Cytogenetic, fluorescent in situ hybridization & reverse transcriptase-polymerase chain reaction analysis in acute promyelocytic leukaemia patients.
OBJECTIVE
The presence of t(15;17) or PML-RAR alpha fusion transcript is the diagnostic hallmark of patients with acute promyelocytic leukaemia (APL). Cytogenetic (CG), fluorescent in situ hybridization (FISH) and reverse transcriptase-polymerase chain reaction (RT-PCR) are mainly the techniques used for detecting this abnormality. The objective of this study was to compare and assess the role of CG, FISH and RT-PCR in the diagnosis of APL.


METHODS
CG, FISH and RT-PCR analysis were performed in 29 patients with APL (28 M3, 1 M3v; 27 studied at diagnosis and 2 at relapse).


RESULTS
Karotypes obtained in 25 patients revealed t(15;17) in 21 normal karyotype in 3 and trisomy 8 in 1 patient. In 26 patients FISH was positive for PML-RAR alpha fusion in both interphase (IP) and metaphase, two were negative and one patient had no cells for FISH analysis. IP FISH confirmed the fusion of PML-RAR alpha in all patients with t(15;17) detected by CG. RT-PCR was positive in the 22 patients analyzed (7 patients did not have RT-PCR). PCR was positive in the 3 patients with cytogenetically normal karyotypes and in one patient when karyotyping was a failure. CG detected 21 (72.4%) patients with t(15;17) of which additional chromosomal abnormalities were detected in 20 per cent of patients with successful karyotype.


CONCLUSIONS
FISH and RT-PCR were useful in detecting PML-RAR alpha fusion in cytogenetically normal patients and those in when karyotyping was a failure and can be used in routine analysis for rapid confirmation of t(15;17) in patients with acute myeloid leukaemia.
Departments of Haematology, Christian Medical College & Hospital, Vellore, India.
S
S
Shivakumar
B
B
Poonkhuzhali
S
S
Gunasekaran
A
A
Srivastava
M
M
Chandy
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002884:Chromosomes, Human, Pair 15; D002886:Chromosomes, Human, Pair 17; D020732:Cytogenetic Analysis; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015473:Leukemia, Promyelocytic, Acute / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014178:Translocation, Genetic
D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; C093476:promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein