Serum procalcitonin as a diagnostic aid in patients with acute bacterial septic arthritis

Procalcitonin as a Predictor of Septic Knee Arthritis: A Retrospective Cohort Study

INTRODUCTION

Differentiating septic arthritis from aseptic arthritis (AA) of the knee is difficult without arthrocentesis. Although procalcitonin (PCT) has shown diagnostic value in identifying bacterial infections, it has not been established as a reliable marker for identifying septic arthritis (SA). Recent studies have shown promise in the use of PCT as a useful systemic marker for identifying septic arthritis versus AA. This observational retrospective review compares PCT with routine inflammatory markers as a tool for differentiating septic arthritis versus AA in patients with acute, atraumatic knee pain.

METHODS

Fifty-three consecutive patients (24 SA, 29 AA) were retrospectively reviewed at one institution with concern for SA. SA was diagnosed based on a physical examination, laboratory markers, and arthrocentesis. Laboratory indices were compared between the septic arthritis and AA groups. Data analysis was conducted to define sensitivity and specificity. Receiver operator characteristic curve analysis and regression were conducted to determine the best marker for acute SA of the knee.

RESULTS

Using multiple logistic regression, bacteremia (OR 6.75 ± 5.75) was determined to be the greatest predictor of SA. On linear regression, concomitant bacteremia (coef 3.07 ± 0.87), SA (coef 2.18 ± 0.70), and the presence of pseudogout crystals (coef 1.80 ± 0.83) on microscopy predicted an increase in PCT. Using a PCT cutoff of 0.25 ng/mL yields a sensitivity of 91.7% and specificity of 55.2% for predicting SA; however, the ideal cutoff in our series was 0.32 ng/mL with a sensitivity of 79.2% and specificity of 72.4%. PCT was superior to the white blood cell count, erythrocyte sedimentation rate, and C-reactive protein in the area under the receiver-operating characteristic curve analysis.

DISCUSSION

Procalcitonin seems to be the most sensitive and specific systemic marker in differentiating septic from AA.

Extra-pulmonary applications of procalcitonin: an updated literature review

INTRODUCTION

: Procalcitonin (PCT) is a biomarker with established performance in the differentiation between bacterial and viral infections, predominantly in pulmonary infections, as well as the diagnosis and prognosis of bacterial sepsis. However, the role of PCT in extra-pulmonary infections is not well described.

AREAS COVERED

: We reviewed the role of PCT in commonly experienced extra-pulmonary infections including meningitis, diabetic foot infection, prosthetic joint infection, osteomyelitis, and skin and soft tissue infection. PubMed and Medline online libraries were searched, from 2013 till 2022, for relevant articles.

EXPERT OPINION

: For meningitis, PCT could distinguish bacterial from viral meningitis. PCT distinguished septic arthritis from different types of arthritis but had variable performance in discriminating septic arthritis from crystal arthropathy. For periprosthetic joint infections, results were inconclusive. PCT had a potential role in diagnosis of more complex infections such as osteomyelitis and diabetic foot infections, but further studies are needed for a definitive cutoff. In skin and soft tissue infections, PCT performance was more variable requiring further investigation to define cutoff for the discrimination of cellulitis from necrotizing fasciitis. We find that PCT performed best for meningitis and helps in the reduction of unnecessary antibiotic treatment, but has variable outcomes with other extra-pulmonary infections.

What are the best diagnostic tests for diagnosing bacterial arthritis of a native joint? : a systematic review of 27 studies

AIMS

This study aimed to answer two questions: what are the best diagnostic methods for diagnosing bacterial arthritis of a native joint?; and what are the most commonly used definitions for bacterial arthritis of a native joint?

METHODS

We performed a search of PubMed, Embase, and Cochrane libraries for relevant studies published between January 1980 and April 2020. Of 3,209 identified studies, we included 27 after full screening. Sensitivity, specificity, area under the curve, and Youden index of diagnostic tests were extracted from included studies. We grouped test characteristics per diagnostic modality. We extracted the definitions used to establish a definitive diagnosis of bacterial arthritis of a native joint per study.

