Composition of the cellular infiltrate in patients with simple and complex appendicitis

Pediatric perforated appendicitis diagnosis based on the C-reactive protein/prealbumin ratio

Pediatric perforated appendicitis, prone to multiple complications, necessitates identifying potential serum biomarkers for early diagnosis and intervention. A cross-sectional study was conducted on patients under 16 with acute appendicitis, admitted to Hainan Women and Children's Medical Center from January 2019 to July 2023. The patients were categorized into perforated and non-perforated groups. Among the 313 included patients, 106 (33.87%, 95% CI 28.59-39.14%) developed perforation. The C-reactive protein to prealbumin ratio (CPA) showed a significant difference between the perforated and non-perforated groups [6.63 (2.9-13.02) vs. 0.7 (0.11-2.18), p < 0.001]. The AUC of CPA on the ROC curve was 0.691 (95% CI 0.513-0.869, p = 0.084) in patients under 4. In patients aged 4-9, the sensitivity of CPA > 3 predicting perforation was 76.2%, with a specificity of 81.6%, and an AUC of 0.816 (95% CI 0.747-0.886, p < 0.001). For patients aged 9-16, the sensitivity of CPA > 2.2 predicting perforation was 85%, with a specificity of 85.7%, and an AUC of 0.919 (95% CI 0.859-0.979, p < 0.001). CPA > 3 and CPA > 2.2 can predict perforated appendicitis in patients aged 4-9 and 9-16, respectively.

Enhanced Th17 responses in the appendix of children with complex compared to simple appendicitis are associated with microbial dysbiosis

Introduction

Appendicitis is one of the most common causes of acute abdominal surgery in children. The clinical course of appendicitis ranges from simple to complex appendicitis. The mechanisms underlying the heterogeneity of appendicitis in children remain largely unclear. Dysregulated T cell responses play an important role in several inflammatory diseases of the intestine, but the extend of T cell dysregulation in appendicitis in children is less well known.

Methods

To characterize appendiceal T cells in simple and complex appendicitis we performed in-depth immunophenotyping of appendiceal-derived T cells by flow cytometry and correlated this to appendiceal-derived microbiota analyses of the same patient.

Results

Appendix samples of twenty children with appendicitis (n = 8 simple, n = 12 complex) were collected. T cells in complex appendicitis displayed an increased differentiated phenotype compared to simple appendicitis, including a loss of both CD27 and CD28 by CD4+ T cells and to a lesser extent by CD8+ T cells. Frequencies of phenotypic tissue-resident memory CD69+CD4+ T cells and CD69+CD8+ T cells were decreased in children with complex compared to simple appendicitis, indicating disruption of local tissue-resident immune responses. In line with the increased differentiated phenotype, cytokine production of in particular IL-17A by CD4+ T cells was increased in children with complex compared to simple appendicitis. Furthermore, frequencies of IL-17A+ CD4+ T cells correlated with a dysregulation of the appendiceal microbiota in children with complex appendicitis.

Conclusion

In conclusion, disruption of local T cell responses, and enhanced pro-inflammatory Th17 responses correlating to changes in the appendiceal microbiota were observed in children with complex compared to simple appendicitis. Further studies are needed to decipher the role of a dysregulated network of microbiota and Th17 cells in the development of complex appendicitis in children.

Analysis of type I hypersensitivity-induced inflammatory response in children of different age groups with acute appendicitis

OBJECTIVE

To explore the differences in type I hypersensitivity-induced inflammatory response among children of different age groups with acute appendicitis.

METHODS

We selected children diagnosed with "acute appendicitis" who underwent surgery in the Department of General Surgery of Anhui Provincial Children's Hospital from January 2022 to June 2022 and collected their basic data. We divided them into two groups according to age: the infant group (less than 3 years old) and the pediatric group (3-14 years old). The gender, age, onset time, hospital stay, preoperative white blood cells, percentage of neutrophils, C-reactive protein (CRP), and enzyme-linked immunosorbent assay (ELISA) were collected to determine the levels of immunoglobulin E (IgE), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-6 (IL-6), and interleukin-9 (IL-9) in appendicular lavage fluid, and the differences between the two groups were compared.

