Analysis of synovial biomarkers with a multiplex protein microarray in patients with PJI undergoing revision arthroplasty of the hip or knee joint

Synovial Fluid Biomarkers for the Diagnosis of Periprosthetic Joint Infection-A Systematic Review and Meta-Analysis of Their Diagnostic Accuracy According to Different Definitions

BACKGROUND

Different synovial fluid biomarkers have emerged to improve periprosthetic joint infection (PJI) diagnosis. The goals of this paper were (i) to assess their diagnostic accuracy and (ii) to evaluate their performance according to different PJI definitions.

METHODS

A systematic review and meta-analysis was performed using studies that reported diagnostic accuracy of synovial fluid biomarkers using validated PJI definitions published from 2010 to March 2022. A database search was performed through PubMed, Ovid MEDLINE, Central, and Embase. The search identified 43 different biomarkers with four being the more commonly studied, with 75 papers overall: alpha-defensin; leukocyte esterase; synovial fluid C-reactive protein; and calprotectin.

RESULTS

Overall accuracy was higher for calprotectin, followed by alpha-defensin, leukocyte esterase, and synovial fluid C-reactive protein with sensitivities of 78 to 92% and specificities of 90 to 95%. Their diagnostic performance was different according to which definition was adopted as the reference. Specificity was consistently high across definitions for all four biomarkers. Sensitivity varied the most with lower values for the more sensitive European Bone and Joint Infection Society or Infectious Diseases Society of America definitions with higher values for the Musculoskeletal Infection Society definition. The International Consensus Meeting 2018 definition showed intermediate values.

CONCLUSION

All evaluated biomarkers had good specificity and sensitivity, making their use acceptable in the diagnosis of PJI. Biomarkers perform differently according to the selected PJI definitions.

Host bone microstructure for enhanced resistance to bacterial infections

Postoperative bacterial infection is a serious complication of orthopedic surgery. Not only infections that develop in the first few weeks after surgery but also late infections that develop years after surgery are serious problems. However, the relationship between host bone and infection activation has not yet been explored. Here, we report a novel association between host bone collagen/apatite microstructure and bacterial infection. The bone-mimetic-oriented micro-organized matrix structure was obtained by prolonged controlled cell alignment using a grooved-structured biomedical titanium alloy. Surprisingly, we have discovered that highly aligned osteoblasts have a potent inhibitory effect on Escherichia coli adhesion. Additionally, the oriented collagen/apatite micro-organization of the bone matrix showed excellent antibacterial resistance against Escherichia coli. The proposed mechanism for realizing the antimicrobial activity of the micro-organized bone matrix is by the controlled secretion of the antimicrobial peptides, including β-defensin 2 and β-defensin 3, from the highly aligned osteoblasts. Our findings contribute to the development of anti-infective strategies for orthopedic surgeries. The recovery of the intrinsically ordered bone matrix organization provides superior antibacterial resistance after surgery.

Novel diagnostic markers for periprosthetic joint infection: a systematic review

Background

Identifying novel biomarkers that are both specific and sensitive to periprosthetic joint infection (PJI) has the potential to improve diagnostic accuracy and ultimately enhance patient outcomes. Therefore, the aim of this systematic review is to identify and evaluate the effectiveness of novel biomarkers for the diagnosis of PJI.

Methods

We searched the MEDLINE, EMBASE, PubMed, and Cochrane Library databases from January 1, 2018, to September 30, 2022, using the search terms "periprosthetic joint infection," "prosthetic joint infection," or "periprosthetic infection" as the diagnosis of interest and the target index, combined with the term "marker." We excluded articles that mentioned established biomarkers such as CRP, ESR, Interleukin 6, Alpha defensin, PCT (procalcitonin), and LC (leucocyte cell count). We used the MSIS, ICM, or EBJS criteria for PJI as the reference standard during quality assessment.

Results

We collected 19 studies that analyzed fourteen different novel biomarkers. Proteins were the most commonly analyzed biomarkers (nine studies), followed by molecules (three studies), exosomes (two studies), DNA (two studies), interleukins (one study), and lysosomes (one study). Calprotectin was a frequently analyzed and promising marker. In the scenario where the threshold was set at ≥50-mg/mL, the calprotectin point-of-care (POC) performance showed a high sensitivity of 98.1% and a specificity of 95.7%.

Conclusion

None of the analyzed biomarkers demonstrated outstanding performance compared to the established parameters used for standardized treatment based on established PJI definitions. Further studies are needed to determine the benefit and usefulness of implementing new biomarkers in diagnostic PJI settings.

