Acute promyelocytic leukemia (APL), an AML subtype, is characterized morphologically by abnormal promyelocytes. Molecular studies show three possible bcr isoforms of PML- RARα fusion gene . This study undertakes analysis of PML-RARα bcr isoforms and their correlation with hematological parameters and response to treatment in Indian patients.
To study different bcr isoforms in Indian patients and to find any correlation with various hematological parameters and response to treatment
Settings and Design:
Patients diagnosed as APL on morphology or flowcytometry and confirmed by RQ PCR were included in the study. Treated APL patients or patients with relapse and on follow up were excluded from the study.
Methods and Material:
Twenty patients over thirty one months period were included. The clinical, hematological & morphological features were analysed, the latter using routine & special cytochemical stains on blood and bone marrow .
Flow cytometric evaluation using 4-color Beckman Coulter FC 500 and molecular studies using RT PCR FusionQuant® kits for bcr-1, bcr-2 and bcr-3 on the instrument Rotor Gene™ 3000 were performed .
Statistical analysis used:
Student t test was applied to correlate different bcr isoforms with various haematological parameters and response to treatment.
In our study , M:F ratio was 1.5:1 with median age 42 years, Hb - 8.0 g/dl, TLC-7900/μl, and platelet – 35000/ μl and varied clinical presentation. Four patients were microgranular variants and rest hypergranular . MPO and CAE positivity was 100% and 33.33% for NSE. Molecular analysis revealed bcr1 in 42.85% , bcr2 in 14.28% and bcr 3 in 38.09 % patients. No correlation was found between bcr isoforms , different hematological parameters and response to treatment.
Higher incidence of bcr-1 was found in Indian APL patients with no significant correlation between different hematological parameters and response to treatment.