Sickle Cell Patients (sickle + cell_patient)

Distribution by Scientific Domains

Selected Abstracts

Development and validation of a pediatric severity index for sickle cell patients,

Xandra W. van den Tweel
There is no instrument to measure severity of sickle cell disease (SCD) in pediatric patients that is generally accepted. The aim of this study was to develop and validate a severity index for SCD in children. We developed an index consisting of 12 items and tested its validity of the index using data from 92 children. We tested whether different scores were obtained for patients classified by severity both subjectively and objectively by a partially validated existing index. Furthermore, we tested whether the index could differentiate patients classified according to genotype or the number of ,-gene deletions and evaluated whether the score on the index was correlated with the average number and days of hospitalizations/year, age and a risk of death score. We explored the effect of three different weighting systems (Score A, B, and C) to summarize these items. All weightings demonstrated a significant difference between the scores of mild, moderate, and severely affected patients, as classified by a subjective rating or with an existing index (P < 0.01). The index clearly differentiated patients by genotype (P < 0.01) or ,-gene deletions (P < 0.01). The correlation with hospitalization was moderate. Age and the risk of death score were weakly associated with the pediatric severity index for SCD. This is the first pediatric SCD severity index that was developed and validated using modern clinimetric methodology. The validity and reliability of this index should be further evaluated in a prospective study including a larger cohort, preferably diagnosed at birth. Am. J. Hematol., 2010. 2010 Wiley-Liss, Inc. [source]

Liver biopsy results in patients with sickle cell disease on chronic transfusions: Poor correlation with ferritin levels

Lina B. Karam MD
Abstract Background: Chronic transfusions are effective in preventing stroke and other complications of sickle cell disease. The aim of this study was to determine whether serum ferritin levels correlated with liver iron content in sickle cell patients on chronic transfusion. Procedure: Forty-four liver biopsy specimens from 38 patients with homozygous sickle cell anemia (HbSS) and one patient with sickle thalassemia receiving chronic transfusions were studied. Five patients underwent a second liver biopsy for follow up. Three ferritin measurements were used to calculate a mean for each patient. The association between serum ferritin levels and liver iron quantitation was measured using the Spearman rank correlation, and sensitivity and specificity were determined for selected threshold values of serum ferritin. Results: Serum ferritin levels ranged from 515 to 6076 ng/ml, liver iron concentration ranged from 1.8 to 67.97 mg/g dry weight. The amount of iron per gram liver dry weight was moderately correlated with serum ferritin values (r,=,0.46). The correlation of duration of transfusion with serum ferritin (r,=,0.40) and with liver iron content (r,=,0.41) also indicated moderate correlation. Liver biopsy results led to changes in the management after 29/44 (66%) of the biopsies. Serum ferritin ,2500 ng/ml predicted high liver iron content (,7 mg/g), with a sensitivity of 62.5% and a specificity of 77.8%. Conclusion: We found a poor correlation between serum ferritin levels and liver iron content (LIC). Despite being on chelation therapy, many patients on chronic transfusion had high levels of liver iron. Measurement of LIC is highly recommended in these patients. Pediatr Blood Cancer 2008;50:62,65. 2007 Wiley-Liss, Inc. [source]

Serum ferritin underestimates liver iron concentration in transfusion independent thalassemia patients as compared to regularly transfused thalassemia and sickle cell patients

Zahra Pakbaz MD
Abstract Serum ferritin (SF) and liver iron concentration (LIC), as measured by SQUID biosusceptometry, were assessed in a convenience sample of transfusion independent thalassemia patients (nTx-Thal, n,=,26), regularly transfused thalassemia (Tx-Thal, n,=,89), or sickle cell patients (SCD, n,=,45) to investigate the severity of iron overload and the relationship between SF and LIC in nTx-Thal compared to SCD and Tx-Thal. SF correlated with LIC (RS,=,0.53, P,<,0.001), but was found to be a poor predictor for LIC. SF was significantly lower (P,<,0.001) in nTx-Thal patients than in other groups, despite similar LIC values. The SF-to-LIC ratio was significantly lower in nTx-Thal compared to Tx-Thal and SCD patients (median of 0.32, 0.87, and 1.2, respectively: P,<,0.001). Due to underestimation of LIC by ferritin levels, chelation treatment may be delayed or misdirected in patients with thalassemia intermedia. Pediatr Blood Cancer 2007;49:329,332. 2007 Wiley-Liss, Inc. [source]

Cerebral oximetry improves detection of sickle cell patients at risk for nocturnal cerebral hypoxia,