Serum versus synovial fluid interleukin-6 for periprosthetic joint infection diagnosis: a systematic review and meta-analysis of 30 diagnostic test accuracy studies

BACKGROUND

Early and accurate detection of periprosthetic joint infection (PJI) after hip and/or knee arthroplasty remains challenging. This systematic review and meta-analysis of diagnostic test accuracy studies aimed to evaluate the diagnostic accuracy of serum and synovial fluid interleukin (IL)-6 in detecting PJI.

METHODS

We searched 3 databases for studies through December 31, 2021, using medical sub-headings terms and keywords. Studies reported sensitivity and specificity of serum and synovial fluid IL-6 in detecting PJI were considered. We calculated the pooled sensitivity, specificity, positive and negative likelihood ratio, diagnostic odds ratio (DOR), and the area under the summary receiver operating characteristic curve (AUC) to evaluate the diagnostic accuracy of serum and synovial fluid IL-6.

RESULTS

Thirty studies were included. The pooled sensitivity, specificity, positive and negative likelihood ratio, DOR, and AUC of serum IL-6 in detecting PJI were 0.76 (0.69-0.81), 0.88 (0.82-0.92), 6.2 (4.3-9.0), 0.28 (0.22-0.35), 22 (14-36), and 0.88 (0.85-0.91), respectively. However, synovial fluid IL-6 achieved a pooled sensitivity of 0.87 (0.75-0.93), specificity of 0.90 (0.85-0.93), positive and negative likelihood ratio of 8.5 (5.3-13.6) and 0.15 (0.08-0.29), DOR of 57 (21-156), and AUC of 0.94 (0.92-0.96), which were higher than serum IL-6.

CONCLUSIONS

Synovial fluid IL-6 test may be a promising test for PJI after hip and/or knee arthroplasty. However, considering the limited volume of synovial fluid and invasive acquisition of synovial fluid IL-6, serum IL-6 test may be also considered.

Osteoporosis in patients with rheumatoid arthritis is associated with serum immune regulatory cellular factors

OBJECTIVE

Osteoporosis (OP) is a comorbidity of rheumatoid arthritis (RA) that largely causes disability. This study discussed the expression patterns of serum immunoregulatory factors and their clinical significance in RA patients complicated with OP.

METHODS

A total of 116 RA patients were enrolled. Bone mineral density (BMD) was measured using dual energy X-ray absorptiometry to allocate patients to OP group (N = 62) and non-OP group (N = 54). CRP, rheumatoid factor, IgG, IgA, and IgM were detected using rate nephelometry. Erythrocyte sedimentation rate (ESR) and bone metabolic indexes were detected using Microsed automatic ESR analyzer and Cobas e601 automated immunoassay systems and reagents. IL-17, IL-6, TNF-α, IL-10, and IL-4 levels were determined using ELISA kit and their prediction values on OP were analyzed using the ROC curve. Influencing factors of OP incidence were analyzed using logistic regression model.

RESULTS

RA patients with OP showed increased age, disease course, tender and swollen joints, ESR, CRP, DAS28 scores, β-CTX, IL-17, IL-6, and TNF-α, and decreased 25(OH)D3, IL-10, and IL-4. DAS28 was positively correlated with IL-17, IL-6, and TNF-α, and negatively correlated with IL-10 and IL-4. DAS28, IL-17, IL-10, and IL-4 were independently correlated with OP in RA patients. The combination of DAS28, IL-17, IL-10, and IL-4 can better predict the incidence of OP complication in RA patients.

CONCLUSION

IL-17, IL-6, TNF-α, IL-10, and IL-4 were associated with disease activity of RA patients complicated with OP. A combination of DAS28, IL-17, IL-10, and IL-4 might predict OP incidence in RA patients.

Combination of Synovial Fluid IL-4 and Polymorphonuclear Cell Percentage Improves the Diagnostic Accuracy of Chronic Periprosthetic Joint Infection

Background

Synovial fluid biomarkers have been found to improve the diagnosis of chronic periprosthetic joint infection (PJI); however, no “gold standard” exists yet. Interleukin-4 (IL-4) and polymorphonuclear cell (neutrophil) count in the synovial fluid are crucial in mediating local inflammation during bacterial infections and could be valuable biomarkers for PJI.

Methods

This prospective study was conducted to investigate the diagnostic potential of synovial fluid IL-4 (SF-IL4) and polymorphonuclear cell percentage (SF-PMN%) for chronic PJI. A total of 110 patients who underwent revision arthroplasty between January 2019 and October 2020 were enrolled, and 11 patients were excluded. Of 99 patients, 43 were classified as having PJI and 56 as having aseptic failures according to the 2013 Musculoskeletal Infections Society criteria. In all patients, SF-IL4, SF-PMN%, serum C-reactive protein (CRP), and serum erythrocyte sedimentation rate (ESR) were quantified preoperatively. The diagnostic value for each biomarker was analyzed, and optimal cutoff values were calculated.