RESULTS

There were 15 children in the infant group and 15 in the pediatric group. There was no significant difference between the two groups with respect to onset time and gender. The hospitalization time in the pediatric group was (5.7 ± 2.1) d, the preoperative white blood cells were (14.3 ± 3.7) × 10^9/mL, neutrophil percentage was (84.5 ± 6.3)%, and CRP was (20.0 ± 17.9) mg/mL. The hospitalization time of the infant group was (8.0 ± 3.1) d, the preoperative white blood cells were (19.0 ± 3.8) × 10^9/mL, neutrophil percentage was (77.8 ± 10.4)%, and CRP was (42.5 ± 25.0) mg/mL. The differences between the two groups were significant. There was no significant difference in IL-5 concentration between the two groups in the appendicular lavage fluid. IgE (610.74 ± 72.56) ng/mL, IL-4 (30.80 ± 12.04) ng/mL, IL-6 (118.09 ± 14.29) ng/mL, IL-9 (133.94 ± 16.00) ng/mL were found in the infant group, and IgE (495.61 ± 95.09) ng/mL, IL-4 (22.68 ± 7.05) ng/mL, IL-6 (98.22 ± 22.18) ng/mL and IL-9 (107.86 ± 27.34) ng/mL were found in the pediatric group, and the differences between the two groups were statistically significant.

CONCLUSIONS

The inflammatory response in children with acute appendicitis was associated with type I hypersensitivity-induced inflammatory responses, and the type I hypersensitivity was more intense in children in the lower age group.

Non-culture-based studies of the appendiceal microbiota: a systematic review

Aims: To review studies examining the appendiceal microbiota and microbial changes in acute appendicitis. Methods: After a systematic literature search, 11 studies examining the appendiceal microbiota (414 samples) using non-culture-based methods were included. Results: The appendiceal microbiota showed decreased α-diversity compared with fecal microbiota. Inflamed and uninflamed appendices showed differences in β-diversity, and there was an increased abundance of oral-associated bacteria in inflamed versus uninflamed appendices. Conclusion: The appendiceal microbiota exhibits lower α-diversity than the fecal microbiota, with an increased abundance of oral-associated bacteria. Compared with uninflamed appendices, the appendix microbiota in acute appendicitis also showed increased abundance of oral-associated bacteria, but no bacterial profile unique to either complicated or uncomplicated appendicitis was found.

The development and application of pediatric complicated appendicitis prediction model

BACKGROUND

Acute appendicitis in children refers to the acute inflammation of the appendix, which accounts for 20% ∼ 30% of cases of acute abdomen in pediatric surgery.

OBJECTIVE

This study aimed to establish a decision tree model of complicated appendicitis in children using appendiceal ultrasound combined with an inflammatory index and evaluated its clinical efficacy in pediatric patients.

METHODS

A total of 395 children admitted to the Emergency Department of the Shanghai Children's Hospital from January 2018 to December 2021 and diagnosed with appendicitis by postoperative pathology were retrospectively analyzed. According to the postoperative pathology, the children were divided into a complicated and non-complicated appendicitis group, respectively. Routine laboratory inflammatory indicators, including white blood cell count, N(%), neutrophil (Neu) count, Neu/lymphocyte ratio (NLR), C-reactive protein (CRP), and procalcitonin were collected from the two groups. Collecting data on ultrasound examination of the appendix includes whether the appendix diameter is thickened, whether the echogenicity of the mesenteric rim surrounding the appendix is enhanced, whether there is rich blood supply in the appendix, and whether there are fecaliths in the appendix lumen. The risk factors for complicated appendicitis were screened out by univariate and multivariate logistic regression analyses, the binary logistic regression prediction and decision tree models were established, respectively, and the receiver operating characteristic (ROC) curve was used to verify the accuracy of the two prediction models.

RESULTS

Binary logistic regression analysis showed that CRP, NLR, the presence of an appendicolith, and peripheral retina echo enhancement were independent risk factors for complicated appendicitis in children (P< 0.05). The decision tree model had an overall accuracy of 79%, an area under the ROC curve (AUC) of 0.809 (95% confidence interval [CI] 0.780-0.865), and sensitivity and specificity of 71.3% and 77.7%, respectively. The logistic regression model had an overall accuracy of 74.9%, an AUC value of 0.823 (95% CI, 0.765-0.853), a sensitivity value of 80.3%, and a specificity of 71.8%.

CONCLUSION

This predictive model, based on ultrasound of the appendix combined with inflammatory markers, provides a useful method to assist pediatric emergency physicians in diagnosing childhood appendicitis. The decision tree model reflected the interaction of various indexes, and the model was simple, intuitive, and effective.

