Neutrophil Ratio of White Blood Cells as a Prognostic Predictor of Clostridioides difficile Infection

Introduction: A leukocyte count ≥15,000 cells/mL and serum creatinine of >1.5 mg/dL have been reported as two important predictors of severe CDI. However, the association of the differential ratios of blood leukocytes, and the prognosis of Clostridioides difficile infection (CDI) is not clear. Materials and Methods: A clinical study was conducted at medical wards of Tainan Hospital, Ministry of Health and Welfare in southern Taiwan between January 2013 and April 2020. Hospitalized adults (aged ≥20 years) with hospital-onset CDI (ie, symptom onset after at least 48 hours of admission) were included. Results: A total of 235 adults with an average age of 75.7 years and female predominance (51.5%), including 146 (62%) adults with non-severe CDI and 87 (38%) severe CDI, were included for analysis. Patients with severe CDI had a higher crude in-hospital mortality rate than patients with non-severe CDI (35.6% vs 18.5%, P = 0.005). Multivariate analysis revealed no association between a leukocyte count >15,000 cell/mL at the onset of CDI and in-hospital mortality (odds ratio [OR] 1.66, P = 0.21). In contrast, a neutrophil ratio >75% (OR 2.65, P = 0.02), serum creatinine >1.5 mg/L (OR 3.42, P = 0.03), and CDI caused by isolates harboring the tcdC gene (OR 3.54, P = 0.02) were independently associated with in-hospital mortality. Patients with a neutrophil ratio >85%, 80– 85%, or 75–80% of serum leukocytes had a higher mortality rate (34.8%, 30.3%, or 34.4%, respectively) than patients with a neutrophil ratio of 70–75% or ≤75% (12.5% or 13.9%, respectively). Conclusion: Serum creatinine >1.5 mg/L, a high neutrophil ratio of blood leukocytes (>75%), and the causative C. difficile harboring the tcdC gene was independent prognostic predictors in hospitalized adults with CDI.