scholarly journals Deferasirox Decreases Liver Iron Concentration in Iron-Overloaded Patients with Myelodysplastic Syndromes, Aplastic Anemia and Other Rare Anemias

2015 ◽  
Vol 134 (4) ◽  
pp. 233-242 ◽  
Author(s):  
Yutaka Kohgo ◽  
Akio Urabe ◽  
Yurdanur Kilinç ◽  
Leyla Agaoglu ◽  
Krzysztof Warzocha ◽  
...  

Iron overload in transfusion-dependent patients with rare anemias can be managed with chelation therapy. This study evaluated deferasirox efficacy and safety in patients with myelodysplastic syndromes (MDS), aplastic anemia (AA) or other rare anemias. A 1-year, open-label, multicenter, single-arm, phase II trial was performed with deferasirox (10-40 mg/kg/day, based on transfusion frequency and therapeutic goals), including an optional 1-year extension. The primary end point was a change in liver iron concentration (LIC) after 1 year. Secondary end points included changes in efficacy and safety parameters (including ophthalmologic assessments) overall as well as in a Japanese subpopulation. Overall, 102 patients (42 with MDS, 29 with AA and 31 with other rare anemias) were enrolled; 57 continued into the extension. Mean absolute change in LIC was -10.9 mg Fe/g dry weight (d.w.) after 1 year (baseline: 24.5 mg Fe/g d.w.) and -13.5 mg Fe/g d.w. after 2 years. The most common drug-related adverse event was increased serum creatinine (23.5%), predominantly in MDS patients. Four patients had suspected drug-related ophthalmologic abnormalities. Outcomes in Japanese patients were generally consistent with the overall population. Results confirm deferasirox efficacy in patients with rare anemias, including a Japanese subpopulation. The safety profile was consistent with previous studies and ophthalmologic parameters generally agreed with baseline values (EUDRACT 2006-003337-32).

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3726-3726
Author(s):  
Peter Nielsen ◽  
Tim H. Bruemmendorf ◽  
Regine Grosse ◽  
Rainer Engelhardt ◽  
Nicolaus Kroeger ◽  
...  

Abstract Patients with myelodysplastic syndromes (MDS), osteomyelofibrosis (OMF), or severe aplastic anemia (SAA) suffer from ineffective erythropoiesis due to pancytopenia, which is treated with red blood cell transfusion leading to iron overload. Especially in low-risk patients with mean survival times of > 5 years, potentially toxic levels of liver iron concentration (LIC) can be reached. We hypothesize that the higher morbidity seen in transfused patients may be influenced by iron toxicity. Following a meeting in Nagasaki 2005, a consensus statement on iron overload in myelodysplastic syndromes has been published, however, there is still no common agreement about the initiation of chelation treatment in MDS patients. In the present study, a total of 67 transfused patients with MDS (n = 20, age: 17 – 75 y), OMF (n = 4, age: 48 – 68 y), SAA (n = 43, age: 5 – 64 y) were measured by SQUID biomagnetic liver susceptometry (BLS) and their liver and spleen volumes were scanned by ultrasound at the Hamburg biosusceptometer. Less than 50 % were treated with DFO. LIC (μg/g-liver wet weight, conversion factor of about 6 for μg/g-dry weight) and volume data were retrospectively analyzed in comparison to ferritin values. Additionally, 15 patients (age: 8 – 55 y) between 1 and 78 months after hematopoietic cell transplantation (HCT) were measured and analyzed. LIC values ranged from 149 to 8404 with a median value of 2705 μg/g-liver, while serum ferritin (SF) concentrations were between 500 and 10396 μg/l with a median ratio of SF/LIC = 0.9 [(μg/l)/(μg/g-liver)] (range: 0.4 to 5.2). The Spearman rank correlation between SF and LIC was found to be highly significant (RS = 0.80, p < 0.0001), however, prediction by the linear regression LIC = (0.83± 0.08)·SF was poor (R2 = 0.5) as found also in other iron overload diseases. Although iron toxicity is a long-term risk factor, progression of hepatic fibrosis has been observed for LIC > 16 mg/g dry weight or 2667 μg/g-liver (Angelucci et al. Blood2002; 100:17–21) within 60 months and significant cardiac iron levels have been observed for LIC > 350 μmol/g or 3258 μg/g-liver (Jensen et al. Blood2003; 101:4632-9). The Angelucci threshold of hepatic fibrosis progression was exceeded by 51 % of our patients, while 39 % were exceeding the Jensen threshold of potential risk of cardiac iron toxicity. The total body iron burden is even higher as more than 50 % of the patients had hepatomegaly (median liver enlargement factor 1.2 of normal). A liver iron concentration of about 3000 μg/g-liver or 18 mg/g-dry weight has to be seen as latest intervention threshold for chelation treatment as MDS patients are affected by more than one risk factor. A more secure intervention threshold would be a LIC of 1000 μg/g-liver or 4 – 6 mg/g-dry weight, corresponding with a ferritin level of 900 μg/l for transfused MDS patients. Such a LIC value is not exceeded by most subjects with heterozygous HFE-associated hemochromatosis and is well tolerated without treatment during life-time. Non-invasive liver iron quantification offers a more reliable information on the individual range of iron loading in MDS which is also important for a more rational indication for a chelation treatment in a given patient.


