12th Congress of the European Hematology ... - Haematologica

12 th Congress of the European Hematology Association
mg/L H2O2. Similarly, the FORD test uses, preformed stable and colored
radicals and determines the decrease in absorbance that is proportional
to the blood antioxidant concentration of the sample according to the
Lambert Beer’s law. In the presence of an acidic buffer (pH=5.2) and a
suitable oxidant (FeCl3) the chromogen, which contains 4-Amino-N,Ndiethylaniline
sulfate forms a stable and colored radical cation photometrically
detectable at 505nm. Antioxidant compounds in the sample
reduce the radical cation of the chromogen quenching the color and producing
a decoloration of the solution, which is proportional to their concentration.
The absorbance values obtained for the samples are compared
with a standard curve obtained using Trolox (6-Hydroxy-2,5,7,8tetramethylchroman-2-carboxylic
acid), a permeable cell derivative of
vitamin E commonly employed as an antioxidant. Results. The main
results of the study showed that: a) free oxygen radical levels were
increased both in TI (2.71±0.68 mmol/LH2O2) and SCD patients
(3.42±0.94 mmol/L H2O2), respectively and b) free oxygen radicals
defense levels were normal both in TI (1.23±0.18 mmol/L Trolox) and
SCD patients (1.22±0.20 mmol/L Trolox), respectively. The intraassay
and interassay coefficients of variation were 3.7% and 6.2%, respectively
for FORT, while The intraassay and interassay coefficients of variation
were 4.2% and 6.6%, respectively for FORD. Conclusions. The determination
of free oxygen radicals and free oxygen radicals defense seem
to play an important role in the generation of oxidative stress, an imbalance
between oxidants and antioxidants that can lead to oxidative damage
and is involved in the pathogenesis of several diseases, such as thalassaemia
intermedia and sickle cell disease. The methodology described
above is simple, reliable, rapid and reproducible.
0807
FRAMESHIFT CD41/42 (-TTCT) MUTATION IDENTIFIED BY RT-LIGHT CYCLER AND
MOLECULAR CHARACTERIZATION BY AUTOMATIC SEQUENCING. FIRST CASES
DESCRIBED IN SPAIN
P. Ropero, 1 S. de la Iglesia, 2 F.A. González, 1 R. Paúl, 1
R. Sánchez-Dominguez, 1 M. Polo, 1 A. Villegas1
1 2 Hospital Clínico San Carlos, MADRID; H. U. de Gran Canarias Dr. Negrín,
LAS PALMAS DE GRAN CANARIAS, Spain
Background. The thalassemias are hereditary anemias. In the β-thalassaemia
(β-thal) there is deficient or absent synthesis of β-globin. A high
incidence of β-thal occurs in populations of Mediterranean and African
origin. Smaller, but significant concentrations of β-thal exist throughout
the Middle-Eastern, India, Pakistan, and China, and sporadic cases have
been described in most ethnic groups. More than 150 β-thal mutations
have been described. However, each population group displays its own
mutations. In Spain, as in other Mediterranean regions the most frequents
mutations are CD 39 (C->T); IVS-1-nt1 (G->A); IVS-1-nt6 (T-
>C) and IVS-1-nt110 (G->A). However, a large number of uncommon
alleles have been observed both in Spain and other populations. The
frameshift mutation CD41/CD42 (-TTCT) is a very common allele in
Chine population but is rare in the Mediterranean region although it
has been recorded in East Asian population. Aims. We described the
three first Spanish patients with the frameshift CD41/42 (-TTCT) mutation.
