vaso-occlusive crises due to sickle red blood cell dehydration. Vaso-occlusive crises are common painful events responsible for a variety of clinical complications; overall mortality is increased and life expectancy decreased compared to the general population. Experimental studies suggest that intravenous magnesium has proven to be well-tolerated in individuals hospitalised for the immediate relief of acute (sudden onset) painful crisis and has the potential to decrease the length of hospital stay. Some in vitro studies and open studies of long-term oral magnesium showed promising effect on pain relief but failed to show its efficacy. The studies show that oral magnesium therapy may prevent sickle red blood cell dehydration and prevent recurrent painful episodes. There is a need to access evidence for the impact of oral and intravenous magnesium effect on frequency of pain, length of hospital stay and quality of life.

OBJECTIVES

To evaluate the effects of short-term intravenous magnesium on the length of hospital stay and quality of life in children and adults with sickle cell disease. To determine the effects of long-term oral magnesium therapy on the frequency of painful crises and the quality of life in children and adults with sickle cell disease.

SEARCH METHODS

We searched the Cochrane Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books.Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 01 December 2016.Date of last search of other resources (clinical trials registries): 29 March 2017.

SELECTION CRITERIA

We searched for published and unpublished randomized controlled studies of oral or intravenous magnesium compared to placebo or no magnesium.

DATA COLLECTION AND ANALYSIS

Authors independently assessed the study quality and extracted the data using standard Cochrane methodologies.

MAIN RESULTS

We included five randomized placebo-controlled studies with a total of 386 participants (aged three to 53 years). Two shorter parallel studies (n = 306) compared intravenous magnesium sulphate to placebo (normal saline) for admission to hospital due to a vaso-occlusive crisis, for which we were able to analyse data. The quality of evidence was moderate for studies presenting this comparison mainly due to limitations due to risk of bias and imprecision. Two of the three longer-term studies comparing oral magnesium pidolate to placebo had a cross-over design. The third was a parallel factorial study which compared hydroxyurea and oral magnesium to each other and to placebo over a longer period of time; we only present the comparison of oral magnesium to placebo from this study. The quality of evidence was very low with uncertainty of the estimation.The eight-hourly dose levels in the two studies of intravenous magnesium were different; one used 100 mg/kg while the second used 40 mg/kg. Only one of these studies (n = 104) reported the mean daily pain score while hospitalised (a non-significant difference between groups, moderate quality evidence). The second study (n = 202) reported a number of child- and parent-reported quality of life scores. None of the scores showed any difference between treatment groups (low quality evidence). Data from one study (n = 106) showed no difference in length of stay in hospital between groups (low quality evidence). Both studies reported on adverse events, but not defined by severity as we had planned. One study showed significantly more participants receiving intravenous magnesium experienced warmth at infusion site compared to placebo; there were no differences between groups for other adverse events (low quality evidence).Three studies (n = 80) compared oral magnesium pidolate to placebo. None of them reported data which we were able to analyse. One study (n = 24) reported on the number of painful days and stated there was no difference between two groups (low quality evidence). None of the studies reported on quality of life or length of hospital stay. Two studies (n = 68) reported there were no differences in levels of magnesium in either plasma or red blood cells (moderate quality evidence). Two studies (n = 56) reported adverse events. One reported episodes of mild diarrhoea and headache, all of which resolved without stopping treatment. The second study reported adverse events as gastrointestinal disorders, headache or migraine, upper respiratory infections and rash; which were all evenly distributed across treatment groups (moderate quality evidence).

AUTHORS' CONCLUSIONS

Moderate to low quality evidence showed neither intravenous magnesium and oral magnesium therapy has an effect on reducing painful crisis, length of hospital stay and changing quality of life in treating sickle cell disease. Therefore, no definitive conclusions can be made regarding its clinical benefit. Further randomized controlled studies, perhaps multicentre, are necessary to establish whether intravenous and oral magnesium therapies have any effect on improving the health of people with sickle cell disease.

CT abdominal imaging findings in patients with sickle cell disease: acute vaso-occlusive crisis, complications, and chronic sequelae

Sickle cell disease (SCD) is the most prevalent hemoglobinopathy. Survival in patients with SCD has improved over the past few decades. These patients experience a lifetime of repeated acute pain crises, which are thought to result from sickling and microvascular occlusions; acute abdominal pain is common. Moreover, repeated crises often lead to organ dysfunction, such as asplenia, hepatic failure, and renal failure. The spleen, liver, biliary system, kidneys, and gastrointestinal tract can all be affected. Patients may undergo CT to further direct clinical management. We review the spectrum of CT imaging findings of abdominal manifestations in patients with SCD, from the acute microvascular occlusive pain crisis to the potential complications and chronic sequelae.

Expected Sonographic Appearance of the Spleen in Children and Young Adults With Sickle Cell Disease: An Update

OBJECTIVES

To update the imaging literature regarding spleen appearances in young patients with sickle cell disease (SCD).

METHODS

We conducted a retrospective study and included 112 patients age 0 to 21 years with SCD who had at least 1 abdominal sonogram at our institution between 1999 and 2011. Radiologic findings were compared between risk groups by χ(2) analysis. Findings were correlated with other imaging modalities when available.

RESULTS

In our cohort, 35.7% of patients had autosplenectomy, and 8.0% had undergone surgical splenectomy. Only 5.0% of individuals age 0 to 5 years had autosplenectomy. In those who had not undergone surgical splenectomy or autosplenectomy, 76.2% had echogenic spleens, heterogeneous-appearing spleens, or both, and patients with the homozygous sickle cell anemia (HbSS) genotype were more likely to have an abnormal spleen echo texture. Patients treated with transfusions had echogenic spleens and had a higher frequency of splenic regeneration nodules. Most patients (80%) with splenomegaly did not require surgical splenectomy after 5.7 years of follow-up.