Author(s):  
Janet L Kwiatkowski ◽  
Mona Hamdy ◽  
Amal El Beshlawy ◽  
Fatma S.E. Ebeid ◽  
Mohammed Badr ◽  
...  

Many people with sickle cell disease (SCD) or other anemias require chronic blood transfusions, which often causes iron overload and requires chelation therapy. The iron chelator deferiprone is often used in individuals with thalassemia syndromes, but data in patients with SCD are limited. This open-label study (NCT02041299) assessed the efficacy and safety of deferiprone in patients with SCD or other anemias receiving chronic transfusion therapy. A total of 228 patients (mean age: 16.9 [range 3-59] years; 46.9% female) were randomized to receive either oral deferiprone (n = 152) or subcutaneous deferoxamine (n = 76). The primary endpoint was change from baseline at 12 months in liver iron concentration (LIC), assessed by R2* magnetic resonance imaging (MRI). The least squares mean (standard error) change in LIC was −4.04 (0.48) mg/g dry weight for deferiprone vs −4.45 (0.57) mg/g dry weight for deferoxamine, with noninferiority of deferiprone to deferoxamine demonstrated by analysis of covariance (least squares mean difference 0.40 [0.56]; 96.01% confidence interval, −0.76, 1.57). Noninferiority of deferiprone was also shown for both cardiac T2* MRI and serum ferritin. Rates of overall adverse events (AEs), treatment-related AEs, serious AEs, and AEs leading to withdrawal did not differ significantly between the groups. AEs related to deferiprone treatment included abdominal pain (17.1% of patients), vomiting (14.5%), pyrexia (9.2%), increased alanine transferase (9.2%) and aspartate transferase levels (9.2%), neutropenia (2.6%), and agranulocytosis (0.7%). The efficacy and safety profiles of deferiprone were acceptable and consistent with those seen in patients with transfusion-dependent thalassemia.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 633-633 ◽  
Author(s):  
Norbert Gattermann ◽  
Mathias Schmid ◽  
Matteo Della Porta ◽  
Kerry Taylor ◽  
John F Seymour ◽  
...  

