Pulmonary Haemodynamics in Sickle Cell Disease Are Driven Predominantly by a High-Output State Rather Than Elevated Pulmonary Vascular Resistance: A Prospective 3-Dimensional Echocardiography/Doppler Study

Aims

Patients with sickle cell disease have significant morbidity and mortality. Pulmonary hypertension is suggested to be an important contributor but its nature and severity in these patients and how best to non-invasively assess it are controversial. We hypothesised that a high-output state rather than primary pulmonary vascular pathology may be the major abnormality in sickle cell disease. This study aimed to evaluate the characteristics and severity of pulmonary hypertension in patients with sickle cell disease using detailed echocardiography.

Methods and Results

We undertook a prospective study in 122 consecutive stable outpatients with sickle cell disease and 30 age, gender and ethnicity-matched healthy controls. Echocardiographic evaluation included 3D ventricular volumes, sphericity, tissue Doppler, and non-invasive estimation of pulmonary vascular resistance. 36% of patients had a tricuspid regurgitant velocity ≥2.5 m.s^-1 but only 2% had elevated pulmonary vascular resistance and the prevalence of right ventricular dysfunction was very low. Patients with raised tricuspid regurgitant velocity had significantly elevated biventricular volumes and globular left ventricular remodelling, related primarily to anaemia. In a subgroup of patients who underwent cardiac catheterization, invasive pulmonary haemodynamics confirmed the echocardiographic findings.

Conclusions

Elevated cardiac output and left ventricular volume overload secondary to chronic anaemia may be the dominant factor responsible for abnormal cardiopulmonary haemodynamics in patients with sickle cell disease. 3D echocardiography with non-invasive estimation of pulmonary vascular resistance represents a valuable approach for initial evaluation of cardiopulmonary haemodynamics in sickle cell disease.     

Dactylitis in a child with sickle cell trait

Dactylitis commonly occurs in patients with homozygous hemoglobin S disease (sickle cell anemia), sickle cell-hemoglobin C disease or sickle cell-β-thalassemia. A case is reported of dactylitis associated with sickle cell trait, a very rare occurrence. It may be that in this patient the disorder was secondary to severe diarrhea and dehydration.     

Erythrocytic ecdysis in smears of EDTA venous blood in eight patients with sickle cell anemia

The light-microscope finding of red cell membrane fragments in the form of long filamentous processes and myelin bodies in the blood smears of a patient with sickle cell anemia has recently been described. This phenomenon has been termed erythrocytic ecdysis. We examined the blood smears of all sickle cell anemia patients admitted to the Cook County Hospital and those attending the hemoglobinopathy clinic between October 1979 and December 1981. Nine instances of erythrocytic ecdysis were uncovered. Associated clinical conditions included congestive heart failure, acute viral syndrome, pneumonia, and metastatic malignancy. Transient ecdysis associated with congestive heart failure was noted for one patient during two separate admissions one year apart. Ecdysis is a transient form of erythrocytic fragmentation occurring in sickle cell anemia. Its pathogenesis is unknown. The role of regional circulatory stasis and hypoxia in the induction of erythrocyte membrane damage in sickle cell anemia needs investigation.     

Painful crises in sickle cell disease--patients' perspectives.

One hundred and two patients returned structured questionnaires sent to clinics for sickle cell disease in the United Kingdom in order to gain greater insight into the patients'' perception of painful crises. Most patients who suffer pain crises experience a prodromal stage that should be investigated further to find out if prophylaxis is possible. Cold, exertion, and tiredness were the most important precipitating factors. Despite the increase in the amount of knowledge about sickle cell disease in recent years, and though 29 out of 88 patients (30-40%) believed that medical services were improving, 33 out of 88 (30-40%) were still experiencing long delays in being treated in hospital. A third of patients do not seem to receive adequate pain relief.     

Improved survival in homozygous sickle cell disease: lessons from a cohort study.

OBJECTIVE: To examine whether simple interventions in a sickle cell clinic improve survival in sickle cell disease. DESIGN: Survival curve analysis and hazard ratios in a cohort study followed from birth. SETTING: MRC Laboratories (Jamaica) at the University of the West Indies, and Victoria Jubilee Hospital, Kingston, Jamaica. SUBJECTS: 315 patients with homozygous sickle cell disease detected during the screening of 100,000 consecutive non-operative deliveries between June 1973 and December 1981 at the main government maternity hospital, Kingston, Jamaica. INTERVENTIONS: Prophylactic penicillin to prevent pneumococcal septicaemia, parental education in early diagnosis of acute splenic sequestration, close monitoring in sickle cell clinic. MAIN OUTCOME MEASURES: Survival. RESULTS: Survival appeared to improve, the log rank test for trend comparing the first, second, and last third of the study reaching borderline significance (P = 0.05). Combined deaths from acute splenic sequestration and pneumococcal septicaemia-meningitis declined significantly (test for trend, P = 0.02). CONCLUSION: Early diagnosis and simple prophylactic measures significantly reduce deaths associated with homozygous sickle cell disease.     