Results

The patient demographics did not significantly vary. The area under the curve of SF-IL4 and SF-PMN% was 0.97 and 0.89, respectively, higher than that for serum ESR (0.72) and serum CRP (0.83). The combination of SF-IL4 and SF-PMN% provided higher specificity (97.0%) and accuracy (96.0%) when the cut-off values were 1.7 pg/mL and 75%, respectively.

Conclusion

SF-IL4 is a valuable biomarker for chronic PJI detection, and the combination of SF-IL4 and SF-PMN% improved the diagnostic value of chronic PJI, and further studies are needed until its clinical application.

Synovial fluid calprotectin performs better than synovial fluid polymerase chain reaction and interleukin-6 in the diagnosis of periprosthetic joint infection : a systematic review and meta-analysis

AIMS

The preoperative diagnosis of periprosthetic joint infection (PJI) remains a challenge due to a lack of biomarkers that are both sensitive and specific. We investigated the performance characteristics of polymerase chain reaction (PCR), interleukin-6 (IL6), and calprotectin of synovial fluid in the diagnosis of PJI.

METHODS

We performed systematic search of PubMed, Embase, The Cochrane Library, Web of Science, and Science Direct from the date of inception of each database through to 31 May 2021. Studies which described the diagnostic accuracy of synovial fluid PCR, IL6, and calprotectin using the Musculoskeletal Infection Society criteria as the reference standard were identified.

RESULTS

Overall, 31 studies were identified: 20 described PCR, six described IL6, and five calprotectin. The sensitivity and specificity were 0.78 (95% confidence interval (CI) 0.67 to 0.86) and 0.97 (95% CI 0.94 to 0.99), respectively, for synovial PCR;, 0.86 (95% CI 0.74 to 0.92), and 0.94 (95% CI 0.90 to 0.96), respectively, for synovial IL6; and 0.94 (95% CI 0.82 to 0.98) and 0.93 (95% CI 0.85 to 0.97), respectively, for synovial calprotectin. Likelihood ratio scattergram analyses recommended clinical utility of synovial fluid PCR and IL6 as a confirmatory test only. Synovial calprotectin had utility in the exclusion and confirmation of PJI.

CONCLUSION

Synovial fluid PCR and IL6 had low sensitivity and high specificity in the diagnosis of PJI, and is recommended to be used as confirmatory test. In contrast, synovial fluid calprotectin had both high sensitivity and specificity with utility in both the exclusion and confirmation of PJI. We recommend use of synovial fluid calprotectin studies in the preoperative workup of PJI. Cite this article: Bone Joint J 2022;104-B(3):311-320.

Failure Analysis in Multiple TKA Revisions-Periprosthetic Infections Remain Surgeons' Nemesis

BACKGROUND

The aim of this study was to categorize reasons for failure and to analyze the survivorship of multiple total knee arthroplasty (TKA) revisions.

METHODS

The study retrospectively evaluated all multiple TKA revisions performed between 2005 and 2015 at the authors' institutions. Sixty-three patients (35 female, 28 male, age 64 ± 10 years, follow-up 55 ± 36 months) underwent a total of 157 re-revision TKA surgeries (range 2-5). The revision indications were divided up into main diagnoses. Survivorship was evaluated by mixed model analysis.

RESULTS

The main overall reason for re-revision was periprosthetic joint infection (PJI) (48%), followed by instability (12%), polyethylene wear (11%), malpositioning (8%), and aseptic loosening (8%). Survivorship shortened with an increasing number of revision surgeries (p = 0.003). While PJI was in 38% of all cases, the reason for the first revision, incidence increased constantly with the number of revisions (48% at second revision, 55% at third revision, 86% at fourth revision, and 100% at fifth revision, p = 0.022). If periprosthetic infection caused the first revision, patients showed an average of two more septic revisions at follow-up than patients with an aseptic first revision indication (p < 0.001). In 36% of cases, the reason for follow-up surgery in case of periprosthetic infection was again PJI.

CONCLUSION

The probability of survival of the implanted knee arthroplasty is significantly reduced with each subsequent revision. Periprosthetic infection is the main cause of multiple revisions.

Tissue-level cytokines in a rodent model of chronic implant-associated infection

Systemic cytokine concentrations have been extensively studied in implant-associated infections, providing sensitive diagnostic markers. However, less is known about the relationships of tissue-level cytokines surrounding the joint. The aim of this study was to define the cytokine profiles of tissues to investigate the use of these cytokines as markers of debridement in chronic joint infection. Using a rodent model, muscle samples were obtained from rats following Kirschner wire implantation and infection with Staphylococcus aureus to determine if: (1) differences exist in cytokine concentrations with proximity to infection, and (2) localized infection-specific markers can be identified on a tissue level to potentially serve as debridement markers in the future. Samples were collected from 4 distinct locations, and the concentrations of interleukin(IL)-1α, IL-1β, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, granulocyte-macrophage colony-stimulating factor, interferon-γ, and tumor necrosis factor-α were quantified in each sample, relative to the amount of tissue. Cytokine concentrations differed with proximity to the joint when implant or infection was present, and tissues at the operative knee joint showed the highest levels of most cytokines. Additionally, IL-1β, IL-4, and IL-6 showed promise, beyond diagnostics, as tissue-level indicators of infection response. Ultimately, this study illustrated that tissue-level evaluation provided insight into infection-specific response, and these markers may be useful for guiding the debridement of implant-associated infections.

