Liver Stiffness Measurement by Vibration Controlled Transient Elastography Does Not Correlate to Hepatic Iron Overload in Children With Sickle Cell Disease

Abstract Abstract 1646 Liver transient elastography (FibroScan) is an interesting new technology that allows estimation of hepatic fibrosis through measurement of liver stiffness. The technique is based on changes in tissue elasticity induced by hepatic fibrosis and is considered as a noninvasive, reproducible and reliable method to assess hepatic fibrosis as well as to diagnose liver cirrhosis. Hepatic iron overload is a severe complication of chronic transfusion therapy in patients with hemoglobinopathies and plays an important role in the development of hepatic fibrosis and cirrhosis. Iron overload is present in several cases of sickle cell disease (SCD) including sickle cell anemia (HbS/HbS) and double heterozygous sickle-cell/beta-thalassemia (HbS/beta-thal). The aim of the study was to evaluate liver fibrosis by measuring the liver rigidity (Liver Stiffness Measurement, LSM, kPascals) using transient elastography (FibroScan, Echosens, Paris, France) in patients with SCD and explore possible correlations with clinical and laboratory characteristics of the patients, including iron overload. We studied 110 consecutive patients with SCD who are followed-up in the Thalassemia Center of Laikon General Hospital in Athens, Greece. Forty-four patients were males and 66 females; their median age was 44 years (range: 21–73 years). Twenty-two patients had HbS/HbS and 88 patients had HbS/beta-thal. On the day of Fibroscan, all patients had a thorough hematology and biochemical evaluation, including hemoglobin, reticulocyte counts, serum ferritin, liver biochemistry, bilirubin, lactate dehydrogenase (LDH) and serology for viral hepatitis. Liver iron concentration was evaluated by magnetic resonance imaging (MRI) T2* in all patients. The median LSM of all patients was 6.1 kPascals (range: 3.4–48.8 kPascals) with no differences between HbS/HbS (6.1 kPascals, 3.5–17.3 kPascals) and HbS/beta-thal (6.1 kPascals, 3.4–48.8 kPascals) patients (p=0.835). LSM values strongly correlated with liver MRI T2* values (r=0.337, p<0.001), serum ferritin (r=0.328, p=0.001), number of transfusions (r=0.332, p=0.001), bilirubin (r=0.299, p=0.003), LDH (r=0.287, p=0.004), Hb (r=-0.275, p=0.006) and reticulocyte counts (r=0.244, p=0.015). LSM values showed also strong positive correlations with biochemical indicators of liver function: gamma-glutamyl transpeptidase (r=0.522, p<0.0001), glutamic oxaloacetic transaminase (r=0.484, p<0.0001), glutamic pyruvic transaminase (r=0.422, p<0.0001), alkaline phosphatase (r=0.334, p=0.001), gamma-globulin (r=0.296, p=0.005) and weak correlation with PT-International Normalized Ratio (r=0.184, p=0.094). The above correlations were similar in patients with HbS/HbS and in patients with HbS/beta-thal. However, in HbS/HbS patients the correlation between LSM and liver T2* values was very strong (r=0.770, p=0.001). Patients who were regularly transfused had higher values of LSM (median: 6.7 kPascals, range: 2.3–48.8 kPascals) compared with patients who were sporadically transfused or were not transfused (4.4 kPascals, 3.6–17.5 kPascals, p=0.003). Patients who were under iron chelation therapy had lower values of LSM (6.3 kPascals, 3.4–15 kPascals) compared with those who did not receive iron chelators (13.9 kPascals, 8.5–17.3 kPascals, p=0.013). We found no correlations between the presence of HBV or HCV positivity and the levels of LSM. In conclusion, FibroScan may constitute a reliable and easy to apply noninvasive method to assess liver fibrosis in patients with SCD; the strong correlations between LSM values with MRI T2* values and serum ferritin supports this observation. Furthermore, FibroScan seems also to reflect the presence of chronic hepatic injury in these patients. If our results are confirmed by other studies, FibroScan may be regularly used in the management of SCD patients in whom liver is the main target organ of the disease. Disclosures: No relevant conflicts of interest to declare.

