Does Everything That’s Counted Count? Value of Inflammatory Markers for Following Therapy and Predicting Outcome in Diabetic Foot Infection

Abstract

To assess the severity of inflammation associated with diabetic foot infection (DFI), values of inflammatory markers such as white blood count (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and neutrophil to lymphocyte ratio (NLR) are often measured and tracked over time. It remains unclear if these markers can aid the clinician in the diagnosis and management of DFI, and ensure more rational use of antibiotics. Hospitalized adult patients (n = 379) with DFI were retrospectively assessed for abnormal inflammatory markers, correlation between values of inflammatory markers, and clinical diagnosis on initial admission and on last follow-up. At admission, WBC, ESR and NLR were each elevated in patients with osteomyelitis and only ESR was significantly elevated in patients with soft tissue infection only. Only WBC was significantly elevated in patients with osteomyelitis compared with uninfected diabetic feet on last follow-up. Considering the predictive performance of these inflammatory markers, they demonstrated excellent positive predictive value at admission, and excellent negative predictive value at the last follow-up visit. Moreover, the number of elevated markers was further associated with probability of infection both at admission and last follow-up.

Is routine measurement of the serum C‐reactive protein level helpful during antibiotic therapy for diabetic foot infection?

“…Third, we conducted only the standard laboratory test for serum CRP. Thus, our findings may not apply to other inflammatory markers, such as pro‐calcitonin, 2,4,5 erythrocyte sedimentation rate, 2,4,6 interleukins 2, 6 or 8, 2,4 serum leukocyte counts, 4 tumour necrosis factors, 2,4 monocyte chemotactic protein, 4 macrophage inflammatory protein‐1 alpha, 4 neutrophil to lymphocyte ratios, 6 procollagen type 1 N propeptides, 2,4 or high‐resolution CRPs. However, these other markers are seldom used in daily clinical practice and all are more expensive than the standard CRP.…”

“…Evidence for the value of monitoring CRP in patients with DFIs remains unclear, especially as the CRP peak almost always lags behind the clinical evolution by ~2 days 1,5 . While some scientific literature supports using the quantitative serum CRP level in diagnosing the presence or severity of a DFI, 1,4–7 infectious diseases experts generally emphasize that no therapeutic decision should depend solely on this laboratory result 8,9 . We undertook this study to provide more information based on the utility of routine serum CRP controlling during DFI therapy.…”

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

“…While their values could well assist in infection evaluation, reports on their efficacy widely vary in the DFU literature. While Michail et al reported significantly higher values in osteomyleitis cases compared to ulcers with soft tissue infection for both parameters,17 Ong et al found no significance 18. Furthermore…”

“…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 . 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.…”

“…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. No study to our knowledge investigated such parameter performance in patients who had a definitive postoperative diagnosis of osteomyelitis.…”