Granulocyte Transfusions in Pediatric Hemato-Oncology: Neutrophil Response and CRP Kinetics

Background: Granulocyte transfusions (GTXs) are used in neutropenic pediatric hemato-oncology patients with infections unresponsive to antimicrobial therapy, but their clinical benefit remains uncertain. Methods: We retrospectively reviewed all pediatric patients who received GTXs between 2013 and 2023 at a tertiary medical center. We assessed associations between GTX administration, absolute neutrophil count (ANC) increment, and C-reactive protein (CRP) reduction as a surrogate marker of treatment response. Results: Forty-nine patients received 312 GTXs across 56 episodes: 47 for therapeutic use during active infection and nine for secondary prophylaxis. Higher ANC increments were observed after transfusions containing ≥0.6 × 10⁹ neutrophils/kg from same-day collections. ANC rises were transient, typically declining within 24 hours. CRP levels decreased significantly after the first GTX (p = 0.001) and more markedly by the end of treatment (p < 0.001). ANC increment was significantly associated with CRP reduction (p = 0.006). GTX-related adverse events occurred in 3% of transfusions. Infection-related mortality was 17% in the treatment group, while no severe infections occurred in the secondary prophylaxis group. Conclusions: GTXs appear to be a safe adjunctive therapy in high-risk neutropenic children with severe infections. The observed correlation between ANC increment and CRP reduction supports a potential therapeutic effect and warrants further prospective evaluation.