Comparison of neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, and C-reactive protein in predicting osteomyelitis in patients with diabetic foot ulcer

Introduction

Neutrophil/lymphocyte ratio (NLR) and platelet/ lymphocyte ratio (PLR) are readily available and inexpensive biomarkers that have received great attention for diagnosing type 2 diabetes(T2DM) complications. The objective of the present cross-sectional study was to compare diagnostic values of these biomarkers with C-reactive protein(CRP) in detecting diabetic foot ulcer (DFU) and osteomyelitis (OS) and discriminating between the degree of DFU according to Wagner's classification.

Methods

A total of 217 individuals (42 healthy controls, 40 T2DM patients without DFU, and 135 patients with DFU) were enrolled. The DFU patients were classified according to Wagner's classification into grade 1, grade 2, and grade 3. Blood samples were obtained and various biochemical and hematological parameters including creatine, CRP, HbA1c, NLR, and PLR were measured.

Results

The levels of CRP, PLR, and NLR were significantly higher in the patients with DFU and OS compared to healthy controls and T2DM patients without DFU. The median values of CRP were correlated with the severity of DFU and increased with DFU grades. The highest values of CRP, NLR, and PLR were observed in the DFU patients with OS which were significantly higher than those of DFU patients with grades 1 and 2 as well as T2DM patients without DFU. The PLR and NLR had no significant performance in diagnosing DFU patients with grades 1 and 2 from the patients without DFU.

Conclusion

NLR and PLR could be useful for diagnosing OS but cannot be used for detecting lower grades of DFU. CRP showed higher performance in detecting OS compared to PLR and NLR.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01327-w.

Significance of Neutrophil to Lymphocyte Ratio (NLR) and Platelet Lymphocyte Ratio (PLR) in Diabetic Foot Ulcer and Potential New Therapeutic Targets

Diabetic foot ulcer (DFU) is a well-known complication of diabetes and a significant burden on the national health systems. The neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio are inexpensive and easily accessible biomarkers that have proved to be useful in several inflammatory, infectious and cardiovascular diseases. We carried out a comprehensive review examining the association of NLR and PLR with the onset and progression of DFU. PLR and NLR were significantly increased in patients with DFU, compared with a control group of T2DM patients without DFU, and correlate well with DFU severity, evaluated by Wagner and IWGDF grading scales. In patients with diabetic foot infections (DFI), elevated NLR and PLR were correlated with osteomyelitis, increased risk of amputation, and septic complications. The significance of the elevated value of these biomarkers in DFU is related to chronic hyperglycemia and low-grade systemic inflammation, atherosclerotic and vascular complications, and also the associated septic factor. Serial, dynamic follow-up can provide useful information in planning and monitoring DFU treatment, as well as in risk stratification of these vulnerable patients. Further randomized studies are needed to set the cut-off values with clinical significance.

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

Basic inflammatory markers have been extensively studied to differentiate between non-infected and infected diabetic foot ulcers (DFUs). Very rarely, basic haematological tests such as white cell count (WCC) and platelet counts were used as performance markers for DFU infection severity. The aim is to investigate these biomarkers in patients with DFU treated exclusively with surgery. In this retrospective comparative study, we included 154 procedures comparing a conservative surgery group (n = 66 for infected DFU) and a minor amputation group (n = 88 for infected DFU with osteomyelitis). Outcomes were set as the preoperative values of: WCC, neutrophils (N), lymphocytes (L), Monocytes (M), Platelets (P), red cell distribution width (RDW) and the ratios N/L, L/M and P/L. Area under curve (AUC) of the receiver operating characteristic (ROC) was calculated based on the diagnosis of minor amputation as a positive result. Cutoff point values with the highest sensitivity and specificity were obtained for each outcome. The highest AUC values were for WCC (0.68), neutrophils (0.68), platelets (0.7) and P/L ratio (0.69) with corresponding cut-off values of 10,650/mm3 , 76%, 234,000/mcL and 265, respectively. The highest sensitivity was for the platelet count (81.5%) while the highest specificity was for L/M (89%) and P/L ratios (87%). Postoperative values showed similar results. Simple routine blood tests could serve as inflammatory performance markers to help predict the severity of infection in patients treated surgically for infected DFU.

