Clinical significance of serum procalcitonin, C-reactive protein, interleukin-6 and tumor necrosis factor-alpha levels in the diagnosis of bacterial infectious diseases

Abstract

Objective To explore the clinical significance of serum procalcitonin (PCT), C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) levels in the diagnosis of bacterial infectious diseases. Methods From January 2018 to January 2019, 107 patients with infectious diseases admitted to Weishan Branch of Dongyang People's Hospital were divided into bacterial infection group (61 cases) and non-bacterial infection group (46 cases) according to whether bacterial infection occurred or not.And 50 healthy people from Weishan Branch of Dongyang People's Hospitalwere selected as control group.Peripheral venous blood was collected 24 h after admission, and the serum was separated.The PCT content was determined by dry immunofluorescence method, CRP content was determined by immunoscattering rate method, and IL-6 and TNF-α contents were determined by enzyme-linked immunosorbent assay (ELISA). The serum PCT, CRP, IL-6 and TNF-α levels, the positive rates of PCT, CRP, IL-6 and TNF-α, and the combined diagnostic efficacy of PCT, CRP, IL-6 and TNF-α were compared among the three groups. Results Theserum PCT [(4.73±0.87)ng/L], CRP [(24.31±5.42)mg/L], IL-6 [(15.48±3.24)μg/L] and TNF-α[(19.39±3.24)μg/L] in the bacterial infection group were higher than those in the non-bacterial infection group and the control group which in the non-bacterial infection group were higher than those in the control group, there were statistically significant differences among the three groups (F=19.832, 10.271, 24.352, 29.318, all P<0.05). The positive rates of PCT (95.08%), CRP (93.44%), IL-6 (80.33%) and TNF-α (75.41%) in the bacterial infection group were higher than those in the non-bacterial infection group and the control group, which in the non-bacterial infection group (34.78%, 39.13%, 50.00%, 45.65%) were higher than those in the control group (2.00%, 2.00%, 6.00%, 8.00%), the differences were statistically significant (χ2=16.521, 14.352, 10.298, 7.489, all P<0.05). The sensitivity and specificity of combined diagnosis of PCT, CRP, IL-6 and TNF-α were higher than those of individual indicator. Conclusion Serum PCT, CRP, IL-6 and TNF-α levels are significantly increased in patients with bacterial infectious diseases.The sensitivity and specificity of combined diagnosis are high, which can be used as a basis for the diagnosis of bacterial infectious diseases. Key words: Bacterial infectious diseases; Procalcitonin; C-reactive protein; Interleukin-6; Tumor necrosis factor-alpha; Non-bacterial infectious diseases; Healthy examinees; Diagnosis