This mutation has been detected in a RT-PCR Light Cycler and molecularly
characterized by automatic sequencing. Methods. Three patients
from Las Palmas de Gran Canarias (Canary Island, Spain) were sent us
to molecular characterization, because in the screening of the most
prevalent β-thal mutations of the Mediterranean area which were carry
out by Real Time PCR (RT-PCR Light Cycler) with the probe
CD37/39A the temperature of melting (TM) was different, did not correspond
with usual TM. The molecular characterization was carrying
out by automatic sequencing in an ABI-PRISM DNA Automated
Sequencer. Results. The most relevant haematological data are. I1a [Hb
11.4 g/dL; MVC 64.7 fL; HB A2 5.3%; Hb F 0.9%; Iron normal]; I1b [Hb
12.3 g/dL; MVC 64.6 fL; HB A2 6.6%; Hb F 1.2%; Iron normal]; I2b [Hb
11.5 g/dL; MVC 60.6 fL; HB A2 5.8%; Hb F 0.9%; Iron normal]. In the
RT-PCR Light Cycler with the probes CD37/39 S (CCCTTGGACCCA-
GAGGTTCTTTGAGTCCT-F) and CD37/39 A (LcRED640-
TGGGGATCTGTCCACTCCTGATGCTGTTATG-P) the TM of normal
sequence is 70.53ºC±0.80 and CD39 mutation 62.67ºC±0.92 (Br. J.
Hematol 2002; 119: 554-557) in ours patients the TM of mutated allele
was 57.45ºC. Automatic sequencing of the exon 2 of β gene globin
demonstrated the deletion of 4 bp (-TTCT) between CD 41/42 which
originate a frameshift and a βº-thalassemia. Summary and Conclusions.
This work once again demonstrates the heterogeneity of β-thal in Spain.
To study the phenotype of our patients could confirm if this mutation
is an example of genetic migration or whether it has arisen independently
in our different ethnic group. Technologically the use of methods
302 | haematologica/the hematology journal | 2007; 92(s1)
of screening in thalassemia is not sufficient, although they can orient in
the identification of the molecular alterations, therefore in molecular
biology all techniques are complementary.
0808
TREATMENT WITH THE ONCE-DAILY, ORAL IRON CHELATOR DEFERASIROX IS EFFECTIVE
AND WELL TOLERATED IN β-THALASSAEMIA PATIENTS WITH A HIGH IRON BURDEN
A. Taher, 1 A. El-Beshlawy, 2 A. Al Jefri, 3 M. Elalfy, 4 K. Al Zir, 5 S. Daar, 6
G. Damanhouri, 7 U. Krahn, 8 D. Pfluger, 8 D. Hadler8 1 American University Beirut, BEIRUT, Lebanon; 2 Cairo University, CAIRO,
Egypt; 3 King Faisal Specialist Hosp & Res Ctr, RIYADH, Saudi Arabia; 4 Ain
Shams University, CAIRO, Egypt; 5 National Thalassemia Center, DAMAS-
CUS, Syria; 6 Sultan Qaboos University, MUSCAT, Oman; 7 King Abdul Aziz
University Hospital, JEDDAH, Saudi Arabia; 8 Novartis Pharma AG, BASEL,
Switzerland
Background. Although it is well established that transfusional iron
overload leads to progressive organ dysfunction and early death unless
effectively controlled, many patients are currently inadequately treated
due to poor compliance with deferoxamine infusions. The 1-year ESCA-
LATOR trial evaluated deferasirox in heavily iron-overloaded β-thalassaemia
patients, all of whom had previously received deferoxamine or
deferiprone. Aims. To evaluate the efficacy and safety of, and compliance
with, deferasirox in patients with high iron burden and history of inadequate
chelation. Methods. Entry criteria included contraindications/
unsatisfactory therapeutic response to, or unacceptable toxicity/noncompliance
with, previous chelation therapy. All patients had baseline
liver iron concentration (LIC) ≥2 mg/g dw, serum ferritin (SF) levels ≥500
ng/mL, and initially received deferasirox 20 mg/kg/day: based on results
from another study the protocol was amended mid-study to allow dose
adjustment according to monthly SF trends. LIC was measured at baseline
and end-of-study (EOS). Primary endpoint was treatment success,
defined as LIC reduction ≥3 if baseline LIC ≥10, or final LIC of 1-7 if
baseline LIC 2'7 (therapeutic
goal, LIC reduction), LIC decrease was 4.0±6.4 (p