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We evaluated 81 thalassaemia major and 4 thalassaemia intermedia patients (48 M, 37 F), median age 17 years; 62/85 patients were HCV-positive, 3/85 HIV-positive, 19/85 were splenectomized. Forty normal healthy children were recruited as the control group. The number of thrombotic events was studied retrospectively. Platelet poor plasma was filtered and quick-frozen at -70 degrees C until time of assay. APC resistance was measured in an activated thromboplastin time and results were expressed as normalized ratio. All tests were done with diluted 1 in 5 (v/v) factor V deficient plasma and with undiluted plasma. Molecular genetic investigation of factor V gene was performed with polymerase chain reaction, followed by digestion of amplified products with restriction enzyme Mnl I. Data obtained with molecular investigation revealed the presence of 4 heterozygous subjects for factor V Leiden (4.7%). Functional tests were able to detect all heterozygotes for factor V Leiden both with undiluted and with diluted plasma, and there were no false negative subjects. However, undiluted plasma revealed a greater number of false positive subjects (n=15) than did diluted plasma. Therefore, tests done with undiluted and diluted plasma revealed a 100% sensitivity, while specificity was 81% for undiluted plasma and 97% for diluted plasma. Only one thrombotic event was observed in one of the 85 studied patients, as a case of stroke in a thalassaemia intermedia patient with APC resistance. In the same patient an additional thrombogenic risk factor was represented by a pronounced haematocrit increase at the beginning of her transfusion regimen.

It is well known that thalassemic patients exhibit an increased frequency of thrombotic events. Most individuals with resistance to activated protein C (APCR) are the result of a point mutation replacing Arg 506 with Gln in the factor V aminoacidic sequence (factor V Leiden). Recently APCR has been shown to account for up to 50% of cases of thrombophilia. In this report, we describe a 10 year old thalassemic intermedia patient heterozygous for Factor V R506Q who developed a stroke following transfusion. Coagulation laboratory values were all within the normal range and there was no evidence of a lupus anticoagulant. Computerized brain tomography showed an ischemic area in the left temporo-parietal region. At follow-up, plasma from the patient demonstrated APCR and molecular diagnostic testing revealed heterozygosity for factor V R506Q. We suggest that the heterozygosity for factor V Leiden could increase the thrombotic risk in thalassemia intermedia. We believe it may be beneficial to screen all intermedia thalassemic patients for APCR especially before starting a transfusional regimen.

We assessed the iron load content in 36 beta-thalassemia patients by NMR correlating the results with serum ferritin levels. 22 of them were affected by beta-thalassemia major on hyper-transfusional regimen (Group A), 4 by beta-thalassemia intermedia (Group B) and 10 by beta-thalassemia major, who had been previously bone marrow transplanted (Group C). In A and C Groups the liver showed the lowest signal intensity on spin echo images (p less than 0.01; p less than 0.06, respectively). A significant correlation between the summation of signals obtained from all the examined organs and serum ferritin levels was observed by evaluating both all the patients globally (r = 0.78; p less than 0.001) and the A and C Group patients. This correlation was confirmed only in the liver both in all the patients (r = 0.77; p less than 0.001) and in A and C Group patients, when the signals obtained from each organ were evaluated.

Selected hemostatic parameters of 23 children affected by beta-thalassemia major were studied and compared to an age- and sex-matched group. Plasma prekallikrein level was reduced in all patients, splenectomized or not. In splenectomized patients, platelet count and in vitro platelet aggregability were significantly increased and Protein C was slightly increased. The activated partial thromboplastin time was prolonged and the normotest reduced. Finally, a reduction in the plasma levels of fibrinogen and of vitamin K-dependent proteins, including the antithrombotic Protein C, was observed in nonsplenectomized patients. Our data indicate that the hemostatic system in patients with thalassemia major may be altered. The relationship between these laboratory changes and clinical manifestations remains to be established.

The kinetics of 99mTc(Sn) methylene diphosphonate [99mTc(Sn)MDP] were evaluated by means of compartmental analysis in 5 normal children and 17 thalassemic subjects. Blood and urine activity were analyzed with a computer program which generates intercompartmental rate constants by an iterative least-square method providing a best-fit to the input data. The amount of tracer in each compartment (corrected for decay) was determined as a function of time. The transfer rate of 99mTc(Sn)MDP from blood to extracellular fluid and lamellar bone (K1-3) was about 20% higher in thalassemic subjects than in normal children. The transfer rate of 99mTc(Sn)MDP from blood to woven bone (K1-4) was about 57% higher in thalassemic subjects. A faster rate of spread into woven bone appears to be the major cause of higher bone uptake of 99mTc(Sn)MDP in thalassemic subjects, which suggests that in these patients bone tissue reoccupies the space previously replaced by hyperplastic marrow. Moreover, the increased bone extraction rate revealed a correlation between anemia and bone metabolic activity.

