Received 15 May 2005 Accepted: 20 July Published online: 12 November 2005

Abstract Thirty six patients with acute promyelocytic leukemia were studied by reverse transcriptase – polymerase chain reaction (RT-PCR) and real-time PCR. There was concordance between the results achieved by both the methods except in one case, which was negative by RT-PCR but positive by real-time PCR. The prevalence of bcr3 (short isoform) was found to be significantly higher than that of bcr1 (long isoform) (64 vs. 36%, P=0.03). No correlation was found between age, sex, and white blood cell (WBC) count at diagnosis. Molecular remission was achieved in 66.6% of patients with bcr3 isoform. Median WBC count at presentation was found to be higher than that in the West.

Keywords Acute promyelocytic leukemia – PML/RAR? isoform – Hematological remission – Molecular remission – Reverse transcription – polymerase chain reaction(RT-PCR) – Real-time PCR

Real-time PCR (RotorGene 3000, Corbet Research, Australia) was performed using TaqMan probes, and primers designated for each type of PML-RAR? transcript were synthesized according to Cassinat et al.[?]. (Tibmolbiol, Berlin Germany, provided by Professional Biotech, New Delhi).

Acknowledgements We are grateful to Professional Biotech Pvt Ltd for assistance with real-time PCR studies. We also thankful to Ms. Noor Sabri, Nitin and Ms.Anshu Khattar for technical assistance.