Vitamin E correlates inversely with non-transferrin-bound iron in sickle cell disease

Decreased serum vitamin E levels are found in homozygous sickle cell disease (SCD). Excessive transfusions may lead high non-transferrin-bound iron (NTBI). Hypothesizing a relationship between the two, vitamin E (measured using high performance liquid chromatography) was significantly lower in 30 SCD patients than in 30 age-/sex-matched controls (P < 0.001), but NTBI (bleomycin assay) was higher (P < 0.001). Vitamin E was lower in 10 transfused patients than in 20 non-transfused patients (P < 0.001) with a significant inverse correlation between the NTBI and vitamin E (r = -0.58, P < 0.001). NTBI associated with iron overload in SCD may increase the potential for oxidative damage and low vitamin E activity may compound this effect.     

Osteopenia and vitamin D deficiency in children with sickle cell disease

Objectives: To assess the prevalence in children with sickle cell disease of low bone mineral density (BMD), a feature found in up to 82% of adults but not well known in children. Methods: In 53 children (45 SS, 4 SC, 4 Sβ‐thalassemia) with a mean age of 12.8 ± 2.4 years, we assessed height; weight; sexual maturation; number of hospitalizations, painful crises, and transfusions in the last 3 years; calcium intake; steady‐state hemoglobin and leukocyte count; calcaemia, phosphataemia, and calciuria/creatinuria; serum 25‐(OH)D and PTH concentrations; and osteocalcin, urinary deoxypyridinoline, and the C‐terminal component of pro‐collagen type I. BMD was assessed using dual X‐ray absorptiometry. Results: Mean lumbar spine Z‐score was ?1.1 ± 1.3 (?3.9 to +1.8). The Z score was significantly lower in girls than in boys in the prepubertal subgroup (?1.74 ± 0.27 vs. ?0.53 ± 0.31) (P = 0.0169), but not in the pubertal group (?1.15 ± 0.41 vs. ?1.33 ± 0.70). BMD was not associated with any of the disease‐severity markers in girls but was unexpectedly associated with fewer vaso‐occlusive crises and hospitalizations in boys. BMD did not correlate with hemoglobin or leukocyte counts. Vitamin D deficiency [25‐(OH)D < 12 ng/mL] was found in 76% of patients and secondary hyperparathyroidism (PTH > 46 pg/mL) in 38%. BMD was not related to calcium intake, vitamin D status, osteocalcin, or bone resorption markers. Conclusion: A slight BMD decrease was found in SCD children, starting before puberty and being more marked in females. The decrease was unrelated to disease severity, vitamin D deficiency, or bone hyperresorption, suggesting abnormal bone formation as the underlying mechanism.     

Cell cycle distribution defect in PHA-stimulated T lymphocytes of sickle cell disease patients

T lymphocytes from normal human controls and sickle cell disease (SCD) patients were isolated from peripheral blood and cultured for 72 hours following addition of phytohemagglutinin. The ratio for the fraction of cells in DNA synthesis (S phase) over the fraction in G2 phase (S/G2) was significantly higher in SCD patients in comparison to the controls (mean +/- SD) (4.01 +/- 0.78 vs. 2.78 +/- 0.76, P less than 0.02). Following in vivo zinc supplementation to two subjects, the S/G2 ratio was normalized. We conclude that the distribution of T lymphocytes in cell cycle is altered in SCD patients and that this effect may be zinc-dependent.     

Relationship of plasma alpha tocopherol to index of clinical severity in individuals with sickle cell anemia.

Several parameters of micronutrition related to antioxidant activity are reduced in individuals with sickle cell anemia (SCA). The data presented here suggest that vitamin E, specifically alpha tocopherol, has a significant correlation (r = -0.38, P < 0.04) with a retrospective survey of clinical events and a significant correlation with a prospective survey of clinical events (r = -0.42, P < 0.03). The survey of clinical events score takes into account important vaso-occlusive manifestations in SCA. Differences in plasma vitamin E levels explained about 15% of the variability in the clinical manifestations of SCA in the population studied. Previously reported data from our lab suggests that the differences in alpha tocopherol levels are not related to dietary intake. Vitamin E may play an important role in modulating the ability of sickle hemoglobin containing erythrocytes to produce vaso-occlusion. Alternatively, it may simply be a marker of disease activity. Studies are ongoing at our center to determine if the relationship of alpha tocopherol to clinical events is causal.     