Clinical training in human immunodeficiency virus disease for community physicians. The Los Angeles experience.

In the past decade, the increased number of persons being treated for infection with the human immunodeficiency virus (HIV) has placed an enormous burden on specialty clinics. This is especially true in Los Angeles, where care of patients with the acquired immunodeficiency syndrome (AIDS) has been termed a "crisis" situation. Especially in its early stages, HIV disease can be appropriately managed by primary care physicians who provide patients with medical and psychological counseling and refer them to specialists when major AIDS-related complications develop. Physicians completing their training as recently as 5 years ago, however, received little systematic preparation in the care of HIV-infected patients and thus may lack important skills such as the ability to recognize opportunistic infections early in their course. By means of a 1-week intensive preceptorship in a high-volume AIDS clinic, we are preparing community physicians to assume a more active role in providing care for this growing patient population. In the preceptorship, participants receive one-on-one training from specialists in infectious diseases, pulmonary diseases, and hematology and oncology, as well as from internists and family physicians. Evaluation of the clinical experience demonstrated a greater level of confidence on the part of program participants in treating HIV-infected patients and showed that participants screen and test high-risk patients in their practices and devote a substantial proportion of their practices to caring for HIV-infected patients.     

Routine Paediatric Sickle Cell Disease (SCD) Outpatient Care in a Rural Kenyan Hospital: Utilization and Costs

Background

More than 70% of children with sickle cell disease (SCD) are born in sub-Saharan Africa where the prevalence at birth of this disease reaches 2% or higher in some selected areas. There is a dearth of knowledge on comprehensive care received by children with SCD in sub-Saharan Africa and its associated cost. Such knowledge is important for setting prevention and treatment priorities at national and international levels. This study focuses on routine care for children with SCD in an outpatient clinic of the Kilifi District Hospital, located in a rural area on the coast of Kenya.

Objective

To estimate the per-patient costs for routine SCD outpatient care at a rural Kenyan hospital.

Methods

We collected routine administrative and primary cost data from the SCD outpatient clinic and supporting departments at Kilifi District Hospital, Kenya. Costs were estimated by evaluating inputs - equipment, medication, supplies, building use, utility, and personnel - to reflect the cost of offering this service within an existing healthcare facility. Annual economic costs were similarly calculated based on input costs, prorated lifetime of equipment and appropriate discount rate. Sensitivity analyses evaluated these costs under different pay scales and different discount rate.

Results

We estimated that the annual economic cost per patient attending the SCD clinic was USD 138 in 2010 with a range of USD 94 to USD 229.

Conclusion

This study supplies the first published estimate of the cost of routine outpatient care for children born with SCD in sub-Saharan Africa. Our study provides policy makers with an indication of the potential future costs of maintaining specialist outpatient clinics for children living with SCD in similar contexts.     

Autologous immune complex nephritis associated with sickle cell trait: diagnosis of the haemoglobinopathy after renal structural and immunological studies.

A renal tubular epithelial antigen (RTE)--anti-RTE autologous immune complex nephritis associated with sickle cell anaemia (SS) has been reported, but immune complex nephritis has never been described in patients with sickle cell trait (SA). During investigation of a child with "asymptomatic proteinuria" cryoprecipitable complexes of RTE-anti-RTE were detected in the serum and granular deposits of RTE, immunoglobulins, and complement localised on the glomerular basement membranes. Morphological and ultrastructural studies showed increased mesangial matrix, sickled red blood cells in the glomeruli and vessels, and tubular and interstitial abnormalities. These findings prompted haemoglobin electrophoretic studies, which showed previously undiagnosed haemoglobin SA in this patient and her family. These observations suggest that nephritis mediated by similar immunopathogenic mechanisms may be associated with SS and SA haemoglobinopathy. Under some conditions patients with sickle cell trait may experience haemodynamic and oxygenation abnormalities, which may be aetiological factors in the immune complex nephritis associated with SS disease.     

