C-Reactive Protein, Procalcitonin, and a Novel Pathogenesis and Therapeutic Target of Thrombocytopenia in Sepsis

Objective. The aim of the study is to analyze the clinical characteristics, pathogen distribution, and drug sensitivity information of adult sepsis, and to provide reference for empirical clinical use; to explore the relationship between C-reactive protein (CRP) and calcitonin (PCT) The clinical value in the diagnosis of adult sepsis. Methods. We collected 455 cases of hospitalized patients with positive blood culture, including 352 cases with sepsis and 103 cases without sepsis; 1609 cases of hospitalized patients with suspected infection and negative blood culture, including 287 cases of sepsis, and 518 cases of non-infectious systemic inflammatory response syndrome (SIRS) and 804 cases of local infection. Age, gender, route of admission, admission status, CRP, PCT, and white blood cell (WBC) levels were collected from the patients. The differences between the factors were statistically analyzed, and the receiver operating characteristic curve (ROC curve) was plotted to obtain the optimal cut-off values of CRP and PCT and their area under the curve (AUC), and to compare the CRP, PCT and PCT, and the CRP + PCT tandem to diagnose sepsis sensitivity and specificity. Results. (1) 387 pathogenic strains were isolated from blood cultures of patients with sepsis, 71.06% Gram-negative, 26.87% Gram-positive and 2.07% fungi. (2) Among Gram-positive bacteria, Staphylococcus aureus was 87.5% resistant to penicillin and sensitive to vancomycin, milantropine, and teicoplanin; among Gram-negative bacteria, Escherichia coli was resistant to piracillin The resistance rate was 73.1%, fully susceptible to viraemia (100%) and resistant to imipenem, amikacin, and lacillin/tazole. (3) Among patients with positive blood cultures, CRP and PCT levels were higher in patients with sepsis than in those without sepsis. Pairwise comparison of ROC curves showed that the diagnostic value of PCT was greater than that of CRP ( $P=0.016$ ). Conclusion. CRP and PCT have a good reference value for diagnosis of sepsis patients and determination of the degree of infection in septic patients, especially PCT is more valuable for diagnosis of sepsis.

Antimicrobial Photodynamic Therapy Involving a Novel Photosensitizer Combined With an Antibiotic in the Treatment of Rabbit Tibial Osteomyelitis Caused by Drug-Resistant Bacteria

Osteomyelitis is deep tissue inflammation caused by bacterial infection. If such an infection persists, it can lead to dissolution and necrosis of the bone tissue. As a result of the extensive use of antibiotics, drug-resistant bacteria are an increasingly common cause of osteomyelitis, limiting the treatment options available to surgeons. Photodynamic antibacterial chemotherapy has attracted increasing attention as a potential alternative treatment. Its advantages are a broad antibacterial spectrum, lack of drug resistance, and lack of toxic side effects. In this study, we explored the impact of the new photosensitizer LD4 in photodynamic antimicrobial chemotherapy (PACT), both alone and in combination with an antibiotic, on osteomyelitis. A rabbit tibial osteomyelitis model was employed and microbiological, histological, and radiological studies were performed. New Zealand white rabbits (n = 36) were randomly divided into a control group, antibiotic group, PACT group and PACT + antibiotic group for treatment. In microbiological analysis, a reduction in bacterial numbers of more than 99.9% was recorded in the PACT group and the PACT + antibiotic group 5 weeks after treatment (p < 0.01). In histological analysis, repair of the damaged bone tissue was observed in the PACT group, and bone repair in the PACT + antibiotic group was even more significant. In radiological analysis, the X-ray Norden score showed that the severity of bone tissue defects or destruction followed the pattern: PACT + antibiotic group < PACT group < antibiotic group < control group.

Diagnostic test accuracy of serum procalcitonin compared with C-reactive protein for bone and joint infection in children and adolescents: a systematic review and meta-analysis

OBJECTIVE

The objective of this review was to synthesize the best available evidence for the diagnostic test accuracy of serum procalcitonin compared with serum C-reactive protein for suspected osteomyelitis and septic arthritis in hospitalized children and adolescents.

INTRODUCTION

Measurement of serum C-reactive protein remains a routine investigation for the diagnosis of osteoarticular infection in children and adolescents. Measurement of serum procalcitonin has been shown to outperform C-reactive protein in adults with osteomyelitis and septic arthritis. Before procalcitonin can be considered as a potential replacement or add-on test in children and adolescents, a systematic review and meta-analysis targeting this population should be conducted.

INCLUSION CRITERIA

Original studies reporting the diagnostic accuracy of procalcitonin and/or C-reactive protein in children and adolescents between one month and 18 years of age admitted to hospital with suspected osteoarticular infection were included. Studies must have compared the index test to at least one reference test. Reference test was defined as positive culture or polymerase chain reaction confirmation of a pathogen from blood, bone biopsy, or joint fluid aspirate in combination with at least two of the following: i) purulent material from sterile site, ii) positive radiological findings consistent with osteoarticular infection, and ii) symptoms and signs consistent with osteomyelitis and/or septic arthritis.

METHODS

The JBI methodology for systematic reviews of diagnostic test accuracy was followed. Information was sourced from four databases (MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Web of Science) and four gray literature sources (MedNar, OpenGrey, Google Scholar, and ProQuest Dissertations and Theses). Only studies published in English were considered. The methodological quality of selected studies was formally evaluated, sensitivity and specificity data were extracted, and 95% confidence intervals determined. Meta-analysis was performed to estimate summary points using a bivariate model and to generate a hierarchical summary receiver operating characteristic (HSROC) curve with global measures of test accuracy performance, such as likelihood ratio and diagnostic odds ratio. A narrative was provided where meta-analysis was not appropriate.

RESULTS

Eight studies were included in the review. Four of these studies used a common C-reactive protein test threshold of 20 mg/L. At this threshold, the estimated pooled sensitivity of C-reactive protein was 0.86 (0.68-0.96) and the pooled specificity was 0.9 (0.83-0.94). Using a hierarchical summary receiver operating characteristic model from six studies, the diagnostic odds ratio for C-reactive protein was estimated to be 39.4 (14.8-104.9) with a positive likelihood ratio 5.3 (2.3-11.9) and a negative likelihood ratio 0.1 (0.07-0.2). There were insufficient studies from this review to statistically evaluate the diagnostic accuracy of procalcitonin.

CONCLUSION

Clinicians should continue to measure serum C-reactive protein as the preferred inflammatory marker in hospitalized children and adolescents with suspected osteomyelitis or septic arthritis. More evidence is needed before incorporating procalcitonin routinely into clinicians' diagnostic test strategy. Improvements with the design, quality, and reporting of procalcitonin diagnostic test assays in children and adolescents with osteoarticular infection is needed.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42019140276.

Novel strategies to diagnose prosthetic or native bone and joint infections

INTRODUCTION

Bone and Joint Infections (BJI) are medically important, costly and occur in native and prosthetic joints. Arthroplasties will increase significantly in absolute numbers over time as well as the incidence of Prosthetic Joint Infections (PJI). Diagnosis of BJI and PJI is sub-optimal. The available diagnostic tests have variable effectiveness, are often below standard in sensitivity and/or specificity, and carry significant contamination risks during the collection of clinical samples. Improvement of diagnostics is urgently needed.

AREAS COVERED

We provide a narrative review on current and future diagnostic microbiology technologies. Pathogen identification, antibiotic resistance detection, and assessment of the epidemiology of infections via bacterial typing are considered useful for improved patient management. We confirm the continuing importance of culture methods and successful introduction of molecular, mass spectrometry-mediated and next-generation genome sequencing technologies. The diagnostic algorithms for BJI must be better defined, especially in the context of diversity of both disease phenotypes and clinical specimens rendered available.

EXPERT OPINION

Whether interventions in BJI or PJI are surgical or chemo-therapeutic (antibiotics and bacteriophages included), prior sensitive and specific pathogen detection remains a therapy-substantiating necessity. Innovative tests for earlier and more sensitive and specific detection of bacterial pathogens in BJI are urgently needed.

Acute osteoarticular infections in children are frequently forgotten multidiscipline emergencies: beyond the technical skills

Acute osteoarticular infections (AOI) should be treated as top emergencies. The first few days following the inception of infection are ultra-critical to long-term prognosis.A comprehensive road map for management of childhood AOI is still lacking despite recent advances in microbiology and imaging (magnetic resonance imaging). The many faces of childhood AOI warrant a multidiscipline approach to management.Laboratory and imaging findings of are still debatable and should not overshadow or delay a management plan based on the experienced physician's clinical judgment.Ample evidence-based practice supports the use of a few days of intravenous antibiotic administration followed by oral therapy until correlative clinical and basic laboratory (acute phase reactants) results improve.The growing body of evidence on 'high-risk' children/neonates of AOI warrants continual clinical extra-vigilance in identifying these patient subsets.Open drainage and debridement remain the mainstay of treatment of septic hips, whereas for other joints the use of alternative surgical techniques should be individualized or on case-by-case basis.Because the consequences of misdiagnosis of AOI are usually grave and permanent, proactive treatment/overtreatment is justified in the event of unconfirmed but suspicious diagnosis. Cite this article: EFORT Open Rev 2021;6:584-592. DOI: 10.1302/2058-5241.6.200155.