Toxic Unbound Iron and Membrane Injury in b-Thalassemia and Sickle Cell Disease: Elevated Non-Transferrin Bound Iron (NTBI) and Malondialdehyde (MDA).

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3608-3608
Author(s):  
Patrick B. Walter ◽  
Ellen Fung ◽  
David W. Killilea ◽  
Qing Jiang ◽  
Bruce N. Ames ◽  
...  

Abstract Objective: Chronic red blood cell transfusion therapy is life-saving for patients with β-thalassemia (THL) and sickle cell disease (SCD), but often results in severe iron overload. Clinical observations suggest that organ dysfunction (heart, liver, endocrine dysfunction, bone disease) resulting from iron overload is seen more often in patients with THL than SCD. This study examines the possible correlation between increased organ injury in these patients and oxidative stress, iron metabolism, inflammation and plasma vitamin E. Methods: Markers of oxidant stress were compared in 18 subjects with THL (7M, 24 ± 9 yrs) and 11 with SCD (7M, 13 ± 4 yrs) with 10 disease-free controls (5M, 27 ± 12 yrs). All THL and SCD patients admitted to the study were healthy and had not had a recent medical event including vascular crises for SCD within the last 4 months. Blood was drawn from fasted subjects, prior to blood transfusion, and plasma, serum and cells were separated by centrifugation. Plasma levels of malondialdehyde (MDA), a marker of lipid peroxidation, were determined by GC-MS. Non-transferrin bound iron (NTBI), protein carbonyls and tocopherol content were measured by HPLC. C Reactive Protein (CRP) was determined by ELISA. Liver iron content was analyzed by ICP-mass spectrometry from disease patients. Results: Table 1 Values are means ± SD (subject n). Within a row, underlined values are significantly different from control and starred values are significantly different between THL and SCD (P<0.05). Parameter Control THL SCD Values are means ± SD (subject n). With* in a row, daggered † values are significantly different from control and starred * values are significantly different between THL and SCD (P<0.05) Ferritin, ng/ml 65.0 ± 70.9 (10) 1915.0 ± 1030.6 (18)† 2514.7 ± 1152.6 (11)† NTBI, μM −1.0 ± 0.4 (9) 4.0 ± 1.6 (16) *† 1.9 ± 2.1 (11) (c)† MDA, pmol/ml 20.3 ± 14.2 (9) 36.4 ± 20.5 (18)† 27.0 ± 11.4 (11) ALT, U/l 34.9 ± 7.7 (9) 59.2 ± 31.1 (18) *† 36.1 ± 11.0 (11)† α-tocopherol, μM 22.7 ± 3.4 (10) 14.9 ± 4.6 (17)† 15.3 ± 4.0 (11)† γ-tocopherol, μM 1.8 ± 0.7 (10) 3.5 ± 2.2 (17)† 5.5 ± 1.4 (11) *† CRP, mg/L 0.8 ± 0.7 (11) 1.1 ± 1.2 (18) 2.7 ± 3.2 (10)† carbonyls, nmol/mg 0.6 ± 0.1 (10) 0.7 ± 0.3 (17) 0.6 ± 0.1 (11) MDA, ALT, and NTBI, were higher in THL despite evidence for lower body iron burden in THL relative to SCD (liver iron: 9 ± 7.1 vs. 15 ± 5.6 mg/g dry weight). In contrast, evidence for inflammation such as ferritin and CRP were significantly higher in SCD. g-tocopherol was significantly higher in SCD relative to THL. Conclusions: These preliminary findings suggest that THL patients have higher levels of toxic free iron and more evidence for tissue injury than SCD. SCD patients may be protected, in part, by greater inflammation and unique antioxidant reserves. The prospective Multicenter Study of Iron Overload in SCD and THL will determine whether these biomarkers are predictors of differences in end organ failure in these two diseases.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 791-791 ◽  
Author(s):  
Tom Adamkiewicz ◽  
Miguel R. Abboud ◽  
Julio C. Barredo ◽  
Melanie Kirby-Allen ◽  
Ofelia A. Alvarez ◽  
...  