Collapsing glomerulopathy in sickle cell disease: a case report

Introduction

Sickle cell disease has been associated with many renal structural and functional abnormalities. Collapsing glomerulopathy or the collapsing variant of focal segmental glomerulosclerosis is a rare clinicopathologic entity in patients with sickle cell disease that requires timely diagnosis and aggressive management.

Case presentation

In this case report we describe a 21-year-old African-American woman with a medical history of significant sickle cell disease and asthma. She was admitted for pain, decreased urine output, bilateral leg swelling and reported weight gain. During her period of hospitalisation she developed acute renal failure requiring dialysis. Further investigation revealed the collapsing variant of focal segmental glomerulosclerosis.

Conclusions

Although focal segmental glomerulosclerosis is a common feature of sickle cell nephropathy, the collapsing variant of focal segmental glomerulosclerosis or collapsing glomerulopathy has been rarely documented. Even when other risk factors are controlled, collapsing glomerulopathy has a very poor prognosis. This is a rare case of a patient with massive proteinuria presenting as acute renal failure with a very poor response to corticosteroids and a much faster rate of progression to end-stage renal disease.

     

Physicians' private clinics in a Northern Thai Town — Patient-healer “Collaboration” and the shape of biomedical practice

Physicians' private clinics in small Northern Thai towns offer the patient the services of official biomedicine's most sophisticated clinical talent, and the physicians themselves an opportunity to significantly supplement their incomes. The clinic form, while familiar to Westerners and Japanese, has been adapted to the Northern Thai medical environment and Northern Thai notions of the therapeutic process. Because of sociocultural constraints and the pressure of the plural medical environment, physicians' private clinics result in a collaboration between patient and practitioner in which some prerogatives of each are compromised and others upheld to shape a clinical institution that satisfies the needs of each. This paper discusses three private clinics in a small Northern Thai town from the perspectives of the physicians and the patients, and then describes the collaboration that shapes practices within the clinics.     

The use of a free flap in homozygous sickle cell disease

This paper describes what is thought to be the first reported use of a free flap in a patient with homozygous sickle cell disease. The utilization of a free flap in homozygous sickle cell disease should be questioned because the obligate period of ischemia to which the flap must be subjected during the transfer from donor to recipient sites might lead to intravascular sickling in the flap and flap failure. Review of the literature suggests that by reducing the level of sickle hemoglobin to the range of 25 to 40 percent, the risk of failure of a free flap is not significantly increased in the homozygous sickle cell patient. Furthermore, there is good evidence to suggest that a well-vascularized muscle flap provides optimal coverage, reversing the pathophysiologic cycle of the sickle cell ulcer. Thus in cases of multiply recurrent sickle cell ulcers in areas devoid of a local well-vascularized muscle flap, a free muscle flap is indicated, may be the procedure of choice, and can be performed successfully. We report a patient with a 4-year history of multiple recurrent sickle cell ulcers of the left ankle treated with a gracilis free flap. This patient has been followed for 2 years and continues to be free of recurrent ulceration.     

Haptoglobin for the treatment of sickle cell disease

There are three haptoglobin phenotypes in humans designated: Hp1–1, Hp2–1, and Hp2–2. The Hp1–1 phenotype has been shown to be protective against certain diseases, and this has been suggested to be the result of better anti-inflammatory and antioxidative properties compared to haptoglobin polymers of the other phenotypes when clearing cell-free haemoglobin. We propose the use of haptoglobin for the treatment of sickle cell disease, where an oxidative state exists caused by a high level of cell-free haemoglobin. A significant number of sickle cell disease patients are severely affected and experience regular acute painful episodes resulting in hospitalisation.Therapeutic treatments for sickle cell disease are limited and therefore haptoglobin could represent a vital alternative therapy. A method has been developed as part of the commercial fractionation of plasma for preparing haptoglobin enriched for dimers. This is significant as it uses a mixture of plasma of all haptoglobin phenotypes, and allows annual production of hundreds of kilograms quantities of haptoglobin that may be required to allow treatment of thousands of sickle cell disease patients worldwide.     

Glycosylated hemoglobins in a diabetic patient with sickle cell anemia

Results of analysis of blood samples from a diabetic sickle cell anemia (SS) patient and 4 nondiabetic SS patients for glycosylated hemoglobins by Bio-Rex 70 chromatography, high-pressure liquid chromatography, and affinity chromatography are presented. Glycosylated components of Hb S and Hb A2 and total glycosylated hemoglobins were quantitated in this manner. The levels of the various glycosylated hemoglobins were increased twofold in the diabetic patient compared to nondiabetic SS patients. The glycosylated hemoglobin levels in the diabetic SS patient and in the nondiabetic SS patients, however, were significantly lower than the levels normally seen in nonsickle diabetics and normal adults, respectively. In contrast to a previously reported diabetic SS patient, the present case appears to be not severely affected by sickle cell disease.     