The use of the ratio of C-reactive protein to albumin for the diagnosis of complicated appendicitis in children

PURPOSE

No reliably specific marker for complicated appendicitis has been identified. The ratio of serum C-reactive protein (CRP) to albumin (ALB) (CRP/ALB ratio) is a new inflammation-based prognostic score that is associated with the severity of inflammation. The aim of this study was to evaluate the predictive value of CRP/ALB ratio for the diagnosis of complicated appendicitis in children.

METHODS

A retrospective study of 296 children with acute appendicitis was conducted with assessments of demographic data, clinical symptoms, pre-operative laboratory results, abdominal ultrasound examinations and clinical outcomes. According to the postoperative pathological results, patients were divided into a simple appendicitis group (169 patients) and a complicated appendicitis group (127 patients). SPSS version 22.0 was used to analyse the data.

RESULTS

Of the 296 patients, CRP/ALB ratio was higher in complicated appendicitis than in simple appendicitis (P < 0.05). Logistic regression analysis showed that higher levels of white blood cell count (WBC), CRP, CRP/ALB ratio, and increased incidence in submucosal layer loss and appendicolith were independent risk factors for complicated appendicitis in children. Receiver operating characteristic curve analysis showed that the area under the curve of the CRP/ALB ratio (0.883) was larger than that of WBC (0.702), CRP (0.802), ALB (0.835), submucosal layer loss (0.633) and appendicolith (0.673). A CRP/ALB ratio ≥ 1.39 was found to be a significant marker in the prediction of complicated appendicitis, with 86.61% sensitivity and 84.62% specificity. Patients with a CRP/ALB ratio ≥ 1.39 had a 31.263 times higher chance of having complicated appendicitis (95% CI: 16.449-59.418) than those with a CRP/ALB ratio < 1.39.

CONCLUSION

The admission CRP/ALB ratio was significantly higher in children with complicated appendicitis. The CRP/ALB ratio is a novel but promising haematological marker that aids in the differentiation of acute complicated and simple appendicitis.

Low intra-operative diagnostic accuracy does not affect postoperative treatment of acute appendicitis

BACKGROUND

The intra-operative classification of appendicitis defines postoperative treatment. The correct designation can influence patient recovery, complications and hospital costs. Recent research has shown that intra-operative classification criteria varies among surgeons, and is not always the same as the pathologist's report. Classification accuracy can lower costs by preventing unnecessary treatment or sub-optimal interventions.

METHODS

During a period of 4 months, N = 133 appendix specimens were received and evaluated by the pathology department of a single teaching hospital. Five surgeons extracted the specimens and one experienced pathologist drew the histopathology reports. A comparison between the surgeons' classifications and the pathologist's was made. Classification accuracy was determined and statistical analyses was performed using chi-square, and p values were obtained. A p < 0.05 was considered significant.

RESULTS

A total of N = 133 specimens were obtained, 127 belonged to patients following emergency surgery due to acute abdominal pain; the other six were from elective hemi-colectomies for right colonic adenocarcinomas, and were not included. Of the 127 specimens analyzed, 14 (11%) were negative, 21 (16.5%) were edematous, 81 (63.7%) were phlegmonous and 11 (8.6%) were gangrenous. A total of 18 (14%) perforated appendices were also reported. Surgical accuracy was 60.6% (N = 67) with a statistically significant p < 0.001. Only five patients with incorrect intraoperative classifications received unnecessary or lacked treatment.

CONCLUSIONS

An overall accuracy of 60.6% is seen when the surgical classification is compared to the pathological classification. Although the surgeons' accuracy is low when comparing intra-operative versus histopathological classification, this variation in designation does not affect postoperative treatment significantly.

Blockage of C-C Chemokine Ligand 2 Alleviated the Appendicitis-Induced Injury in Rabbit Model

C-C chemokine ligand 2 (CCL2), a low-molecular-weight cytokine, is upregulated in inflammation-related diseases. However, the underlying function of CCL2 remains unknown in human appendicitis. The present study aimed to examine the role of CCL2 in appendicitis. An enzyme-linked immunosorbent assay was performed to examine the secretion of CCL2 in the peripheral blood of patients with simple and complex appendicitis, respectively. A flow cytometry assay was used to quantify the level of the CCL2 receptor, CCR2. Moreover, we constructed an appendicitis model in rabbits. Quantitative real time-polymerase chain reaction and Western blot were used to determine CCL2 and CCR2 levels in the appendicitis model. CCL2 antibodies were used to silence the endogenous activity of CCL2 in vivo. Magnetic resonance imaging and a histopathology assay were used to examine the appendicitis-induced injury in rabbits. Our results suggested that CCL2 and its main receptor CCR2 were upregulated in patients with appendicitis, particularly those with complex appendicitis (gangrenous and perforated appendicitis). Moreover, CCL2 silencing alleviated the appendicitis-induced injury in rabbits. Our findings not only illustrate the potential value of CCL2 as a biomarker in appendicitis diagnosing but also provide novel insight into appendicitis treatment.

