A lipid–immune network signature defines susceptibility to asparaginase-associated pancreatitis

BACKGROUND: Asparaginase is essential for curing acute lymphoblastic leukemia (ALL), but its use is limited by asparaginase-associated pancreatitis (AAP), a severe and unpredictable toxicity lacking validated prospective biomarkers. We sought to define early systemic molecular features of susceptibility to AAP. METHODS: We performed longitudinal lipidomic and proteomic profiling in two independent pediatric ALL cohorts (n = 161; 79 AAP cases, 82 controls) using paired blood samples collected before asparaginase exposure and at the end of induction therapy (including a single dose of asparaginase), thereby capturing pre-injury biology rather than consequences of pancreatitis. We applied differential abundance and network-based analyses, and integrated lipid-cytokine associations using proteomics. RESULTS: Across cohorts, we identified a reproducible lysophosphatidylcholine (LPC)-centered signature characterized by attenuated induction therapy-associated LPC responses and disruption of LPC co-regulation at the network level. Proteomic profiling revealed enrichment of cytokine signaling pathways, and integrative analyses demonstrated altered lipid-cytokine coupling, including a flip in association direction for LPC species and interleukin-18 (IL-18) between cases and controls. Although IL-18/LPC ratios do not differ globally, elevated post-induction IL-18/LPC ratios identify AAP risk within a protocol-defined very high-risk ALL subgroup (AUC = 0.81). CONCLUSION: These findings support a systems-level model in which failure of coordinated lipid-immune responses under therapeutic stress confers vulnerability to AAP, providing a framework for validation and mitigation strategies. TRIAL REGISTRATION: NCT00400946; NCT01574274; NCT03020030 (parent trials). FUNDING: Servier Pharmaceuticals (IIT-95014-027-USA); SDRC (P30DK116074); Stanford SPARK; Fonds de Recherche du Québec - Santé; Fondation Charles-Bruneau; The Leukemia & Lymphoma Society of Canada.