Admission levels of serum amyloid a and procalcitonin are more predictive of the diagnosis of acute appendicitis compared with C-reactive protein

Management of Intra-Abdominal Infections: The Role of Procalcitonin

Patients with intra-abdominal sepsis suffer from significant mortality and morbidity. The main pillars of treatment for intra-abdominal infections are (1) source control and (2) early delivery of antibiotics. Antibiotic therapy should be started as soon as possible. However, the duration of antibiotics remains a matter of debate. Prolonged antibiotic delivery can lead to increased microbial resistance and the development of nosocomial infections. There has been much research on biomarkers and their ability to aid the decision on when to stop antibiotics. Some of these biomarkers include interleukins, C-reactive protein (CRP) and procalcitonin (PCT). PCT's value as a biomarker has been a focus area of research in recent years. Most studies use either a cut-off value of 0.50 ng/mL or an >80% reduction in PCT levels to determine when to stop antibiotics. This paper performs a literature review and provides a synthesized up-to-date global overview on the value of PCT in managing intra-abdominal infections.

The Use of Procalcitonin in the Diagnosis of Acute Appendicitis: A Systematic Review

BACKGROUND

Acute appendicitis (AA) is one of the most common surgical pathologies. Its diagnosis is often carried out based on clinical signs and symptoms, with additional minimally invasive tests (i.e., blood testing) done to support the diagnosis. Procalcitonin (PCT) is a relatively novel biomarker that is starting to be used by clinicians for patients admitted into hospitals with a variety of infections. Its level can be used to identify the presence of infection. The aim of this review is to assess how useful PCT is as a biomarker in supporting clinicians' assessment of patients with suspected appendicitis.

METHODS

A systematic literature search was carried out, yielding a total of 16 primary research papers deemed appropriate for appraisal.

RESULTS

The usefulness of PCT in aiding the diagnosis of AA depends on the severity of appendicitis. Patients who experience complicated appendicitis (CAA) such as perforation, gangrene, or necrosis have a significantly raised PCT level (p<0.05) compared to those with uncomplicated appendicitis (UAA) and a variety of other non-appendiceal intra-abdominal pathologies.

CONCLUSIONS

The use of PCT in UAA is weak, however, PCT was deemed useful in helping predict CAA, thus helping portray the severity of infection. This, in turn, will help ensure patients are taken to the operating theatre in a timely and safe manner for subsequent appendicectomy.

Diagnostic Accuracy of Serum Amyloid A in Acute Appendicitis: A Systematic Review and Meta-Analysis

Background: Serum amyloid A has been widely reported as a useful biochemical marker in the diagnoses of acute appendicitis. The aim of this study was to appraise the diagnostic accuracy of serum amyloid A in the diagnosis of acute appendicitis. Methods: A systematic search of several databases was conducted. The search time was from the beginning of the databases creation to March 1, 2021, and the languages were restricted to English and Chinese. Clinical studies using serum amyloid A for the diagnosis of acute appendicitis were included. The overall sensitivity and specificity were calculated by using a bivariable mixed effects model. Heterogeneity was tested using I² statistics. This study has been registered on the International Prospective Register of Systematic Reviews (PROSPERO; no. CRD42021241343). Results: Five studies comprising 668 participants were eligible for inclusion. The overall sensitivity and specificity of serum amyloid A in diagnosing acute appendicitis were 0.87 (95% confidence interval [CI], 0.79-0.92) and 0.74 (95% CI, 0.59-0.85), respectively. The positive and negative likelihood were 3.3 (95% CI, 2.1-5.4) and 0.18 (95% CI, 0.11-0.28), respectively. The area under the summary receiver operating characteristic curves was 0.89 (95% CI, 0.86-0.91). The heterogeneity was significant (I² = 82%; 95% CI [63%-100%]). Conclusions: Serum amyloid A has good diagnostic accuracy for acute appendicitis. It is expected that serum amyloid A could be helpful in the early clinical diagnosis of acute appendicitis.