Splenic sepsis in sickle cell disease

We describe two patients with sickle cell disease (SCD) who developed infections situated in the spleen. One patient had a splenic abscess and there was strong clinical evidence for an infected splenic infarct in the second patient. SCD predisposes to splenic infection because of functional hyposplenism, defective phagocyte function and splenic infarction. Splenic infections can occur in patients who might be considered to have an absent spleen and the diagnosis of splenic abscess should be considered in individuals with SCD who present with fever and abdominal pain.     

Acute renal infarction in sickle cell disease

End organ failure in sickle cell disease has classically been attributed to changes in the microvasculature. A case is reported in which sudden and complete loss of blood flow to the left kidney occurred during a painful crisis in a woman with homozygous SS disease. The findings are most consistent with occlusion of the renal artery.     

Reduced vitamin E antioxidant capacity in sickle cell disease is related to transfusion status but not to sickle crisis

In homozygous sickle cell disease (SCD), decreased serum Vitamin E is present. Excessive transfusions may lead to iron overload. We hypothesised a relationship between the two and found that Vitamin E type antioxidant capacity was significantly lower in 30 SCD patients than in 30 age- and sex-matched controls (P < 0.001). Antioxidant capacity was lower in 10 transfused patients compared with 20 non-transfused patients (P < 0.001). Transfusional iron overload in SCD may increase the potential for oxidative damage, and low antioxidant capacity may compound this effect.     

Current developmental screening practices in young children with sickle cell disease

Despite recent developmental screening guidelines, rates of neurodevelopmental disorders (NDDs) remain lower than expected in children with sickle cell disease (SCD). A retrospective chart review identified 276 eligible patients; 214 charts were available for developmental screening and 207 charts for autism-specific screening. Developmental surveillance/screening was conducted in 70% of charts and autism-specific screening in 19% of charts. Validated tools were used in 32% of developmental screenings and 92% of autism-specific screenings. Many children (57%) were screened outside recommended ages. In conclusion, children with SCD are not regularly receiving appropriate developmental screening and surveillance by their healthcare providers.     

Unexplained lymphadenopathy in sickle cell disease

Progressive lymphadenopathy in a previously healthy female adult with homozygous sickle cell disease (SCD) was found to be due to infection with the human immunodeficiency virus (HIV). Detailed questioning identified several risk factors for HIV in this apparently low-risk patient. Parenteral therapy and heterosexual relationships while abroad may place such SCD patients at risk of HIV infection and its sequelae. The additional risk due to the underlying immunological abnormalities which have been identified in SCD patients is unclear in the absence of prospective studies or reported cases.     

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.     

Splenic abscess and sickle cell disease

This is a report of our experience with 10 cases of splenic abscess in patients with sickle cell disease (SCD). All presented with fever and abdominal pain and were found to have a tender enlarged spleen. Two were found to have a ruptured spleen and five of them were septicemic on presentation. Although both ultrasound and CT-scan of the abdomen were of diagnostic value, we found CT-scan more accurate and reliable in the diagnosis of splenic abscess. Ultrasound and/or CT-scan should be used routinely in the evaluation of SCD patients who present with fever and abdominal pain, especially if they have a tender enlarged spleen. Diagnostic aspiration under CT-scan or ultrasound guidance should be used in doubtful cases to differentiate between splenic abscess and a large splenic infarct. All our patients were managed by peri operative antibiotics and splenectomy with no mortality. Salmonella was the commonest causative organism. Although CT-guided aspiration of splenic abscess is being advocated recently, we feel splenectomy should be the treatment of choice in patients with SCD as there is no point in preserving a non-functioning spleen that is present in the majority of patients. CT-guided aspiration may be employed as a temporary measure for those patients who are at high surgical risk with unilocular abscess. Am. J. Hematol. 58:100–104, 1998. © 1998 Wiley-Liss, Inc.     

