Albumin to Globulin ratio, Neutrophil to Lymphocyte ratio, and Globulin levels do not outperform ESR or CRP when diagnosing periprosthetic joint infection.

To evaluate the relative performance of clinical readouts including serum C-reactive protein (CRP) levels, the erythrocyte sedimentation rate (ESR), globulin (GLB) levels, the albumin to GLB ratio (A/G), and the neutrophil to lymphocyte ratio (NLR) when diagnosing periprosthetic joint infection (PJI). Clinical data was collected from 115 individuals diagnosed in our department between January 2017 and December 2020 with either chronic PJI (29 female, 24 male; median age 71.00 years [range, 41-94 years]) or aseptic loosening (30 female, 32 male; median age 68.50 years [range, 34-85 years]). Patient demographic data were compared, and the relative sensitivity and specificity of preoperative GLB, ESR, CRP, NLR, and A/G values as predictors of PJI diagnosis were assessed. Median globulin levels in the PJI and aseptic groups were 31.700 g/L (interquartile range [IQR], 28.400-35.300) and 26.600 g/L (IQR, 24.375-30.550), respectively (p < 0.001). The median A/G values in the PJI and aseptic groups were 1.150 (IQR, 0.960-1.255) and 1.510 (IQR, 1.265-1.670), respectively (p < 0.001). The median NLR values in the PJI and aseptic groups were 2.510 (IQR, 1.900-3.335) and 1.850 (IQR, 1.425 to 2.362), respectively (p < 0.001). The median ESR values in the PJI and aseptic groups were 53.000 mm/h (IQR, 35.000-76.500) and 16.000 mm/h (IQR, 7.000-33.000), respectively (p < 0.001). Median CRP levels in the PJI and aseptic groups were 24.890 mg/L (IQR, 10.595-54.095) and 2.245 mg/L (IQR, 0.865-8.6075), respectively (p < 0.001). Area under the receiver operating characteristic (ROC) curve (AUC) values for CRP, ESR, GLB, A/G, and NLR were 0.841 (95% confidence interval, 0.761-0.903), 0.850 (0.771-0.910), 0.747 (0.658-0.824), 0.779 (0.692-0.851), and 0.708 (0.616-0.789), respectively. When GLB > 26.6 g/L, A/G < 1.32, and NLR > 2.1 were utilized as threshold values to diagnose PJI, GLB and A/G were found to exhibit superior sensitivity (90.57%, 81.13%) to that observed for CRP (71.70%) and ESR (79.25%), but the specificity of these two metrics (GLB: 51.61%, A/G: 72.58%) was significantly reduced relative to that for CRP (87.10%) or ESR (75.81%). ROC analyses further revealed that NLR did not exhibit significant advantages in sensitivity (73.58%) or specificity (70.97%) relative to CRP or ESR. Globulin levels, NLR values, and A/G values do not outperform ESR or CRP levels when used to diagnose PJI.

Jiao JB ，Huang JC ，Chen X ，Jin Y ... -  《BMC MUSCULOSKELETAL DISORDERS》

Globulin, the albumin-to-globulin ratio, and fibrinogen perform well in the diagnosis of Periprosthetic joint infection.

Wang H ，Zhou H ，Jiang R ，Qian Z ，Wang F ，Cao L ... -  《BMC MUSCULOSKELETAL DISORDERS》

C-reactive protein (CRP)/albumin-to-globulin ratio (AGR) is a valuable test for diagnosing periprosthetic joint infection: a single-center retrospective study.

The diagnosis of periprosthetic joint infection (PJI) is challenging for clinicians, and the commonly used methods are too complicated and expensive for many clinical practices. The neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the platelet-to-mean-platelet-volume ratio (PVR), globulin (GLB), the albumin-to-globulin ratio (AGR), and the C-reactive protein (CRP)/AGR ratio are simple biomarkers for infection and can be easily determined from routine blood tests. Due to their low cost and ready availability in clinical practice, many clinicians have considered the diagnostic value of these biomarkers for PJI. The aim of our study is to determine the value of NLR, PLR, PVR, GLB, AGR, and CRP/AGR for the diagnosis of PJI. One hundred sixty-four patients who received revision surgery after total knee or total hip replacements were enrolled, 47 in a PJI group and 117 in an aseptic failure group. Receiver operating characteristic (ROC) analysis was used to evaluate the performance of NLR, PLR, PVR, GLB, AGR, and CRP/AGR for the diagnosis of PJI, and their performance levels were then compared with those of CRP and the erythrocyte sedimentation rate (ESR). The levels of all tested biomarkers were significantly higher in patients with PJI (all P < 0.05). ROC analysis showed that CRP/AGR performed best in diagnosing PJI, with an area under curve (AUC) value of 0.902, and the AUCs of NLR (0.740), PLR (0.721), PVR (0.668), GLB (0.719), and AGR (0.767) were all lower than those for CRP (0.896) and ESR (0.829). CRP/AGR was a valuable test for diagnosing PJI, but other novel biomarkers had only limited diagnostic value. Level III.

Wu H ，Pan L ，Meng Z ，Liu H ，Yang X ，Cao Y ... -  《-》

Evaluation of Serum Albumin and Globulin in Combination With C-Reactive Protein Improves Serum Diagnostic Accuracy for Low-Grade Periprosthetic Joint Infection.