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Effectiveness of a top up transfusion programme in preventing cerebrovascular damage in a birth cohort of sickle cell disease

The Physician ◽

10.38192/1.6.2.24 ◽

2020 ◽

Vol 6 (2) ◽

pp. 1-8

Author(s):

Nadia Ibrahim ◽

Sabah Mahmood ◽

Sandra O'Driscoll ◽

Subarna Chakravorty

Keyword(s):

Sickle Cell Disease ◽

Iron Overload ◽

Sickle Cell ◽

Stroke Prevention ◽

Cerebrovascular Event ◽

Secondary Stroke Prevention ◽

Cell Disease ◽

Hepatic Iron Overload ◽

Significant Burden ◽

Haemoglobin S

Regular transfusions are effective in managing strokes in paediatric sickle cell patients. However, there are associated risks, including alloimmunisation and iron overload. This study evaluated the efficacy of top-up transfusions in primary and secondary stroke prevention in a single tertiary paediatric centre in Central London. Forty-seven children with sickle cell disease who received transfusions in the last decade were included. No patient on a primary stroke prevention transfusion programme had a cerebrovascular event during the study period but 9.5% on secondary stroke prevention programme did. Twenty-one per cent of patients in this cohort converted to exchange transfusions following transfer to adult services, of which 11% had subsequent strokes. Targeted pre-transfusion haemoglobin S % was not always met; 43% of HbS% readings in a 12- month period were above the set target of 30% and 37% were above the set target of 50%. About a third of patients had evidence of severe hepatic iron overload, but no significant cardiac iron. 25% of patients became alloimmunised, but not severe enough to warrant discontinuation of the transfusion programme. Although transfusions are effective for primary stroke prevention, iron overload remains a significant burden.

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TRANSIENT ELASTOGRAPHY (TE) IS A USEFUL TOOL FOR ASSESSING THE RESPONSE OF LIVER IRON CHELATION IN SICKLE CELL DISEASE PATIENTS

Mediterranean Journal of Hematology and Infectious Diseases ◽

10.4084/mjhid.2018.049 ◽

2018 ◽

Vol 10 (1) ◽

pp. e2018049 ◽

Cited By ~ 1

Author(s):

SOPHIA DELICOU

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Chelation Therapy ◽

Transient Elastography ◽

Liver Stiffness ◽

Iron Chelation ◽

Easy Access ◽

Cell Disease ◽

Serious Adverse Events ◽

Liver Iron

Sickle cell disease patients often need regular blood transfusions to improve both the quality of life and survival from the veno-occlusive complications of the disease. Deferasirox, a convenient long acting oral agent, has recently been introduced in clinical practice with promising efficacy.This study aims to evaluate the association of liver stiffness and possible fibrosis with iron deposition and confirm the use of elastography as a validated test of responding to chelation with low cost and easy access. 15 patients with sickle cell disease and systemic or occasional transfusionswere evaluated with MRI,transient elastography and biochemistry, for liver iron(LIC) and liver stiffness(LSM) before onset and one year after taking Deferasirox.All patients completed the study.Our results showed improvement in hepatic iron and hepatic stiffness after chelation therapy; Furthermore ALT, AST, LDH and ferritin levels have improved after 12 months of therapy with deferasirox.During the study no serious adverse events were encountered indicating the safety of the drug.Transient liver elastography findings correlate with serum ferritin and LIC in patients with sickle cell disease and it is a useful tool for assessing the response of liver iron chelation therapy. Keywords: Sickle cell disease, iron chelation, transient elastography, transfusion, iron overload

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Iron Trafficking and Distribution in Transfusional Overload: Insights From Comparing Diamond Blackfan Anemia with Sickle Cell Disease and Thalassemia

Blood ◽

10.1182/blood.v120.21.995.995 ◽

2012 ◽

Vol 120 (21) ◽

pp. 995-995 ◽

Cited By ~ 1

Author(s):

John B. Porter ◽

Patrick B Walter ◽

Lynne D Neumayr ◽

Patricia Evans ◽

Marcela G Weyhmiller ◽

...