RESULTS

Overall, 28 unique diagnostic tests for diagnosing bacterial arthritis of a native joint were identified. The following five tests were deemed most useful: serum ESR (sensitivity: 34% to 100%, specificity: 23% to 93%), serum CRP (sensitivity: 58% to 100%, specificity: 0% to 96%), serum procalcitonin (sensitivity: 0% to 100%, specificity: 68% to 100%), the proportion of synovial polymorphonuclear cells (sensitivity: 42% to 100%, specificity: 54% to 94%), and the gram stain of synovial fluid (sensitivity: 27% to 81%, specificity: 99% to 100%).

CONCLUSION

Diagnostic methods with relatively high sensitivities, such as serum CRP, ESR, and synovial polymorphonuclear cells, are useful for screening. Diagnostic methods with a relatively high specificity, such as serum procalcitonin and synovial fluid gram stain, are useful for establishing a diagnosis of bacterial arthritis. This review helps to interpret the value of various diagnostic tests for diagnosing bacterial arthritis of a native joint in clinical practice. Cite this article: Bone Joint J 2021;103-B(12):1745-1753.

Discriminative Accuracy of Procalcitonin and Traditional Biomarkers in Pediatric Acute Musculoskeletal Infection

OBJECTIVES

Septic arthritis (SA) is responsible for 20% of pediatric musculoskeletal infections (MSKI) and can have significant consequences. Early detection of SA is critical, and procalcitonin (PCT) has emerged as a promising biomarker. This study assessed the test performance of PCT and traditional biomarkers for suspected SA.

METHODS

We conducted a prospective study at two pediatric emergency departments (ED). Data collected measured serum levels of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell (WBC) count, and PCT. Box and whisker plots were generated to compare the of the biomarkers by positive MSKI or a non-MSKI diagnosis. The diagnostic performance of biomarkers was examined using the area under the receiver operating characteristic curve (AUC), and optimal cut -points were identified using the Liu method.

RESULTS

Procalcitonin performed reasonably well for detection of MSKI (AUC, 0.72; confidence interval [95% CI], 0.59-0.84). However, CRP and ESR performed better (AUC, 0.88 and 0.78, respectively). White blood cell count was not predictive of MSKI. Patients with a PCT value >0.1 ng/mL, ESR values >19.5 mm/h, and a temperature higher than 99.0°F were more than twice as likely to have acute MSKI. A high CRP level was most predictive of acute MSKI, and patients with levels >2.38 mg/dL were 3.5 times more likely to have acute MSKI.

CONCLUSIONS

Procalcitonin is a potential biomarker for the clinical differential of MSKI in the pediatric ED. Additional research is warranted to establish the optimal diagnostic level for PCT, to increase sample size, and to examine any impact on cost.

A narrative review of the last decade's literature on the diagnostic accuracy of septic arthritis of the native joint

While septic arthritis can be a straightforward diagnosis, there are many cases when the diagnosis is difficult to make. The aim of this study was to review the last decade’s literature on the diagnosis of septic arthritis of the native joint in adults and summarize that data in an easy to follow algorithm to clarify how the last decade’s data may be applied to the diagnosis of septic arthritis. A search of PubMed and CINAHL databases was performed to identify studies that compared results diagnostic tests for septic arthritis. We cross referenced this search with searches of additional databases (including Cochrane Library and Scopus) to confirm similar search results. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool was used by two independent reviewers to determine study quality and risk of bias. After applying inclusion and exclusion criteria to the initial search, 15 papers total were included for analysis. All 15 papers were of high quality methodology as determined by the QUADAS tool. There were 26 different diagnostics tests used across the 15 papers included for review. Three of those diagnostic tests had specificity and sensitivity greater than 80%. Eight tests had a positive likelihood ratio of ≥10. Three tests had a negative likelihood ratio < 0.1, indicating that they may help to rule out septic arthritis. A flowchart was created to summarize the findings of our review, so that physicians may reference this visual in making the appropriate diagnosis when the commonly held standards of cell count, gram stain, and culture aren’t enough to make the diagnosis.