Serum immune markers can be useful in the diagnosis of periprosthetic joint infection (PJI) by detecting long-lasting abnormal immunological conditions. The purpose of this study was to examine whether serum immune markers can improve the diagnostic accuracy of PJI. We enrolled 51 PJI, 45 aseptic loosening, and 334 osteoarthritis patients for assessment of the discriminatory accuracy of serum markers including white blood cell count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and D-dimer, total protein, albumin (Alb), globulin (Glb), neutrophil-lymphocyte ratio, lymphocyte-monocyte ratio, platelet-lymphocyte ratio, albumin-globulin ratio (AGR), CRP-albumin ratio (CAR), and CRP-AGR ratio (CAGR). These diagnostic accuracies for low-grade PJI were also calculated in patients who had serum CRP levels < 10 mg/L. Among serum markers, Alb, Glb, AGR, CRP, ESR, CAR, and CAGR had highly accurate diagnostic accuracy for PJI, with area under the curve of 0.92, 0.90, 0.96, 0.97, 0.92, 0.97, and 0.98, respectively. In low-grade PJI patients, area under the curve of CRP, ESR, CAR, and CAGR (0.69, 0.80, 0.65, and 0.82, respectively) was decreased but that of Alb, Glb, and AGR (0.90, 0.88, and 0.95, respectively) remained high, indicating the diagnostic utility of these immune markers. The sensitivity and specificity of AGR with cutoff value of 1.1 were demonstrated as 0.92 and 0.89, respectively, and with cutoff value of 1.2, 1.00, and 0.79, respectively, in the diagnosis of low-grade infection. Our results demonstrate the potential value of Alb, Glb, AGR, and combination indices of these immune makers with CRP in improving preoperative serum diagnosis for PJI, especially in low-grade PJI. Diagnostic- Level II.

Choe H ，Kobayashi N ，Abe K ，Hieda Y ，Tezuka T ，Inaba Y ... -  《-》

Different biomarker ratios in peripheral blood have limited value in diagnosing periprosthetic joint infection after total joint arthroplasty: a single-center, retrospective study.

Periprosthetic joint infection (PJI) is a severe complication that can occur after total joint arthroplasty (TJA). The timely and accurate diagnosis of PJI is the key to treatment. This study investigated the diagnostic value of platelet to lymphocyte ratio (PLR), platelet count to mean platelet volume ratio (PVR), neutrophil to lymphocyte ratio (NLR) and monocyte to lymphocyte ratio (MLR) in PJI after total knee arthroplasty (TKA) and total hip arthroplasty (THA). We performed a retrospective analysis of the patients who underwent revision hip or knee arthroplasty at our Institute between June 2015 and June 2020. Of the 187 patients reviewed, 168 were included in the study. According to the diagnostic criteria of the Musculoskeletal Infection Society (MSIS), 58 patients were in the PJI group, and 110 patients were in the aseptic loosening (AL) group. We recorded and compared the preoperative peripheral blood white blood cell (WBC) count, platelet count (PLT), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), PLR, PVR, NLR, and MLR in both groups. The diagnostic performance of the WBC, PLT, PLR, PVR, NLR, and MLR individually and in combination with the ESR and CRP for PJI diagnosis was evaluated by receiver operating characteristic (ROC) curves, and the sensitivity, specificity, positive predictive value, and negative predictive value were calculated. Compared to those in the AL group, the mean WBC, PLT, ESR, CRP, PLR, PVR, NLR, and MLR in the peripheral blood of the PJI group were significantly greater (P < 0.05). The analysis of the ROC curve revealed that the ESR, CRP, PLR, PVR, NLR, and MLR in peripheral blood had moderate effectiveness in diagnosing PJI, with area under the curve (AUC) values of 0.760 (95% CI: 0.688-0.823), 0.758 (95% CI: 0.687-0.821), 0.714 (95% CI: 0.639-0.781), 0.709 (95% CI: 0.634-0.777), 0.723 (95% CI: 0.649-0.789), and 0.728 (95% CI: 0.654-0.793), respectively. Conversely, the WBC and PLT counts demonstrated poor diagnostic value for PJI, with AUC values of 0.578 (95% CI: 0.499-0.653) and 0.694 (95% CI: 0.619-0.763), respectively. The results of the prediction model calculations revealed that the combined AUC of the WBC, PLT, ESR, CRP, PLR, PVR, NLR, and MLR was the highest at 0.853 (95% CI, 0.790-0.909), indicating good value in the diagnosis of PJI, with a sensitivity of 82.8% and a specificity of 72.7%. Moreover, the novel composite of parameters improved the accuracy and reliability in diagnosing PJI compared to the traditional biomarkers ESR and CRP (P = 0.015). Our study suggested that the diagnostic value of the peripheral blood biomarkers PLR, PVR, NLR, and MLR for diagnosing PJI is limited and not superior to that of the ESR or CRP. However, when the WBC, PLT, ESR, CRP, PLR, PVR, NLR, and MLR are combined, the diagnostic performance of PJI in TJA patients can be improved.

Deng L ，Wang J ，Yang GY ，Hou YZ ，Li KW ，Sun B ，Wang SH ... -  《BMC MUSCULOSKELETAL DISORDERS》