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

To investigate the clinical features and outcomes of infants (<1 year old) with acute lymphoblastic leukemia (IALL).

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.

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)%.

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.