Impact of Simultaneous Presence of Multiple PML-RARA Isoforms on Phenotype in Patients with Acute Promyelocytic Leukaemia.

Abstract

To determine the coexistence of multiple PML-RARA transcripts in adult APL (acute promyelotic leukaemia) patients, and its impact on the patients' laboratory parameters, treatment responses, and prognoses. Cross-sectional study. Place and Duration of the Study: Department of Medical Genetics, Medical Faculty of Necmettin Erbakan University, Konya, Turkiye, from January 2015 to March 2023. The study group consisted of individuals diagnosed with APL. RNA isolation was performed by taking blood or bone marrow samples and the presence of breakpoints in PML-RARA bcr1, bcr2, and bcr3 was detected using the real-time PCR. However, the quantification of PML-RARA fusion transcripts cannot be provided using the utilised kit. Twelve women and eight men were examined with a mean age of 38 years (range: 19-80), and 46.5 years (range: 22-60) were examined, respectively. When evaluating patients based on isoforms, it was found that 40% had multiple isoforms. Nineteen (95%) patients achieved haematologic remission after the treatment. Only one patient who had three different isoforms did not achieve remission. The estimated median survival for patients with a single isoform and those with multiple isoforms was 78.1 months (95% CI: 37.8-117.6) and 71.7 months (46.2-97.2), respectively. Two of the patients with multiple isoforms were lost in the early stage, whereas no early-stage mortality was recorded among patients with a single isoform. Identifying PML-RARA isoform subtypes is important for predicting prognosis and informing clinical follow-up. Acute promyelocytic leukaemia, Breakpoint cluster region, Isoform, PML-RARA.