Abstract Background: Many patients (pts) with myelodysplastic syndromes (MDS) [particularly those with Low- or Int-1-risk] are susceptible to iron overload from ongoing blood transfusions and increased dietary iron absorption. Deferasirox (Exjade®) has shown efficacy in maintaining or reducing body iron (assessed by liver iron concentration [LIC] and serum ferritin [SF]) in MDS pts. More recently, the efficacy and safety of deferasirox in pts with various underlying anemias, including MDS, was evaluated in the large EPIC study. Data for MDS pts are presented here. Methods: The EPIC study was a 1-yr, openlabel, single-arm, multicenter trial. Pts with transfusion-dependent MDS and SF ≥1000 ng/ mL, or SF &lt;1000 ng/mL but requiring &gt;20 transfusions or 100 mL/kg of blood and an R2 MRI-confirmed LIC &gt;2 mg Fe/g dry weight (dw), received an initial deferasirox dose of 10–30 mg/kg/day. SF was assessed monthly and protocol-specified dose adjustments in steps of 5–10 mg/kg/day (range 0–40 mg/kg/day) were done every 3 mths based on SF trends and safety markers. Primary efficacy endpoint was the change in SF from baseline at 12 mths. Safety assessments included monitoring of adverse event (AE) and laboratory parameters. Results: 341 MDS pts (204 M, 137 F; mean age 67.9 yrs, range 11–89 yrs) with median baseline SF of 2730 (range 951–9465) ng/mL were enrolled. Mean transfusion duration was 3.6 yrs, and pts received a mean of 116.4 mL/kg of blood in the previous yr. Almost half (48.4%) of all pts had not received any prior chelation therapy; 40.0% had previously received deferoxamine (DFO), 4.1% deferiprone, 7.0% combination DFO/ deferiprone, and 0.3% other therapy. Overall, mean actual dose of deferasirox over 1 yr of treatment was 19.2±5.4 mg/kg/day. At 12 mths, there was a significant reduction in median SF from baseline (by LOCF: –253.0 ng/mL; P=0.0019). Median SF (range) ng/mL values at baseline, 3, 6, 9 and 12 mths were 2729.5 (951–9465; n=336), 2358.0 (534–46569; n=263), 2209.5 (357–10066; n=230), 2076.0 (358–25839; n=197) and 1903.5 (141–10155; n=174), respectively. Overall, 48.7% of pts (n=166) discontinued therapy. Reasons for withdrawal included AEs [n=78, 23% (n=44, 13% for drug-related AEs)], consent withdrawal (n=33, 10%), unsatisfactory therapeutic effect (n=6, 2%), lost to follow-up (n=2, &lt;1%), death (n=26, 8%, none treatment-related as per investigators’ assessments) and other (n=21, 6%). Most common investigator-assessed drug-related AEs were diarrhea (n=110, 32%), nausea (n=45, 13%), vomiting (n=26, 8%), abdominal pain (n=26, 8%), upper abdominal pain (n=25, 7%), rash (n=23, 7%), and constipation (n=21, 6%). Only 25 pts discontinued study drug for drug-related GI AEs. Most AEs were mild-to-moderate (95%) in severity. In total, 14.7% had two consecutive serum creatinine values &gt;33% above baseline (in normal range), 10.6% had two values above ULN, and 24.9% had both two consecutive values &gt;33% and &gt;ULN; 19 pts had dose decreases and 10 dose interruptions due to abnormal creatinine; there were no progressive increases. One patient (&lt;1%) with normal baseline alanine aminotransferase had an increase that exceeded &gt;10xULN on two consecutive visits. Conclusions: In this large cohort of MDS pts with iron overload, deferasirox provided significant reduction in SF levels over 1-yr treatment with appropriate dose adjustments every 3 mths based on SF trends and safety markers. The AE profile in this study is consistent with previously reported deferasirox data in MDS pts. The discontinuation rate was higher in this subgroup. Investigations are ongoing to assess possible contributing factors including associated comorbidities, age of pts, and others.


Blood ◽  
2011 ◽  
Vol 118 (4) ◽  
pp. 884-893 ◽  
Author(s):  
M. Domenica Cappellini ◽  
Mohamed Bejaoui ◽  
Leyla Agaoglu ◽  
Duran Canatan ◽  
Marcello Capra ◽  
...  

