Reza Yekani - Department of Biochemistry and Biophysics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran,Iran.
Melody Omraninava - Assistant Professor, Hospital Administration Research Center ,Sari Branch, Islamic Azad University, Sari, Iran.
Farzam Nasrollahnejad - Department of Medical Sciences, Faculty of Medicine, Sari Branch, Islamic Azad University, Sari, Iran.
Fatemeh Ghasemi Talouki - Department of Medical Sciences, Faculty of Medicine, Sari Branch, Islamic Azad University, Sari, Iran.
Shahriyar Namdar - Assitant Professor, Neurology Department, Faculty of Medicine, Sari Branch, Islamic Azad University, Sari,Iran.

Abstract Introduction: Uncomplicated urinary tract infection (UTI) is a widespread global ailment. The aim of this investigation was to evaluate the diagnostic efficacy of procalcitonin (PCT) in discriminating acute pyelonephritis from other lower urinary tract infections. Methods: This applied research concentrated on patients with acute pyelonephritis who were referred to Hazrat Valiasr Qaemshahr Hospital. A straightforward (random) sampling technique was implemented. Leukocyte count, ESR, serum CRP, and PCT measurements were obtained from all patients. Results: Procalcitonin demonstrated positive results in ۹۸.۵% of pyelonephritis cases and ۵% of cystitis cases, signifying a statistically significant differentiation (P=۰.۰۰۱). The diagnostic accuracy of procalcitonin was ۹۷.۷%, while its sensitivity and specificity were ۹۸.۵% and ۹۵%, respectively. A notable correlation between serum PCT and CRP levels was observed in patients with acute pyelonephritis (P=۰.۰۳۸). The serum level of PCT in patients with acute pyelonephritis did not manifest any statistically significant variances based on age, gender, or history of urinary tract infection (P > ۰.۰۵). Discussion and Conclusion: Based on the findings of this study and comparisons with existing research, it can be deduced that procalcitonin functions as a dependable indicator for distinguishing acute pyelonephritis from other urinary tract infections. Consequently, its utilization for this purpose is recommended. Ultimately, conducting further studies with a larger sample size and in a multicenter manner is advised to validate the findings obtained in this study.

Keywords: Acute pyelonephritis, leukocyte count, erythrocyte sedimentation rate, C-reactive protein, procalcitonin.