Diagnostic value of Procalcitonin, C-reactive protein-to-lymphocyte ratio (CLR), C-reactive protein and neutrophil-to-lymphocyte ratio (NLR) for predicting patients with Bacteraemia in the intensive care unit

BACKGROUND

To explore the diagnostic value of procalcitonin (PCT), C-reactive protein-to-lymphocyte ratio (CLR), C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio (NLR) for predicting patients with bacteremia in the intensive care unit (ICU).

METHODS

This case-control study included 359 patients with suspected bacteremia were divided into a bacteremia group (n = 152) and a control group (n = 207) from September 2018 to April 2023. Patient data were collected using a laboratory information system (LIS). ROC curves for PCT, CLR, CRP, and NLR in predicting patients with bacteremia.

RESULTS

For PCT, CLR, CRP and NLR to predict patients with bacteremia in the ICU, the AUCs were 0.991(95%CI: 0.974-0.998), 0.960(95%CI: 0.935-0.978), 0.955(95%CI: 0.928-0.974), and 0.898(95%CI:0.862-0.927), respectively; the optimal thresholds were 0.248 ng/mL, 47.52 mg/109, 48.32 mg/L, and 6.51, respectively; the sensitivities were 95.4(95%CI: 90.7-98.1), 88.2(95%CI: 81.9-92.8), 87.5(95%CI: 81.2-92.3), and 86.8(95%CI:80.4-91.8), respectively; and the specificities were 95.7(95%CI: 91.9-98.0), 90.8(95%CI: 86.0-94.4), 90.3(95%CI: 85.5-94.0), and 85.0(95%CI:79.4-89.6), respectively. The sensitivities of PCT, CLR, CRP and NLR for predicting bacteremia due to E. coli infection are as high as over 90%, the specificity of PCT is 100, and the sensitivity of NLR is 100. The sensitivity of CRP for predicting bacteremia due to non-Enterobacer infection is 100.

CONCLUSIONS

Compared with those in the control group, PCT, CLR, CRP and NLR were significantly greater in the bacteremia group. The PCT, CLR, CRP, and NLR can all predict the occurrence of bacteremia. The PCT had the highest sensitivity and specificity in predicting bacteremia in ICU patients.

Can C-Reactive Protein-Lymphocyte Ratio Be Used as a Screening Tool to Confirm the Diagnosis of Periprosthetic Joint Infection?

Background

This study aimed to investigate whether periprosthetic joint infection (PJI) can be predicted by the C-reactive protein-to-lymphocyte ratio (CLR), whether this ratio increases the accuracy of PJI diagnosis, and whether it is more sensitive than other blood values and ratios.

Methods

The patients were divided into two groups: the septic revision (SR) group and the aseptic revision (AR) group. In cases of septic revision, the diagnosis of PJI was made based on the criteria proposed by the European Bone and Joint Infection Society (EBJIS). The groups were compared in terms of age, sex, body mass index, comorbidity, and preoperative laboratory results. The sensitivity, specificity, and diagnostic performance of the values and ratios were analyzed and compared.

Results

The receiver operating characteristic (ROC) analysis for the CLR gave a diagnostic value of 15.52, which provided a sensitivity of 91.1% and a specificity of 64.2% for PJI. The CLR gave lower specificity and higher sensitivity compared to the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values. The ROC analysis showed that the CLR had a similar area under the curve (AUC) with the ESR and CRP (0.808). The CLR had a higher specificity than other ratios (platelet volume ratio, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio) and a higher value of the AUC. In the multivariate analysis, the CLR (hazard ratio, 1.088; 95% confidence interval, 1.063-1.113; p < 0.001) was found to be a significant risk factor. As CLR increased by one unit, the risk of PJI increased by 1.088 times, and it was statistically significant (p < 0.001).

Conclusions

The findings of this study suggest that CLR can serve as a valuable screening tool for diagnosing PJI. CLR demonstrated higher sensitivity in predicting PJI compared to ESR and CRP, and it exhibited greater specificity than other infection markers.

C-Reactive Protein-to-Albumin Ratio (CAR) and C-Reactive Protein-to-Lymphocyte Ratio (CLR) are Valuable Inflammatory Biomarker Combination for the Accurate Prediction of Periprosthetic Joint Infection

Background

Periprosthetic joint infection (PJI) is a catastrophic complication after total joint arthroplasty (TJA). Timely and accurate diagnosis is important for the management of PJI. Currently, many biomarkers are available for the diagnosis of PJI, but which inflammatory biomarker combination has the best diagnostic value has not been reported.

Materials and Methods

We retrospectively analyzed 244 patients who underwent revision knee or hip arthroplasty in our institution. They were divided into two groups: 87 in the PJI group and 157 in the aseptic failure (AF) group. The preoperative C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), CRP-to-albumin ratio (CAR), CRP-to-lymphocyte ratio (CLR), neutrophil-to-albumin ratio (NAR) and platelet-to-albumin ratio (PAR) were determined and compared between the two groups. Receiver operating characteristic curve (ROC) and area under the curve (AUC) were used to assess the diagnostic value of all biomarkers, and the optimal cut-off value, positive predictive value (PPV) and negative predictive value (NPV) were further calculated by the Youden index.

Results

The NLR, PLR, CAR, CLR, NAR and PAR of the PJI group were significantly higher than those of the AF group (P<0.001). According to the ROC and AUC results, the diagnostic value of CAR and CLR was considered excellent with AUCs of 0.931 and 0.935, respectively. The diagnostic value of NAR (0.739) and PAR (0.785) were fair, the diagnostic value of NLR (0.694) was poor, and PLR (0.535) had no diagnostic ability. Subgroup analysis showed no significant differences in combined inflammatory biomarkers between the two groups.

Conclusion

CAR and CLR are valuable combined inflammatory biomarkers for diagnosing PJI, while other markers were of limited value for the diagnosis of PJI.