Abstract Patients with β-thalassemia require lifelong iron chelation therapy from early childhood to prevent complications associated with transfusional iron overload. To evaluate long-term efficacy and safety of once-daily oral iron chelation with deferasirox, patients aged ≥ 2 years who completed a 1-year, phase 3, randomized trial entered a 4-year extension study, either continuing on deferasirox (deferasirox cohort) or switching from deferoxamine to deferasirox (crossover cohort). Of 555 patients who received ≥ 1 deferasirox dose, 66.8% completed the study; 43 patients (7.7%) discontinued because of adverse events. In patients with ≥ 4 years' deferasirox exposure who had liver biopsy, mean liver iron concentration significantly decreased by 7.8 ± 11.2 mg Fe/g dry weight (dw; n = 103; P < .001) and 3.1 ± 7.9 mg Fe/g dw (n = 68; P < .001) in the deferasirox and crossover cohorts, respectively. Median serum ferritin significantly decreased by 706 ng/mL (n = 196; P < .001) and 371 ng/mL (n = 147; P < .001), respectively, after ≥ 4 years' exposure. Investigator-assessed, drug-related adverse events, including increased blood creatinine (11.2%), abdominal pain (9.0%), and nausea (7.4%), were generally mild to moderate, transient, and reduced in frequency over time. No adverse effect was observed on pediatric growth or adolescent sexual development. This first prospective study of long-term deferasirox use in pediatric and adult patients with β-thalassemia suggests treatment for ≤ 5 years is generally well tolerated and effectively reduces iron burden. This trial was registered at www.clinicaltrials.gov as #NCT00171210.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 439-439 ◽  
Author(s):  
Jong Wook Lee ◽  
Sung-Soo Yoon ◽  
Zhi Xiang Shen ◽  
Hui-Chi Hsu ◽  
Arnold Ganser ◽  
...  

Abstract Background: Patients with aplastic anemia (AA) can be effectively treated with bone marrow transplantation or immunosuppressive/immunomodulatory therapy, but many will require repeated blood transfusions to manage symptoms of severe anemia and are subsequently at risk of accumulating excessive body iron. Reduction in iron burden across a range of transfusion-dependent anemias, including AA, has been previously demonstrated with deferasirox (Exjade®). More recently, the EPIC trial enrolled the largest cohort of patients with AA undergoing iron chelation to date. The efficacy and safety of deferasirox in these patients are presented. Methods: Enrolled patients had transfusion-dependent AA and serum ferritin (SF) levels of □1000 ng/mL, or &lt;1000 ng/mL with a history of multiple transfusions (&gt;20 transfusions or 100 mL/kg of red blood cells) and an R2 MRI-confirmed liver iron concentration (LIC) &gt;2 mg Fe/g dry weight. Deferasirox was administered at an initial dose of 10–30 mg/kg/day depending on transfusion requirements, with dose adjustments in steps of 5–10 mg/kg/day (in the range 0–40 mg/kg/day) based on assessment of SF trends and safety markers indicative of iron toxicity. SF was assessed every 4 weeks and the primary efficacy endpoint was the change at week 52 from baseline. Safety assessments included adverse event (AE) monitoring and assessment of laboratory parameters. Results: In total, 116 AA patients (67 males, 49 females; mean age 33.3 years) were enrolled. Median baseline SF was 3254.0 ng/mL; patients received a mean of 115.8 mL/kg of blood in the year prior to enrollment. Approximately two-thirds of patients (68.1%) had received no prior chelation therapy. Of those who had, patients received deferoxamine (DFO; n=31, 26.7%) or combination DFO/deferiprone (n=6, 5.2%). After 12 months, median SF decreased significantly by 964.0 ng/mL from baseline median of 3254.0 ng/mL (P=0.0003). This occurred at an average actual deferasirox dose of 17.6±4.8 mg/kg/day. The median change in SF from baseline was –970.0 ng/mL (P&lt;0.0001; 3263.0 ng/mL [baseline]; 0.20 mg/kg/day [mean iron intake]) in patients receiving a mean actual deferasirox dose &lt;20 mg/kg/day (n=75) and −883.8 ng/mL (P=0.27; 3238.0 ng/mL [baseline]; 0.29 mg/kg/day [mean iron intake]) in those receiving 20–&lt;30 mg/kg/day (n=40). Overall, 88 patients (76%) completed the study; reasons for discontinuation included AEs (n=13, 11%), consent withdrawal (n=6, 5%), lost to follow-up (n=1, 1%) and various other reasons (n=3, 3%). In addition, five patients (4%) died during the study (one death related to pneumonia, three due to sepsis and one as a result of hepatic adenoma rupture). No death was suspected by investigators to be treatment related. The most common drug-related AEs (investigator-assessed) were: nausea (n=26, 22%), diarrhea (n=18, 16%), rash (n=13, 11%), vomiting (n=10, 9%), dyspepsia (n=9, 8%), abdominal pain (n=7, 6%), upper abdominal pain (n=7, 6%), and anorexia (n=7, 6%). Most AEs were mild or moderate in severity (&gt;95%). 29 patients (25.0%) had an increase in serum creatinine &gt;33% above baseline and the upper limit of normal (ULN) on two consecutive visits; there were no progressive increases. One patient (0.9%) had an increase in alanine aminotransferase (ALT) that exceeded &gt;10xULN on two consecutive visits; ALT levels were elevated in this patient at baseline. Conclusions: Over a 1-year treatment period, deferasirox significantly reduced iron burden in transfusion-dependent, iron overloaded patients with AA. Despite the high iron burden, most patients had received no prior chelation therapy, indicating a clear need for iron chelation in this patient population. Overall, deferasirox was generally well tolerated in these AA patients with the majority of AEs being mild to moderate.