Knee orthopedic problems in newborns and infancy: a review

PURPOSE OF REVIEW

We present the reader with insight on the most common disorders of the knee in newborns and infants. Knee issues in this population may confuse the first contact physicians due to certain peculiarities of the immature immune system, small size and underdevelopment of joint anatomy. Data presented here are recent and significant, and something to bear in mind when caring for children of this age.

RECENT FINDINGS

With the advent of new diagnostic methods, a shift in the causative agent of pediatric knee infections has been noted. Minimally invasive methods such as arthrocentesis and arthroscopy are successfully employed in treatment of knee problems in newborns and infants. A trial of conservative therapy in congenital patellar instability can give good results, and obviate the need for surgery in some cases. Various syndromes that affect the knee have specific characteristics that need to be recognized early to avoid problems in the future.

SUMMARY

Although rare, knee problems in infants can and do occur. Their cause varies significantly and good outcomes require a multidisciplinary approach. Early diagnosis, referral and initiation of treatment protocols can significantly influence the fate of the joint and with it the patients' functional status for life.

Group B streptococcus is the most common pathogen for septic arthritis with unique clinical characteristics: data from 12 years retrospective cohort study

Background

Group B Streptococcus (GBS) emerged as the frequent pathogen for septic arthritis. There was no study comparing risks, clinical presentations and outcomes between GBS septic arthritis and other bacterial septic arthritis.

The aim of this study is to evaluate the differences in risks, clinical presentations, and outcomes of GBS septic arthritis and other bacterial septic arthritis, and identify independent risks and clinical presentations suggesting GBS septic arthritis.

Method

Medical records of patients diagnosed with non-gonococcal bacterial arthritis admitted in Phramongkutklao Hospital during 2006–2018 were reviewed. Associated risks, clinical presentations and outcomes were compared between GBS septic arthritis (GBS group) and other bacterial septic arthritis (other bacterial group).

Result

Two hundred and thirty one cases of non-gonococcal bacterial arthritis confirmed by positive joint fluid cultures and/or hemocultures were included. The three most common pathogens were GBS (37.7%), Staphylococcus aureus (23.4%) and Streptococcus viridans (7.4%). GBS group was more commonly found in rainy season than other bacterial group. Patients in GBS group were less likely to have underlying diseases and had more number of involved joints than those in other bacterial group. The clinical presentations more commonly found in GBS group than other bacterial group were oligo-polyarthritis, upper extremities joint involvement, axial joint involvement, tenosynovitis and central nervous system involvement.

Multivariate analysis found the independent associated factors of GBS arthritis are tenosynovitis, oligo-polyarthritis and rainy season.

Conclusions

GBS is now the most common pathogen for bacterial septic arthritis. The independent associated factors of GBS arthritis were oligo-polyarthritis, tenosynovitis and rainy season.

Electronic supplementary material

The online version of this article (10.1186/s41927-019-0084-5) contains supplementary material, which is available to authorized users.

Role of biomarkers in the diagnosis of bacterial infections in rheumatic diseases

In modern rheumatology, the problem of differential diagnosis of bacterial infection and active rheumatic process still retains its relevance. At the same time, it is very important to search for a biomarker - the gold standard for the diagnosis of an infection in patients with rheumatic diseases (RDs) in order to rapidly determine a treatment policy. This review analyzes the diagnostic significance and possibility of using some laboratory markers for bacterial infections in modern rheumatology. It emphasizes the importance of a multimarker approach that allows increasing the significance of individual parameters in the diagnosis of infections in RD.

