Serum procalcitonin level as a biomarker for the differential diagnosis between infectious and non-infectious systemic inflammatory response syndrome: a prospective case–control study

Background and Aim: Considering the importance of sepsis and its complications in the mortality of the patients admitted to different parts of hospital and the importance of early diagnosis and timely and appropriate treatment in the patients' survival, we investigated the value of procalcitonin serum level for the differential diagnosis between infectious and non-infectious SIRS in the patients referring to Tohid Hospital in Sanandaj. Material and Methods: In this descriptive analytical (case-control) study, we measured procalcitonin level in SIRS positive patients who had been referring to Tohid Hospital in Sanandaj. After obtaing the results of the lab.tests the patients were divided into two groups of infectious SIRS (case group) and non-infectious (control group) based on the final diagnosis made by our infectious diseases specialist. Patients with&nbsp; history of antibiotic intake within the last 48 hours, mechanical trauma, heat stroke, recent surgery, cancer and severe burn were excluded from the study. Each group consisted of 30 patients. Using SPSS software, data were analyzed by independent T-test to compare the quantitative data between the two groups. We also used Pearson correlation test to investigate the relationship between procalcitonin serum level and variables related to vital signs and blood markers. P<0.05 was considered significant. Results: Mean procalcitonin serum level in the case group was significantly higher than that in the control group, and the patients with higher respiratory rate and higher WBC counts had significant increase in procalcitonin serum level. Results of this study showed that the sensitivity, specificity and accuracy of procalcitonin test at the threshold of 0.52 ng / ml were 70%, 94% and 81.7%, respectively, and positive and negative predictive values were 75.7% and 91.3%, respectively. Conclusion: According to the results, procalcitonin level had a significant sensitivity and specificity in the differential diagnosis between infectious and non-infectious SIRS and can be considered as a diagnostic test along with other clinical and paraclinical criteria in the early stages of these disorders. This can be helpful in making early diagnosis and timely administration of medications. Keywords: Procalcitonin, Systemic inflammatory response syndrome, Sepsis. &nbsp; Received: Feb 17, 2018&nbsp;&nbsp;&nbsp;&nbsp; Accepted: May 22, 2018