Iron Load Can Be Severe and Presents Early in DBA Patients Even When Receiving Adequate Chelation Treatment

Abstract 1268

Fifty nine patients with clinical and laboratory features consistent with Diamond Blackfan anaemia attend the DBA clinic at St. Mary's Hospital. The median age is 8.8 years (1.1 – 40.9). Two patients presented in utero (3.3%), 36 patients (61%) in the first twelve weeks of life, 12 patients (20.3%) from 3 to 12 months, 6 patients (10.1%) 1 to 5 years, 2 patients (3.4%) 5 to 10 years and 1 patient (1.6%) later than 18 years of age. Thirty five patients (59.3%) had systemic features [the heart was involved in 17 patients (27.1%)], 7 patients (11.8%) had short stature only and 17 patients (28.8%) no systemic abnormalities.

Twenty nine patients (49.1%) are transfusion dependent, 11 (18.6%) steroid responsive, 7 (11.8%) are in remission, eight (13.5%) have undergone a bone marrow transplant achieving normal haemopoiesis, 3 (5%) have never developed anaemia of sufficient severity to warrant treatment and 3 are deceased (two transfusion dependent patients due to overwhelming sepsis and one following unrelated bone marrow transplantation). Twenty two transfusion dependent patients have initiated chelation treatment: 19 patients (82.5%) are currently taking deferasirox and 3 (13.6%) continuous intravenous desferrioxamine as intensification treatment.

Transfusion dependent patients have had their iron load assessed by a combination of techniques: ferritin, MRI T2*, FerriScan and liver biopsy. Sixteen patients had severe hepatic iron load (LIC > 10 mg/g DW, maximum 38.6 mg/g DW): four before initiation of chelation treatment, 8 following chelation with desferrioxamine and 4 following deferasirox treatment. Seven of the patients had severe hepatic iron load (maximum 29.17 mg/g DW) despite of maintaining the ferritin < 1500 μg/L with adequate chelation treatment following guidelines for thalassaemia. Severe hepatic iron load was seen as early as in the 2^nd year of life (17.3 mg/g DW). In patients with severe hepatic iron load, significant reductions achieved with chelation treatment as measured by liver biopsy or FerriScan were not reflected in an increase in T2* measurement until the treatment was advanced. In addition, FerriScan showed higher LIC values than liver biopsy in keeping with its ability to provide an overall measurement not affected by fibrosis. Three patients had cardiac iron load (T2* < 20 ms) in childhood, including 2 below the age of 6 years. Seven patients required intensification of chelation with continuous intravenous desferrioxamine, which was successful in all but one despite of the use of 50 mg/kg/day. In summary, iron overload is a significant clinical problem in patients with DBA, even when receiving adequate chelation treatment with current guidelines and at a young age. It cannot be recognised by measurement of ferritin only and it requires an algorithm that uses all available techniques in an age appropriate manner from two years of age for its detection and management.