Value of serum procalcitonin for the diagnosis of bacterial septic arthritis in daily practice in rheumatology

INTRODUCTION/OBJECTIVES

Septic arthritis is a diagnostic and therapeutic emergency because of a high morbidity and mortality. Nevertheless, the etiologic diagnosis is often difficult. The aim of our study was to determine if serum procalcitonin was a discriminatory biomarker in case of arthritis of undetermined etiology.

METHOD

Patients were separated in five groups: gouty arthritis, calcium pyrophosphate deposition arthritis, osteoarthritis or post-traumatic arthritis ("mechanical" arthritis), chronic inflammatory rheumatic arthritis, and septic arthritis. Levels of serum white blood cells, C-reactive protein and procalcitonin were measured.

RESULTS

Ninety-eight patients were included: 18 in the "gout" group, 26 in the "calcium pyrophosphate deposition arthritis" group, 16 in the mechanical group, 18 in the "chronic inflammatory rheumatic" group, and 20 in the "sepsis" group. The area under the receiver operating characteristic curve of white blood cells, C-reactive protein, and procalcitonin levels to diagnose a septic arthritis were 0.69 (IC95% 0.55-0.83), 0.82 (IC95% 0.73-0.91), and 0.87 (IC95% 0.76-0.98) respectively. For a cutoff of 0.5 ng/ml, procalcitonin sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were 65%, 91%, 65%, 91%, 7.2, and 0.4, respectively. Serum C-reactive protein and procalcitonin levels were correlated, were not different in sepsis or gout groups, and were higher in non-septic arthritis with poly-arthritis than with mono-arthritis (p < 0.05).

CONCLUSIONS

Serum procalcitonin is a useful biomarker in arthritis management with diagnosis performances higher than those of other biomarkers (white blood cells, C-reactive protein).Key Points• Diagnostic performances of serum procalcitonin level in septic arthritis are higher than those of serum C-reactive protein or white blood cells levels.• Serum procalcitonin levels are not different in septic arthritis or gouty arthritis.• Serum procalcitonin levels are higher in non-septic arthritis with poly-arthritis than with mono-arthritis.

[Infections of non-prosthetically treated joints]

BACKGROUND

Septic arthritis is a common orthopedic emergency. Immediate establishment of the diagnosis and administration of an adequate therapy is paramount in minimizing morbidity and mortality in this severe condition.

OBJECTIVE

The aim of the present review was to evaluate the existing evidence in order to give an overview on current best practice in diagnostics and treatment of septic arthritis in adults and children.

RESULTS

Joint infections result from either hematogenous spread or direct inoculation of bacteria into the joint, mostly iatrogenically. Predisposing risk factors include recent orthopedic joint surgery, i. v. drug abuse, pre-existing inflammatory and degenerative joint diseases and old age. Although pathogens differ in different populations and age groups Staphylococcus aureus is the single most frequently isolated causative organism, followed by streptococci. Although diagnosis is based on an integration of medical patient history, clinical and laboratory findings and imaging studies, joint fluid analysis remains the mainstay in establishing a valid diagnosis. The range of differential diagnostics is broad and includes non-infectious inflammatory joint diseases, such as gout or reactive arthritis. Once a diagnosis has been established treatment should be started immediately. Treatment is based on adequate antibiotic therapy and joint drainage until dryness. There is a paucity of studies on the optimal antibiotic regimen, route of application and duration of therapy. Moreover, no high-quality studies exist on the optimal mode of joint drainage. While superiority has yet to be shown, operative treatment in terms of arthroscopic lavage must be considered the standard of care in Germany. Finally, despite promising results in children, the role of corticosteroids as an adjunct to antibiotic treatment in adults has yet to be clarified.