CONCLUSIONS

Twenty years ago, children with HbSS SCD were expected to have autosplenectomy by age 5 years. There have been changes in the radiologic appearance of the spleen in patients with SDC, likely due to improved supportive care and the use of acute and chronic transfusion therapy. We found that autosplenectomy is rare by age 5 years, and during childhood and adolescence, the spleen typically appears echogenic, heterogeneous, or both, depending on disease severity.

Changes seen on computed tomography of the chest in mildly symptomatic adult patients with sickle cell disease

OBJECTIVE

To describe and quantify the main changes seen on computed tomography of the chest in mildly symptomatic adult patients with sickle cell disease, as well as to evaluate the radiologist accuracy in determining the type of hemoglobinopathy.

MATERIALS AND METHODS

A prospective study involving 44 adult patients with sickle cell disease who underwent inspiration and expiration computed tomography of the chest. The frequency of tomography findings and the extent of involvement are reported. We also calculated radiologist accuracy in determining the type of hemoglobinopathy by analyzing the pulmonary alterations and morphology of the spleen.

RESULTS

The changes found on computed tomography scans, in descending order of frequency, were as follows: fibrotic opacities (81.8%); mosaic attenuation (56.8%); architectural distortion (31.8%); cardiomegaly (25.0%); lobar volume reduction (18.2%); and increased caliber of peripheral pulmonary arteries (9.1%). For most of the findings, the involvement was considered mild, five or fewer lung segments being affected. The accuracy in determining the type of hemoglobinopathy (HbSS group versus not HbSS group) was 72.7%.

CONCLUSION

In adult patients with sickle cell disease, the main tomography findings reflect fibrotic changes. In addition, computed tomography can be helpful in differentiating among hemoglobinopathies.

Antibody persistence after serogroup C meningococcal conjugate vaccine in children with sickle cell disease

BACKGROUND

A decline of protective antibody titers after MCC vaccine has been demonstrated in healthy children, this may be an issue of concern for risk groups. The aim of this study was to evaluate the persistence of bactericidal antibodies after MCC vaccine in sickle cell disease (SCD) patients. The type of vaccine used and booster response were also analyzed.

METHODS

SCD patients (n=141) previously immunized with MCC vaccines had blood drawn 2-8 years after the last priming dose. They were distributed according to age at primary immunization into groups: <2 years and 2-13 years and evaluated by years since vaccination (2-3, 4-5 and 6-8). Serum bactericidal antibodies with baby rabbit complement (rSBA) and serogroup C-specific IgG concentrations were measured. The correlate of protection was rSBA titer ⩾8. Subjects with rSBA <8 received a booster dose and antibody levels re-evaluated after 4-6 weeks.

RESULTS

For children primed under 2years of age rSBA titer ⩾8 was demonstrated in 53.3%, 21.7% and 35.0%, 2-3, 4-5, 6-8years, respectively, after vaccination, compared with 70.0%, 45.0% and 53.5%, respectively, for individuals primed at ages 2-13years. rSBA median titers and IgG median levels were higher in the older group. Six to eight years after vaccination the percentage of patients with rSBA titers ⩾8 was significantly higher in the group primed with MCC-TT (78.5%) compared with those primed with MCC-CRM197 [Menjugate® (33.3%) or Meningitec® (35.7%)] (p=0.033). After a booster, 98% achieved rSBA titer ⩾8.

CONCLUSION

Immunity to meningococcal serogroup C in SCD children declines rapidly after vaccination and is dependent on the age at priming. Booster doses are needed to maintain protection in SCD patients. Persistence of antibodies seems to be longer in individuals primed with MCC-TT vaccine comparing to those immunized with MCC-CRM197.

Folate supplementation in people with sickle cell disease

BACKGROUND

Sickle cell disease is a group of disorders that affects haemoglobin, which causes distorted sickle- or crescent-shaped red blood cells. It is characterized by anaemia, increased susceptibility to infections and episodes of pain. The disease is acquired by inheriting abnormal genes from both parents, the combination giving rise to different forms of the disease. Due to increased erythropoiesis in people with sickle cell disease, it is hypothesized that they are at an increased risk for folate deficiency. For this reason, children and adults with sickle cell disease, particularly those with sickle cell anaemia, commonly take 1 mg of folic acid orally every day on the premise that this will replace depleted folate stores and reduce the symptoms of anaemia. It is thus important to evaluate the role of folate supplementation in treating sickle cell disease.

OBJECTIVES

To analyse the efficacy and possible adverse effects of folate supplementation (folate occurring naturally in foods, provided as fortified foods or additional supplements such as tablets) in people with sickle cell disease.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also conducted additional searches in both electronic databases and clinical trial registries.Date of last search: 07 December 2015.

SELECTION CRITERIA

Randomised, placebo-controlled trials of folate supplementation for sickle cell disease.

DATA COLLECTION AND ANALYSIS

Four review authors assessed the eligibility and risk of bias of the included trials and extracted and analysed the data included in the review. We used the standard Cochrane-defined methodological procedures.

