Clinical study on two PML-RARα fusion gene isoforms in patients with acute promyelocytic leukemia

Objective To illustrate the clinical relevance of distinct PML-RARα fusion gene isoforms in acute promyelocytic leukemia (APL). Methods The nested reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the long (L) or short (S) PML-RARα fusion gene isoforms in 92 newly diagnosed APL so as to evaluate the clinical feature, therapeutic reaction and prognosis of the two fusion gene isoforms. Results PML-RARα fusion gene was positive in all 92 APL patients, of which 52(56.5 %) was L type and 40 (43.5 %) was S type. There were no significant differences between L type and S type in the aspect of sex, age, white blood cell count,the percentage of bone marrow blasts plus promyeloeytes and chromosome before treatment. And there were no significant differences between the two isoforms in complete remission (CR) rate, the time of getting CR as well as the occurrence of retinoic acid syndrome (RAS), disseminated intravascular coagulation (DIC), intraeranial hemorrhage. Also, there were no significant differences in overall survival rate (OS) and relapse-free survival rate (RFS) between the two isoforms. Conclusion PML-RARα fusion gene isoforms in APL were not correlated with clinical therapeutic effect or prognosis. Key words: Leukemia, promyelocytic, acute;  PML-RARα fusion gene;  Receptors, retinoic acid