Author(s):  
Vipul V. Chemburkar ◽  
Archit A. Gupta ◽  
Devdas S. Shetty ◽  
Ruchi R. Agarwal

Background: Liver iron overload is considered to be the histological hallmark of genetic hemochromatosis. The accurate estimation of iron overload is important to establish the diagnosis of hemochromatosis. The aim of the present study was to estimate T2* liver value, quantify liver iron concentration (in milligram of iron per gram dry weight) and find out the appropriate therapy for patients with iron overload according to severity index.Methods: A cross-sectional observational study was carried out in Department of Radio Diagnosis, at B.Y.L. Nair Hospital and medical college, Mumbai from June 2017 to August 2018. A total of 50 cases were enrolled for the present study.Results: Male predominance (66.0%) was seen. Mean duration of disease among the studied cases was 10.52±6.06 years, with minimum and maximum duration of disease of 1 and 26 years respectively. Eight percent had compliance to visit and treatment among the enrolled cases.Conclusions: MRI was concluded to be potentially useful non-invasive method for evaluating liver iron stones in a wide spectrum of haematological and liver diseases.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 943-943
Author(s):  
Kris V Kowdley ◽  
Nishit B Modi ◽  
Frank Valone ◽  
Victor M. Priego ◽  
Christopher Ferris ◽  
...  

Abstract Introduction: Patients with hereditary hemochromatosis (HH) require continued phlebotomies to limit end-organ damage. Approximately 25% of patients in maintenance felt receiving phlebotomies was "inconvenient" or "very inconvenient" (Brisott et al, 2011). Patient compliance with phlebotomies generally declines with time (Hicken et al, 2003), and therapeutic phlebotomies may not be medically suitable for some HH patients. Rusfertide, a peptide mimetic of hepcidin, is an effective regulator of iron distribution and utilization that has demonstrated control of iron in an animal model of HH. Methods: We conducted an open-label, dose-finding efficacy study that investigated subcutaneous rusfertide in HH patients on a stable phlebotomy regimen of 0.25 to 1 phlebotomy per month for at least 6 months. Patients with clinical laboratory abnormalities and those receiving iron chelation therapy or erythrocytapheresis were excluded. Subjects received individually titrated rusfertide doses once or twice a week to maintain transferrin saturation (TSAT) below 45% and were followed for 6 months. Study measures included TSAT, serum iron, transferrin and ferritin, liver iron concentration (LIC) measured by MRI, and adverse events (AEs). Results: Sixteen subjects (10 male/6 female) were enrolled. Mean age and weight were 62.5 years and 88.1 kg, respectively. LIC values were maintained at pre-study levels, with minimal use of phlebotomies during the duration of the study (Figure 1A). Average pre-study phlebotomy rate was 0.27 phlebotomies/month compared to 0.03 phlebotomies/month during the study (p&lt;0.0001; Figure 1B). There was a dose- and concentration-dependent decrease in serum iron and TSAT (Figure 2A and 2B). Transferrin levels were relatively constant over the course of the study. There were no notable changes in hematological parameters such as hematocrit, erythrocytes, leucocytes, or platelets. Rusfertide was generally well tolerated. Adverse events reported in 2 or more subjects included diarrhea, fatigue, injection site reactions (erythema, induration, pain, pruritis), dizziness, and headache. Conclusions: Rusfertide demonstrated a pharmacodynamic effect in reducing TSAT and serum iron, with corresponding significant reduction in the number of phlebotomies, and with LIC maintained at pre-study levels with minimal use of phlebotomies. These data indicate rusfertide was well tolerated in patients with HH and controls LIC, supporting development of rusfertide as a potential treatment for HH. Figure 1 Figure 1. Disclosures Kowdley: PTG: Consultancy, Research Funding. Modi: Protagonist Therapeutics: Current Employment. Valone: Protagonist Therapeutics: Current Employment, Current equity holder in publicly-traded company. Gupta: Protagonist Therapeutics: Current Employment.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3619-3619 ◽  
Author(s):  
Maria Cappellini ◽  
Mohamed Bejaoui ◽  
Silverio Perrotta ◽  
Leyla Agaoglu ◽  
Antonios Kattamis ◽  
...  