MAIN RESULTS

One trial, undertaken in 1983, was eligible for inclusion in the review. This was a double-blind placebo-controlled quasi-randomised triaI of supplementation of folic acid in people with sickle cell disease. A total of 117 children with homozygous sickle cell (SS) disease aged six months to four years of age participated over a one-year period (analysis was restricted to 115 children).Serum folate measures, obtained after trial entry at six and 12 months, were available in 80 of 115 (70%) participants. There were significant differences between the folic acid and placebo groups with regards to serum folate values above 18 µg/l and values below 5 µg/l. In the folic acid group, values above 18 µg/l were observed in 33 of 41 (81 %) compared to six of 39 (15%) participants in the placebo (calcium lactate) group. Additionally, there were no participants in the folic acid group with serum folate levels below 5 µg/l, whereas in the placebo group, 15 of 39 (39%) participants had levels below this threshold. Haematological indices were measured in 100 of 115 (87%) participants at baseline and at one year. After adjusting for sex and age group, the investigators reported no significant differences between the trial groups with regards to total haemoglobin concentrations, either at baseline or at one year. It is important to note that none of the raw data for the outcomes listed above were available for analysis.The proportions of participants who experienced certain clinical events were analysed in all 115 participants, for which raw data were available. There were no statistically significant differences noted; however, the trial was not powered to investigate differences between the folic acid and placebo groups with regards to: minor infections, risk ratio 0.99 (95% confidence interval 0.85 to 1.15); major infections, risk ratio 0.89 (95% confidence interval 0.47 to 1.66); dactylitis, risk ratio 0.67 (95% confidence interval 0.35 to 1.27); acute splenic sequestration, risk ratio 1.07 (95% confidence interval 0.44 to 2.57); or episodes of pain, risk ratio 1.16 (95% confidence interval 0.70 to 1.92). However, the investigators reported a higher proportion of repeat dactylitis episodes in the placebo group, with two or more attacks occurring in 10 of 56 participants compared to two of 59 in the folic acid group (P < 0.05).Growth, determined by height-for-age and weight-for-age, as well as height and growth velocity, was measured in 103 of the 115 participants (90%), for which raw data were not available. The investigators reported no significant differences in growth between the two groups.The trial had a high risk of bias with regards to random sequence generation and incomplete outcome data. There was an unclear risk of bias in relation to allocation concealment, outcome assessment, and selective reporting. Finally, There was a low risk of bias with regards to blinding of participants and personnel. Overall the quality of the evidence in the review was low.There were no trials identified for other eligible comparisons, namely: folate supplementation (fortified foods and physical supplementation with tablets) versus placebo; folate supplementation (naturally occurring in diet) versus placebo; folate supplementation (fortified foods and physical supplementation with tablets) versus folate supplementation (naturally occurring in diet).

AUTHORS' CONCLUSIONS

One doubIe-blind, placebo-controlled triaI on folic acid supplementation in children with sickle cell disease was included in the review. Overall, the trial presented mixed evidence on the review's outcomes. No trials in adults were identified. With the limited evidence provided, we conclude that, while it is possible that folic acid supplementation may increase serum folate levels, the effect of supplementation on anaemia and any symptoms of anaemia remains unclear.Further trials may add evidence regarding the efficacy of folate supplementation. Future trials should assess clinical outcomes such as folate concentration, haemoglobin concentration, adverse effects and benefits of the intervention, especially with regards to sickle cell disease-related morbidity. Trials should include people with sickle cell disease of all ages and both sexes, in any setting. To investigate the effects of folate supplementation, trials should recruit more participants and be of longer duration, with long-term follow up, than the trial currently included in this review.

The current state of imaging pediatric hemoglobinopathies

The hemoglobinopathies are a group of genetic disorders with a broad spectrum of clinical manifestations and radiologic findings. The imaging of pediatric hemoglobinopathies, which is influenced by concomitant hemosiderosis and the sequela of chelation therapy, has evolved over the years along with ever-improving technology. This article reviews and illustrates the most common radiographic and cross-sectional imaging findings of the 2 best known and clinically relevant hemoglobinopathies in pediatric patients, sickle cell disease and β-thalassemia.

Intravenous magnesium sulfate for vaso-occlusive episodes in sickle cell disease

BACKGROUND AND OBJECTIVE

Vaso-occlusive episodes (VOEs) are the most common complication of sickle cell disease in children. Treatment with magnesium seems to improve cellular hydration and may result in reduced vaso-occlusion. This study aimed to determine if intravenous (IV) magnesium sulfate (MgSO4) reduces length of stay (LOS) in hospital, pain scores, and cumulative analgesia when compared with placebo.

METHODS

Randomized, double-blind, placebo-controlled trial in children aged 4 to 18 years requiring admission to hospital with a sickle cell disease VOE requiring IV analgesia. Participating children received IV MgSO4 (100 mg/kg) every 8 hours or placebo in addition to standard therapy. We used a t test or Mann-Whitney test (continuous variables), Fisher's exact test, or χ2 test (frequencies). P values were considered significant if <.05, and 95% confidence intervals were calculated for the difference between groups.

RESULTS

One hundred six children were randomly assigned to the study, and 104 were included. Fifty-one (49%) received MgSO4. Children's mean age was 12.4 years (range: 4-18 years; SD: 3.8 years), and 56 (54%) were females. There was no significant difference in the primary outcome measure, LOS in hospital, with a mean of 132.6 and 117.7 hours in the MgSO4 and placebo groups, respectively (P = .41). There was no significant difference between groups for the secondary outcomes of mean pain scores (4.9 ± 2.6 vs 4.8 ± 2.6, respectively; P = .92) or analgesic requirements (continuous morphine infusion [P = .928], boluses of IV morphine [P = .82], acetaminophen [P = .34], ibuprofen [P = .15], naproxen [P = .10]). Only minor adverse events were recorded in both groups. Pain at the infusion site was more common in the MgSO4 group.

CONCLUSIONS

IV MgSO4 was well tolerated but had no effect on the LOS in hospital, pain scores, or cumulative analgesia use in admitted children with a VOE.

Distinctive mutation spectrum of the HBB gene in an urban eastern Indian population

ABSTRACT Hemoglobinopathies such as β-thalassemia (β-thal) and sickle cell anemia (or Hb S [β6(A3)Glu→Val]) impose a major health burden in the Indian population. To determine the frequencies of the HBB gene mutations in eastern Indian populations and to compare with the available data, a comprehensive molecular analysis of the HBB gene was done in the normal Odisha State population. Using polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), amplification refractory mutation system (ARMS) and DNA sequencing techniques, β-thal and sickle cell anemia mutations were characterized in 267 healthy individuals. Entire HBB gene sequencing showed 63 different mutations including 11 new ones. The predominant mutation HBB: c.9T > C was observed at a high frequency (19.57%) in the normal population. In the urban population of Odisha State, India, carrier frequency of hemoglobinopathies was found to be 18.48%, and for β-thal, the carrier rate was 14.13%, which is very high indeed. In the absence of a complete cure by any expensive treatment and drug administration, this information would be helpful for planning a population screening program and establishing prenatal diagnosis of β-thal in order to reduce the burden of such a genetic disease.

