Diagnostic value of mean platelet volume (MPV) in differentiating pyelonephritis from acute cystitis in children with urinary tract infection

Diagnostic value of mean platelet volume (MPV) in differentiating pyelonephritis from acute cystitis in children with urinary tract infection Abstract Background and aims: Urinary tract infections (UTIs) are among the most common bacterial and frequently recurring infection during childhood particularly in the first 3 months of earlier life that can be involved upper UTI (pyelonephritis) and lower UTI (cystitis). Approximately 10-30% of children experience a urinary tract infection in the early years of life. The prevalence of UTI in some developing countries was reported 36.8%. Enterobacteriaceae groups of bacteria have been detected as the most common organism cause of UTI and are related to 85 percent of all cases of UTI. Among different strains, Escherichia coli has been known as more than half of UTI and corresponding of the most frequently infection in young children. Three main criteria and important diagnostic of UTI are included: fever, Pyuria, growth of the organism more than 100000 colonies in culture. Moreover, antibiotic resistance has become an important and concerning problem among pediatric patients with UTI in all the world. In other hand, urinary reflux and scar caused by it in kidney tissue, failure in kidney growth and function, chronic renal failure and finally dialysis and graft kidney in children are issues that need to notice and earlier diagnosis of it is so important. DMSA scanning is a gold standard to determine of Renal parenchymal involvement. DMSA scanning has a high cost to diagnose and also, it is not available in clinical centers and children expose to dangerous radioactive. Although clinical symptoms including fever, abdominal pain, backache, nausea, Anorexia and inflammatory markers including WBC, ESR and CRP can be detected the location of UTI but these symptoms are not reliable. So, a practical approach, fast and safe is require to determine of differentiate between pyelonephritis and cystitis.  Separation and diagnostic of pyelonephritis from cystitis based on the clinical manifestation in young children and infants may be difficult and pyelonephritis may be cause to kidney scar and the next stage high blood pressure and renal failure. For therapeutic approach to pyelonephritis is demanded to prolong consumption of antibiotics in comparison to cystitis and consequently, the differentiate of pyelonephritis from cystitis may be beneficial in diagnosis. The recent studies have shown, Platelets play important role in Inflammatory response and the mean platelet volume (MPV) because of easy and being available is an important index in detection of inflammatory. The aim of this study was to investigate the value of MPV in differentiation of pyelonephritis from cystitis in children with UTI. Materials and methods: In this Analytical Cross- sectional and diagnostic study was approved by the Ethics Committee of Babol University of Medical Sciences, Babol, Iran, with the ethics code IR. MUBABOL1724132572. A total of 141 children (1 month to 18 years) with urinary tract infections hospitalized in pediatric Hospital of Amirkola, Babol enrolled from 2015 to 2020. The eligibility criteria is including positive urine culture and exclusion criteria including pediatric patient without positive urine culture and symptoms with Uncertainty of cystitis and pyelonephritis, Non-cooperation of the patient, taking medicine that effects on the size and number of platelet and blood history of Bernard-Soulier syndrome, gene mutation myh9, ITP). MPV was investigated and compared between patients with pyelonephritis and cystitis. Diagnostic value of MPV by statistical indicators specificity, sensitivity and AUC were calculated and finally Statistical analysis of data was carried out using the SPSS (v 16.0) software package. For quantitative data, mean ± standard deviation is approved while for qualitative data, absolute and relative frequency are considered. The statistical tests were used for comparison including: chi-square test, independent sample t-test, Mann- Whitney,  Spearman's rank correlation coefficient, ROC (Receiver Operating Characteristics Curve) and Kolmogorov–Smirnov test. A P- value of less than 0/05 was assumed as statistically significant. The amount of MPV difference in all patients with acute cystitis and pyelonephritis was analyzed by independent sample t-test. Correlation was used for investigating of relation between MPV with ESR, CRP and leukocyte among two groups of cystitis and pyelonephritis. And also, ROC analysis was used for investigating, comparison and characteristics and the level of under the MPV curve in children with cystitis and pyelonephritis. Results: Among 141 patients with UTI, 63.8% with pyelonephritis and 36.2% with cystitis enrolled in this study. MPV in patients with reflux was detected 8.67± 0.95 fl and in patients without reflux was detected 8.66± 0.99 fl. This finding was no statistically significant difference between MPV and reflux (P= 0.96). Escherichia coli was detected the most common pathogen in both groups of pyelonephritis and cystitis. There was no significant relationship between MPV and the type of organism (P= 0.373). The result of laboratory variables investigation in both groups of pyelonephritis and cystitis were detected 8.7 fl and 8.5 fl respectively. There was no statistically significant difference between two groups (P= 0.329). MPV comparison results between two groups (pyelonephritis and cystitis) showed there was no Statistically significant difference between two groups. There was no statistically significant correlation between MPV and CRP, ESR and leucocyte too. Conclusion: According to the result of our study, the role of MPV in differentiates of pyelonephritis from acute cystitis was detected. The evidence of this study showed MPV has Low diagnostic value in differentiate of pyelonephritis from acute cystitis in children with UTI. So, applying of MPV is not recommended and it needs to more studies for this aim. Also, because of the lowest sensitivity and specificity of MPV in differentiate of upper and lower UTI and inn other hand, there is no relationship with ESR, CRP and leucocyte, using of MPV is not a logical implement for separate of pyelonephritis and cystitis. So, more studies and investigates on other criteria for finding of Para-clinical finding are so important in diagnostic.