Suitability of serum cytokine profiling for early diagnosis of implant-associated infections after orthopaedic surgery: A preliminary prospective study

sCD14-ST and Related Osteoimmunological Biomarkers: A New Diagnostic Approach to Osteomyelitis

Osteomyelitis (OM) is a major challenge in orthopedic surgery. The diagnosis of OM is based on imaging and laboratory tests, but it still presents some limitations. Therefore, a deeper comprehension of the pathogenetic mechanisms could enhance diagnostic and treatment approaches. OM pathogenesis is based on an inflammatory response to pathogen infection, leading to bone loss. The present study aims to investigate the potential diagnostic role of a panel of osteoimmunological serum biomarkers in the clinical approach to OM. The focus is on the emerging infection biomarker sCD14-ST, along with osteoimmunological and inflammatory serum biomarkers, to define a comprehensive biomarker panel for a multifaced approach to OM. The results, to our knowledge, demonstrate for the first time the diagnostic and early prognostic role of sCD14-ST in OM patients, suggesting that this biomarker could address the limitations of current laboratory tests, such as traditional inflammatory markers, in diagnosing OM. In addition, the study highlights a relevant diagnostic role of SuPAR, the chemokine CCL2, the anti-inflammatory cytokine IL-10, the Wnt inhibitors DKK-1 and Sclerostin, and the RANKL/OPG ratio. Moreover, CCL2 and SuPAR also exhibited early prognostic value.

Inflammatory blood parameters as prognostic factors for implant-associated infection after primary total hip or knee arthroplasty: a systematic review

BACKGROUND

Implant-associated infection (IAI) is a potential complication following total hip (THA) or knee arthroplasty (TKA). The initial phase of the inflammatory process can be measured by applying one of the inflammatory blood parameters (IBP). This systematic review aims to assess the response of IBP to trauma caused by orthopedic surgery and evaluate the clinical utility of quantitative measurements of IBP as prognostic factors for infection.

METHODS

All studies indexed in Ovid MEDLINE (PubMed), Ovid EMBASE, the Cochrane Library and the ISI Web of Science databases, from inception until January 31, 2020, were analyzed. Studies included were those on adults who underwent THA or TKA with minimum follow up of 30 days after surgery. In addition to minimum follow up, data on the prognostic factors for pre- or post-THA/TKA IAI were mandatory. The Quality Assessment of Diagnostic Accuracy tool (version 2) (QUADAS-2) and Standards for Reporting of Diagnostic Accuracy Studies guideline 2015 (STARD) were used for quality assessment.

RESULTS

Twelve studies fulfilled the inclusion and exclusion criteria. C-reactive protein was analyzed in seven studies, interleukin-6 in two studies and erythrocyte sedimentation rate in eight studies. White blood cell count and procalcitonin were analyzed in the only study. The overall quality of included studies was low. A potential for other cytokines (IL-1ra, IL-8) or MCP-1 was observed.

CONCLUSIONS

This is the first systematic review of IBP response to orthopedic surgery which identified some IBP for pre/post-operative screening, despite insufficient data supporting their prognostic potential for patient risk stratification.

A Multidimensional Bioinformatic Platform for the Study of Human Response to Surgery

OBJECTIVE

To design and establish a prospective biospecimen repository that integrates multi-omics assays with clinical data to study mechanisms of controlled injury and healing.

SUMMARY BACKGROUND DATA

Elective surgery is an opportunity to understand both the systemic and focal responses accompanying controlled and well-characterized injury to the human body. The overarching goal of this ongoing project is to define stereotypical responses to surgical injury, with the translational purpose of identifying targetable pathways involved in healing and resilience, and variations indicative of aberrant peri-operative outcomes.

METHODS

Clinical data from the electronic medical record combined with large-scale biological data sets derived from blood, urine, fecal matter, and tissue samples are collected prospectively through the peri-operative period on patients undergoing fourteen surgeries chosen to represent a range of injury locations and intensities. Specimens are subjected to genomic, transcriptomic, proteomic, and metabolomic assays to describe their genetic, metabolic, immunologic, and microbiome profiles, providing a multidimensional landscape of the human response to injury.

RESULTS

The highly multiplexed data generated includes changes in over 28,000 mRNA transcripts, 100 plasma metabolites, 200 urine metabolites, and 400 proteins over the longitudinal course of surgery and recovery. In our initial pilot dataset, we demonstrate the feasibility of collecting high quality multi-omic data at pre- and post-operative time points and are already seeing evidence of physiologic perturbation between timepoints.

CONCLUSIONS

This repository allows for longitudinal, state-of-the-art genomic, transcriptomic, proteomic, metabolomic, immunologic, and clinical data collection and provides a rich and stable infrastructure on which to fuel further biomedical discovery.