Sickle cell disease: the need for a public health agenda

Sickle cell disease (SCD) is a collection of inherited blood disorders that affect a substantial number of people in the U.S., particularly African Americans. People with SCD have an abnormal type of hemoglobin, Hb S, which polymerizes when deoxygenated, causing the red blood cells to become misshapen and rigid. Individuals with SCD are at higher risk of morbidity and mortality from infections, vaso-occlusive pain crises, acute chest syndrome, and other complications. Addressing the public health needs related to SCD is an important step toward improving outcomes and maintaining health for those affected by the disorder. The objective of this study was to review public health activities focusing on SCD and define the need to address it more comprehensively from a public health perspective. We found that there has been some progress in the development of SCD-related public health activities. Such activities include establishing newborn screening (NBS) for SCD with all states currently having universal NBS programs. However, additional areas needing focus include strengthening surveillance and monitoring of disease occurrence and health outcomes, enhancing adherence to health maintenance guidelines, increasing knowledge and awareness among those affected, and improving healthcare access and utilization. These and other activities discussed in this paper can help strengthen public health efforts to address SCD.

Sonographic Findings in Sudanese Children With Sickle Cell Anemia

This study aims to evaluate the type and prevalence of abdominal sonographic abnormalities in children with sickle cell anemia (SCA). Ninety patients were screened by abdominal sonography. The sonographic abnormal findings were 91% in the liver, 62.2% in the spleen, 14.4% in the gallbladder, and 4.4% in the kidneys. Sonographic imaging revealed hepatomegaly in 79 (87.8%) patients. Three patients (3.3%) had hypoechoic liver lesions. One patient had multiple hypoechoic liver lesions that proved to be an abscess. Gallstones were reported in 10 patients, the youngest of whom was 2.5 years old. The overall prevalence of gallstones was 11.1%, and it increased with age. Two patients (2.2%) had thickened gallbladder wall, and only 1 patient (1.1%) had a sludged gallbladder. Autosplenectomy (asplenia) was detected in 43 (47.8%) patients. Seven (7.8%) patients had hypoechoic lesions. Hyperechoic lesions with spleenomegaly were found in 6 (6.6%) patients. Normal renal echogenecity was reported in 86 (95.6%) patients, 3 (3.3%) patients reported focal hyperechoic lesions, and 1 patient (1.1%) reported an anechoic lesion. In conclusion, abdominal sonographic imaging of patients with SCA revealed a high prevalence of abnormalities in the liver, gallbladder, and spleen but a low prevalence in the kidney.

Septic arthritis in adults with sickle cell disease often is associated with osteomyelitis or osteonecrosis

BACKGROUND

Septic arthritis is a known complication of sickle cell disease (SCD) in children, and the association with osteomyelitis and osteonecrosis has been described. However, it is unclear whether this association applies to adults.

QUESTIONS/PURPOSES

We therefore asked whether septic arthritis is a frequent complication in adults with SCD and whether it also is associated with osteomyelitis or osteonecrosis.

METHODS

We retrospectively reviewed the charts of 2000 consecutive adult patients diagnosed with SCD and recorded symptoms, select findings during physical examination, laboratory data, and select radiographic CT, and MRI observations.

RESULTS

Fifty-nine of the 2000 patients (3%) had septic arthritis, 56 of the 59 patients had hemoglobin SS. Thirty-six of the 59 infections (61%) were in the hip. The most frequent findings were pain, swelling, fever greater than 38.2 degrees C (71% of cases), a leukocyte count exceeding 15,000/mm(3) (range, 7900-32,300/mm(3)), a Westergren sedimentation rate greater than 24 mm/hour, and C-reactive protein exceeding 20 mg/L. Cultures were positive in 96% of the joint aspirates. Staphylococcus and Gram-negative infection predominated; no patients had Salmonella joint infections. Preexisting factors of bacterial arthritis included osteonecrosis (29 patients) and osteomyelitis (37 cases) in childhood. Diabetes, rheumatoid arthritis, glucocorticoids, and immunoparesis related to medical treatment by hydroxyurea were associated comorbidities. CT and MRI confirmed the diagnosis of associated osteonecrosis or osteomyelitis and allowed joint aspiration and detection of soft tissue abscess.

CONCLUSIONS

The incidence of septic arthritis in adults with SCD is low, but often is associated with osteomyelitis or osteonecrosis.

LEVEL OF EVIDENCE

Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Multidetector CT scan in the evaluation of chest pain of nontraumatic musculoskeletal origin

Acute nontraumatic chest pain is a common presenting symptom to the emergency department. Often, it is evaluated by MDCT with PE, aortic dissection, or coronary artery protocols. The parameters used for these MDCT protocols are very similar to those used in protocols for dedicated imaging of the musculoskeletal system. Thus, these studies are not only effective in evaluating for these traditional vascular causes of chest pain, but also in evaluating musculoskeletal causes of chest pain, including those of infectious, rheumatologic, and systemic causes. In essence, every MDCT of the chest is also a musculoskeletal examination of the chest and anyone interpreting these images must be familiar with the MDCT-imaging appearance of common musculoskeletal causes of acute nontraumatic chest pain.

Immunogenicity and tolerability of a virosome influenza vaccine compared to split influenza vaccine in patients with sickle cell anemia

The immunogenicity and tolerability of virosome and of split influenza vaccines in patients with sickle cell anemia (SS) were evaluated. Ninety SS patients from 8 to 34 years old were randomly assigned to receive either virosome (n=43) or split vaccine (n=47). Two blood samples were collected, one before and one 4-6 weeks after vaccination. Antibodies against viral strains (2006) A/New Caledonia (H1N1), A/California (H3N2), B/Malaysia were determined using the hemagglutinin inhibition test. Post-vaccine reactions were recorded over 7 days. Seroconversion rates for H1N1, H3N2 and B were 65.1%, 60.4% and 83.7% for virosome vaccine, and 68.0%, 61.7% and 68.0% for split vaccine. Seroprotection rates for H1N1, H3N2 e B were 100%, 97.6% and 69.7% for virosome, and 97.8%, 97.8% and 76.6% for split vaccine. No severe adverse reactions were recorded. Virosome and split vaccines in patients with sickle cell anemia were equally immunogenic, with high seroconversion and seroprotection rates. Both vaccines were well tolerated.