Abstract Between 1995 and 2004, two NIH-sponsored studies (STOP/STOP II) showed that children with sickle cell disease (SCD) and abnormal transcranial Doppler blood flow measurements (high stroke risk) are protected from stroke with regular blood transfusions. Iron overload, which may lead to complications and requires iron removal therapy, was monitored by serum ferritin (SF). Liver iron concentration (LIC) measurement was not mandated by protocol and was performed at investigator discretion. Biopsy dates and lab values were captured during STOP/STOP II, providing an opportunity to validate SF against LIC. 75 LICs on 36 patients (19 female, 17 male) at 8 centers were obtained. No liver biopsy complications were reported. LICs were correlated with STOP/STOP II core laboratory SF and alanine aminotransferase (ALT) obtained within 180 days of LICs. Median age at first biopsy was 11.1 years (range, 4.5–17.8), median time from start of transfusion was 36 months (range, 2–100). Iron removal treatment was initiated a median 23 months (range, 4–108) from start of transfusion, with deferoxamine (n=27), and/or exchange transfusion (n=9). 21 pts (58%) had multiple LIC measures: 2 (n=9), 3 (n=8), 4 (n=2), 5 (n=2). Last LICs on iron removal therapy were obtained a median 72 months (range, 35–124) from start of transfusion. Correlation between SFs and LICs were r=-0.06 (n=18) for first LICs obtained prior to iron removal therapy, r=0.50 (n=17) for last LICs obtained on iron removal therapy, and r=0.51 for all LICs (n=60). Pts with single/last LIC &gt;=15 mg/gram dry liver were significantly more likely to have ALTs &gt;=45 IU/L compared to those with LICs &lt;15 mg/gram (5/12 vs. 1/18; odds ratio 12.1; 95% CI 1.2–123.6; p=0.03). Pts with LIC &gt;=15 mg/gram and ALT &gt;=45 IU/L tended to have higher SFs then those with normal ALT (mean SF 4927 ng/ml, 95% CI 1739–8115 vs. mean SF 2255 ng/ml, 95% CI 1599–2912). 37% (7/19) of pts with LIC &gt;=15 mg/gram had SFs &lt;2000 ng/ml. 55% (11/20) of pts with repeated LICs, had last LICs &lt;15 mg/gram after initiation of iron removal therapy. SF did not correlate with LICs after initiation of blood transfusion therapy and correlated weakly after initiation of iron removal therapy. Over 1/3 of children with evidence of significant iron overload, as measured by LICs, had low serum SFs (&lt;2000 ng/ml), leading to a potentially erroneous interpretation of low iron stores. A significant portion of pts with elevated LICs had evidence of liver injury (ALT elevation). SF elevation observed in some pts may be due in part to end organ injury. Sustained iron overload control was achieved in over 1/2 of pts examined with repeated LICs.


Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 76-79 ◽  
Author(s):  
Paul Harmatz ◽  
Ellen Butensky ◽  
Keith Quirolo ◽  
Roger Williams ◽  
Linda Ferrell ◽  
...  

Chronic transfusion therapy is being used more frequently to prevent and treat the complications of sickle cell disease. Previous studies have shown that the iron overload that results from such therapy in other patient populations is associated with significant morbidity and mortality. In this study we examined the extent of iron overload as well as the presence of liver injury and the predictive value of ferritin in estimating iron overload in children with sickle cell disease who receive chronic red blood cell transfusions. A poor correlation was observed between serum ferritin and the quantitative iron on liver biopsy (mean 13.68 ± 6.64 mg/g dry weight;R = 0.350, P = .142). Quantitative iron was highly correlated with the months of transfusion (R = 0.795, P < .001), but serum ferritin at biopsy did not correlate with months of transfusion (R = 0.308, P = .200). Sixteen patients had abnormal biopsies showing mild to moderate changes on evaluation of inflammation or fibrosis. Liver iron was correlated with fibrosis score (R = 0.50, P = .042). No complications were associated with the liver biopsy. Our data suggest that, in patients with sickle cell disease, ferritin is a poor marker for accurately assessing iron overload and should not be used to direct long-term chelation therapy. Despite high levels of liver iron, the associated liver injury was not severe.


Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 76-79 ◽  
Author(s):  
Paul Harmatz ◽  
Ellen Butensky ◽  
Keith Quirolo ◽  
Roger Williams ◽  
Linda Ferrell ◽  
...  

Abstract Chronic transfusion therapy is being used more frequently to prevent and treat the complications of sickle cell disease. Previous studies have shown that the iron overload that results from such therapy in other patient populations is associated with significant morbidity and mortality. In this study we examined the extent of iron overload as well as the presence of liver injury and the predictive value of ferritin in estimating iron overload in children with sickle cell disease who receive chronic red blood cell transfusions. A poor correlation was observed between serum ferritin and the quantitative iron on liver biopsy (mean 13.68 ± 6.64 mg/g dry weight;R = 0.350, P = .142). Quantitative iron was highly correlated with the months of transfusion (R = 0.795, P &lt; .001), but serum ferritin at biopsy did not correlate with months of transfusion (R = 0.308, P = .200). Sixteen patients had abnormal biopsies showing mild to moderate changes on evaluation of inflammation or fibrosis. Liver iron was correlated with fibrosis score (R = 0.50, P = .042). No complications were associated with the liver biopsy. Our data suggest that, in patients with sickle cell disease, ferritin is a poor marker for accurately assessing iron overload and should not be used to direct long-term chelation therapy. Despite high levels of liver iron, the associated liver injury was not severe.


Hematology ◽  
2013 ◽  
Vol 2013 (1) ◽  
pp. 447-456 ◽  
Author(s):  
John Porter ◽  
Maciej Garbowski

Abstract The aims of this review are to highlight the mechanisms and consequences of iron distribution that are most relevant to transfused sickle cell disease (SCD) patients and to address the particular challenges in the monitoring and treatment of iron overload. In contrast to many inherited anemias, in SCD, iron overload does not occur without blood transfusion. The rate of iron loading in SCD depends on the blood transfusion regime: with simple hypertransfusion regimes, rates approximate to thalassemia major, but iron loading can be minimal with automated erythrocyte apheresis. The consequences of transfusional iron overload largely reflect the distribution of storage iron. In SCD, a lower proportion of transfused iron distributes extrahepatically and occurs later than in thalassemia major, so complications of iron overload to the heart and endocrine system are less common. We discuss the mechanisms by which these differences may be mediated. Treatment with iron chelation and monitoring of transfusional iron overload in SCD aim principally at controlling liver iron, thereby reducing the risk of cirrhosis and hepatocellular carcinoma. Monitoring of liver iron concentration pretreatment and in response to chelation can be estimated using serum ferritin, but noninvasive measurement of liver iron concentration using validated and widely available MRI techniques reduces the risk of under- or overtreatment. The optimal use of chelation regimes to achieve these goals is described.


Author(s):  
Shilpa Jain ◽  
Mark T. Gladwin

Sickle cell disease crises are precipitated by an acute occlusion of microvessels, which can lead to end organ ischaemia reperfusion injury and acute haemolysis. Acute fat emboli syndrome, acute lung injury (the acute chest syndrome), acute pulmonary hypertension, and cor pulmonale, haemorrhagic and occlusive stroke, and systemic infection represent the most common life-threatening complications observed in current ICU practice. General principles of management in all patients admitted to the critical care unit are hydration, antibiotics, pain control, and maintenance of oxygenation and ventilation. Red blood cell transfusion therapy is the treatment of choice for most complications of sickle cell disease requiring intensive care management. Transfusion of sickle negative, leukoreduced red blood cells, phenotypically matched for Rhesus and Kell antigens is the minimum standard of care in sickle cell disease patients as they have a high incidence of red blood cell alloimmunization.