Lymphoadenopathic Syndrome (LAS), diagnosed also with histologycal studies, is described in a polytransfused 11-year old boy affected by beta-thalassemia major. After three days of the admission he suffered a serious acute diarrhea by Aeromonas hydrophila, an opportunistic enteric bacteria demonstrated, up to date, in immunocompromised patients and never in AIDS patients. It is important to remark that beta-thalassemic patients are at high risk from HIV infections, either for the chronic need of transfusions and for the impairment of the immunological functions.

A longitudinal study has been conducted on serum ferritin concentrations in children with thalassemia major treated with desferrioxamine (DFO), both intramuscularly and by continuous subcutaneous infusion, in order to evaluate the time interval after which iron chelation becomes effective. In a first group of 19 children, treated intramuscularly with DFO at a dose of 20 mg/kg for 20 days a month, ferritin levels were followed for 739 days and a progressive increase with a significant linear correlation with time was seen. The daily increase was calculated to be 8.53 +/- 1.95 ng/ml. In the second group of 12 children treated with DFO by continuous subcutaneous infusion (greater than or equal to 20 mg/kg/day for 6 days a week), the increase in ferritin was markedly lower, the mean daily value being 4.77 +/- 3.30 ng/ml. Only after the first 360 days of treatment did the serum ferritin decrease, by 1.95 +/- 3.32 ng/ml/day, in spite of a mean daily iron contribution from blood transfusions of 7.09 +/- 2.69 mg/day. These changes in serum ferritin led us to conclude that one can only expect to obtain a decrease in the body's iron overload after more than a year of treatment with subcutaneous DFO.

This report describes a couple at risk for beta-thalassaemia in which one spouse was heterozygous for classical high Hb A2 beta-thalassaemia while the other had the compound heterozygous state for beta+-thalassaemia and a beta-chain variant. This variant comigrates on carboxymethyl-cellulose columns (CMC) with gamma-chains, indicating that globin separation on CMC columns could not have been used for fetal diagnosis. The beta-chain variant migrates separately from the other globin chains on HPLC and the respective abnormal haemoglobin can be separated by isoelectrofocusing. Oligonucleotide hybridization showed that both parents were carriers of the beta+ IVS-1, nt 6 mutation. Prenatal diagnosis was successfully accomplished by oligonucleotide analysis on trophoblast DNA. This case indicates that an Antenatal Service should have alternative methods to CMC columns so as to carry out prenatal diagnosis of beta-thalassaemia in uncommon cases.

We report the results of a longitudinal echocardiographic survey on 15 children with thalassemia major, who had received multiple transfusions. The average interval between the two examinations was 2.9 +/- 0.7 years. At the second examination the mean hemoglobin (Hb) level for the group was higher because of the increased number of transfusions. During the same period of time the chelating treatment with desferrioxamine was administered subcutaneously instead of intramuscularly. The following echocardiographic parameters have been measured: left ventricular dimension, diastolic (LVDd); left ventricular dimension, systolic (LVDs); septal thickness, diastolic (STd); free wall, diastolic (FWd); left atrial dimension (LAD); aortic root (AoR); fractional shortening (FA); velocity of circumferential shortening (VCF). At the first examination 6 patients had abnormal values of LVDd, STd and AoR; 10 subjects had increased LAD; the mean Hb levels of the patients with abnormal STd and LAD was significantly lower than in normals (p less than 0.05 and less than 0.01 respectively). At the second examination 8 patients had abnormal LVDd values and 7 had increased LAD. Only the patients with increased LVDd had lower Hb values. Patients with increased LAD had received more transfusions. The following functional parameters were found to be decreased at the second study: FA (29 +/- 3.3 vs 32.6 +/- 7; p less than 0.05); VCF (1.16 +/- 0.25 vs 0.99 +/- 0.14; p less than 0.05). From the results it appears that the change of treatment improved some parameters (STd, AoR, LAD), but was unable to arrest the deterioration of the LV contractile efficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Thyroid function was investigated by a TRH test in 24 clinically prepubertal children, 3-15 years old with beta-thalassaemia major; in 7 of them the test was repeated once and in 2 twice at intervals of at least 12 months. Basal T4, T3, TBG and TSH levels and the TSH levels during a TRH test were determined and correlated with age and serum ferritin levels. Basal serum T4, T3 and TBG levels were lower and serum TSH levels were higher during the test and in the basal state in thalassaemia major children than in control children. These results show a compensated sub-clinical primary hypothyroidism. The transversal study did not show any significant correlation between the hormonal parameters studied and chronological age or serum ferritin levels. In contrast, the longitudinal study showed a significant correlation between pituitary-thyroidal axis function and siderosis (positive correlations between the variations of TSH levels as delta, peak, 30 and 45 min values and the variations of serum ferritin levels). The thyroid impairment seems not to be correlated with serum ferritin levels in the transversal study because of the presence of an individual different sensitivity of the gland to the iron overload. The ferritin dependence of this impairment is shown only by longitudinal studies where individual differences in sensitivity of the gland are absent.(ABSTRACT TRUNCATED AT 250 WORDS)