A retrospective study of joint infections in patients with systemic lupus erythematosus

The aim of this study was to analyze the clinical characteristics of systemic lupus erythematosus (SLE) patients with joint infections. We retrospectively reviewed the medical records of 11,734 SLE patients admitted to Peking Union Medical College Hospital (PUMCH) from January 1990 to December 2016. Twenty patients who developed joint infections were identified. Subjects without joint infections (designated as control patients) were selected from the pool of SLE patients using a 1:4 systematic sampling method. The median disease duration from SLE onset to joint infection was 23 months (range 4 to 156 months). The symptoms of patients with joint infections manifested as joint pain (all cases), swelling (14 cases), and fever (15 cases). All patients had oligo-arthritis, and the knee was the joint most commonly affected joint. There were 7 patients in the Salmonella group and 5 in the Staphylococcus aureus group. One patient was infected with Streptococcus, and 7 patients were infected with Mycobacterium. SLE patients with and without joint infections demonstrated significant differences (P < 0.05) regarding the following symptoms: pre-existing arthritis (65.0 vs 33.8%), gastrointestinal involvement (5.0 vs 26.3%), cardiac damage (5.0 vs 31.3%), elevated C-reactive protein (CRP) (80.0 vs 22.5%), and elevated SLE Disease Activity Index (SLEDAI) score (≥5) (30.0 vs 77.5%). When an SLE patient presents with pre-existing arthritis and suddenly develops asymmetric oligo- or large-joint swelling and pain with elevated CRP levels and low disease activity, joint infections should be considered. Early treatment could protect the joint and improve functional outcomes.

Serum procalcitonin levels as a diagnostic marker for septic arthritis: A meta-analysis

BACKGROUND

The aim of this study was to assess the value of serum procalcitonin (PCT) levels as a diagnostic marker for septic arthritis (SA) via meta-analysis.

METHODS

We searched PubMed, Embase and the Cochrane Library, as well as the reference lists of relevant articles, for studies published up to May 21, 2015 and did not impose language restrictions. We selected original studies reporting the usefulness of PCT or C-reactive protein (CRP) as a diagnostic marker for SA. We summarized test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic curves, and bivariate random effects models. Prespecified subgroup analyses and meta-regression analyses were also performed.

RESULTS

This meta-analysis comprised 10 studies including 838 patients. The overall sensitivity of serum PCT levels for the diagnosis of SA in these studies was 0.54 (95% CI, 0.41-0.66), and the specificity of PCT was 0.95 (95% CI, 0.87-0.98). The positive likelihood ratio (LR) was 10.97 (95% CI, 4.65-25.89); the negative LR was 0.49 (95% CI, 0.38-0.62); and the area under ROC curve (AUROC) was 0.82 (95% CI, 0.78-0.85). Six studies also examined the usefulness of CRP levels as a marker for the diagnosis of SA. The sensitivity and specificity of CRP were 0.45 (95% CI, 0.35-0.55) and 0.079 (95% CI, 0.0.021-0.25), respectively, and the positive LR, negative LR and AUROC curve were 0.48 (95% CI, 0.39-0.61), 6.79 (95% CI, 2.04-23.81), and 0.30 (95% CI, 0.26-0.34), respectively.

CONCLUSION

PCT is more valuable than CRP for distinguishing SA from non-SA.

Septic Arthritis of Native Joints

Septic arthritis is a rheumatologic emergency that may lead to disability or death. Prompt evacuation of the joint, either by arthrocentesis at the bedside, open or arthroscopic drainage in the operating room, or imaging-guided drainage in the radiology suite, is mandatory. Methicillin-resistant Staphylococcus aureus (MRSA) has become a major cause of septic arthritis in the United States. MRSA joint infection seems to be associated with worse outcomes. Antibiotic courses of 3 to 4 weeks in duration are usually adequate for uncomplicated bacterial arthritis. Treatment duration should be extended to 6 weeks if there is imaging evidence of accompanying osteomyelitis.