Metabolomics and Inflammatory Mediator Profiling for the Differentiation of Life-Threatening and Non-Severe Appendicitis in the Pediatric Population

While children with appendicitis often have excellent clinical outcomes, some develop life-threatening complications including sepsis and organ dysfunction requiring pediatric intensive care unit (PICU) support. Our study applied a metabolomics and inflammatory protein mediator (IPM) profiling approach to determine the bio-profiles of children who developed severe appendicitis compared with those that did not. We performed a prospective case-control study of children aged 0-17 years with a diagnosis of appendicitis. Cases had severe disease resulting in PICU admission. Primary controls had moderate appendicitis (perforation without PICU); secondary controls had mild appendicitis (non-perforated). Serum samples were analyzed using Proton Nuclear Magnetic Resonance (¹H NMR) Spectroscopy and Gas Chromatography-Mass Spectrometry (GC-MS); IPM analysis was performed using plasma bead-based multiplex profiling. Comparisons were made using multivariate data statistical analysis. Fifty-three children were included (15 severe, 38 non-severe). Separation between severe and moderate appendicitis demonstrated excellent sensitivity and specificity (100%, 88%; 14 compounds), separation between severe and mild appendicitis also showed excellent sensitivity and specificity (91%, 90%; 16 compounds). Biomarker patterns derived from metabolomics and IPM profiling are capable of distinguishing children with severe appendicitis from those with less severe disease. These findings provide an important first step towards developing non-invasive diagnostic tools for clinicians in early identification of children who are at a high risk of developing severe appendicitis.

Novel molecular biomarkers and diagnosis of acute appendicitis in children

Reliable and efficient diagnosis of pediatric appendicitis is essential for the establishment of a clinical management plan and improvement of patient outcomes. Current strategies used to diagnose a child presenting with a suspected appendicitis include laboratory studies, clinical scores and diagnostic imaging. Although these modalities work in conjunction with each other, one optimal diagnostic strategy has yet to be agreed upon. The recent introduction of precision medicine techniques such as genomics, transcriptomics, proteomics and metabolomics has increased both the diagnostic sensitivity and specificity of appendicitis. Using these novel strategies, the integration of precision medicine into clinical practice via point-of-care technologies is a plausible future. These technologies would assist in the screening, diagnosis and prognosis of pediatric appendicitis.

Role of circulating fibrocytes in the diagnosis of acute appendicitis

Background

Improved diagnostic biomarkers are required for acute appendicitis. The circulating fibrocyte percentage (CFP) is increased in inflammatory states, but has not been studied in acute appendicitis. This study aimed to determine CFP in acute appendicitis and compare diagnostic accuracy with standard serological biomarkers.

Methods

A prospective cohort study was carried out between June 2015 and February 2016 at University Hospital Limerick. The CFP was determined by dual‐staining peripheral venous samples for CD45 and collagen I using fluorescence‐activated cell sorting, and correlated with histopathological diagnoses. The accuracy of CFP in determining histological acute appendicitis was characterized and compared with the white cell count, C‐reactive protein concentration, neutrophil count, lymphocyte count and neutrophil : lymphocyte ratio.

Results

Of 95 adults recruited, 15 were healthy individuals and 80 had suspected appendicitis at presentation. Forty‐six of these 80 patients had an appendicectomy, of whom 34 had histologically confirmed appendicitis. The CFP was statistically higher in patients with pathologically proven acute appendicitis than in healthy controls (median 6·1 (i.q.r. 1·6–11·6) versus 2·3 (0·9–3·4) per cent respectively; P = 0·008). The diagnostic accuracy of CFP, as determined using the area under the receiver operating characteristic (ROC) curve, was similar to that of standard biomarkers. In multinomial regression analysis, only raised CFP was retained as an independent prognostic determinant of acute appendicitis (odds ratio 1·57, 95 per cent c.i. 1·05 to 2·33; P = 0·027).

Conclusion

The CFP is increased in histologically confirmed acute appendicitis and is as accurate as standard serological biomarkers in terms of diagnosis.

Diagnostic accuracy of procalcitonin for overall and complicated acute appendicitis in children: a meta-analysis

Background

Diagnostic value of procalcitonin (PCT) for acute appendicitis (AA) has been evaluated in adult patients, but the application in children remains controversial. The aim of this study was to evaluate the diagnostic value of PCT for overall and complicated AA in children.

