Clinical and Laboratory Characteristics of Bloodstream Infections in Children, Adolescents, and Young Adults With Cancer

Background: Bloodstream infection (BSI) is a main complication in patients with cancer, especially in those who develop severe and prolonged neutropenia. It can progress to sepsis, which is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, and to septic shock, characterized by sepsis with persisting hypotension requiring vasopressors; in these cases, hospital mortality can exceed 40%. Aim of the study: The primary aim of this study is to describe the clinical and laboratory characteristics, the isolated pathogens and their antimicrobial resistance of BSIs in patients with cancer treated in our Pediatric Hematology and Oncology Unit. The secondary aim is to assess the role of clinical and laboratory features in the discrimination between gram-positive and gram-negative BSIs and to evaluate the significance of C-reactive protein (CRP) and procalcitonin (PCT) as biomarkers to differentiate among several subtypes of BSI. Materials and methods: A retrospective analysis was conducted on all patients with cancer and a clinically significant BSI diagnosed between January 1, 2018, and December 31, 2022, in our Pediatric Hematology and Oncology Unit. All data were collected from medical records and subsequently analyzed. Results: Ninety-eight clinically relevant BSIs, involving 69 patients, were revealed; the median age was 8.4 years (range 0.3-33.2). Most BSIs (53/98, 54%) were reported in patients with hematologic malignancies. Seventy-two episodes (73.5%) occurred in the presence of severe neutropenia. Fifty-three cases of BSIs (54%) are characterized by signs and symptoms of sepsis. Higher CRP levels measured at 24, 48, and 72 hours since hospitalization and higher PCT levels at admission, 24, and 48 hours were observed in BSIs of patients with signs and symptoms of sepsis. Gram-negative BSIs were associated with signs and symptoms of sepsis more frequently than gram-positive ones (62.5% vs. 40.4%, P -value 0.04). Furthermore, a lower mean platelet count at admission and a higher mean PCT value measured at 24 hours were found in gram-negative BSIs ( P -value 0.03 and 0.0004, respectively). Conclusions: BSI is a major complication in pediatric patients with cancer, especially in those who develop severe neutropenia, and it can lead to life-threatening organ dysfunctions, septic shock, and death. CONS were the most common cause of bacteriemia. Gram-negative bacteria are more likely to be isolated in case of lower platelet counts at admission, higher PCT values at 24 hours, and signs/symptoms of sepsis. Elevated CRP and PCT seem to be useful in detecting patients at increased risk for a more aggressive course and an unfavorable outcome. These parameters could be used for the rapid initiation of the most appropriate empirical antimicrobial treatment.