Inflammatory markers for prediction of acute pyelonephritis

Urinary tract infections can cause acute pyelonephritis by affecting renal parenchym and also can lead to acute cystitis and urethritis by affecting lower urinary tract. Kidney with acute pyelonephritis has a risk of permanent damage and this situation can lead deterioration of renal function, chronic renal failure and hypertension in later times. Distinction of acute pyelonephritis and lower urinary tract infections especially childhood age group is not able to be done exactly either clinical findings or often used diagnostic parameters. In this study, we aimed to determine the availability of inflammatory markers such as leukocyte counts, neutrophil counts, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), blood serum interleukin 6 (IL-6) and interleukin-8 (IL-8) at differential diagnosis of acute pyelonephritis and lower urinary tract infections. Totally 51 patients who are diagnosed as urinary tract infection in urine cultures, are between 3 months and at the age of 16, consult with the complaints of fever to Child Emergency Department and Child Health&Disease Polyclinic of Medical Faculty of Zonguldak Bulent Ecevit University (BEU), are included in this study for this purpose. Before initiation of antibiotic treatment, blood samples was collected for CRP, leukocyte counts, neutrophil counts, ESR, IL-6, IL-8 and PCT levels. The patients who have dimercaptosuccinic acid (DMSA) scintigraphy within the first 7 days, are diagnosed as urinary tract infection, were divided into two groups: According to renal parenchymal involvement, 23 of them were diagnosed as having an acute pyelonephritis, 28 patients were diagnosed as having a lower UTI. Systemic inflammatory markers including neutrophil count (p=0,014), CRP (p<0,001) and ESR (p=0,006) were found significantly higher in children with acute pyelonephritis group than in the lower UTI group. There was no significant difference between IL-6, IL-8 and PCT levels in patients with acute pyelonephritis group or lower UTI group. When cut-off value for the CRP was accepted 10 mg/l, sensitivity was % 100 and specificity was % 60,7. When cut-off value for the erythrocyte sedimentation rate was accepted 20 mm/h, sensitivity was % 86,9 and specificity was % 46,4. When cut-off value for absolute neutrophil count was accepted %70, sensitivity was % 39,1 and specificity was % 78,5. DMSA examination which is regarded as gold standard at acute pyelonephritis diagnosis, is not able to be found in each center, exposes the patients to radiation and is not able to be separated acute parenchymal damage from old skar. Considering these reasons, it was concluded that , neutrophil count, CRP and ESR measurements, which are more readily available and lower cost tests, may be useful inflammatory markers at differential diagnosis of acute pyelonephritis and cystitis. It is thought that CRP can be used at the differential diagnosis of acute pyelonephritis and lower urinary tract infection, due to its high sensitivity and specificity. Nonetheless, prospective studies which were applied more people, are required in order to confirm our results.