Invasive Fungal Infection in Patients With Initial Treatment of Pediatric Acute Lymphoblastic Leukemia: A Single-Center Study in Japan

The prognosis for pediatric hematological malignancies has improved greatly, but infectious diseases, especially invasive fungal infection (IFI), are an important complication that may make it difficult to continue treatment. In this study, IFIs in the treatment of the initial diagnosis of acute lymphoblastic leukemia (ALL), excluding relapse and transplantation, were investigated retrospectively. The patients were 152 first-diagnosed ALL cases (85 males and 67 females) admitted to our hospital between April 2007 and December 2024. The median age of these patients was 6.8 years. The median leukocyte count was 10.2×10 9 /L and the cell surface markers of the blasts were B precursor in 124 cases, T in 20 cases, mature B in 3 cases, and mixed lineage in 5 cases. The diagnosis of IFI was based on EORTC/MSG diagnostic criteria. Sixteen of the 152 patients (10.5%) were found to have IFIs; one was “proven,” 7 were “probable,” and 8 were “possible.” The median time of IFI onset from the start of ALL treatment was 41 days (−7 to 258 d), with 56.3% of cases occurring at first onset of ALL or during induction therapy. Although 4 of 16 patients with IFIs died, IFI was the direct cause of death in 2 cases. Age 7.5 years or older was the only risk factor for IFI.