Pilot study of the diagnostic value of CRP:albumin ratio for osteomyelitis in patients with diabetic foot ulcers

Update of biomarkers to diagnose diabetic foot osteomyelitis: A meta-analysis and systematic review

The aim of this study was to evaluate the diagnostic characteristics of biomarker for diabetic foot osteomyelitis (DFO). We searched PubMed, Scopus, Embase and Medline for studies who report serological markers and DFO before December 2022. Studies must include at least one of the following diagnostic parameters for biomarkers: area under the curve, sensitivities, specificities, positive predictive value, negative predictive value. Two authors evaluated quality using the Quality Assessment of Diagnostic Accuracy Studies tool. We included 19 papers. In this systematic review, there were 2854 subjects with 2134 (74.8%) of those patients being included in the meta-analysis. The most common biomarkers were erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and procalcitonin (PCT). A meta-analysis was then performed where data were evaluated with Forrest plots and receiver operating characteristic curves. The pooled sensitivity and specificity were 0.72 and 0.75 for PCT, 0.72 and 0.76 for CRP and 0.70 and 0.77 for ESR. Pooled area under the curves for ESR, CRP and PCT were 0.83, 0.77 and 0.71, respectfully. Average diagnostic odds ratios were 16.1 (range 3.6-55.4), 14.3 (range 2.7-48.7) and 6.7 (range 3.6-10.4) for ESR, CRP and PCT, respectfully. None of the biomarkers we evaluated could be rated as 'outstanding' to diagnose osteomyelitis. Based on the areas under the curve, ESR is an 'excellent' biomarker to detect osteomyelitis, and CRP and PCT are 'acceptable' biomarkers to diagnose osteomyelitis. Diagnostic odds ratios indicate that ESR, CRP and PCT are 'good' or 'very good' tools to identify osteomyelitis.

The impact of inflammatory biomarkers on amputation rates in patients with diabetic foot ulcers

Diabetic Foot Ulcers (DFUs) are a major complication of diabetes, often leading to amputation. Understanding the relationship between haematological inflammatory markers and the incidence of amputation in DFU patients with infectious complications is crucial for improving management and outcomes. This retrospective study, conducted from May 2020 to October 2022, involved 109 patients with DFUs, categorised into amputation (AM) and non-amputation (NAM) groups. Patients were evaluated for various factors, including demographic data, DFU duration, and blood parameters such as haemoglobin A1c (HbA1c), haemoglobin (Hb), albumin (ALB), white blood cell count (WBC), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), C-reactive protein (CRP), platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and lymphocyte-to-monocyte ratio (LMR). Statistical analyses were performed using independent sample t-tests, Mann-Whitney U test and logistic regression. The univariate analysis showed no significant difference in BMI, DM duration or DFU duration between groups. However, significant differences were noted in PCT, Hb, ESR, ALB, HbA1c and WBC levels, and in inflammatory ratios (NLR, PLR and LMR). Multivariate logistic regression identified CRP, NLR and PLR as independent risk factors for amputation. The study highlights CRP, PLR and NLR as key independent risk factors for amputation in patients with DFUs. These easily obtainable markers from routine blood tests can effectively aid in predicting the risk of osteomyelitis and amputation, enhancing clinical decision making and patient care strategies.

The infected diabetic foot: Modulation of traditional biomarkers for osteomyelitis diagnosis in the setting of diabetic foot infection and renal impairment

The objective of this paper was to investigate erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP) in diagnosing pedal osteomyelitis (OM) in patients with and without diabetes, and with and without severe renal impairment (SRI). This was a retrospective cohort study of patients with moderate and severe foot infections. We evaluated three groups: Subjects without diabetes (NDM), subjects with diabetes and without severe renal insufficiency (DM-NSRI), and patients with diabetes and SRI (DM-SRI). SRI was defined as eGFR <30. We evaluated area under the curve (AUC), cutoff point, sensitivity and specificity to characterize the accuracy of ESR and CRP to diagnose OM. A total of 408 patients were included in the analysis. ROC analysis in the NDM group revealed the AUC for ESR was 0.62, with a cutoff value of 46 mm/h (sensitivity, 49.0%; specificity, 76.0%). DM-NSRI subjects showed the AUC for ESR was 0.70 with the cutoff value of 61 mm/h (sensitivity, 68.9%; specificity 61.8%). In DM-SRI, the AUC for ESR was 0.67, with a cutoff value of 119 mm/h (sensitivity, 46.4%; specificity, 82.40%). In the NDM group, the AUC for CRP was 0.55, with a cutoff value of 6.4 mg/dL (sensitivity, 31.3%; specificity, 84.0%). For DM-NSRI, the AUC for CRP was 0.70, with a cutoff value of 8 mg/dL (sensitivity, 49.2%; specificity, 80.6%). In DM-SRI, the AUC for CRP was 0.62, with a cutoff value of 7 mg/dL (sensitivity, 57.1%; specificity, 67.7%). While CRP demonstrated relatively consistent utility, ESR's diagnostic cutoff points diverged significantly. These results highlight the necessity of considering patient-specific factors when interpreting ESR results in the context of OM diagnosis.

