The Role of Serum Procalcitonin, Interleukin-6, and Fibrinogen Levels in Differential Diagnosis of Diabetic Foot Ulcer Infection

Abstract

Aims We aimed to evaluate the roles of interleukin-6 (IL-6), PCT, and fibrinogen levels in the differential diagnosis of the patients with infected diabetic foot ulcer (IDFU) and noninfected diabetic foot ulcer (NIDFU) and to compare those with C-reactive protein (CRP), white blood cell (WBC), and erythrocyte sedimentation rate (ESR). Methods Patients over 18 years with a diagnosis of type 2 diabetes mellitus and DFU who were followed up in our hospital between 1 January 2016 and 1 January 2017 were included in the study. In addition to this patient group, patients with diabetes but without DFU were determined as the control group. Results Thirty-eight patients with IDFU, 38 patients with NIDFU, and 43 patients as the control group were included in the study. Fifty-six point three percent of the patients who participated in the study were males, and the mean age was 61.07 ± 11.04 years. WBC, ESR, CRP, IL-6, and fibrinogen levels of the cases with IDFU were determined to be significantly higher compared to the cases in NIDFU (p < 0.01). The area under the ROC curve (AUROC) value was highest for CRP (0.998; p < 0.001), and the best cut-off value for CRP was 28 m/L. The best cut-off values for fibrinogen, IL-6, ESR, and WBC were 480 mg/dL, 105.8 pg/mL, 31 mm/h, and 11.6 (103 μ/L), respectively. Conclusion Serum PCT levels were not found to be effective in the discrimination of IDFU and NIDFU. Serum IL-6 and fibrinogen levels seem to be two promising inflammatory markers in the discrimination of IDFU.

Diagnosis of infection in the foot in diabetes: a systematic review

“…About half of the studies we included investigated the value of the WBC for assessing infection of a DFU, and these generally found no significant correlation between the WBC counts and the infection severity . All but two studies of serum PCT values reported that they were significantly higher in infected than noninfected DFU; in one other study, PCT was found significantly higher in patients with osteomyelitis . No published study has reported a correlation between the level of PCT and the severity of infection according to the IDSA/IWGDF classification.…”

“…Studies have investigated the role of various inflammatory biomarkers measured in blood for diagnosing infection and in distinguishing skin/soft tissue infection from osteomyelitis in diabetic patients with a foot ulcer . Most of the published studies have addressed the value of WBC, ESR, CRP, or PCT by comparing serum levels with the presence of clinical signs of infection . About half of the studies we included investigated the value of the WBC for assessing infection of a DFU, and these generally found no significant correlation between the WBC counts and the infection severity .…”

“…Most of the published studies have addressed the value of WBC, ESR, CRP, or PCT by comparing serum levels with the presence of clinical signs of infection . About half of the studies we included investigated the value of the WBC for assessing infection of a DFU, and these generally found no significant correlation between the WBC counts and the infection severity . All but two studies of serum PCT values reported that they were significantly higher in infected than noninfected DFU; in one other study, PCT was found significantly higher in patients with osteomyelitis .…”

“…References: Huang et al, 46 Gardner et al, 47 Mutluoglu et al, 48 Demetriou et al, 49 papers returned by our search string, only 35 met our criteria for inclusion in this review; these consisted of 28 prospective cohort studies, three meta-analyses, two systematic reviews, and two casecontrol studies. As the IWGDF/IDSA consensus definition and classification of DFIs were not published until 2004, 52,53 and we used these recommendations as a basis for the selection of the papers, we chose not to refer to studies published before this date, except for four 36,38,40,45 13,63 of serum PCT values reported that they were significantly higher in infected than noninfected DFU; in one other study, PCT was found significantly higher in patients with osteomyelitis. 32 No published study has reported a correlation between the level of PCT and the severity of infection according to the IDSA/ IWGDF classification.…”

Guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019 update)

“…Of particular note is the WBC level, as it is used as part of the IDSA/IWGDF criteria for classifying infection as severe/grade 4. The available studies found little correlation with infection severity, with about half of the patients diagnosed with a DFI having a normal WBC . In most studies, ESR values have been higher in patients with an IDFU compared with a noninfected DFU (NIDU) .…”