AIMing for survival

\(\bf Background:\) Sepsis, a life-threatening condition caused by a dysregulated host response to infection, remains a major cause of mortality worldwide. Identifying reliable biomarkers for prognosis and treatment is urgently needed. This study investigates the role of the Apoptosis Inhibitor of Macrophages (AIM), also known as CD5L, as a potential prognostic biomarker and therapeutic target in sepsis. \(\bf Methods:\) We measured free and total AIM concentrations in 90 septic patients enrolled in SepsisDataNet.NRW cohort (German Clinical Trial Registry No. DRKS00018871; http://www.sepsisdatanet.nrw). Blood samples were collected on days 1, 4, and 8, and AIM levels were quantified using ELISA. Kaplan-Meier analysis and Cox regression were performed to assess the association between AIM levels and 30-day survival. Western blot analysis was performed to detect AIM in human serum IgM and in the IgM-enriched intravenous immunoglobulin IVIG preparation Pentaglobin®. \(\bf Results:\) High total AIM concentrations (>85 ng/ml) were significantly associated with improved 30-day survival on day 1 (HR: 3.131, 95% CI: 1.629-6.019, p = 0.009), 4 (HR: 2.525, 95% CI: 1.198-5.322, p = 0.0042), and day 8 (HR: 2.317, 95% CI: 0.8565-6.266, p = 0.0457). Free AIM showed a significant association with survival only on day 8 (HR: 2.374, 95% CI: 0.8721-6.461, p = 0.0393). \(\bf Conclusion:\) Total AIM concentration is a significant predictor of a 30-day survival in sepsis, supporting its potential use as a prognostic biomarker. Our findings also suggest that AIM may serve as a valuable prognostic biomarker and a potential target for immune-modulating therapies, including IgM-enriched intravenous immunoglobulins (IVIGs).