Asthma is a risk factor for acute chest syndrome and cerebral vascular accidents in children with sickle cell disease

BACKGROUND: Asthma and sickle cell disease are common conditions that both may result in pulmonary complications. We hypothesized that children with sickle cell disease with concomitant asthma have an increased incidence of vaso-occlusive crises that are complicated by episodes of acute chest syndrome. METHODS: A 5-year retrospective chart analysis was performed investigating 48 children ages 3-18 years with asthma and sickle cell disease and 48 children with sickle cell disease alone. Children were matched for age, gender, and type of sickle cell defect. Hospital admissions were recorded for acute chest syndrome, cerebral vascular accident, vaso-occlusive pain crises, and blood transfusions (total, exchange and chronic). Mann-Whitney test and Chi square analysis were used to assess differences between the groups. RESULTS: Children with sickle cell disease and asthma had significantly more episodes of acute chest syndrome (p = 0.03) and cerebral vascular accidents (p = 0.05) compared to children with sickle cell disease without asthma. As expected, these children received more total blood transfusions (p = 0.01) and chronic transfusions (p = 0.04). Admissions for vasoocclusive pain crises and exchange transfusions were not statistically different between cases and controls. SS disease is more severe than SC disease. CONCLUSIONS: Children with concomitant asthma and sickle cell disease have increased episodes of acute chest syndrome, cerebral vascular accidents and the need for blood transfusions. Whether aggressive asthma therapy can reduce these complications in this subset of children is unknown and requires further studies.     

Effectiveness of focused structural massage and relaxation massage for chronic low back pain: protocol for a randomized controlled trial

Background

Hypertension affects 29% of the adult U.S. population and is a leading cause of heart disease, stroke, and kidney failure. Despite numerous effective treatments, only 53% of people with hypertension are at goal blood pressure. The chronic care model suggests that blood pressure control can be achieved by improving how patients and physicians address patient self-care.

Methods and design

This paper describes the protocol of a nested 2 × 2 randomized controlled trial to test the separate and combined effects on systolic blood pressure of a behavioral intervention for patients and a quality improvement-type intervention for physicians. Primary care practices were randomly assigned to the physician intervention or to the physician control condition. Physician randomization occurred at the clinic level. The physician intervention included training and performance monitoring. The training comprised 2 internet-based modules detailing both the JNC-7 hypertension guidelines and lifestyle modifications for hypertension. Performance data were collected for 18 months, and feedback was provided to physicians every 3 months. Patient participants in both intervention and control clinics were individually randomized to the patient intervention or to usual care. The patient intervention consisted of a 6-month behavioral intervention conducted by trained interventionists in 20 group sessions, followed by 12 monthly phone contacts by community health advisors. Follow-up measurements were performed at 6 and 18 months. The primary outcome was the mean change in systolic blood pressure at 6 months. Secondary outcomes were diastolic blood pressure and the proportion of patients with adequate blood pressure control at 6 and 18 months.

Discussion

Overall, 8 practices (4 per treatment group), 32 physicians (4 per practice; 16 per treatment group), and 574 patients (289 control and 285 intervention) were enrolled. Baseline characteristics of patients and providers and the challenges faced during study implementation are presented. The HIP interventions may improve blood pressure control and lower cardiovascular disease risk in a primary care practice setting by addressing key components of the chronic care model. The study design allows an assessment of the effectiveness and cost of physician and patient interventions separately, so that health care organizations can make informed decisions about implementation of 1 or both interventions in the context of local resources.

Trial registration

ClinicalTrials.gov identifier NCT00201136     

Fundamental Interventions: How Clinicians Can Address the Fundamental Causes of Disease

In order to enhance the “structural competency” of medicine—the capability of clinicians to address social and institutional determinants of their patients’ health—physicians need a theoretical lens to see how social conditions influence health and how they might address them. We consider one such theoretical lens, fundamental cause theory, and propose how it might contribute to a more structurally competent medical profession. We first describe fundamental cause theory and how it makes the social causes of disease and health visible. We then outline the sorts of “fundamental interventions” that physicians might make in order to address the fundamental causes.     