Mitral valve replacement in sickle cell disease

Cardiac dysfunction, including mitral valve regurgitation and congestive heart failure, can occur in patients with sickle cell disease. However, major surgery poses a greater risk in this population. This paper reports on the management of a patient with sickle cell disease who underwent successful replacement of the mitral valve.

Healthcare utilization and expenditures for low income children with sickle cell disease

BACKGROUND

While multiple studies have examined the healthcare burden of sickle cell disease (SCD) in adults, few have specifically focused on healthcare utilization and expenditures in children. The objective of this study was to characterize the healthcare utilization and costs associated with the care of low-income children with SCD in comparison to other children of similar socioeconomic status.

PROCEDURE

For the study period, 2004-2007, we conducted a retrospective, cross-sectional descriptive analysis of administrative claims data from a managed care plan exclusively serving low-income children with Medicaid and the State Children's Health Insurance Plan (SCHIP). Patient demographics, continuity of insurance coverage, healthcare utilization, and expenditures were collected for all children enrolled with SCD and the general population within the health plan for comparison.

RESULTS

On average, 27% of members with SCD required inpatient hospitalization and 39% utilized emergency care in a given calendar year. Both values were significantly higher than those of the general health plan population (P < 0.0001). Across the study period, 63% of members with SCD averaged one well child check per year and 10% had a minimum of one outpatient visit per year to a hematologist for comprehensive specialty care.

CONCLUSIONS

Low-income children with SCD demonstrate significantly higher healthcare utilization for inpatient care, emergency center care, and home health care compared to children with similar socio-demographic characteristics. A substantial proportion of children with SCD may fail to meet minimum guidelines for outpatient primary and hematology comprehensive care.

Models of comprehensive multidisciplinary care for individuals in the United States with genetic disorders

Approaches to providing comprehensive coordinated care for individuals with complex diseases include the medical home approach, the chronic care model in primary care, and disease-specific, multidisciplinary specialty clinics. There is uneven availability and utilization of multidisciplinary specialty clinics for different genetic diseases. For 2 disorders (ie, hemophilia and cystic fibrosis), effective national networks of specialty clinics exist and reach large proportions of the target populations. For other disorders, notably, sickle cell disease, fewer such centers are available, centers are less likely to be networked, and centers are used less widely. Models of comanagement are essential for promoting ongoing communication and coordination between primary care and subspecialty services, particularly during the transition from pediatric care to adult care. Evaluation of the effectiveness of different models in improving outcomes for individuals with genetic diseases is essential.

Cardiac involvement in sickle beta-thalassemia

Cardiovascular involvement is a leading cause of mortality and morbidity in patients with inherited hemoglobinopathies, but it has not been adequately assessed in sickle beta-thalassemia. We evaluated 115 sickle beta-thalassemia patients, aged 34 +/- 14 years, along with 50 healthy controls, by resting echocardiography. Patients with systolic left ventricular (LV) dysfunction or severe pulmonary hypertension (PHT) also underwent left and right cardiac catheterization and cardiac magnetic resonance imaging (CMR). Left and right chamber dimensions, LV mass, and cardiac index were significantly higher in patients compared to controls (p < 0.001 in most cases). Three patients (2.9%) had reduced LV ejection fraction (<55%); mean LV ejection fraction was significantly lower in patients (p < 0.001). Left and right ventricular systolic tissue Doppler indices and LV diastolic tissue Doppler indices were also impaired in patients. All three patients with systolic LV dysfunction had normal coronary arteries and mild myocardial iron load (CMR T2* values, 18-25 ms). Systolic pulmonary artery pressure was significantly higher in patients compared to controls (p = 0.002); PHT was present in 28 patients (27%), while severe PHT in three (2.9%). In three patients with severe PHT, only one had impaired LV ejection fraction and increased pulmonary wedge pressure. Overall, three patients (2.9%) had a history of heart failure, two with systolic LV dysfunction, and one with severe PHT. Cardiac involvement in sickle beta-thalassemia concerns biventricular dilatation and dysfunction along with PHT, leading to congestive heart failure.

Pharmacogenetic insights into codeine analgesia: implications to pediatric codeine use

Codeine has been used medicinally since the 1800s as an analgesic and antitussive agent. Although very few studies have methodically examined the safety of codeine use in the pediatric age group, it is nonetheless commonly prescribed to children and breastfeeding mothers. Empirical evidence over the last century has suggested variability in the efficacy of codeine, and recent genomic advancements have shed important light on the mechanisms leading to such variability. Aside from evaluating the role of genetic variability in drug-metabolizing enzymes, receptors and transporters, the development of the blood–brain-barrier and the ontogeny of drug-metabolizing enzymes must also be considered in newborns and young children.

Impact of proximity to comprehensive sickle cell center on utilization of healthcare services among children with sickle cell disease

BACKGROUND

The impact of comprehensive care on utilization of healthcare services by children with sickle cell disease (SCD) has not been fully evaluated. We compared the medical care utilization and mortality in children less than 20 years of age with SCD in four regions in the state of Tennessee with and without a comprehensive sickle cell center (CSCC).

METHODS

Rates of hospitalizations, outpatient and emergency department (ED) visits, and deaths were measured in a cohort of children aged <20 years with SCD, enrolled in TennCare, from January 1995 to December 2002. TennCare data linked to Tennessee vital records were used to define the population and identify the outcomes. The patients were classified into one of four regions based on their residential address on the day of their hospitalization or outpatient visit.

