302. Role of Inflammatory Markers in Diagnosing Diabetic Foot Infection: A Meta-Analysis

Abstract

BackgroundDiabetic foot ulcers (DFUs) cause significant morbidity and put great economic burden on patient and healthcare facilities. Infection is the main driving force behind admissions related to DFU. Culture of soft tissue or bone is invaluable in diagnosing infection but is time consuming. Inflammatory markers including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and procalcitonin (PCT) are rapid, simple, and inexpensive laboratory tests that can aid in early diagnosis of diabetic foot infection (DFI) and monitor response to treatment. We did a meta-analysis to compare diagnostic performance of inflammatory markers for detecting DFI.MethodsWe searched PubMed, Embase, and Cochrane databases from their inception to December 2017. This meta-analysis was performed according to PRISMA guidelines. We included studies based on following inclusion criteria: (1) at least one of the biomarkers (ESR, CRP, PCT) was evaluated; (2) both sensitivity and specificity were measured as outcomes; and (3) sufficient data were available to construct 2 × 2 contingency table. We used bivariate random effect regression model to pool the sensitivity and specificity of the targeted biomarkers.ResultsA comprehensive literature search identified a total of 73 studies. Twelve studies met our inclusion criteria. Number of studies reporting data on each individual biomarker was as follows: 11 for ESR, seven for CRP, and five for PCT. Pooled sensitivity and specificity for ESR were calculated to be 0.84 (95% CI 0.76–0.89) and 0.82 (95% CI 0.73–0.89) with area under receiver operating characteristic curve (AUROC) of 0.90 (95% CI 0.87–0.92). Pooled sensitivity and specificity for CRP were found to be 0.64 (95% CI 0.46–0.80) and 0.87 (95% CI 0.75–0.93) with AUROC of 0.85 (95% CI0.82–0.88). Pooled sensitivity and specificity for PCT were 0.74 (95% CI 0.62–0.83) with AUROC of 0.84 (95% CI 0.81–0.87).ConclusionESR could be beneficial in ruling out infection in persons who have low suspicion of disease. For those who have high suspicion of disease, PCT could be helpful in ruling in infection. Clinicians should avoid ordering both ESR and CRP because role of CRP is limited. All inflammatory markers need standardization of threshold levels for detecting infection. Disclosures All authors: No reported disclosures.

Basic haematological tests as inflammatory performance markers of patients treated either by conservative surgery or minor amputation for infected diabetic foot ulcers

“…Many inflammatory markers such as CRP, ESR, procalcitonin and WCC have been extensively investigated as diagnostic markers in the setting of diabetic foot infection. 16 Each of these markers was found to be significantly associated to the severity of infection with different reported thresholds. However, very few studies researched basic haematological blood elements as performance tools for infection severity.…”

“…The current IWGDF guidelines to diagnose osteomyelitis are based on a combination of tests which includes C‐reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin, plain X‐ray, magnetic resonance imaging (MRI), probe‐to‐bone and bone biopsy 4 . Besides the MRI and the golden test of bone biopsy which both have high rates of sensitivity and specificity, the inflammatory markers such as CRP, ESR, procalcitonin and white cell count (WCC) have been extensively studied to differentiate between non‐infected and infected DFU 16 . However, few studies investigated the performance of WCC when differentiating between infected DFU with and without osteomyelitis 17–19 .…”

“…4 Besides the MRI and the golden test of bone biopsy which both have high rates of sensitivity and specificity, the inflammatory markers such as CRP, ESR, procalcitonin and white cell count (WCC) have been extensively studied to differentiate between non-infected and infected DFU. 16 However, few studies investigated the performance of WCC when differentiating between infected DFU with and without osteomyelitis. [17][18][19] Additionally, we are aware of only one study which recorded the variations of the platelet count for patients with IWGDF Grade 2 and 3 wounds.…”

IWGDF/IDSA guidelines on the diagnosis and treatment of diabetes‐related foot infections (IWGDF/IDSA 2023)

“…A highly elevated ESR (≥70 mm/h) has a sensitivity, specificity, and AUC for the diagnosis of DFO of 81%, 80%, and 0.84, respectively. 62 Compared with ESR, CRP levels tend to rise more quickly with infection and fall more quickly with the resolution of infection. Serum values of CRP have consistently been found to be significantly higher in infected than noninfected DFUs and in patients with noninfected DFU than in those with no foot ulcer, with levels increasing significantly with the severity of infection.…”

“…Serum values of CRP have consistently been found to be significantly higher in infected than noninfected DFUs and in patients with noninfected DFU than in those with no foot ulcer, with levels increasing significantly with the severity of infection. 62,63 Compared to WBC and ESR, CRP has shown higher diagnostic accuracy for grade 2 (infected) DFU. 63 Studies of serum PCT levels have also found that levels were significantly higher in infected DFU than noninfected DFU, but there was little correlation between the values and the infection severity.…”