The diagnostic effect of α-defensin, D-dimer, and IL-6 in periprosthetic joint infection: A systematic review and diagnostic meta-analysis

BACKGROUND

Periprosthetic joint infection (PJI) is the most common complication after artificial joint replacement as previously reported. However, the main problem at present is its difficulty in diagnosis. This systematic review and meta-analysis aimed to compare the diagnostic accuracy of α-defensin, D-dimer, and interleukin-6 (IL-6) in clinical practice.

METHOD

Online databases were systematically searched until June 18th, 2020 with keywords and medical sub-headings terms. Studies mentioned the sensitivity and specificity of biological markers in detecting PJI were included in our study. The sensitivity, specificity, and diagnostic odds ratios (DORs) were obtained after integration.

RESULTS

A total of 34 studies with 1036 patients diagnosing as PJI were included for comparing α-defensin, D-dimer, and IL-6. The sensitivity and specificity of α-defensin for PJI were 0.88 and 0.96, and the DOR was 189 (95% CI 72-496), respectively. The sensitivity and specificity of D-dimer (0.82 and 0.72) and IL-6 (0.80 and 0.89) were lower than α-defensin.

CONCLUSION

The detection of α-defensin is a promising biomarker for diagnosing PJI. The optional cut-off needs to be curtained when using other biomarkers.

Synovial Complement Factors in Patients with Periprosthetic Joint Infection after Undergoing Revision Arthroplasty of the Hip or Knee Joint

The role and diagnostic value of the synovial complement system in patients with low-grade periprosthetic joint infection (PJI) are unclear. We sought to evaluate, for the first time, the usefulness of synovial complement factors in these patients by measuring the individual synovial fluid levels of complement factors (C1q, C3b/iC3b, C4b, C5, C5a, C9, factor B, factor D, factor H, factor I, properdin, and mannose-binding lectin [MBL]). The patients (n = 74) were classified into septic (n = 28) and aseptic (n = 46). Receiver-operator characteristic curves and a multiple regression model to determine the feasibility of a combination of the tested cytokines to determine the infection status were calculated. The synovial fluid levels of C1q, C3b/C3i, C4b, C5, C5a, MBL, and properdin were significantly elevated in the PJI group. The best sensitivity and specificity was found for C1q. The multiple regression models revealed that the combination of C1q, C3b/C3i, C4b, C5, C5a, and MBL was associated with the best sensitivity (83.3%) and specificity (79.2%) for a cutoff value of 0.62 (likelihood ratio: 4.0; area under the curve: 0.853). Nevertheless, only a combined model showed acceptable results. The expression patterns of the complement factors suggested that PJI activates all three pathways of the complement system.

Interleukin-18 and -10 may be associated with lymph node metastasis in breast cancer

Reports on the expression of interleukin (IL)-10 in breast cancer are rare. The present study investigated the correlation between IL-18 and −10 in breast cancer, and assessed their clinical significance. Breast cancer (n=104) and breast fibroadenoma (n=31) tissues that were surgically removed and pathologically confirmed at Jinan Central Hospital Affiliated to Shandong University (Jinan, China) between November 2016 and January 2019 were collected. The expression of IL-18 and −10 was observed via immunohistochemistry. Breast cancer tissues were positive for IL-18 expression, which was primarily located in the cell membrane and cytoplasm. A significant difference in IL-18 expression was observed between breast cancer and fibroadenoma tissues (75.0 vs. 19.4%; P<0.001). IL-10 was expressed in breast cancer tissues and primarily located in the cytoplasm. Breast cancer tissues showed a significantly higher level of IL-10 expression compared with breast fibroadenoma tissues (78.8 vs. 22.6%; P<0.001). The regions of positive IL-18 and −10 expression were consistent. Tissues with positive expression of IL-18 and/or −10 had a significantly higher rate of lymph node metastasis than those with negative expression (IL-18: 67.9 vs. 42.3%; P=0.035; and IL-10: 67.1 vs. 40.9%; P=0.047). In conclusion, IL-18 is highly expressed in breast cancer and correlates positively with IL-10. Both IL-18 and −10 may correlate positively with lymph node metastasis in breast cancer.