C-reactive protein and albumin kinetics after antibiotic therapy in community-acquired bloodstream infection

OBJECTIVES: We assessed C-reactive protein (CRP) and plasma albumin (PA) kinetics to evaluate community-acquired bloodstream infection (CA-BSI) patients' 1-year outcomes.

METHODS: Population-based study, with CRP and PA measurements on day 1 (D1) and D4. Relative CRP variations in relation to D1 CRP value were evaluated (CRP-ratio). Patients were classified as fast response, slow response, non-response, and biphasic response.

RESULTS: A total of 935 patients were included. At D4, the CRP-ratio was lower in survivors on D365 in comparison with D4-D30 non-survivors and D30-D365 non-survivors (p < 0.001). In comparison with fast response patients, non-response and biphasic response patients had 2.74 and 5.29 increased risk, respectively, of death in D4-D30 and 2.77 and 3.16 increased risk, respectively, of death in D31-D365. PA levels remained roughly unchanged from D1-D4, but lower D1 PA predicted higher short and long-term mortality (p < 0.001). The discriminative performance of the CRP-ratio and D1 PA to identify patients with poor short and long-term mortality after adjustments was acceptable (AUROC = 0.79).

CONCLUSIONS: Serial CRP measurements at D1 and D4 after CA-BSI is clinically useful to identify patients with poor outcome. Individual patterns of CRP-ratio response with PA at D1 further refine our ability of predicting short or long-term mortality.