Abstract: Objective This study aims to investigate the impact of albumin level on the incidence of severe infections and the long prognosis in childhood acute lymphoblastic leukemia (ALL). Method A retrospective analysis was conducted on 202 ALL patients diagnosed and treated at the Anhui Provincial Children's Hospital from January 2018 to October 2021. Baseline data, changes in body composition and albumin levels during chemotherapy, the occurrence of infections, and overall survival (OS) were collected. SPSS 26.0 software was used for the analysis of the related factors, with P<0.05 considered statistically significant. Results Out of the 202 children, 51 cases (25.24%) developed severe infections. Multivariate analysis indicated that the albumin level on the 15th day (D15) and WBC ≥50×10⁹/L at the time of diagnosis were independent risk factor for severe infection (P<0.05). Albumin levels on D15, in combination with other factors, predicted a high probability of developing severe infections, 55.55% of the death cases died of severe infection in the first induction period,failure to achieve negative results for minimal residual disease (MRD) on day 33 were independent risk factors affecting the overall survival(P<0.05). Conclusion Children with acute lymphoblastic leukemia are susceptible to severe infections during the initial induction period, and the decrease of albumin on day 15 is a risk and predictive factor for severe infections, which is an important cause of early chemotherapy-related death. and the MRD on day33 remain positive affecting the OS. Clinical practice should focus on enhanced support, particularly albumin supplementation, to achieve better treatment outcomes.

Key words: Acute Lymphoblastic Leukemia, Pediatric patient, Severe Infections, Albumin, Overall Survival Rate