Gastrointestinal PCR panel results and antibiotic use in acute gastroenteritis cases: How appropriate are we in our usage?

BACKGROUND

We aimed to determine the pathogens detected by the Gastrointestinal (GI) PCR panel in patients with acute gastroenteritis (AGE), the evaluation of antibiotic use in these patients, and the investigation of the role of laboratory parameters in differentiating viral and bacterial etiologies.

METHODS

The demographic characteristics, GI PCR panel results, laboratory investigations, antibiotic usage, and appropriateness of antibiotic treatment were investigated in AGE patients.

RESULTS

A total of 175 adult patients with AGE and GI PCR panel results were included in the study. The most common pathogens were EPEC (24.6%) and C. difficile (18.3%). Among the 102 patients receiving antibiotic treatment, 34.3% were evaluated as inappropriate antibiotic use. WBC, CRP, procalcitonin, CRP/albumin ratio, and procalcitonin/albumin ratio were found to be significantly higher in cases with bacterial origin.

CONCLUSIONS

The utilization of GI PCR panels in AGE patients has revolutionized the field of diagnostics by providing rapid and accurate identification of pathogens. In units without the possibility of GI PCR testing, CRP, procalcitonin, CRP/albumin ratio and procalcitonin/albumin ratio may be useful in the decision of antibiotic treatment.

Predictive Value of C-Reactive Protein to Albumin Ratio for Amputation Risk in Diabetic Foot Infection

Diabetic foot infections are one of the complications of diabetes mellitus resulting in extremity amputation and mortality. This study aimed to examine the predictive value of the C-reactive protein (CRP) to albumin ratio (CAR) for amputation risk in diabetic foot infection. Data from 178 patients were retrospectively examined. We found the cut point value of 15.45 according to the receiver operating characteristic (ROC) curve to show the predictive value of CAR for amputation risk in the overall population. We then divided the patients into two groups low (<15.45, n = 96) and high risk (≥15.45, n = 82) according to their CAR value. Matching based on propensity scores produced 64 patients in each group and showed that the amputation rate was high in the high-risk groups (50 vs 25%, P = .003). In the multivariate analysis in the matching group, previous amputation, antibiotic therapy in the last 3 months, and CAR (Odds ratio [OR]: 1.30, 95%Confidence interval [CI]: 1.01-1.45, P < .001) were independent predictors of amputation. These parameters may be useful to predict amputation risk in these patient groups.

The infected diabetes-related foot: Comparison of erythrocyte sedementation rate/albumin and C-reactive protein/albumin ratios with erythrocyte sedimentation rate and C-reactive protein to differentiate bone and soft tissue infections

The objective of this study was to evaluate the effectiveness of C-reactive protein (CRP)/albumin, erythrocyte sedimentation rate (ESR)/albumin ratio, ESR, CRP and albumin to differentiate bone and soft tissue infection in persons with diabetes. We retrospectively evaluated 242 individuals admitted to hospital with diabetes-related foot infections (DFI). We categorised DFI cases as either bone (OM) or soft tissue infection based on bone culture and/or histology. We evaluated the diagnostic accuracy of CRP, ESR, albumin, CRP/albumin and ESR/albumin as biomarkers to diagnose OM in persons with diabetes. The median age was 53 years (74% male). There were 224 diabetes-related patients of which 125 had been diagnosed with osteomyelitis. The ESR/albumin and CRP/albumin ratios cut-points were >17.84 and >1.83, respectively. ESR/albumin and CRP/albumin ratios had similar diagnostic parameters: AUC (0.71, 0.71), sensitivity (70.0%, 57.0%), specificity (62.0%, 75.0%), positive predictive value (67.0%, 71.0%) and negative predictive value (66.0% and 71.0%). In contrast diagnostic efficiency of CRP and ESR were AUC 0.71 and 0.71, sensitivity (45.6%, 71.2%), specificity (85.5%, 60.7%), positive predictive value (70.0%, 65.9%) and negative predictive value (59.5%, 66.4%), respectively. When comparing area under the curves, the results showed that ESR/albumin was not significantly different to ESR alone (Delong test pvs ESR  >0.1). Similarly, CRP/albumin was not significantly different to CRP alone (Delong test pvs CRP  >0.1). In conclusion, ESR/albumin and CRP/albumin ratios provided comparable results as using ESR and CRP alone.