Ashok B. Raj MD
Abstract We previously used cerebral oximetry to identify low cerebral venous oxygen saturation in waking children with sickle cell disease (SCD). Because arterial oxyhemoglobin desaturation is common during sleep in SCD patients, this study compared both waking and sleeping systemic arterial and cerebral venous oxygenation dynamics in children with and without SCD. Seventeen African-American (AA) children with homozygous SCD [8 (4,15) years; 29% male; normal transcranial Doppler velocities] were compared with a control cohort (CON) comprised of six healthy AA children [9 (4,16) years, 33% male]. Standard all-night polysomnographic recordings were performed, including measurement of arterial oxygen saturation by pulse oximetry (SpO2). Regional cerebral oxygen saturation (rSO2) was measured non-invasively with cerebral oximetry. Intra-cohort comparisons examined the influence of sleep on SpO2 and rSO2 in the subjects. Inter-cohort comparisons of SpO2, rSO2, and the rSO2/SpO2 ratio assessed the impact of SCD on systemic and cerebral oxygenation during wakefulness and sleep. Cohort differences in SpO2 were not statistically significant in either wakefulness or sleep. However, only in the SCD cohort was the magnitude of SpO2 change statistically significant (P,=,0.002). In contrast, both waking and sleep rSO2 cohort median values did differ significantly [awake: CON 76 (67,86) vs. SCD 62 (58,71), P,=,0.01; sleep: CON 65 (60,77) vs. SCD 55 (48,61), P,=,0.01)]. The waking rSO2/SpO2 ratio was also significantly lower in the SCD group [CON 0.78 (0.68,0.88) vs. SCD of 0.66 (0.61,0.72); P,=,0.015]. During sleep, the ratio was also significantly lower in the SCD group [CON 0.71 (0.66,0.81) vs. SCD 0.59 (0.52,0.65); P,=,0.011]. Our findings suggest that SCD patients may be at increased risk of cerebral hypoxia during both wakefulness and sleep. Pediatr Pulmonol. 2006, 41:1088,1094. 2006 Wiley-Liss, Inc. [source]

Lung function tests in sickle cell patients

Chloe I. Bloom
No abstract is available for this article. [source]

Vasoactive factors in sickle cell disease: In vitro evidence for endothelin-1-mediated vasoconstriction

Sitki Ergul
Abstract While systemic plasma endothelin-1 (ET-1) levels are increased during acute crisis in sickle cell disease, the relative levels of potent vasoactive factors that contribute to the regulation of vascular function, such as ET-1, NO, and cell-free hemoglobin, during the course of periodic vaso-occlusive episodes remain unclear. Moreover, whether and to what extent sickling-induced release of ET-1 alters vascular tone is not completely understood. To investigate the sequential changes in circulating vasoactive factors, we measured plasma ET-1, NO metabolites (NOx), and cell-free hemoglobin (Hb) before (steady-state), during (crisis), and after a vaso-occlusive (post-crisis) episode. Steady-state ET-1 levels (fmol/mL) increased from 2.3 0.4 to 11.0 1.4 and 4.2 1.0 during crisis and post-crisis periods, respectively. There was no significant difference in plasma NOx levels. Cell-free Hb levels were significantly higher in sickle cell patients in all phases as compared to the control group, and especially during crisis cell-free Hb levels were elevated by 4-fold (209,000 31,000 vs. 46,000 5,300 ng/mL in steady-state). Conditioned medium from human pulmonary artery endothelial cells exposed to sickled erythrocytes prepared by deoxygenation induced contraction of aortic rings, and this effect was blocked by an ETA receptor antagonist. These findings indicate that ET-1 is the predominant contractile factor released by cultured endothelial cells upon exposure to deoxygenated sickled SS erythrocytes and ET-1,NO,NO scavenger balance is altered in favor of vasoconstriction during an acute episode in SCD. Am. J. Hematol. 76:245,251, 2004. 2004 Wiley-Liss, Inc. [source]

Plasma levels of advanced glycation end products are associated with haemolysis-related organ complications in sickle cell patients

Erfan Nur
Summary Oxidative stress plays an important role in the pathophysiology of sickle cell disease (SCD). Plasma levels of advanced glycation end products (AGEs) are increased under oxidative conditions and are associated with disease severity in diabetes and inflammatory diseases. We investigated whether AGEs are increased in sickle cell patients and whether they are associated with SCD-related complications. Plasma levels of the AGEs pentosidine, N, -(carboxymethyl)lysine (CML) and N, -(carboxyethyl)lysine (CEL) were measured using single-column high performance liquid chromatography with fluorescence detection (pentosidine) and ultra performance liquid chromatography-tandem mass spectrometry (CML and CEL). Plasma levels of pentosidine and CML were increased in HbSS/HbS,0 -thalassaemia (n = 60) and HbSC/HbS,+ -thalassaemia (n = 42) patients during steady state as compared to healthy HbAA controls (n = 30) without increments during painful crisis. CEL levels were comparable between all groups. Pentosidine and CML levels correlated significantly to haemolytic rate during the clinically asymptomatic state while pentosidine was significantly related to the number of haemolysis-related organ complications. The increased plasma AGE levels in sickle cell patients and their association with haemolysis and haemolysis-related complications suggest AGEs might be implicated in the pathophysiology of the haemolytic phenotype of SCD. Measurement of AGEs might be useful in predicting organ complications in SCD. [source]