Methods

The PubMed, EMBASE, Web of Science, Cochrane Database of Systematic Reviews, Chinese National Knowledge Infrastructure, and Wanfang were searched along with reference lists of relevant articles up to January 2018 without language restrictions. Original articles that reported the performance of PCT in the diagnosis of pediatric AA and associated complications were selected. To assess the diagnostic value of PCT, sensitivity, specificity, diagnostic odds ratios (DORs), summary receiver operating characteristic (ROC) curves, area under the curve (AUC), and 95% confidence intervals (95% CIs) were estimated.

Results

Seven qualifying studies (504 confirmed AA and 368 controls) from 6 countries for overall AA and 4 studies (187 complicated AA and 185 uncomplicated AA) for complicated AA from 3 countries were identified. The pooled sensitivity and specificity of PCT for the diagnosis of pediatric AA were 0.62 (95% CI: 0.57–0.66) and 0.86 (95% CI: 0.82–0.89), respectively. The DOR was 21.4 (95% CI: 3.64–126.1) and the AUC was 0.955. PCT was more accurate in diagnosing complicated appendicitis, with a pooled sensitivity of 0.89 (95% CI: 0.84–0.93), specificity of 0.90 (95% CI: 0.86–0.94), and DOR of 76.73 (95% CI: 21.6–272.9).

Conclusion

This meta-analysis showed that PCT may have potential value in diagnosing pediatric AA. Moreover, PCT had greater diagnostic value in identifying pediatric complicated appendicitis.

Cytokines and Chemokines in Pediatric Appendicitis: A Multiplex Analysis of Inflammatory Protein Mediators

OBJECTIVES

We aimed to demonstrate the potential of precision medicine to describe the inflammatory landscape present in children with suspected appendicitis. Our primary objective was to determine levels of seven inflammatory protein mediators previously associated with intra-abdominal inflammation (C-reactive protein-CRP, procalcitonin-PCT, interleukin-6 (IL), IL-8, IL-10, monocyte chemoattractant protein-1-MCP-1, and serum amyloid A-SAA) in a cohort of children with suspected appendicitis. Subsequently, using a multiplex proteomics approach, we examined an expansive array of novel candidate cytokine and chemokines within this population.

METHODS

We performed a secondary analysis of targeted proteomics data from Alberta Sepsis Network studies. Plasma mediator levels, analyzed by Luminex multiplex assays, were evaluated in children aged 5-17 years with nonappendicitis abdominal pain (NAAP), acute appendicitis (AA), and nonappendicitis sepsis (NAS). We used multivariate regression analysis to evaluate the seven target proteins, followed by decision tree and heat mapping analyses for all proteins evaluated.

RESULTS

185 children were included: 83 with NAAP, 79 AA, and 23 NAS. Plasma levels of IL-6, CRP, MCP-1, PCT, and SAA were significantly different in children with AA compared to those with NAAP (p < 0.001). Expansive proteomic analysis demonstrated 6 patterns in inflammatory mediator profiles based on severity of illness. A decision tree incorporating the proteins CRP, ferritin, SAA, regulated on activation normal T-cell expressed and secreted (RANTES), monokine induced by gamma interferon (MIG), and PCT demonstrated excellent specificity (0.920) and negative predictive value (0.882) for children with appendicitis.

CONCLUSIONS

Multiplex proteomic analyses described the inflammatory landscape of children presenting to the ED with suspected appendicitis. We have demonstrated the feasibility of this approach to identify potential novel candidate cytokines/chemokine patterns associated with a specific illness (appendicitis) amongst those with a broad ED presentation (abdominal pain). This approach can be modelled for future research initiatives in pediatric emergency medicine.

