Effect of phosphoinositide-phospholipase c beta1 monoallelic deletion in low-risk MDS patients treated with darbepoetin.

Abstract

6609 Background: Myelodysplastic syndromes (MDS) are a heterogeneous group of hematologic diseases with a variable risk of evolution into acute myeloid leukemia, moreover recent results proved that phosphoinositide- phospholipase (PI-PLC) C beta1 monoallelic deletion is associated with a higher risk of AML evolution. We examined the treatment outcome of low-risk MDS pts with beta1 monoallelic deletion treated with EPO. Methods: Before treatment, by FISH analysis we assessed the presence of PI-PLCbeta1monoallelic deletion in thirty low-risk MDS pts (16 male 14 female median age 65 years) who received EPO (darbepoetin 40,000 every 2 weeks). Results: The PI-PLCbeta1 mono-allelic deletion was found in 9/30 low risk MDS pts; four of them showed a rapid evolution into AML, whilst the remaining five pts did not respond to EPO treatment. Conclusions: The PI-PLCbeta1 mono-allelic deletion is associated with a worse clinical outcome even in low-risk MDS patients who apparently have a good response profile for EPO (recent diagnosis, absence of transfusion dependence, EPO levels < 500). No significant financial relationships to disclose.