Evaluation of platelet indices in children with renal scarring based on diagnostic accuracy criteria and Cohen's kappa.

Background: Renal scarring is a significant complication in recurrent urinary tract infections (UTIs) in children that can lead to hypertension and end-stage renal disease. The present study evaluates whether platelet indices may be predictive of renal scarring.

Methods: Sixty-nine patients aged 1-18 years with recurrent UTIs, whose medical records were reviewed to collect data on the presence of upper/lower UTIs and the results of scintigraphic investigations with 99m-technetium dimercaptosuccinic acid, were included in the study. The platelet, platelet indices (mean platelet volume [MPV]), platelet distribution width, plateletcrit, and C-reactive protein (CRP) values of the patients during UTI episodes were reviewed retrospectively.

Results: Mean platelet volume and CRP values were higher in the renal scarring group than in the non-renal scarring group (P < 0.001 and P = 0.003, respectively). Increases in MPV and CRP values were independent risk factors for renal scarring (OR = 5.781 [1.431-23.347] and OR = 1.922 [1.77-3.141], respectively). The sensitivity, specificity, positive and negative predictive values, and diagnostic odds ratio values of MPV at a cut-off of >8.2 fL for renal scarring discrimination were 62.5%, 88.89%, 75.00%, 81.63%, and 13.33 [1.35-3.83], respectively. The sensitivity, specificity, positive and negative predictive values, and diagnostic odds ratio values of CRP at a cut-off of 1.97 mg/L for renal scarring were 58.33%, 91.11%, 77.78%, 80.39%, and 14.35 [1.36-3.97], respectively.

Conclusion: Both MPV and CRP can be used as predictive markers for renal scarring. While MPV had higher sensitivity, CRP had a higher specificity and diagnostic odds ratio in predicting renal scarring.