The role of fibrocytes in sickle cell lung disease

Background

Interstitial lung disease is a frequent complication in sickle cell disease and is characterized by vascular remodeling and interstitial fibrosis. Bone marrow-derived fibrocytes have been shown to contribute to the pathogenesis of other interstitial lung diseases. The goal of this study was to define the contribution of fibrocytes to the pathogenesis of sickle cell lung disease.

Methodology/Principal Findings

Fibrocytes were quantified and characterized in subjects with sickle cell disease or healthy controls, and in a model of sickle cell disease, the NY1DD mouse. The role of the chemokine ligand CXCL12 in trafficking of fibrocytes and phenotype of lung disease was examined in the animal model. We found elevated concentration of activated fibrocytes in the peripheral blood of subjects with sickle cell disease, which increased further during vaso-occlusive crises. There was a similar elevations in the numbers and activation phenotype of fibrocytes in the bone marrow, blood, and lungs of the NY1DD mouse, both at baseline and under conditions of hypoxia/re-oxygenation. In both subjects with sickle cell disease and the mouse model, fibrocytes expressed a hierarchy of chemokine receptors, with CXCR4 expressed on most fibrocytes, and CCR2 and CCR7 expressed on a smaller subset of cells. Depletion of the CXCR4 ligand, CXCL12, in the mouse model resulted in a marked reduction of fibrocyte trafficking into the lungs, reduced lung collagen content and improved lung compliance and histology.

Conclusions

These data support the notion that activated fibrocytes play a significant role in the pathogenesis of sickle cell lung disease.     

Clinic-based primary care of frail older patients in California.

We surveyed medical directors of primary care clinics in California to learn how those clinics cared for their frail older patients. Of 143 questionnaires sent, 127 (89%) were returned. A median of 30% of all patient encounters were with persons aged 65 or older, and a median of 20% of older patients were considered frail. A total of 20% of the clinics routinely provided house calls to homebound elderly patients. Of clinics involved in training medical students of physicians (teaching clinics), 70% had at least one physician with an interest in geriatrics, compared with 42% of nonteaching clinics (P less than .005). For frail patients, 40% of the clinics routinely performed functional assessment, while 20% routinely did an interdisciplinary evaluation. Continuing education in geriatrics emerged as a significant independent correlate of both functional assessment and interdisciplinary evaluation. Among the 94 clinics with a standard appointment length for the history and physical examination, only 11 (12%) allotted more than 60 minutes for frail patients. The data suggest that certain geriatric approaches are being incorporated into clinic-based primary care in California but do not provide insight into their content or clinical effects.     

Pichia anomala (Candida pelliculosa) Fungemia in a Patient with Sickle Cell Disease

This case report discusses a patient with sickle cell disease who presented with fungemia from Pichia anomala (teleomorph: Candida pelliculosa). The organism was identified as P. anomala by MALDI-TOF VITEK mass spectrometry and VITEK 2 yeast identification card. Pichia anomala should be considered in sickle cell patients with recurrent fungemia.     

Candidate Sequence Variants and Fetal Hemoglobin in Children with Sickle Cell Disease Treated with Hydroxyurea

Background

Fetal hemoglobin level is a heritable complex trait that strongly correlates swith the clinical severity of sickle cell disease. Only few genetic loci have been identified as robustly associated with fetal hemoglobin in patients with sickle cell disease, primarily adults. The sole approved pharmacologic therapy for this disease is hydroxyurea, with effects largely attributable to induction of fetal hemoglobin.

Methodology/Principal Findings

In a multi-site observational analysis of children with sickle cell disease, candidate single nucleotide polymorphisms associated with baseline fetal hemoglobin levels in adult sickle cell disease were examined in children at baseline and induced by hydroxyurea therapy. For baseline levels, single marker analysis demonstrated significant association with BCL11A and the beta and epsilon globin loci (HBB and HBE, respectively), with an additive attributable variance from these loci of 23%. Among a subset of children on hydroxyurea, baseline fetal hemoglobin levels explained 33% of the variance in induced levels. The variant in HBE accounted for an additional 13% of the variance in induced levels, while variants in the HBB and BCL11A loci did not contribute beyond baseline levels.

Conclusions/Significance

These findings clarify the overlap between baseline and hydroxyurea-induced fetal hemoglobin levels in pediatric disease. Studies assessing influences of specific sequence variants in these and other genetic loci in larger populations and in unusual hydroxyurea responders are needed to further understand the maintenance and therapeutic induction of fetal hemoglobin in pediatric sickle cell disease.