Clinical presentation of group B Streptococcus-infected diabetic foot ulcers

OBJECTIVE

Group B Streptococcus (GBS) is a common pathogen in diabetic foot ulcers (DFUs), where it has been found to result in higher rates of soft tissue infection and amputation despite appropriate treatment. In this study, we aim to investigate clinical characteristics and prognosis of GBS DFU infections, especially those with tenosynovial involvement. We hypothesise that GBS-infected DFUs with tenosynovial involvement leads to an increased number of recurrent infections and unexpected returns to the operating room.

METHOD

Data were retrospectively collected from GBS-infected DFU patients surgically treated by an orthopaedic foot and ankle surgeon over a four-year period. Demographics, comorbidities, initial laboratory values and culture results from infected bone samples were recorded. Clinical outcome was assessed by recurrent infection and unplanned reoperation(s) within 3 months following the initial surgery.

RESULTS

In total, 72 patients were treated for GBS-infected DFUs. Intra-operative culture of infected bone identified GBS in 16 patients (22.2%). Significantly more black patients (p=0.017) were afflicted by GBS DFUs. Patients with GBS DFUs had higher initial haemoglobin A1C levels (p=0.019), and those with tenosynovial involvement were likely to require reoperation (p=0.036) and had a greater total number of surgeries (p=0.015) than those without.

CONCLUSION

GBS-infected DFUs are more common in black patients and those with elevated haemoglobin A1Cs. GBS infections with tenosynovial involvement are particularly destructive and require aggressive treatment by surgeons.

The Course of Diabetic Foot Infection in Elderly Patients: Data of Patients From Turkey

With the aging population, it is expected that diabetes and related complications will increase rapidly. The aim of this study was to examine the signs and symptoms of diabetic foot infection in elderly individuals. Patients with diabetic foot infection were grouped as mild, moderate, and severe. Patients aged <65 years and those who did not meet the diagnosis of diabetic foot infection were excluded from the study. Only the first applications of patients who applied to the hospital multiple times with diabetic foot infection diagnosis were evaluated. 314 patients were included in the study. The mean age of the patients was 71.5 (±12). The number of patients aged 75 and over was 125 (39.8%). Of the patients, 25.7% had mild, 61.7% moderate, and 12.4% severe clinical forms. 131 (41.7%) of the patients had osteomyelitis. Amputation was performed in 112 of the patients. Antibiotic treatment was given to 102 patients only. While 89 patients died, a significant correlation was found between all groups between amputation rate and mortality frequency and clinical severity of diabetic foot infection (P < .001). In our study, it was observed that the clinical severity of diabetic foot infection was more severe and the overall mortality rate was higher in geriatric patients. In light of all these data, it can be concluded that an early and comprehensive roadmap should be followed in geriatric patients with diabetic foot infection who have an increased risk of morbidity and mortality.

A New Inflammatory Marker of Clinical and Diagnostic Importance in Diabetic Foot Infection: Systemic Immune-Inflammation Index

Diabetes and associated complications still pose an important public health problem. Osteomyelitis as especially seen in patients with diabetes is associated with increased rates of morbidity and mortality. The present study aimed to investigate the clinical and diagnostic significance of inflammatory markers, including the systemic immune-inflammation index (SII) and erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and procalcitonin (PCT) to differentiate osteomyelitis and cellulitis. The present study included 96 patients with osteomyelitis (Group 1) and 151 patients with cellulitis (Group 2). Inflammatory markers were significantly elevated in Group 1 compared to Group 2 patients (p < 0.05). Furthermore, the correlation coefficients (rho) between SII and ESR, CRP, and PCT were 0.466 (p < 0.001), 0.627 (p < 0.001), and 0.501 (p < 0.001), respectively, as a result of Spearman's Rho analysis. Accordingly, a moderately positive relationship was found between the variables. The area under the curve (AUC) values for SII, ESR, CRP, and PCT in diabetic foot infection patients with osteomyelitis were 0.687, 0.722, 0.692, and 0.641, respectively. As a result of the Likelhood Ratio (LR) test, the cut-off values were 2.182 for SII (sensitivity: 39.8% and specificity: 79.8%), 76.5 mm/h for ESR (sensitivity: 59.1% and specificity: 73.1%), 109.5 mg/mL for CRP (sensitivity: 40.9% and specificity: 79.8%), and 0.44 ng/mL for PCT (sensitivity: 26.1% and specificity: 88.2%). In conclusion, given that the patients with osteomyelitis had much higher ESR, CRP, PCT, and SII levels combined with the fact that SII is a low-cost and easy-to-measure index, suggests that the same may serve as an effective and novel marker alternative to other inflammatory markers for predicting diabetic foot osteomyelitis.