Procalcitonin-guided diagnosis and antibiotic stewardship revisited

Several controlled clinical studies have evaluated the potential of the infection biomarker procalcitonin (PCT) to improve the diagnostic work-up of patients with bacterial infections and its influence on decisions regarding antibiotic therapy. Most research has focused on lower respiratory tract infections and critically ill sepsis patients. A clinical utility for PCT has also been found for patients with urinary tract infections, postoperative infections, meningitis, and patients with acute heart failure with possible superinfection (i.e., pneumonia). In these indications, PCT levels measured on hospital admission were found to substantially reduce the initiation of antibiotic treatment in low-risk situations (i.e., bronchitis, chronic obstructive pulmonary disease exacerbation). For more severe infections (i.e., pneumonia, sepsis), antibiotic stewardship by monitoring of PCT kinetics resulted in shorter antibiotic treatment durations with early cessation of therapy. Importantly, these strategies appear to be safe without increasing the risk for mortality, recurrent infections, or treatment failures. PCT kinetics also proved to have prognostic value correlating with disease severity (i.e., pancreatitis, abdominal infection) and resolution of illness (i.e., sepsis). Although promising findings have been published in these different types of infections, there are a number of limitations regarding PCT, including suboptimal sensitivity and/or specificity, which makes a careful interpretation of PCT in the clinical context mandatory. This narrative review aims to update clinicians on the strengths and limitations of PCT for patient management, focusing on research conducted within the last 4 years.

Significance of Serum Procalcitonin Levels in Differential Diagnosis of Pediatric Pneumonia

The objective of this study was to explore the early diagnosis methods of severe pediatric pneumonia. A total of 65 cases hospitalized in pediatric departments and ICU of our hospital because of severe pneumonia were divided into two groups according to pathogen detection. The groups were as follows: 34 cases of bacterial pneumonia, 32 cases of a non-bacterial pneumonia, and 37 cases of healthy children after physical examination in our hospital as the control group. The peripheral blood was sampled from each of the three groups for procalcitonin (PCT). The pediatric PCT level in peripheral blood of the bacterial pneumonia group was significantly higher than that of non-bacterial pneumonia group and the control group. The statistical differences (each at p < 0.01) and the level of pediatric serum PCT in the bacterial pneumonia group before treatment were statistically different from that in the same group after treatment (p < 0.01), while the level of pediatric serum PCT in non-bacterial pneumonia group before treatment was statistical indifferent from that in the same group after treatment (p > 0.01). PCT level in pediatric peripheral blood is an important diagnostic indicator of bacterial infection and a sensitive indicator of distinction between bacterial pneumonia and the non-bacterial pneumonia, thus being of great significance for clinical and differential diagnosis.

Evaluation of neutrophil-to-lymphocyte ratio as a marker of inflammatory response in septic arthritis

Is neutrophil-to-lymphocyte ratio high in patients with septic arthritis? Septic arthritis may lead to higher rates of morbidity or even mortality if not diagnosed on time. This study was planned to answer the question that “Could neutrophil-to-lymphocyte ratio be utilized to help to diagnose septic arthritis?” The cohort of the study consisted of 39 patients diagnosed with septic arthritis. After ruling out the patients who did not meet the research’s inclusion criteria, the data of 26 patients were evaluated. The control group was collected from healthy volunteers who were admitted to the internal medicine outpatient clinic for a routine medical checkup at the same period (n = 26). Complete blood count (CBC) parameters, C-reactive protein, erythrocyte sedimentation rate, and neutrophil-to-lymphocyte ratios of the septic arthritis and control groups were compared statistically. In comparison, neutrophil-to-lymphocyte ratios of the septic arthritis group were significantly higher than the control group. In conclusion, neutrophil-to-lymphocyte ratio can be utilized in the emergency department or in outpatient clinics to support the diagnosis of septic arthritis.

Septic arthritis in immunocompetent and immunosuppressed hosts

Septic arthritis has long been considered an orthopedic emergency. Historically, Neisseria gonorrhoeae and Staphylococcus aureus have been the most common causes of septic arthritis worldwide but in the modern era of biological therapy and extensive use of prosthetic joint replacements, the spectrum of microbiological causes of septic arthritis has widened considerably. There are also new approaches to diagnosis but therapy remains a challenge, with a need for careful consideration of a combined medical and surgical approach in most cases.