A clinical prediction model for complicated appendicitis in children younger than five years of age

Background

No reliably specific method for complicated appendicitis has been identified in children younger than five years of age. This study aimed to analyze the independent factors for complicated appendicitis in children younger than five years of age, develop and validate a prediction model for the differentiation of simple and complicated appendicitis.

Methods

A retrospective study of 382 children younger than five years of age with acute appendicitis from January 2007 to December 2016 was conducted with assessments of demographic data, clinical symptoms and signs, and pre-operative laboratory results. According to intraoperative findings and postoperative pathological results, acute appendicitis was divided into simple and complicated appendicitis. Univariate and multivariate analyses were used to screen out the independent factors of complicated appendicitis, and develop a prediction model for complicated appendicitis. Then 156 such patients from January 2017 to December 2019 were collected as validation sample to validate the prediction model. Test performance of the prediction model was compared with the ALVARADO score and Pediatric Appendicitis Score (PAS).

Results

Of the 382 patients, 244 (63.9%) had complicated appendicitis. Age, white blood cell count, and duration of symptoms were the independent factors for complicated appendicitis in children younger than five years of age. The final predication model for complicated appendicitis included factors above. In validation sample, the prediction model exhibited a high degree of discrimination (area under the curve [AUC]: 0.830; 95% confidence interval [CI]: 0.762–0.885) corresponding to a optimal cutoff value of 0.62, and outperformed the PAS (AUC: 0.735; 95% CI: 0.658–0.802), ALVARADO score (AUC: 0.733; 95% CI: 0.657–0.801).

Conclusion

Age, white blood cell count, and duration of symptoms could be used to predict complicated appendicitis in children younger than five years of age with acute appendicitis. The prediction model is a novel but promising method that aids in the differentiation of acute simple and complicated appendicitis.

Appendicolith appendicitis is clinically complicated acute appendicitis-is it histopathologically different from uncomplicated acute appendicitis

PURPOSE

Acute appendicitis may present as uncomplicated and complicated and these disease forms differ both epidemiologically and clinically. Complicated acute appendicitis has traditionally been defined as an appendicitis complicated by perforation or a periappendicular abscess, and an appendicolith represents a predisposing factor of complicated disease. There are histopathological differences between uncomplicated acute appendicitis and the previously established traditional forms of complicated acute appendicitis, but to our knowledge, the histopathological differences between uncomplicated acute appendicitis and complicated acute appendicitis presenting with an appendicolith have not yet been reported. The study purpose was to assess these differences with two prospective patient cohorts: (1) computed tomography (CT) confirmed uncomplicated acute appendicitis patients enrolled in the surgical treatment arm of the randomized APPAC trial comparing appendectomy with antibiotics for the treatment of uncomplicated acute appendicitis and (2) patients with CT-verified acute appendicitis presenting with an appendicolith excluded from the APPAC trial.

METHODS

The following histopathological parameters were assessed: appendiceal diameter, depth of inflammation, micro-abscesses, density of eosinophils, and neutrophils in appendiceal wall and surface epithelium degeneration.

RESULTS

Using multivariable logistic regression models adjusted for age, gender, and symptom duration, statistically significant differences were detected in the depth of inflammation ≤ 2.8 mm (adjusted OR 2.18 (95%CI: 1.29-3.71, p = 0.004), micro-abscesses (adjusted OR 2.16 (95%CI: 1.22-3.83, p = 0.008), the number of eosinophils and neutrophils ≥ 150/mm² (adjusted OR 0.97 (95%CI: 0.95-0.99, p = 0.013), adjusted OR 3.04 (95%CI: 1.82-5.09, p < 0.001, respectively).

CONCLUSIONS

These results corroborate the known clinical association of an appendicolith to complicated acute appendicitis.