Specificity and sensitivity of procalcitonin and interleukin-6 in cancer patients with bacteremia and positive blood culture

Abstract

Introduction: The utility of procalcitonin to predict bacteremia in cancer patients with fever has been reported, but few data exist on the utility of interleukin 6. This study aimed to establish the specificity and sensitivity of procalcitonin and interleukin in cancer patients with bacteremia and positive blood culture.

Methods: This cross-sectional study, from a prospective source, was carried out at the Hospital de SOLCA, Guayaquil. The study period was from January to December 2015. Patients of legal age and under 65 years of age with a diagnosis of oncological disease with a diagnosis of SIRS, sepsis, or septic shock were included. The variables were the presence of bacteremia, procalcitonin (PCT), interleukin-6 (IL-6), age, sex, and blood culture report. The sample was nonprobabilistic. Descriptive and inferential statistics were used. Two groups were analyzed: the presence and absence of bacteremia, and a diagnostic test for procalcitonin and interleukin-6 was performed in each group.

Results: A total of 169 patients participated, 69 with positive blood cultures (G1) and 100 controls without bacteremia (G2). Procalcitonin was 14.6 in G1 vs 0.54 ng/ml in G2 (P =0.0001). IL-6 was 1479.47 ng/ml in G1 vs 4.37 ng/ml in G2 (P < 0.001). The sensitivity (S) of PCT was 81.2%, the specificity (E) was 79%, and the area under the curve was 0.862. P<0.0001. The S of IL-6 was 98.6%, the E was 95%, and the area under the curve was 0.996 P<0.0001.

Conclusion: Interleukin-6 is a good test as a predictor of bacteremia in cancer patients due to its high specificity value and to establish that if you have bacteremia, it is due to its high specificity.