RESULTS

The cohort consisted of 1,214 children with 6,393 person-years of follow-up. Fifty-six percent of patients resided in the region with the CSCC. This region had the highest overall rates of hospitalization for all children (P < 0.001), while ED and outpatient visits were higher in other areas. The death rates ranged from 1.8 to 4.3 per 1,000 person-years in the four regions and did not represent statistically significant differences.

CONCLUSION

No clear pattern of improved utilization of medical care services were identified in relation to proximity of residence to a CSCC. This cohort was not large enough to detect small differences in death rates. In addition, other outcomes that incorporate quality of life measures may be more sensitive to differences in medical care.

The pediatric spleen

Many pathological processes affect the spleen in children. As a basis for recognizing pathology, knowledge of the normal imaging appearance of the pediatric spleen is needed. In addition to congenital anomalies and trauma, pathology of the pediatric spleen includes enlargement (splenomegaly), cysts, neoplasms, infection and infarction. Specific diseases processes, including sickle cell anemia and Gaucher disease, may have specific affects on the spleen.

The radiological manifestations of sickle cell disease

Sickle cell disease (SCD) is an inherited abnormality of the beta-globin chain, which causes a spectrum of haemolytic anaemias. Clinical manifestations in SCD include anaemia, jaundice, recurrent vaso-occlusive crises, and infections (particularly by encapsulated bacteria) due to functional asplenia and cerebrovascular accidents. Radiological investigations play a critical role both in the diagnosis and in the primary prevention of the complications of SCD.

Caregiving time in sickle cell disease: psychological effects in maternal caregivers

BACKGROUND

Providing home care for a child with a chronic illness can be stressful for the family. The purpose of this paper is to examine patterns of caregiving and the associated psychological impact on maternal caregivers of children with sickle cell disease (SCD).

PROCEDURE

Fourteen maternal caregivers of children with SCD were interviewed as part of a larger study of maternal caregivers of children with chronic illness. Forty-four caregivers of children with HIV and 36 caregivers of healthy children were included as comparison groups. Interviews included questions regarding amount of time spent providing care for the child (technical care, non-technical care, health care management), hospitalization, emergency room visits, illness stigma, and mental health of the caregiver.

RESULTS

Children with SCD had significantly lower functional status and significantly more hospitalizations in the previous 3 months than children with HIV. Caregivers of children with SCD were more likely to work full-time and had higher incomes than caregivers of children with HIV. The three caregiving groups did not differ significantly on amount of total care, although caregivers of children with SCD and caregivers of children with HIV both reported significantly more time spent in technical care than caregivers of healthy children. Despite lower functional status of the children in the SCD group, when group comparisons on caregiving time variables were adjusted for child's functional status, the differences between groups increased. This appeared to be due to the fact that caregivers in the HIV group spent more time in all caregiving categories except skin, crisis, and other care. In terms of caregiver mental health, caregivers of children with HIV and SCD had significantly higher depressive mood scores than caregivers of healthy children but the groups did not differ on caregiving burden.

CONCLUSIONS

The perceived care burden of caregivers of children with SCD may be related to the unpredictable nature of the crisis care they provide. Additional attention is warranted to developing adequate resources for caregivers of children with SCD to mitigate the stress of unexpected crises.

Systolic and diastolic function in middle aged patients with sickle beta thalassaemia. An echocardiographic study

OBJECTIVE

To evaluate the right and left ventricular systolic and diastolic function in middle aged patients with sickle beta thalassaemia.

METHODS

Forty three patients with sickle beta thalassaemia were recruited for echocardiographic study while 55 controls, matched for age and sex, served as the control group. Parameters measured included: dimensions and wall thickness of left (LV) and right (RV) ventricle and left atrium, LV mass, and cardiac index. LV and RV contractility variables--ejection fraction, circumferential fibre shortening velocity, end systolic stress, end systolic stress/volume index ratio, mitral and tricuspid annulus systolic excursion, and Tei index--were also calculated. The study also evaluated parameters of RV and LV diastolic function including early and late atrioventricular flow velocities (E and A wave respectively), E/A ratio, deceleration time (DT), isovolumic relaxation time (IVRT) as well as pulmonary and hepatic veins systolic to diastolic (S/D) ratio.

RESULTS

Chamber enlargement, greater LV mass index, cardiac index, and RV wall thickness were found in the anaemic group compared with controls. The LV and RV contractility variables of the patients were similar to controls. Conversely the LV and RV Tei index was significantly greater in the patient group. Diastolic dysfunction was present in the anaemic patients resulting from the increased LV and RV A-wave, the longer LVIVRT, RVIVRT, and RVDT, as well as the higher hepatic and pulmonary veins S/D ratio.

CONCLUSIONS

The results show that in middle aged patients with sickle beta thalassaemia the diastolic function is abnormal in both ventricles but still more in RV, whereas the systolic function remains unchanged.

Medical care utilization and mortality in sickle cell disease: a population-based study

The purpose of this study was to evaluate the pattern of medical care utilization and mortality in children and adults with sickle cell disease (SCD) in the state of Tennessee. Rates of hospitalization, emergency department visits, and deaths were measured in a cohort of adults and children with SCD enrolled in TennCare, Tennessee's Medicaid managed health care program, from January 1995 to December 2002. TennCare data linked to Tennessee vital records were used to define the population and identify the outcomes. For children less than 5 years of age, the mortality rate was similar to that of other black Tennessee children (P = 0.71). Among children, the death rate was highest in 10-19 years of age and was 8-fold higher than Tennessee's race- and age-specific rate. Among 20- to 49-year-old patients with SCD, mortality was significantly higher in males than in females (P < 0.001). As compared to the black population without SCD in TennCare, patients with SCD had 7-30 times higher rate of hospitalization and 2-6 times higher rates of emergency department visits (P < 0.001). The death rate in adolescents and young adults with SCD continues to be much higher than population-specific rates. Interventions to prevent morbidity and mortality related to SCD are urgently needed.

