Evaluation of the relationshi̇p between clinical and laboratory features of childhood urinary tract infections and hematological parameters

Introduction: Urinary tract infections (UTIs) are among the most common infections in childhood. In UTI, which can cause serious complications such as renal scarring, renal parenchymal disease, hypertension and end-stage renal disease, if not treated on time and properly, rapid diagnosis and appropriate initiation of treatment are very important in reducing morbidity. In our study; we aimed to examine the use of some ratios and inflammation markers calculated from complete blood count (CBC) parameters, biochemical and serological tests such as albumin and CRP, which are inexpensive, easily accessible and frequently used tests in the diagnosis of UTI and differentiation of lower and upper urinary tract infections. Material and Method: Our study was planned as a single center and retrospective study in Bezmialem Vakif University Medical Faculty Hospital. Between January 2021 and December 2022, outpatients who came to the Pediatric Emergency Service, Child Health and Diseases Outpatient Clinics of our hospital and inpatients who were hospitalized with the diagnosis of UTI in the Pediatrics Clinic were included in our study. The control group consisted of healthy children who did not have any complaints and who came to the Child Health and Diseases Outpatient Clinics of our hospital for healthy child follow-up. Age, gender, microorganism which was isolated in the urine culture, date of the urine culture; fever, nausea, vomiting, irritability, malodor in urine, dysuria, abdominal pain, flank pain, anorexia, enuresis, hematuria, pollakiuria complaints; renal and bladder ultrasonography, voiding cystourethrogram, dimercaptosuccinic acid scintigraphy were done or not during follow-up, if they were done the results of the imaging findings; the leukocyte count in the urine microscopy, the results of the leukocyte esterase (LE) and nitrite tests in the urinalysis of the patients were recorded. WBC, neutrophil, lymphocyte, monocyte and platelet counts, MPV, PDW, PCT, hemoglobin, RDW values from the complete blood count results; serum C-reactive protein (CRP) and albumin levels from serological and biochemical tests and some ratios and indices calculated from these values which were NLR, LMR, PLR, MPVLR, MPV/PC, Hb/RDW, CAR and SII values of both the patient and the control group were calculated and recorded. In addition, the patient group was divided into two groups as cystitis and acute pyelonephritis groups according to the presence of fever symptom at the time of admission. All parameters were compared between patient-control and cystitis-pyelonephritis groups. Data were analyzed with IBM SPSS 22.0 package program. Student's T Test was used for normally distributed variables in comparison of mean differences of continuous variables between patient and control groups; Mann Whitney U Test was used for those not normally distributed, and Chi-Square Test was used for the distribution of categorical variables between groups. The correlation of continuous variables with each other was analyzed using the Spearman correlation coefficient. Mean, standard deviation, median, Q1 (1st quartile), Q3 (3rd quartile), correlation coefficient (rs), frequency and percentage values were given as descriptive statistics, p<0.05 was considered statistically significant. Results: Our study included 341 children between the ages of 1 month and 16 years. Of these, 207 were in the patient group and 134 in the control group. The female:male ratio in the patient group was 4:1. The mean age of the patient group was 67.4 months, and of the control group was 64.9 months. The most common presenting symptom in the patient group was fever, which was seen in 146 patients. The most common complaints after fever were dysuria and abdominal pain. When the urinalysis findings of the patients were examined, it was found that 87.8% were positive for LE and 51.5% were positive for nitrite. The most frequently isolated microorganism in urine culture was E. coli. Ultrasound was performed in 123 of the patients, 81 of them had normal ultrasound results and 42 had pathological findings. The number of patients who were performed VCUG was 26, VUR was detected in 14 patients. DMSA imaging was performed in 25 patients and renal scarring development was detected in 14 of them. When the laboratory parameters of the patient and control groups were compared, in the patient group WBC (p<0.001), neutrophil (p<0.001), monocyte (p<0.001), PDW (p<0.001), NLR (p<0.001), PLR (p=0.002) , CRP (p<0.001), CAR (p<0.001) and SII (p<0.001) were statistically significantly higher than the control group; lymphocyte (p<0.001), RDW (p<0.001), MPV (p<0.001), PCT (p<0.001), LMR (p<0.001), albumin (p<0.001) and MPV/PC (p= 0.045) were found to be statistically significantly lower than the control group. When the laboratory parameters of cystitis and pyelonephritis cases were compared, neutrophil (p=0.021), NLR (p=0.034) and albumin (p<0.001) in the cystitis group; CRP (p<0.001) and CAR (p<0.001) in the pyelonephritis group were found to be significantly higher. Conclusion: In our study, it was thought that the laboratory parameters compared between the patient and control groups may contribute to the prediction of inflammation and UTI. It was concluded that clear results could not be reached in the differentiation of cystitis and pyelonephritis with the parameters other than CRP, albumin, CAR, neutrophil and NLR among the parameters we studied, and that prospective studies with larger patient groups are needed to differentiate cystitis/pyelonephritis. Keywords: Urinary tract infections, cystitis, acute pyelonephritis, hematological parameters, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, systemic immune-inflammation index, CRP-to-albumin ratio