Multisystem laboratory changes before and after blood purification in acute pancreatitis: a real-world descriptive analysis of 141 cases

Background Acute pancreatitis (AP) is a dynamic, multisystem disorder. Blood purification (BP) is increasingly utilized in severe or hypertriglyceridemia-associated AP, yet the overall patterns and cross-dimensional heterogeneity of post-BP laboratory shifts remain poorly characterized. Objective To map the patterns, magnitudes, cross-system correlations, and patient-level heterogeneity of paired laboratory parameter changes observed before and after BP in AP patients using real-world data, strictly without inferring causal efficacy. Methods This retrospective observational study analyzed 141 consecutive AP patients receiving BP (hemoperfusion, plasma exchange, or combined). Paired laboratory indicators across seven biological domains were compared. An exploratory multisystem laboratory change score (0∼6) was constructed to evaluate directional consistency. Rule-based stratification was applied to examine change patterns alongside change-magnitude ranking and subgroup analyses. Results Most laboratory indicators exhibited post-treatment reductions. The largest relative median decreases occurred in IL-6 (−86.79%), serum amylase (−86.67%), and triglycerides (−86.23%). The mean multisystem change score was 4.24 ± 1.34; concurrent directional shifts occurred across ≥3 domains in 87.94% of patients and ≥4 domains in 70.92%. Exploratory stratification identified subgroups exhibiting greater, intermediate, or smaller multidimensional shifts. Correlation analysis demonstrated strong intra-domain synchrony between renal parameters ( r = 0.726), but weak or non-significant cross-domain correlations. Conclusions Patients with AP showed marked, heterogeneous pre- to post-BP multidimensional laboratory shifts. Lacking a contemporaneous control group, these observational changes cannot be causally attributed to BP and reflect the combined influence of natural disease evolution, fluid resuscitation, and concurrent supportive care.