Opioid selection during sickle cell pain crisis and its impact on the development of acute chest syndrome

BACKGROUND

The hallmark of sickle cell disease (SCD) is recurrent, painful vaso-occlusive episodes (VOC) and is the most common reason for hospitalization in SCD patients. Narcotics, particularly morphine, along with fluid hydration are standard treatments for painful episodes but have been associated with the development of acute pulmonary events commonly referred to as acute chest syndrome (ACS). The development of ACS is often preceded by acute infections, painful episodes, rib infarction, bone marrow infarction, and fat embolism. Its pathophysiology remains multifactorial and has become the most common reason for early mortality. Previous episodes of ACS increase the likelihood of repeated acute pulmonary events and subsequent pulmonary hypertension. Nalbuphine hydrochloride (Nubain) is an opioid with the pain relieving potency of morphine but has not been studied for its association in the development of ACS or compared with morphine in its efficacy of pain control in the sickle cell population.

PROCEDURE

We reviewed the medical records retrospectively of patients between the age of 5 and 19 years, admitted for vaso-occlusive crisis to the three children's hospitals in Atlanta between January 1999 and December 2002. A computerized search tool was used to identify patients using the International Classification of Diseases Ninth Revision (ICD-9) diagnosis code 282.60 and 282.62. The final discharge diagnosis of ACS was defined as a new pulmonary infiltrate on chest radiograph after admission and before discharge. We calculated the need for 160 patient admissions for 85% power to detect a difference of approximately 20% in incidence of ACS between the two treatment groups.

RESULTS

There were a total of 37 (21%) episodes of ACS. Of these, 26 (29%) were in the morphine group and 11 (12%) were in the Nubain group (P < 0.01). Patients receiving morphine were more likely to have higher white cell counts on admission (P < 0. 05), and to use continuous infusion for medication administration (49% vs. 3%), P < 0. 001. They also had longer hospital stays than patients who received Nubain (median stay 3 days vs. 4 days, morphine), P < 0. 001.

CONCLUSIONS

The development of ACS during painful episodes is multi-factorial, but opioid selection may increase this rate. Patients on Nubain were less likely to develop ACS, and they had shorter hospital stays. These results were confounded by use of continuous analgesia infusion with PCA. However, Nubain may provide an alternative to morphine in the treatment of sickle cell pain episodes. A prospective clinical trial comparing these two analgesics would be a preferable next step.

Evolutionary explanations in medical and health profession courses: are you answering your students' "why" questions?

BACKGROUND

Medical and pre-professional health students ask questions about human health that can be answered in two ways, by giving proximate and evolutionary explanations. Proximate explanations, most common in textbooks and classes, describe the immediate scientifically known biological mechanisms of anatomical characteristics or physiological processes. These explanations are necessary but insufficient. They can be complemented with evolutionary explanations that describe the evolutionary processes and principles that have resulted in human biology we study today. The main goal of the science of Darwinian Medicine is to investigate human disease, disorders, and medical complications from an evolutionary perspective.

DISCUSSION

This paper contrasts the differences between these two types of explanations by describing principles of natural selection that underlie medical questions. Thus, why is human birth complicated? Why does sickle cell anemia exist? Why do we show symptoms like fever, diarrhea, and coughing when we have infection? Why do we suffer from ubiquitous age-related diseases like arteriosclerosis, Alzheimer's and others? Why are chronic diseases like type II diabetes and obesity so prevalent in modern society? Why hasn't natural selection eliminated the genes that cause common genetic diseases like hemochromatosis, cystic fibrosis, Tay sachs, PKU and others?

SUMMARY

In giving students evolutionary explanations professors should underscore principles of natural selection, since these can be generalized for the analysis of many medical questions. From a research perspective, natural selection seems central to leading hypotheses of obesity and type II diabetes and might very well explain the occurrence of certain common genetic diseases like cystic fibrosis, hemochromatosis, Tay sachs, Fragile X syndrome, G6PD and others because of their compensating advantages. Furthermore, armed with evolutionary explanations, health care professionals can bring practical benefits to patients by treating their symptoms of infection more specifically and judiciously. They might also help curtail the evolutionary arms race between pathogens and antibiotic defenses.

Coexisting Systemic Lupus Erythematosus and Sickle Cell Disease

Systemic lupus erythematosus (SLE) and sickle cell disease (SCD) are relatively common disorders with comparable prevalence among blacks. The coexistence of these 2 conditions in the same individual appears to be rare. We report 4 cases of coexisting SLE and SCD. These patients displayed a broad spectrum of musculoskeletal, central nervous system, and renal complications that may be associated with either SCD or SLE. Because of a substantial overlap between the clinical manifestations of these 2 disorders, the diagnosis of SLE in patients with SCD may be difficult to establish and is often delayed. Up to 23% of patients with SCD may have antinuclear antibodies. All patients in this series had antecedent SCD but new important complications from SLE.

Living with sickle cell disease: the perspective of young people

The study aimed to explore the lived experience of young people with sickle cell disease as they transferred to adult services. A cross-sectional study using semistructured questionnaires is described. Eleven young people (12-16 years) attending a sickle cell and thalassaemia centre as they approached transition from paediatric to adult services were successfully recruited to the study. Sickle cell disease was reported to interfere with various aspects of their 'normal' lives. Fatigue and pain were common symptoms. Reported adherence to prophylaxis was variable. It was concluded that young people with sickle cell disease require support drawing on a range of expertise and that the medical model of service delivery may not meet all their needs.

Health supervision for children with sickle cell disease

Sickle cell disease (SCD) is a group of complex genetic disorders with multisystem manifestations. This statement provides pediatricians in primary care and subspecialty practice with an overview of the genetics, diagnosis, clinical manifestations, and treatment of SCD. Specialized comprehensive medical care decreases morbidity and mortality during childhood. The provision of comprehensive care is a time-intensive endeavor that includes ongoing patient and family education, periodic comprehensive evaluations and other disease-specific health maintenance services, psychosocial care, and genetic counseling. Timely and appropriate treatment of acute illness is critical, because life-threatening complications develop rapidly. It is essential that every child with SCD receive comprehensive care that is coordinated through a medical home with appropriate expertise.

