[Diagnostic PICALM::MLLT10 fusion by transcriptome sequencing in acute myeloid leukemia and its clinical...

A retrospective analysis of clinical data of 8 patients with PICALM::MLLT10 (P/M) fusion gene-positive acute myeloid leukemia (AML) diagnosed by transcriptome sequencing (RNA-seq) at the First Affiliated Hospital of Soochow University from June 2017 to March 2023 was performed. Laboratory findings and treatment status were analyzed, and survival analysis was performed using the Kaplan-Meier method. The 8 patients included 5 males and 3 females, aged 16-35 years, with a median age of 27 years. The platelet count of patients was normal, and 3 patients had mild to moderate anemia. Extramedullary infiltration was present in all patients with clinical manifestations, including 5 patients with mediastinal masses, 2 patients with hepatosplenomegaly, 1 patient with central nervous system leukemia, and 1 patient with cervical lymph node enlargement. Karyotypical analysis revealed 7 patients with an abnormal karyotype, including 6 cases of complex karyotypes. Of these, 4 patients harbored the t(10;11) translocation. The complete remission rate of induction chemotherapy in the patients was 7/8, and 2 patients experienced early recurrence. All patients subsequently underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), The follow-up period ranged from 86 to 812 days, with a median of 330 days. Among the 8 patients, 3 survived and 5 died due to recurrence. Relapse and death only occurred in the P/M fusion gene-positive patients after transplantation. The overall survival rate at 1 year after transplantation was 37.5%. P/M⁺AML has the characteristics of young age at onset, normal platelet count, high incidence of extramedullary infiltration, and high proportion of complex karyotype. RNA-seq can significantly improve the detection rate of this disease type. Allo-HSCT can partially improve the prognosis of P/M⁺AML, and P/M positivity after transplantation can be a warning sign of recurrence, which is an important factor affecting survival.