Advanced Wound Diagnostics: Toward Transforming Wound Care into Precision Medicine

Significance: Nonhealing wounds are an ever-growing global pandemic, with mortality rates and management costs exceeding many common cancers. Although our understanding of the molecular and cellular factors driving wound healing continues to grow, standards for diagnosing and evaluating wounds remain largely subjective and experiential, whereas therapeutic strategies fail to consistently achieve closure and clinicians are challenged to deliver individualized care protocols. There is a need to apply precision medicine practices to wound care by developing evidence-based approaches, which are predictive, prescriptive, and personalized. Recent Advances: Recent developments in "advanced" wound diagnostics, namely biomarkers (proteases, acute phase reactants, volatile emissions, and more) and imaging systems (ultrasound, autofluorescence, spectral imaging, and optical coherence tomography), have begun to revolutionize our understanding of the molecular wound landscape and usher in a modern age of therapeutic strategies. Herein, biomarkers and imaging systems with the greatest evidence to support their potential clinical utility are reviewed. Critical Issues: Although many potential biomarkers have been identified and several imaging systems have been or are being developed, more high-quality randomized controlled trials are necessary to elucidate the currently questionable role that these tools are playing in altering healing dynamics or predicting wound closure within the clinical setting. Future Directions: The literature supports the need for the development of effective point-of-care wound assessment tools, such as a platform diagnostic array that is capable of measuring multiple biomarkers at once. These, along with advances in telemedicine, synthetic biology, and "smart" wearables, will pave the way for the transformation of wound care into a precision medicine. Clinical Trial Registration number: NCT03148977.

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

Clinicians frequently monitor serum C-reactive protein (CRP) levels during therapy for diabetic foot infections (DFIs), but evidence supporting this is unclear. Using a database from prospective controlled DFI trials, with fixed duration of antibiotic therapy, we correlated the CRP levels at study enrolment and at end of therapy (EOT). Among 159 DFI episodes, 93 involved the bone and 66 the soft tissues. Overall, treatment cured 122 infections (77%), while 37 episodes (23%) recurred after a median of 53 days. The median CRP in the groups with cure versus failure differed minimally at enrolment (median 67 vs. 81 mg/L) or EOT (7 vs. 10 mg/L). Similarly, there was negligible difference in the percentage of CRP levels that normalized at EOT (39% vs. 35%). In our prospective cohorts, a blunt iterative monitoring of CRP during DFI treatment, without correlation with clinical findings, failed to predict treatment failures.

Neutrophil-lymphocyte ratio as a link between complex pedal ulcers and poor clinical results after infrainguinal surgical revascularization

BACKGROUND

Our aim was to evaluate the influence of preoperative neutrophil-lymphocyte ratio (NLR) on patency and clinical results after infrainguinal surgical revascularization for chronic limb ischemia.

METHODS

Retrospective analysis of 150 infrainguinal autologous bypasses performed to infragenicular popliteal artery or tibial vessels in 140 (93%) patients with chronic limb-threatening ischemia (CLTI) and in 10 (7%) with disabling claudication. NLR was calculated using blood samples obtained 24 hours preoperatively. The cohort was stratified into 2 groups according to interquartile ranges of NLR: "ELEVATED-NLR" (Quartile 4 N.=37) and "LOW-NLR" (Quartile 1-2-3 N.=113). Reperfused ulcers were described using the WIfI classification. Patency, freedom from MALE and amputation-free survival at 24 months were calculated using the Kaplan-Meier method. Univariate comparisons between NLR groups were performed using the Log-Rank test. Statistical differences on univariate analysis were adjusted in a multivariate model (Cox regression).

RESULTS

NLR values were similar between CLTI and claudication. Ischemic ulcers were more frequent, (83.4% vs. 59.3% P<0.01), more severe (W2-3: 37.8% vs. 22.1% P=0.01) and pedal infection was deeper (fI 2-3: 40.5% vs. 18.6% P=0.003) in "ELEVATED-NLR" group. Severe ischemia (I3) was similar between groups. High NLR values were independent predictors of patency loss (HR: 1.77 CI95% [1.01-3.10] P=0.04), MALE (HR: 2.04 CI95% [1.03-4.04] P=0.04) and worse amputation-free survival (HR:2.10 CI95% [1.06-4.14] P=0.03) rates at 24 months.