Abstract ICL670 (deferasirox) is an investigational once-daily oral iron chelator that has demonstrated the ability to induce sustained, clinically relevant reductions in liver iron content (LIC) in heavily transfused patients with β-thalassemia and iron overload. The efficacy and safety of ICL670 is being assessed in a multicenter, randomized, open-label Phase III study in comparison with deferoxamine (DFO) in patients aged ≥2 years with β-thalassemia and transfusional hemosiderosis. Between March and November 2003, 587 patients began treatment (296 on ICL670; 291 on DFO) in the following 12 countries : Italy (200), Turkey (87), Tunisia (68), US (48), Greece (46), Germany (27), Argentina (24), Belgium (24), Brazil (20), UK (18), Canada (13) and France (12). Based on LIC at baseline (2–3, >3–7, >7–14 and >14 mg Fe/g dw), patients were randomized in a 1:1 ratio to receive either oral ICL670 once daily at doses of 5, 10, 20 or 30 mg/kg, respectively, or subcutaneous DFO at doses of 20–60 mg/kg/day for 5 days/week. Treatment was for one year initially, to be followed by an extension phase during which patients randomized to DFO may switch to ICL670. LIC, the primary outcome variable, was assessed at baseline by liver biopsy or, in some children, non-invasively by magnetic susceptometry using a Superconducting QUantum Interference Device (SQUID). LIC will be reassessed after 12 months of therapy in each patient using the same methodology as at baseline. Liver biopsies are analyzed at a single center (Rennes, France) and SQUID assessments are performed in 3 centers (Turin, Italy; Hamburg, Germany; Oakland, US). At baseline, median (25–75th percentiles) LIC was 13.0 mg Fe/g dw (7.2–21.0) by biopsy and 5.6 (4.0–7.7) in those patients assessed by SQUID. Total body iron balance will be assessed to determine the relative chelation efficacies of ICL670 and DFO. A summary of patient demographics and baseline characteristics (median values or no. of pts) is given in the table. ICL670 has been well tolerated with mild, transient gastrointestinal complaints as the main AEs with a suspected relationship to study drug. As of May 2004, 8 patients on ICL670 and 2 on DFO had discontinued therapy due to AEs. The key efficacy and safety data from the initial 12 months of therapy for all randomized patients will be available late November 2004. Treatment group (by initial dose) ICL670 (n=296) Deferoxamine (n=291) 10 mg/kg n = ≤ 94 20 mg/kg n = 83 30 mg/kg n = 119 <35 mg/kg n = 51 35-<50 mg/kg n = 119 ≥ 50 mg/kg n = 121 Age (yrs) median 15 15 15 15 14 17 No. of pts 2 - <16 years 49 44 60 26 63 56 No. of ≥ pts 16 yrs 45 39 59 25 56 65 No. of males/females 44/50 41/42 54/65 32/19 50/69 61/60 LIC (mg Fe/g dry weight) 4.7 10.6 21.8 4.5 9.1 19.5 No. of pts with biopsy/SQUID* 60/34 69/14 117/0* 36/15 93/26 119/2 Serum ferritin (ng/ml) 1881 1954 3250 1546 2037 2383


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4053-4053
Author(s):  
John C Wood ◽  
Ashley Mo ◽  
Aakanksha Gera ◽  
Montre Koh ◽  
Thomas Coates ◽  
...  

