Hematological parameters in patients with bloodstream infection: A retrospective observational study

To date, the relationship between the causative pathogens and the changes of hematological parameters was rarely referred and deserves further investigation.

A total of 825 adult patients, including 134 negative blood cultures patients and 691 bloodstream infection (BSI) patients, were screened for eligibility in this study. Receiver operating characteristic curves and binary logistic regression models were used to assess the power of hematological parameters to distinguish patients with BSI caused by different pathogens.

Except for platelet-to-lymphocyte ratio (PLR) and platelet larger cell count (P-LCC), the other hematological parameters investigated in the study were significantly different in patients with BSI caused by different pathogens, including Candida. The specific combinations of lymphocyte count (LYM), platelet count (PLT), neutrophil-to-lymphocyte ratio (NLR), mean platelet volume (MPV), MPV-to-PLT ratio (MPV/PLT), platelet larger cell ratio (P-LCR), and C-reactive protein (CRP) can improve the ability to distinguish various BSI from negative blood cultures. The highest area under the curve of was 0.753 (95% CI 0.709-0.797) for positive blood cultures, 0.715 (95% CI 0.658-0.771) for Gram-positive pathogens BSI, 0.777 (95% CI 0.730-0.824) for Gram-negative pathogens BSI, 0.797 (95% CI 0.747-0.846) for Escherichia coli BSI, 0.943 (95% CI 0.899-0.987) for Enterobacter aerogenes BSI, 0.830 (95% CI 0.740-0.921) for Pseudomonas aeruginosa BSI, and 0.767 (95% CI 0.695-0.839) for Staphylococcus aureus BSI.

The specific combinations of hematological parameters can improve the power to distinguish patients with BSI caused by different pathogens. Attention to these parameters can be easily integrated into daily medical activities, without extra costs.