CONCLUSIONS

High preoperative NLR values are associated with severe and deep infected ulcers and predicts primary patency loss, higher major adverse limb events and worse amputation-free survival rates on long-term follow-up after infrainguinal surgical revascularization.

Predicting diabetic foot ulcer infection using the neutrophil-to-lymphocyte ratio: a prospective study

OBJECTIVE

To investigate whether the neutrophil-to-lymphocyte ratio (NLR) may be used in the early stage risk assessment and follow-up in diabetic foot infection.

METHODS

Over a five-year study, NLR values on admission and day 14 of treatment were matched with their laboratory and clinical data in a cohort study. Patients were followed-up or consulted in several clinics or polyclinics (infectious diseases).

RESULTS

Admission time NLR was higher, in severe cases as indicated by both Wagner and PEDIS infection scores (severe versus mild Wagner score NLR 6.7 versus 4.2; p=0.04; for PEDIS score NLR 6.3 versus 3.6; p=0.03, respectively). In patients who underwent vascular intervention (12.6 versus 4.6; p=0.02); amputation indicated (9.2 versus 4.1; p=0.005) and healed afterwards (6.9 versus 4.3; p<0,001), when matched with others. NLR was also found to be correlated with duration of both IV antibiotic treatment (r=0.374; p=0.005) and hospitalisation (r=0.337; p=0.02). Day 14 NLR was higher in patients who underwent vascular intervention (5.1 versus 2.9; p=0.007) when matched to others.

CONCLUSION

Patients with higher NLR values at admission had more severe diabetic foot infection, higher risk for amputation, need for long-term hospitalisation and aggressive treatment. However, they also have more chance of benefit from treatment.

Erythrocyte Sedimentation Rate and C-Reactive Protein in Acute Inflammation

OBJECTIVES

To assess the diagnostic accuracy of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in acute inflammation.

METHODS

PubMed and Scopus were searched and eligible articles were screened for methodologic quality using the Quality Assessment of the Diagnostic Accuracy Studies-Revised. Meta-analysis with calculation of pooled sensitivity (Se), specificity (Sp), and summary area under the curve (SAUC) was performed.

RESULTS

Twenty-nine studies were eligible. Se and Sp were 0.78 and 0.68 (SAUC = 0.80) for ESR in orthopedic infections and 0.79 and 0.70 (SAUC = 0.81) for CRP. For the diagnosis of other various inflammatory conditions, CRP had a superior diagnostic accuracy, with a Se of 0.86, Sp of 0.67, and SAUC of 0.86 compared with a Se of 0.77, Sp of 0.59, and SAUC of 0.75 for ESR. Heterogeneity among studies was elevated. Combined use of ESR and CRP yielded higher diagnostic accuracy.

CONCLUSIONS

Despite observed heterogeneity among studies, ESR and CRP have a similar diagnostic accuracy in assessment of inflammation, especially in orthopedic conditions.

The significance of neutrophil-lymphocyte ratio, platelet-lymphocyte ratio and lymphocyte-monocyte ratio in predicting peripheral arterial disease, peripheral neuropathy, osteomyelitis and amputation in diabetic foot infection

AIMS

The aim of the study was to evaluate the value of neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and lymphocyte to monocyte ratio (LMR) in predicting peripheral arterial disease, peripheral neuropathy, osteomyelitis and need for amputation in diabetic foot infection (DFI).

METHODS

A total of 280 patients were analyzed retrospectively. The NLR, PLR and LMR were evaluated statistically in DFI.

RESULTS

A total of 280 patients were enrolled in the study. PLR was significantly higher in osteomyelitis and NLR was found higher in peripheral arterial disease in DFI (p = 0.008, p = 0.007). A PLR of >187.3 was calculated as the cut off value with 67.9% sensitivity and 59.1% specificity in predicting osteomyelitis. A NLR of >6.5 was calculated as the cut off with 53.3% sensitivity and 63% specificity in predicting peripheral arterial disease. NLR, PLR and LMR had a predictive value in predicting amputation in DFI (p < 0.001, p < 0.001, p = 0.006). NLR and PLR were higher in patients who required amputation than in patients who required debridement/drainage (p < 0.001, p = 0.002). NLR was significant in determining amputation levels (minor or major) (p = 0.013).

CONCLUSIONS

NLR can predict peripheral arterial disease and elevated PLR can predict osteomyelitis in DFI. NLR, PLR and LMR are predictive of the need for amputation in DFI.