RecruitingDiagnostic testiMmune SignAtures and Clinical outComes in APThe MoSAIC study is a prospective, observational study designed to develop an early prediction tool for severe acute pancreatitis (SAP) and define a distinct immunologic profile compared to moderate acute pancreatitis (MAP). The aims are to validate a new multi-cytokine panel for early prediction of SAP and to identify the specific immune cells that correspond with cytokine signatures in early acute pancreatitis to characterize the immune pathways driving the development of SAP. Participants will provide blood samples and complete patient surveys and interviews within 36 hours of hospital presentation, at 48 hours, and hospital day 7 (if admitted). Data on hospital stay, medical history, clinical course, and severity of disease will be collected.