Keyword(s):

Sickle Cell Disease ◽

Iron Overload ◽

Sickle Cell ◽

Research Funding ◽

Hepatic Iron ◽

Iron Loading ◽

Cell Disease ◽

Ineffective Erythropoiesis ◽

Iron Distribution ◽

Diamond Blackfan Anemia

Abstract Abstract 995 Background: β-thalassemia major (TM) is the paradigm for chronic transfusional iron overload, in which the extra-hepatic organ failure is best described. In Sickle Cell Disease (SCD), these consequences appear later and at a lower frequency. In chronically transfused Diamond Blackfan Anemia (DBA), extra-hepatic iron overload, although less well documented, appears to occur early and at high frequency. A Multicenter Study of Iron Overload (MCSIO) aims to explore how key candidate factors affect iron distribution; including inflammation, ineffective erythropoiesis, level of iron overload, and hepcidin synthesis. Plasma non-transferrin bound iron (NTBI) could be a key mechanism by which iron is delivered to tissues and may determine the propensity for extra-hepatic iron distribution. Here we focus on how markers of ineffective erythropoiesis (IE) and erythron expansion impact iron distribution, with particular reference to NTBI and iron distribution determined by MRI. Methods: Iron-overloaded patients (5 TM, 5 SCD, and 5 DBA) with ferritin > 1500 g/dl or LIC > 7 mg/g dry wt, age ≥16, age 0 to 9 at initiation of transfusion and 10 to 20 years of transfusion exposure were enrolled from 3 sites in the US and Europe. 5 non-transfused healthy controls were also enrolled. A detailed medical, transfusion and chelation history were obtained with standardized MRI evaluations for hepatic, cardiac, and pituitary iron deposition. Fasting, early morning blood samples were obtained one day prior to transfusion. Chelation was held for 72 hours prior to each sample. Results: Results are shown in the table as median values. DBA patients had the highest NTBI prior to transfusion despite having the lowest ferritin and LIC levels. GDF15 levels were highest in TM, with similar levels in SCD and DBA. EPO levels were nearly two orders of magnitude higher in DBA than TM or SCD. DBA patients also had the highest median cardiac R2*; two patients showing values above the control range. Whereas the median pituitary R2 in DBA was not above control, two of the patients had the highest R2 values, suggesting heavy iron deposition. EPO values in DBA are nearly two orders of magnitude higher that in SCD or TM despite similar pre-transfusion Hb values. GDF15 values are approximately three times controls, while soluble transferrin receptors (sTfR) values are almost undetectable. With SCD, no patients had increased cardiac iron loading, despite median SF and LIC being the highest in this group. Surprisingly all SCD patients had pituitary R2 values above the upper limit of normal. 1 TM patient had increased cardiac R2* whereas three had increased pituitary iron. In TM, NTBI was strongly correlated with GDF15 (Pearson's Rho=0.93) but in DBA, GDF15 was inversely correlated with NTBI (-.95). Conclusions: High GDF15 levels have been reported in conditions associated with IE, such as TM, but not in DBA. GDF15 reputedly suppresses hepcidin synthesis, thereby increasing iron absorption and potentially NTBI levels. The increased GDF15 in DBA, while sTfr remain less than controls, suggests that erythropoietic precursors do not reach the stage where sTfr are expressed and that this occurs at a later differentiation stage than GDF15. Increasing NTBI in TM with increasing GDF15 is consistent with IE contributing to NTBI formation, but the lack of this relationship in DBA suggest another mechanism for high NTBI. As the erythron is destroyed at a pre-hemoglobinised stage in DBA, IE would not contribute directly to NTBI formation. However, the extremely high EPO levels in DBA may inhibit hepcidin synthesis, as in other conditions, thereby increasing NTBI. This in turn may account for the extra-hepatic iron distribution demonstrated by MRI in DBA. The increased pituitary iron without cardiac loading in the heavily loaded SCD patients suggests that with prolonged exposure to heavy iron overload, the pituitary iron loading may be the first indicator of extra-hepatic deposition. Disclosures: Porter: Novartis: Consultancy, Research Funding. Walter:Novartis: Research Funding. Harmatz:Novartis: Research Funding; Ferrokin: Research Funding. Wood:Ferrokin Biosciences: Consultancy; Shire: Consultancy; Apotex: Consultancy, Honoraria; Novartis: Honoraria, Research Funding. Vichinsky:Novartis: Consultancy, Research Funding; ApoPharma: Consultancy, Research Funding; ARUP Research lab: Research Funding.

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