Platelet Indices as Useful Indicators of Urinary Tract Infection

Background: The changes of platelet parameters can be a useful index for rapid diagnosis of urinary tract infection (UTI), since platelet changes are routinely determined through complete blood count (CBC) test. The correlation between platelet indices, included number (PLTs), mean platelet volume (MPV) and platelet distribution width (PDW), which are the indicators of production and function of platelets, with UTI was evaluated in this study. Materials and Methods: In this descriptive-analytical study, 97 patients with UTI (patient group) and 117 healthy people (control group). The average age for the patient and the control group was 10.84±6.68 and 11.34±7.1 years old, respectively. This study was done during 2016-2018 in Imam Reza Hospital, Kermanshah, west of Iran. The PLT, MPV, PDW, and other inflammatory indices, including white blood cell, neutrophils, lymphocytes, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were evaluated. The diagnosis of bacteria was done using routine microbiological and biochemical methods. The platelet indices were statistically compared between the patients and the control groups (T test and Chi square test). Results: The most common isolated gram negative and gram positive bacteria were E. coli, Citrobacter, and Staphylococcus aureus, respectively. In the patient group, PLT number was significantly higher than that in the control group (p=0.0007), while difference of other indices such as MPV, PDW, neutrophils, lymphocytes, CRP, and ESR were not statistically significant between the two groups. In case of UTI with gram positive bacteria, PLT number (p=0.05) was lower but MPV (p=0.02) and PDW (p=0.045) was higher compared to the UTI with gram negative bacteria. Conclusion: The results of this study showed that the platelet number could be a useful diagnostic index for urinary tract infection. However, more studies need to be done with higher number of patients to evaluate the more details of platelet changes during UTIs.