The diagnostic values of procalcitonin and interleukin 6 in acute appendicitis

OBJECTIVE

Despite the recent use of computed tomography scan and diagnostic laparoscopy, acute appendicitis is still highly misdiagnosed. Timely diagnosis of acute appendicitis is more crucial in children and elderly patients because of vague symptoms and rapid progression to perforation in these age groups, which may result in high rates of morbidity and mortality. The aim of the present study was to find the diagnostic values of procalcitonin and interleukin 6 (IL-6) for diagnosing acute appendicitis in our center.

MATERIAL AND METHODS

Patients who were suspected of acute appendicitis and who were referred to the emergency department of a tertiary care urban hospital in 2016 were enrolled in the study. A 5 mL blood sample was obtained from each patient before appendectomy and was examined for procalcitonin and IL-6. Then, the resected specimen of the appendix was studied by a pathologist, and a definite diagnosis was made.

RESULTS

Eighty patients including 53 (66.3%) men who underwent appendectomy were enrolled in the study. The diagnosis of acute appendicitis was histopathologically confirmed in 60 (75%) patients including 18, 20, and 22 patients with inflammatory, suppurative, and gangrenous/perforated appendicitis, respectively. The sensitivity and specificity of procalcitonin versus IL-6 for diagnosing acute appendicitis were 65% and 80% vs. 76% and 55%, respectively. The sensitivity and specificity of concurrent procalcitonin and IL-6 for diagnosing acute appendicitis were 95% and 55%, respectively.

CONCLUSION

Our study suggests that parallel measurement of procalcitonin and IL-6 decreases unnecessary negative appendectomies.

Diagnostic Accuracy of Serum and Urine S100A8/A9 and Serum Amyloid A in Probable Acute Abdominal Pain at Emergency Department

Study Design

This study was performed to investigate the diagnostic values of some inflammatory biomarkers in abdominal pain.

Methods

Patients over 18 years of age with acute recent abdominal pain who presented to the Emergency Department were evaluated. Serum and urinary samples were taken and evaluated for serum and urine S100A8/A9 and serum amyloid A. All patients were referred to a surgeon and were followed up until the final diagnosis. In the end, the final diagnosis was compared with the levels of biomarkers.

Results

Of a total of 181 patients, 71 underwent surgery and 110 patients did not need surgery after they were clinically diagnosed. Mean levels of serum and urine S100A8/A9 had a significant difference between two groups, but serum amyloid A did not show. The diagnostic accuracy of serum S100A8/A9, urine S100A8/A9, and serum amyloid A was 86%, 79%, and 50%, respectively, in anticipation of the need or no need for surgery in acute abdominal pain.

Conclusions

Our study showed that in acute abdominal pain, serum and urine S100A8/A9 can be useful indicators of the need for surgery, but serum amyloid A had a low and nonsignificant diagnostic accuracy.

Metabolomic and inflammatory mediator based biomarker profiling as a potential novel method to aid pediatric appendicitis identification

Various limitations hinder the timely and accurate diagnosis of appendicitis in pediatric patients. The present study aims to investigate the potential of metabolomics and cytokine profiling for improving the diagnosis of pediatric appendicitis. Serum and plasma samples were collected from pediatric patients for metabolic and inflammatory mediator analyses respectively. Targeted metabolic profiling was performed using Proton Nuclear Magnetic Resonance Spectroscopy and Flow Injection Analysis Mass Spectrometry/Mass Spectrometry and targeted cytokine/chemokine profiling was completed using a multiplex platform to compare children with and without appendicitis. Twenty-three children with appendicitis and 35 control children without appendicitis from the Alberta Sepsis Network pediatric cohorts were included. Metabolomic profiling revealed clear separation between the two groups with very good sensitivity (80%), specificity (97%), and AUROC (0.93 ± 0.05) values. Inflammatory mediator analysis also distinguished the two groups with high sensitivity (82%), specificity (100%), and AUROC (0.97 ± 0.02) values. A biopattern comprised of 9 metabolites and 7 inflammatory compounds was detected to be significant for the separation between appendicitis and control groups. Integration of these 16 significant compounds resulted in a combined metabolic and cytokine profile that also demonstrated strong separation between the two groups with 81% sensitivity, 100% specificity and AUROC value of 0.96 ± 0.03. The study demonstrated that metabolomics and cytokine mediator profiling is capable of distinguishing children with appendicitis from those without. These results suggest a potential new approach for improving the identification of appendicitis in children.

