RT-PCR method with increased sensitivity shows persistence of PML-RARA fusion transcripts in patients in long-term remission of APL

• Published in: Leukemia Vol. 12; no. 9; pp. 1349 - 1354
• Main Authors: TOBAL, K, LIU YIN, J. A
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 01-09-1998; Nature Publishing Group
• Subjects: Amplification; Biological and medical sciences; Fusion protein; Hematology; Humans; Investigative techniques, diagnostic techniques (general aspects); Leukemia, Promyelocytic, Acute - genetics; Medical sciences; Minimal residual disease; Neoplasm Proteins - analysis; Neoplasm Proteins - genetics; Neoplasm, Residual; Oncogene Proteins, Fusion - analysis; Oncogene Proteins, Fusion - genetics; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Patients; Polymerase chain reaction; Polymerase Chain Reaction - methods; Remission; Remission (Medicine); Sensitivity; Sensitivity and Specificity; Time Factors; Chromosomal aberration; RNA-directed DNA polymerase; Genetics; Remission; Diagnosis; Hybrid gene; Biological receptor; Chromosome translocation; Human; Promyelocytic leukemia; Enzyme; Transferases; Acute; Minimal residual disease; Malignant hemopathy; Long term; Polymerase chain reaction; Nucleotidyltransferases; Abnormal chromosome E17; Abnormal chromosome D15; Cytogenetics; Abnormal chromosome; Alpha-Peptide chain; Molecular biology; Retinoic acid
• ISSN: 0887-6924; 1476-5551
• DOI: 10.1038/sj.leu.2401133

RT-PCR methods have been developed, to date, by various groups to amplify the PML-RARA fusion gene produced by the t(15;17) in APL patients. However, these methods lack the necessary sensitivity to detect minimal residual disease (MRD) below the level of 1 leukaemic cell in 10(4) cells. Patients who test positive by these methods after treatment are likely to relapse. However, up to 25% of patients who test negative after treatment relapse within a short period. We have developed a 'hot-start' RT-PCR method for the amplification of PML-RARA with increased sensitivity at the level of two leukaemic cells in 10(6) cells. Using this method we were able to detect MRD in seven out of 15 patients tested in remission. Of the 11 patients in medium to long-term remission, five patients tested positive. None of these 11 patients tested positive with the standard RT-PCR. These results show that some patients in remission of APL continue to express PML-RARA even in long-term remission, when they can be considered clinically 'cured' of their disease.