Blood ◽  
2000 ◽  
Vol 96 (7) ◽  
pp. 2369-2372 ◽  
Author(s):  
Alan S. Wayne ◽  
Steve E. Schoenike ◽  
Charles H. Pegelow

Abstract Chronic red blood cell transfusion can prevent many of the manifestations of sickle cell disease. The medical costs of chronic transfusion and management of associated side effects, especially iron overload, are considerable. This study was undertaken to evaluate the financial impact of chronic transfusion for stroke prevention in patients with sickle cell anemia. Outpatient charges pertaining to hospital-based Medicare uniform bill (UB-92) codes, professional fees, and iron chelation were evaluated. Data were collected on 21 patients for a total of 296 patient months (mean, 14; median, 14 months/patient). Charges ranged from $9828 to $50 852 per patient per year. UB-92, chelation, and physician-related charges accounted for 53%, 42%, and 5% of total charges, respectively. Of UB-92 charges, 58% were associated with laboratory fees and 16% were related to the processing and administration of blood. Charges for patients who required chelation therapy ranged from $31 143 to $50 852 per patient per year (mean, $39 779; median, $38 607). Deferoxamine accounted for 71% of chelation-related charges, which ranged from $12 719 to $24 845 per patient per year (mean, $20 514; median, $21 381). The financial impact of chronic transfusion therapy for sickle cell disease is substantial with charges approaching $400 000 per patient decade for patients who require deferoxamine chelation. These data should be considered in reference to cost and efficacy analyses of alternative therapies for sickle cell disease, such as allogeneic bone marrow transplantation.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3789-3789 ◽  
Author(s):  
Zahra Pakbaz ◽  
Roland Fischer ◽  
Richard Gamino ◽  
Ellen B. Fung ◽  
Paul Harmatz ◽  
...  

Abstract Introduction: Monitoring iron overload by serum ferritin in patients with hemosiderosis is still a routine practice although its limitations are widely studied and well known. Using non-invasive liver iron assessment by quantitative MRI or by biomagnetic liver susceptometry (BLS) with SQUID biomagnetometers would be the better alternative, however, these methods are available at only a few centers worldwide. Objective: To determine the relationship between serum ferritin (SF) and liver iron concentration (LIC), measured by BLS at CHRCO, in patients with different types of hemosiderosis. Methods and Patients: A total of 97 patients with thalassemia (TM: 3 to 52 y, 54% females) and 39 patients with sickle cell disease (SCD: 5 to 49 y, 60% female) were prospectively assessed for LIC and SF. Both tests were performed within 2 weeks of each other. Most patients with TM and SCD were chronically transfused, while 10 b-thalassemia intermedia (TI), 5 HbE/β-thalassemia (HbE), and 5 SCD patients were not on transfusion programs. LIC was measured by LTc SQUID biosusceptometer system (Ferritometer®, Model 5700, Tristan Technologies, San Diego, USA) under the standardized Hamburg-Torino-Oakland protocol. A non-parametric test (U-test) was utilized to analyze differences between SF and LIC data. Results: In chronically transfused TM and SCD patients, the median SF and LIC were very similar (Table I). In TI&HbE patients, ferritin results were disproportionately low with respect to LIC. In order to improve prediction of iron stores by SF, the SF/LIC ratio was calculated. There was a significant difference between the median ratios of the two groups of transfused and non- transfused thalassemia patients, 0.82 vs. 0.32 [μg/l]/[μg/gliver], respectively (p < 0.01). In SCD patients the ratio is significantly (p < 0.01) higher. Conclusion: Present data confirm ferritin to be a poor predictor of liver iron stores both in sickle cell disease and thalassemia. Relying only on ferritin to monitor iron overload in patients with hemosiderosis can be misleading, especially, in sickle cell disease and non-transfused thalassemia patients. Taking into account disease specific ferritin-LIC relations, could improve the prediction of iron stores. However, assessment of liver iron stores is the ultimate method to initiate and adjust chelation treatment in order to avoid progressive organ injury. Table I. Median values and ranges ( − ) of serum ferritin (SF) and liver iron concentration (LIC) in transfused (Tx) and non-transfused (non-Tx) hemosiderosis patients. Patient group n SF μg/l] LIC [mg/gliver ] SF:LIC Thalassemia Tx 82 1721 (209–8867) 3424 (364–7570) 0.82 (0.3–1.8) TI &HbE non-Tx 15 766 (52–2681) 2174 (226–5498) 0.32 (0.1–1.4) SCD Tx 34 2757 (400–9138) 1941 (518–6670) 1.2 (0.6–3.3)


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4840-4840
Author(s):  
Mahogany Oldham ◽  
Gelina Sani ◽  
Stefanie Margulies ◽  
Jennifer Webb ◽  
Robert Sheppard Nickel ◽  
...  

Background: Sickle cell disease (SCD) is typically characterized as a red blood cell disorder but our understanding of the effects on the immune system is limited. Patients with sickle cell disease have been shown to have unique inflammatory profiles, immune phenotypes and function. Others have shown that during vaso-occlusive crises patients with SCD have elevated counts of neutrophils, monocytes, and cytokines as well as increased activity of invariant natural killer T cells (iNKT).We have previously shown that hydroxyurea use is associated with a normalization of the increased NK cell number and function. While there are studies that describe on the effects of single therapy, there is little known about combination therapy. Therefore, our study investigated immunological changes in pediatric patients on combination therapy, which was defined as hydroxyurea added to chronic red blood cell transfusion treatment. Methods: Patient data and peripheral blood samples were collected from an ongoing pilot study of combination therapy hydroxyurea and simple chronic transfusion in patients with SCD previously on chronic transfusion for stroke prevention. A total of 11 patients with hemoglobin SS were studied at two time points; baseline (on chronic RBC transfusion only) and 3 months follow up after initiation of hydroxyurea 20 mg/kg/day. Comparisons were performed using paired t-tests with a p-value <0.05 being considered significant. Results: T, B and NK cell percentage was similar between baseline and after 3 months of combination therapy 62.5% (44.3-71.9) vs 67% (17.6-82.7), 16.29%(8.15-30.2) vs. 13.26% (1.07-32.8) and 7.79% (4.16-14.7) vs. 6.88 (1.54-21) (p>0.05). There were no significant differences between markers of NK cell activation between baseline and 3 months as follows: NKG2D 4.89% (0.47-28.4) vs. 24.38% (0.88-63), and NKp30 8.40% (0.81-58.7) vs. 32.42% (0.45-86.9). However there was a significant decrease in the percentage of mature (CD57+) NK cells 33.8% (10.7-67.6) vs. 23.07%(4.23-37), p =0.005. Similar results were also seen when using absolute values of the different lymphocyte subsets. Conclusion: Combination therapy appears to not affect overall percentages of B, T and NK cells but does appear to decrease the percentage of mature CD57+ NK cells that are known to have increased cytolytic activity. We plan to investigate the implications of these findings using NK functional studies such as cytotoxicity assays and cytotoxic granule release to further elucidate if combination therapy can lead to a decrease in NK cell function to normal levels. Additionally we plan to assess the effect on the immune parameters at 1 year as the hydroxyurea effect is likely time-dependent. These findings may have implications for patients on chronic transfusion therapy who plan to undergo bone marrow transplantation where a reduction in the potential for graft rejection by NK cells is desired. Disclosures No relevant conflicts of interest to declare.


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