Clinical value of a semi-quantitative procalcitonin test in the early diagnosis of sepsis

Objective To evaluate the predictive effect of a semi-quantitative procalcitonin (PCT-Q) measurement in the diagnosis of severe sepsis, and the relationship between serum PCT and the severity of sepsis. Methods According to the definition of sepsis defined by ACCP/SCCM Consensus Conference, 121 ICU patients with signs of suggestive sepsis were enrolled in the study. The serum PCT, C-reactive protein (CRP), white blood cell (WBC) count and percentage of neutrophil estimation of each patient were measured, APACHEⅡ score and SOFA score were calculated at the same time. Results According to the results of bacteria study and clinical manifestation, the 121 patients were divided into 2 groups: sepsis group and non-infectious systemic inflammatory response syndrome (SIRS) group. The results showed that APACHEⅡ score and SOFA score were significantly higher in the patients with sepsis than those with non-infectious SIRS (P0.05). The level of PCT was significantly different between the two groups as studied by the statistical method of Pearson chi-square test (χ2=46.736,P=0.000). Receiver operating characteristic curves (ROC curve) were drawn and areas under these curves were calculated. For the assessment of sepsis, at a cutoff level of PCT ≥2 ng/mL, the sensitivity was 80.65%, the specificity was 77.78%, negative predictive value was 92.11%, and an accuracy rate of 78.51%. Serum PCT has a positive relationship with APACHEⅡ score and SOFA score (P0.01). Conclusions Compared to conventional CRP and WBC, PCT could be a better marker for assessing sepsis of critically ill patients, and also for assessing the response to medication.