Characteristics and factors affecting infection-related morbidity in relapsed acute lymphoblastic leukemia among pediatric patients

Background: Acute lymphoblastic leukemia (ALL) is the most common cancer in children and adolescents. Despite dramatic changes in its treatment, relapse remains a challenge. Children with relapsed ALL are at increased risk of infections, which remain a prominent cause of morbidity in those children receiving intensive chemotherapy. We aimed to assess the frequency and the clinicopathological features of infectious complications other than death and to detect the predictive factors affecting the infectious episodes’ outcome among the relapsed ALL cohort. Patients and methods: An institutional-based retrospective study included all non-lethal infectious episodes experienced by patients younger than 18 during their first ALL relapse treatment at the National Cancer Institute, Cairo University, Egypt, from January 1, 2012, to December 31, 2020. Results: The study included 67 relapsed ALL patients with 133 infectious episodes; 32.3% of episodes had an unfavorable outcome (43/133). During the re-induction phase, respiratory and digestive systems foci were associated with unfavorable outcomes with P-values equal to 0.049 and 0.03, respectively. In the univariate analysis, the presence of a focus of infection (chest/soft tissue) and positive blood cultures are predictors of poor outcome, while in the multivariate analysis, the strongest predictors of unfavorable outcome were the re-induction phase (OR: 4.746, P-value = 0.001), duration of neutropenia more than 18 days (OR: 2.629, P-value = 0.024), and gram-negative multi-drug-resistant (MDR) bacteria (OR: 5.204, P-value = 0.020). Conclusion: Screening for a focus of infection is essential. Prevention with early detection of gram-negative MDR infection is a must to avoid complications.