Limb deformity and metaphyseal abnormalities in thalassaemia major

Radiographic and MRI Features of Deferiprone-Related Arthropathy of the Knees in Patients with β-Thalassemia

OBJECTIVE

This study was undertaken to describe the radiographic and MRI appearances of arthropathy of the knees in 14 patients with beta-thalassemia major undergoing chelation therapy with deferiprone (L1).

MATERIALS AND METHODS

All available radiographs and MRI studies of the knees in 14 beta-thalassemia major patients (mean age, 16.3 years; age range, 7-33 years) undergoing chelation therapy with L1 were retrospectively assessed for changes in the synovium, cartilage, and bone. Imaging findings and signs of knee arthropathy were correlated with chelation therapy and average serum ferritin concentration.

RESULTS

Nine (64%) of the 14 patients developed arthralgia of the knees during treatment with L1. Abnormal imaging findings were present in all symptomatic and two asymptomatic patients (12/14, 86%) and included joint effusion, subchondral bone irregularity, and patellar beaks. Additional MRI findings were thickening and enhancement of the synovium; hypointense bands in the synovium; irregularly thickened epiphyseal and articular cartilage overlying subchondral bone defects; and, on T2-weighted sequences, hyperintense articular cartilage lesions. The degree of knee symptoms at the time of imaging did not reflect the severity of cartilage and subchondral bone changes.

CONCLUSION

Radiologic changes can be seen in L1-related arthropathy and should be recognized. MRI of the knees should be considered in symptomatic children and young adults with thalassemia undergoing L1 chelation therapy for iron overload.

Deferoxamine-induced bone dysplasia in the distal femur and patella of pediatric patients and young adults: MR imaging appearance

OBJECTIVE

We investigated the MR imaging appearance of deferoxamine-induced bone dysplasia in the distal femur and patella in patients with thalassemia major.

MATERIALS AND METHODS

Thirty-five patients with homozygous ss-thalassemia major who were undergoing regular transfusions and chelation therapy underwent coronal T1-weighted MR imaging of the femur, including the femoral head and the distal femoral epiphysis. Additional coronal fat-saturated dual-echo and sagittal T1-weighted images of the distal femur and patella were obtained in 11 patients who were suspected of having distal femoral lesions on the basis of the coronal T1-weighted images of the entire femur.

RESULTS

No dysplastic change was detected in the proximal femur on coronal T1-weighted images. In 22 distal femurs of 11 patients, the following abnormalities were detected on MR imaging: blurred physeal-metaphyseal junction (n = 22), distal metaphyseal areas of hyperintensity (n = 21), physeal widening (n = 18), metadiaphyseal lesions (n = 11), epiphyseal lesions (n = 10), and patellar lesions (n = 2). Physeal widening and distal metaphyseal hyperintense areas were all more pronounced peripherally. Of the 21 distal metaphyseal hyperintensities, lateral abnormalities were larger than medial abnormalities in 16. Of the 18 distal femurs in which physeal widening was detected, the lateral widening was more marked than the medial widening in 12. Patients with MR imaging evidence of bone dysplasia have a significantly (p = 0.003) greater height reduction than patients without such evidence of bone dysplasia.

CONCLUSION

Deferoxamine-induced bone dysplasia in the distal femur and patella is represented by a spectrum of morphologic changes in the epiphysis, physis, metaphysis, and metadiaphysis on MR imaging.

Desferrioxamine-induced long bone changes in thalassaemic patients - radiographic features, prevalence and relations with growth

AIM

To study the radiographic findings of desferrioxamine-induced bone dysplasia, its prevalence and relation to growth in thalassaemic patients.

MATERIALS AND METHODS

A cross-sectional study was performed in 35 thalassaemic patients on a hypertransfusion scheme and chelation therapy at a dose not exceeding 50 mg/kg/day. Radiographs of the left hand taken for bone age assessment in consecutive patients over the past 12 months were evaluated for signs of desferrioxamine-induced bone dysplasia. The findings were correlated with data on growth, chelation and body iron content.

RESULTS

Twelve of 35 patients had evidence of desferrioxamine-induced long bone dysplasia. There was no significant difference in the groups with and without radiographic evidence of bone dysplasia with respect to the height percentile at time of initiation of therapy, height percentile at time of radiography, skeletal age delay, age at starting chelation, chelation dose and duration, units of blood transfused, average chelation dose, and serum ferritin levels at time of radiography. Both groups showed a reduced percentile growth with a significantly greater reduction (P = 0.03) in the patients with dysplastic change.

CONCLUSION

Desferrioxamine-induced bone dysplasia is associated with height reduction and can be seen in patients receiving desferrioxamine chelation therapy at doses of less than 50 mg/kg/day. Awareness of the diagnosis is of importance as reduction of the desferrioxamine dose may improve bone growth.

Recombinant human growth hormone treatment in children with thalassemia major

BACKGROUND

To evaluate the growth hormone reserve and the growth hormone response to recombinant human growth hormone (GH) in prepubertal thalassemic children with growth retardation.

METHODS

Twenty thalassemic patients with short stature and delayed bone age were studied. Patients were randomized into GH-treated (n = 10) and non-GH treated (control; n = 10) groups. The GH-treated group received recombinant human (rh)-GH (Genotropin) at the dose of 0.7 IU/kg per week for 12 months.

RESULTS

There was a significant discordance between GH response to pharmacologic stimuli and physiological secretion of GH/GHRH testing. Following the administration of rhGH, growth velocity increased from 2.47 +/- 0.48 cm/year to 6.27 +/- 0.76 cm/year (P = 0.005), whereas there was not a similar change in the non-GH-treated group. The height velocities of the two groups during the 1 year follow-up period were significantly different (6.27 +/- 0.76 vs 3.99 +/- 0.34 cm/year; P = 0.025). There were significant differences between the height velocity improvements and height velocity standard deviation scores of the two groups as well.

CONCLUSION

The present study has demonstrated that rhGH is a safe and efficacious mode of treatment in thalassemic children.

Growth velocity monitoring of the efficacy of different therapeutic protocols in a group of thalassaemic children

Since intensive chelating therapy for thalassaemic children was introduced, growth rates appear to have diminished. To investigate what factors were responsible we compared velocities of growth in length over a period of 1 year between groups distinguished by different strategies of treatment. Forty-two thalassaemic patients, 30 males aged 4-12 years, and 12 females, 4-10 years old, were assigned from their current treatment into subgroups based upon blood ferritin levels, daily dose of desferrioxamine and urinary zinc levels. CONCLUSION The results confirm that a reduction in desferrioxamine results in greater growth. If blood ferritin is low, the change effect may be greater. Secondly, any zinc deficiency should be treated. The changes in treatment convert a growth velocity of -2 to -3 SDS to a velocity of about -1 SDS.