Sickle cell morbidity profile in Omani children

In order to define the morbidity profile of sickle cell disease in Omani children, we analysed data on 97 children (53 boys, 44 girls) aged < or = 12 years admitted under our care in a regional referral hospital between July 1999 and June 2000. Ninety of them had sickle cell anaemia (HbSS disease) and seven had sickle cell thalassaemia (beta zero). Their mean (SD) steady-state Hb was 7.9 (1.2), range 6-10 g/dl. They were admitted on 316 occasions during the 12-month period. The number of admissions per child ranged from one to 12 (mean 3.3). Vaso-occlusive crises were the main reason for admission (83%), followed by severe anaemia (12%) and infections (4%). During the study period, 31% received blood transfusions. Weight faltering was very common, 68% falling below the 5th percentile of the National Center for Health Statistics reference curves compared with 28% of age- and sex-matched non-sicklers (p < 0.001). Other complications included hypersplenism (four), ischaemic necrosis of the femoral head (two), and one case each of acute chest syndrome, acute splenic sequestration, cholelithiasis and pathological fracture of a lumbar vertebra. Overall, 71% of the children had moderately severe or severe disease. This pattern seems to be attributable, at least in part, to meteorological and genetic factors. The severe morbidity profile reported in this study underscores the need to continue the search for optimal management modalities, including the often emotion-laden issue of prevention.

Genetic screening of newborns

Screening of newborn infants for genetic disease began over 35 years ago as a public health measure to prevent mental retardation in phenylketonuria (PKU). It was so successful that tests for several other genetic disorders were added. We review the current status of this screening, including discussions of the genetic disorders often covered and the results of newborn screening for them. We emphasize recent advances. These include expansion of coverage for genetic disorders with the new methodology of tandem mass spectrometry (MS-MS) and the introduction of molecular (DNA) testing to increase the specificity of testing for several disorders, thereby reducing false-positive rates. These and other advances have also produced issues of criteria for screening, missed cases, and appropriate use of stored newborn specimens.

Exercise-induced myocardial perfusion abnormalities in sickle beta-thalassemia: Tc-99m tetrofosmin gated SPECT imaging study

PURPOSE

To determine the mechanism of myocardial ischemia in patients with sickle beta-thalassemia, we performed a scintigraphic evaluation of myocardial perfusion during exercise.

SUBJECTS AND METHODS

We studied 30 patients with sickle beta-thalassemia, (mean [+/-SD] age, 37 +/- 10 years) who had no electrocardiographic (ECG), radiographic, or echo-Doppler signs of pulmonary hypertension, left ventricular hypertrophy, or impaired contractility. All patients had a hemoglobin level greater than 7 g/dL. Treadmill exercise test was performed according to the Bruce protocol. Myocardial perfusion was assessed by single-photon emission computed tomography, using Tetrofosmin Tc-99 m Myoview as radiotracer, at peak exercise and again 4 hours later.

RESULTS

Eight patients (27%) developed stress-induced scintigraphic perfusion abnormalities that were reversible in all but 1 patient. Subsequent coronary angiograms were normal in all 8 patients. ST segment depression was seen during exercise in 5 of the 7 patients who had reversible perfusion defects. Except for a significantly greater white blood cell count, these 5 patients did not differ from the rest of patients by sex, age, hemoglobin level, percentage hemoglobin F, beta-thalassemia genotype, or risk factors for coronary artery disease. Three of the 5 patients with perfusion and ECG abnormalities (and another with only perfusion defects) developed a stress-induced sickling crisis.

CONCLUSION

Physical stress may induce myocardial ischemia in sickle beta-thalassemia patients with normal coronary arteries and elicit painful crises. The sickling process, activated by exercise, could be the common underlying mechanism.

Sickle cell anemia

Sickle cell anemia (SCA) is a disease caused by production of abnormal hemoglobin, which binds with other abnormal hemoglobin molecules within the red blood cell to cause rigid deformation of the cell. This deformation impairs the ability of the cell to pass through small vascular channels; sludging and congestion of vascular beds may result, followed by tissue ischemia and infarction. Infarction is common throughout the body in the patient with SCA, and it is responsible for the earliest clinical manifestation, the acute pain crisis, which is thought to result from marrow infarction. Over time, such insults result in medullary bone infarcts and epiphyseal osteonecrosis. In the brain, white matter and gray matter infarcts are seen, causing cognitive impairment and functional neurologic deficits. The lungs are also commonly affected, with infarcts, emboli (from marrow infarcts and fat necrosis), and a markedly increased propensity for pneumonia. The liver, spleen, and kidney may experience infarction as well. An unusual but life-threatening complication of SCA is sequestration syndrome, wherein a considerable amount of the intravascular volume is sequestered in an organ (usually the spleen), causing vascular collapse; its pathogenesis is unknown. Finally, because the red blood cells are abnormal, they are removed from the circulation, resulting in a hemolytic anemia. For the patient with SCA, however, the ischemic complications of the disease far outweigh the anemia in clinical importance.

Situational analysis of parenting problems for caregivers of children with sickle cell syndromes

A situational analysis of problematic situations was conducted for 37 caregivers of children with sickle cell disease (SCD) who ranged in age from 5 to 13 years. Participants responded to a semistructured interview related to caring for a child with SCD. The interview included the domains of medication adherence, nutrition, minimizing and coping with pain episodes, social problems, academic difficulties, and children's expression of negative feelings related to having SCD. Caregivers described a total of 356 problems. Almost all caregivers reported experiencing problems with their children's nutrition (n = 35), minimizing pain episodes (n = 34), and their children expressing feelings about having SCD (n = 33). Moderately challenging and emotionally upsetting problems were reported for coping with pain episodes. The total number of problems was significantly higher for boys than for girls. Nutrition issues were more frequently reported for younger children. Findings have salient clinical implications for the care of children with SCD.