Platelet Indices in Patients With Gram-Negative and Gram-Positive Sepsis: A Retrospective Cross-Sectional Study

Different inflammatory processes and sepsis can significantly affect the number of platelets and platelet indices. Therefore, in this study, total platelet count (PLT), thrombocrit (Pct), platelet distribution width (PDW), mean platelet volume (MPV), and platelet-large cell ratio (P-LCR) were analyzed in patients with Gram-negative and Gram-positive bacterial sepsis and in sterile blood cultures.

Inclusion criteria were an increased number of inflammatory parameters (elevated values ​​of leukocytes, C-reactive protein (CRP), procalcitonin (PCT), and positive blood culture. Exclusion criteria were patients who did not have elevated values ​​of inflammatory parameters and did not have a positive blood culture. Samples were collected from patients who had sepsis confirmed by blood cultures at the Department of Microbiology and Molecular Diagnostics at University Clinical Hospital Mostar in the period from 2019 to 2022. Three groups were analyzed, patients who had sterile blood cultures, patients with blood cultures with isolated Gram-positive bacteria, and patients with blood cultures with isolated Gram-negative bacteria. Specific infectious agents were identified for each group of patients. In addition to the above, PLT, Pct, MPV, PDW, P-LCR, PCT, CRP, the total number of leukocytes, and the number of neutrophil leukocytes were analyzed in each group.

The values of PCT, CRP, and the number of neutrophile leukocytes were significantly higher in patients with Gram-negative sepsis as compared to Gram-positive sepsis and to control group. Patients with sepsis have decreased PLT and Ptc and increased values of MPV, PDW, and P-LCR. In sepsis caused by the Gram-negative bacteria, i.e., Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii, the values of the same parameters were more changed compared to sepsis caused by Gram-positive bacteria, i.e., Streptococcus pneumoniae, Enterococcus spp., and methicillin-resistant Staphylococcus aureus (MRSA). When comparing Gram-negative negative bacteria, PLT was lowest in sepsis caused by Escherichia coli, the PDW value was highest in sepsis caused by Acinetobacter baumannii, and MPV and P-LCR were the highest in sepsis caused by Klebsiella pneumoniae.

Our study showed that platelet indices are significantly changed in patients with sepsis. Patients with sepsis have decreased values of PLT and Pct and increased values of MPV, PDW, and P-LCR, indicating an increase in thrombocyte production. Moreover, the results were more prominent in sepsis caused by Gram-negative bacteria compared to sepsis caused by Gram-positive bacteria.