Malignancy in patients with sickle cell disease

Malignancy in patients with sickle cell disease (SCD) has been previously reported, but the types of cancer and its incidence remain undefined. With the advent of hydroxyurea therapy, there is concern about increasing the cancer risk for patients with SCD. The International Association of Sickle Cell Nurses and Physician Assistants identified 52 cases of cancer (49 patients) among 16,613 patients with SCD followed at 52 institutions. The median age at malignancy diagnosis was 34 years (range, 14 months-62 years). Twenty-one cases (40%) occurred in pediatric patients, primarily leukemia (n = 7) or Wilms' tumor (n = 5), with 15 children surviving. Most adults had solid tumors, especially carcinomas, and only nine were known to be alive. Three patients received hydroxyurea before the diagnosis of malignancy. These data provide essential baseline information for the accurate interpretation of future reports of malignancy in patients with SCD, especially those receiving hydroxyurea therapy.     

Cardiac manifestations in sickle cell disease varies with patient genotype

Cardiac involvement is well characterized in sickle cell anaemia (SCA) but cardiac features associated with Haemoglobin SC (HbSC) disease are mostly unknown. We compared 60 patients with HbSC disease (median age 31 years, 25 men) to 60 SCA patients and 60 controls matched for age and gender. Left ventricular ejection fraction (LVEF), left ventricle (LV) mass index (LVMi), cardiac index and peak tricuspid regurgitation velocity (TRV) were measured using echocardiography. LV filling pressures were assessed using the ratio of early diastolic transmitral velocity to tissue velocity (E/e’ ratio). The LVMi was higher in both genotypes compared to controls. However, whereas LV hypertrophy was observed only in 3(5%) HbSC patients, this condition was diagnosed in 27(45%) SCA patients (P < 0·0001). While cardiac index and TRV were similar in HbSC compared to controls, SCA patients exhibited elevated cardiac output and TRV. LVEF was similar in the 3 groups. However, both genotypes had a higher E/e’ ratio compared to controls. Cardiac involvement in SCA was related to anaemia and haemolysis, while LV diastolic dysfunction and TRV in HbSC disease patients were related to arterial hypertension and overweight comorbidities. In summary, cardiac involvement and its determinants are different in HbSC disease and SCA. Patient's genotype should be considered with regard to the echocardiographic indications and findings.     

The management of crisis in sickle cell disease

Abstract: The symptoms and signs of sickle cell disease are exacerbated in times of crisis, characterized by tissue infarction or worsening anaemia. Prompt medical intervention is required in these distressing situations to provide relief and comfort to the patient. Effective analgesia is crucial in treating the painful crisis of sickle cell disease. The haemoglobinopathy may cause hyposthenuria with reduced ability to excrete the sodium load in normal saline. A 5% dextrose solution or 5% dextrose in 25% normal saline is therefore recommended for intravenous hydration. As the leading cause of morbidity and mortality in sickle cell disease, infections call for vigorous antibiotic therapy. Oxygen administration should be reserved for hypoxic patients, and blood transfusion given only when really indicated. Acute chest syndrome and cerebrovascular accidents are life-threatening complications of sickle cell disease whereas priapism can cause important long-term sequelae; all deserve urgent attention. In the long term, comprehensive care is cost-effective in reducing the frequency and adverse effects of sickle cell crisis.     

One hundred years of sickle cell disease

The first formal report of sickle cell disease occurred 100 years ago. This review traces the early historical reports, the evolution of understanding of the genetics, the molecular and chemical basis of sickle haemoglobin, and the advances made over the last 30-40 years in improving the management. Newborn screening and close follow-up, especially early in life, has significantly improved survival but these advances require resources and sophisticated infrastructure. In sub-Saharan Africa over 250 000 births annually suggest that these advances are unlikely to be implemented within the foreseeable future. Prevention of the disease where possible, could reduce the numbers of new patients allowing better facilities for the care of others. As the disease results from the inheritance of abnormal haemoglobin genes from both parents, it is eminently preventable. The unanswered question, whether genotype detection and counselling will influence reproductive decisions, is currently being addressed by a project in central Jamaica.