Peripheral blood haematopoietic progenitor cells in patients with beta thalassaemia major receiving desferrioxamine or deferiprone as chelation therapy.

OBJECTIVES

The main adverse effect of deferiprone is the development of neutropenia, which occurs via an unknown mechanism. We aimed to gain insight into the pathogenesis of deferiprone-induced neutropenia by assessing the peripheral blood haematopoietic progenitor cells.

METHODS

Sixteen patients with beta thalassaemia were studied; nine (Group A) were receiving desferrioxamine and seven (Group B) deferiprone. Ten healthy individuals comprised the control group (Group C).

RESULTS

Granulocyte-erythrocyte-monocyte-megakaryocyte colony forming units were significantly more in Groups A and B compared with Group C. Granulocyte-macrophage colony forming units (CFU-GM) were significantly more in Group B compared with Group C. Macrophage colony forming units were significantly less in Group B compared with Group C. Granulocyte colony forming units (CFU-G) were significantly more in Group A compared with Group C. We found a trend in the difference in the number of CFU-G between patients' groups (P = 0.123). Adding serum from patients receiving deferiprone to cultures of controls resulted in a maturation arrest of the granulocytic lineage.

CONCLUSION

Our findings point to a maturation arrest at the level of CFU-GM as a potential mechanism of deferiprone-induced neutropenia.