S169 Severity of Thrombocytopenia Appears to Correlate With Risk of Bacteremic Cholangitis: Results From a Single Center Retrospective Study

Introduction: Bacteremic cholangitis (BC) has been associated with increased morbidity and mortality. Thrombocytopenia (TCP) appears to be an independent risk factor for bacteremia. However, its prognostic significance in identifying bacteremia remains underexplored. We sought to characterize the relationship between platelet count and bacteremia among patients hospitalized with acute cholangitis. Methods: We performed a retrospective cohort analysis identifying all adult inpatients diagnosed with acute cholangitis between May 2020 and May 2025 at our medical center. Patients were stratified by the lowest platelet count range during hospitalization: <50, 50–99, 100–149, and ≥150 × 10⁹/L. The primary outcome was the presence of bacteremia, defined by positive blood culture during admission. The absolute risk, risk ratio, odds ratio, absolute risk difference, and number needed to harm for bacteremia across platelet count thresholds were calculated and a CAT test for linear association was performed. Results: Out of 459 patients diagnosed with AC, 181 (39.4%) had TCP (<150) and 278 (60.6%) had normal platelet counts. Bacteremia was diagnosed in 29.8% of patients with TCP compared to 8.6% with normal platelet count (risk ratio 3.46 [95% CI: 2.22–5.38]; odds ratio 4.50 [95% CI: 2.66–7.61]). The comparative analysis of bacteremia risk across platelet thresholds is shown in Figure 1 [Figures presented at ACG annual meeting]. The CAT test confirmed a significant linear association between severity of TCP and increased bacteremia risk (P < 0.00000001). Dose-response analysis demonstrated a marked increase in bacteremia rates with progressive TCP across all thresholds. Conclusion: Limitations of our study include retrospective design and inability to adjust for confounding factors that can be associated with TCP. Despite these limitations, our study appears to suggest a linear correlation between severity of TCP and risk of BC. As blood cultures usually take up to 48 hours to result, down trending platelet counts could be an important prognostic indicator to assess the risk of BC and drive clinical decision-making regarding the timing of intervention, especially as studies having shown that timing of endoscopic retrograde cholangiopancreatography impacts outcomes in BC.