Biomarkers of acute appendicitis: systematic review and cost-benefit trade-off analysis

Background

Acute appendicitis is the most common surgical emergency and can represent a challenging diagnosis, with a negative appendectomy rate as high as 20 %. This review aimed to evaluate the clinical utility of individual biomarkers in the diagnosis of appendicitis and appraise the quality of these studies.

Methods

A systematic review of the literature between January 2000 and September 2015 using of PubMed, OvidMedline, EMBASE and Google Scholar was conducted. Studies in which the diagnostic accuracy, statistical heterogeneity and predictive ability for severity of several biomarkers could be elicited were included. Information regarding costs and process times was retrieved from the regional laboratory. European surgeons blinded to these reviews were independently asked to rank which characteristics of biomarkers were most important in acute appendicitis to inform a cost–benefit trade-off. Sensitivity testing and the QUADAS-2 tool were used to assess the robustness of the analysis and study quality, respectively.

Results

Sixty-two studies met the inclusion criteria and were assessed. Traditional biomarkers (such as white cell count) were found to have a moderate diagnostic accuracy (0.75) but lower costs in the diagnosis of acute appendicitis. Conversely, novel markers (pro-calcitonin, IL 6 and urinary 5-HIAA) were found to have high process-related costs including analytical times, but improved diagnostic accuracy. QUADAS-2 analysis revealed significant potential biases in the literature.

Conclusion

When assessing biomarkers, an appreciation of the trade-offs between the costs and benefits of individual biomarkers is needed. Further studies should seek to investigate new biomarkers and address concerns over bias, in order to improve the diagnosis of acute appendicitis.

Electronic supplementary material

The online version of this article (doi:10.1007/s00464-016-5109-1) contains supplementary material, which is available to authorized users.

The use of platelet indices, plateletcrit, mean platelet volume and platelet distribution width in emergency non-traumatic abdominal surgery: a systematic review

Platelet indices (PI) -- plateletcrit, mean platelet volume (MPV) and platelet distribution width (PDW) -- are a group of derived platelet parameters obtained as a part of the automatic complete blood count. Emerging evidence suggests that PIs may have diagnostic and prognostic value in certain diseases. This study aimed to summarize the current scientific knowledge on the potential role of PIs as a diagnostic and prognostic marker in patients having emergency, non-traumatic abdominal surgery. In December 2015, we searched Medline/PubMed, Scopus and Google Scholar to identify all articles on PIs. Overall, considerable evidence suggests that PIs are altered with acute appendicitis. Although the role of PI in the differential diagnosis of acute abdomen remains uncertain, low MPV might be useful in acute appendicitis and acute mesenteric ischemia, with high MPV predicting poor prognosis in acute mesenteric ischemia. The current lack of consistency and technical standards in studies involving PIs should be regarded as a serious limitation to comparing these studies. Further large, multicentre prospective studies concurrently collecting data from different ethnicities and genders are needed before they can be used in routine clinical practice.

Hereditary Angioedema and Gastrointestinal Complications: An Extensive Review of the Literature

Hereditary Angioedema (HAE) is a rare autosomal dominant (AD) disease characterized by deficient (type 1) or nonfunctional (type 2) C1 inhibitor protein. The disorder is associated with episodes of angioedema of the face, larynx, lips, abdomen, or extremities. The angioedema is caused by the activation of the kallikrein-kinin system that leads to the release of vasoactive peptides, followed by edema, which in severe cases can be life threatening. The disease is usually not diagnosed until late adolescence and patients tend to have frequent episodes that can be severely impairing and have a high incidence of morbidity. Gastrointestinal involvement represents up to 80% of clinical presentations that are commonly confused with other gastrointestinal disorders such as appendicitis, cholecystitis, pancreatitis, and ischemic bower. We present a case of an HAE attack presenting as colonic intussusception managed conservatively with a C1 esterase inhibitor. Very few cases have been reported in the literature of HAE presentation in this manner, and there are no reports of any nonsurgical management of these cases.