The diagnostic value of cytokines for the discrimination of vertebral osteomyelitis and degenerative diseases of the spine

Vertebral osteomyelitis (VO) is a primary infection of the endplates of the vertebral bodies with secondary infection of the adjacent intervertebral discs. Diagnosis is often delayed due to unspecific symptoms and a lack of specific infection markers. In this prospective study, we determined the suitability of 27 cytokines for the discrimination of VO and degenerative diseases of the spine and compared its diagnostic potential in relation to the C-reactive protein (CRP), which is widely used as a non-specific inflammation marker in clinical diagnostics. The patients included in this study underwent surgical stabilization of the lumbar and/or thoracic spine with removal of 1 or more affected intervertebral discs, as therapy for VO (n = 16) or for erosive osteochondrosis (EO, control group, n = 20). We evaluated the cytokine and CRP concentrations before (pre-OP = -20-0d where 0 means the day of surgery) and after surgery (post-OP) on days 3-5, 6-11, 40-56, and 63-142. Compared to the control patients pre-OP, a significantly higher elevation of the 4 cytokines IL-6, IL-8, IL-12 (p70), and VEGF as well as CRP were found in the VO patients, showing an area under the curve > 0.80 pre-OP. No significant differences were observed between VO patients with high and low virulent bacteria with respect to all 5 elevated biomarkers. This is the first prospective study in which a broad spectrum of 27 cytokines was analysed via multiplex assay using sera from patients with and without VO. Our results show that, in addition to CRP, 4 different cytokines were significantly altered in VO but not control patients. The results implicate that these candidate cytokines may be used in a multiplex assay for discrimination between VO and degenerative diseases of the spine.

A rat model to investigate quality of recovery after abdominal surgery

Introduction

Major advances in therapies to optimize recovery after surgery have been limited by the lack of an animal model that can mimic major domains of postoperative sickness behavior in humans. We hypothesized that the integration of commonly impaired domains of quality of recovery in humans could be reproduced in a rat model.

Objectives

To create a rat model that can mimic surgical recovery in humans.

Methods

Adult male Sprague-Dawley rats were used in the development of a quality of recovery score after surgery. Six physiological parameters or behaviors were tested in naive, sham, and laparotomized animals. A quality of recovery score was constructed and ranged from 18 (no impairment) to 0 (gross impairment). We treated animals with a nutraceutical intervention consisting of aspirin and eicosapentaenoic acid. Inflammatory markers and specialized proresolving mediators were measured in serum and the intestinal mucosa of rats, respectively.

Results

We observed a significant reduction in quality of recovery scores on postoperative days 1 (median, interquartile: 6 [4.75-8.25] vs naive rats: 17.5 [15.5-18]), 2 (median, interquartile: 13 [11.25-13.25], P < 0.001 vs naive rats: 17 [17-18], P = 0.001), and 3 (median, interquartile: 14.5 [13.5-16] vs naive rats: 17 [15.75-18], P < 0.02). Surgery promoted a significant increase in the concentrations of inflammatory cytokines, but it reduced levels of interleukin-12p70 and macrophage colony-stimulating factor. Lipoxin B4 and 13-HODE were significantly higher in laparotomized rats. Aspirin + eicosapentaenoic acid substantially improved recovery scores and modulated the postsurgical inflammatory response.

Conclusion

Our novel rat model can be used to study mechanisms governing surgical recovery in rats.

The diagnostic value of soluble urokinase-type plasminogen activator receptor (suPAR) for the discrimination of vertebral osteomyelitis and degenerative diseases of the spine

Background

There is still a challenge in discriminating between vertebral osteomyelitis and degenerative diseases of the spine. To this end, we determined the suitability of soluble urokinase-type plasminogen activator receptor (suPAR) and compared the diagnostic potential of suPAR to CRP.

Methods

Patients underwent surgical stabilization of the lumbar and/or thoracic spine with removal of one or more affected intervertebral discs, as therapy for vertebral osteomyelitis (n = 16) or for erosive osteochondrosis (control group, n = 20). In this prospective study, we evaluated the suPAR and CRP levels before (pre-OP) and after surgery (post-OP) on days 3–5, 6–11, 40–56, and 63–142.

Results

The suPAR levels in vertebral osteomyelitis patients were significantly higher than those from controls pre-OP, 3–5 days post-OP, and 6–11 days post-OP. Significantly higher CRP levels were observed in the vertebral osteomyelitis group than in the controls pre-OP and 6–11 days post-OP. Levels of suPAR and CRP correlated positively in all patients in the pre-OP period: r = 0.63 (95% CI: 0.37–0.79), p < 0.0001. The values for the area under the receiver operating characteristics curve (AUC) for pre-OP and the overall model post-OP were 0.88 (95% CI: 0.76–1.00) and 0.84 (95% CI: 0.71–0.97) for suPAR, 0.93 (95% CI: 0.85–1.00) and 0.77 (95% CI: 0.62–0.93) for CRP, and 0.98 (95% CI: 0.96–1.00) and 0.91 (95% CI: 0.82–1.00) for the combination of suPAR and CRP. The AUC for suPAR pre-OP revealed an optimum cut-off value, sensitivity, specificity, NPV, and PPV of 2.96 ng/mL, 0.69, 1.00, 0.80, and 1.00, respectively. For CRP, these values were 11.58 mg/L, 0.88, 0.90, 0.90, and 0.88, respectively.

Conclusion

The present results show that CRP is more sensitive than suPAR whereas suPAR is more specific than CRP. Moreso, our study demonstrated that improvement in the diagnostic power for discrimination of vertebral osteomyelitis and degenerative diseases of the spine can be achieved by a combination of both suPAR and CRP.

Trial registration

ClinicalTrials.gov, NCT02554227, posted Sept. 18, 2015, and updated Aug. 13, 2019