[Clinical Analysis of Infants with Acute Lymphoblastic Leukemia (18 cases)].

OBJECTIVE:To investigate the clinical features and outcomes of infants (<1 year old) with acute lymphoblastic leukemia (IALL). METHODS:The clinical manifestations, laboratory examination results, treatment and prognosis of 18 infants diagnosed with ALL at our department between January 1, 2014 and August 31, 2022 were retrospectively analyzed. RESULTS:Among the 18 cases of IALL, there were 10 males and 8 females. The median age of patients was 6.5 months old (3 months-11 months old). The median white blood cell count (WBC) was 33.63×109/L ［(3.92-470)×109/L］ at initial diagnosis, including 2 patients with WBC≥300×109/L. Flow cytometric immunophenotyping showed a B-lineage infant ALL in all the 18 patients. Eight of the 18 children had abnormal chromosome karyotype analysis. Fusion gene detection showed 12 KMT2A-rearrangement of 18 patients. 15 patients underwent leukemia related mutation gene screening, among which KRAS, NRAS and FLT3 were the most common mutation genes. 4 patients underwent allogeneic hematopoietic stem cell transplantation and two survived. 14 patients received chemotherapy only and ten survived. The 3-year OS rate was (65.5±11.5)%, while the EFS rate was (46.9±12.3)%. CONCLUSION:B-cell ALL and KMT2A rearrangement are prevalent in IALL. The therapeutic effect of IALL with standard childhood ALL protocal is similer to international infant specific protocal.