Abstract Abstract 4053 Poster Board III-988 Introduction Hemoglobinopathies are among the most common genetic diseases in the work. Many hemoglobinopathy patients require lifeline transfusion, iron chelation, and careful monitoring of iron stores. Liver iron concentration (LIC) is an excellent metric of transfusional iron balance and total body iron stores(1). Noninvasive LIC estimation by MRI is gradually replacing liver biopsy but remains limited by cost and availability, particularly in regions where thalassemia is prevalent(2). Quantitative computed tomography (QCT) was proposed as a means to estimate LIC 30 years ago, but there has been surprisingly limited validation(3-5). QCT is cheaper and more available than MRI. Steady improvements in CT instrumentation and standardization warrant a re-evaluation of QCT for iron quantitation. In this study, we determined liver attenuation as a function of MRI-predicted liver iron concentration in 45 patients over a 6 year period. Methods This study represents a convenience sample of all iron-overloaded patients who had undergone both QCT for bone density and LIC measurement by MRI at Children's Hospital Los Angeles. 64 usable observations were obtained in 45 patients; 14 patients had multiple exams(range 2-6). MRI and QCT examinations were considered “paired” if the scans were less than 120 days apart (59 studies). MRI liver R2 and R2* examinations were performed and analyzed as previously described(2). Quantitative CT was performed on a General Electric Hilite Advantage. A single axial 10 mm thick slice was collected at the L1 level using a KVp of 80 at 70 mA for 1 second. Three hydroxyappetite phantoms, calibrated to 0, 125, and 250 Hounsfield units, were placed in scanning platform (CT-T bone densitometry package; GE Medical Systems), approximately 7 cm from mid-vertebral body. Calibration curve was obtained from regions of interest drawn within the three phantoms, using linear regression calculated by custom MATLAB routines. Regions of interest in the liver were drawn in ∼ 9 cm2 regions of the right and left lobe of the liver, as well as a region encompassing the entire cross-sectional area of the liver. Results Most patients had thalassemia major and moderate to severe iron overload, with a LIC of 14.1 ± 14 mg/g dry weight and a cardiac R2* of 70.5 ± 95.0 Hz (median T2* of 30.9 ms). Patients who were receiving regular transfusions were well transfused, with a pre-transfusion hemoglobin of 9-9.5 g/dl. All chronically transfused patients were using deferoxamine until approximately 2005, with most switching to deferasirox in 1/2005. Figure 1 demonstrates MRI-predicted LIC as a function of liver attenuation. There is a strong linear relationship having a slope of 0.591 mg/g dry weight of liver per HU. Normal liver attenuation ranges in non iron overload children and young adults is 57-76 HU. Upper limit of normal corresponds to a predicted LIC of 6 m/g, indicating an intrinsic lack of sensitivity for qCT at low iron concentrations. Time-courses of CT-iron relationship from 14 patients whom had serial evaluations paralleled the regression line and were well constrained by the 95% confidence intervals, suggesting the calibration is suitable for serial analysis (not shown). Whole liver attenuation values were unbiased with respect to values from the right and left lobe; coefficient of variation was 2.2-4.9%. Conclusion The present work represents the largest human validation of QCT for liver iron quantitation. QCT techniques have inadequate sensitivity to discriminate LIC values less than 6 mg/g but are not limited by high iron concentrations. High reproducibility makes them suitable for tracking serial LIC changes. QCT may be an acceptable surrogate for LIC in hospitals lacking the software, personnel, or financial resources to support MRI or SQUID LIC measurements. Acknowledgments: This work supported by NIH HL075592, CDC (U27/CCU922106) and GCRC (NIH #RR00043-43). Disclosures: No relevant conflicts of interest to declare.


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