Acute appendicitis: transcript profiling of blood identifies promising biomarkers and potential underlying processes

Blood RNA Biomarkers Identify Bacterial and Biofilm Coinfections in COVID-19 Intensive Care Patients

Purpose: Secondary opportunistic coinfections are a significant contributor to morbidity and mortality in intensive care unit (ICU) patients, but can be difficult to identify. Presently, new blood RNA biomarkers were tested in ICU patients to diagnose viral, bacterial, and biofilm coinfections. Methods: COVID-19 ICU patients had whole blood drawn in RNA preservative and stored at -80°C. Controls and subclinical infections were also studied. Droplet digital polymerase chain reaction (ddPCR) quantified 6 RNA biomarkers of host neutrophil activation to bacterial (DEFA1), biofilm (alkaline phosphatase [ALPL], IL8RB/CXCR2), and viral infections (IFI27, RSAD2). Viral titer in blood was measured by ddPCR for SARS-CoV2 (SCV2). Results: RNA biomarkers were elevated in ICU patients relative to controls. DEFA1 and ALPL RNA were significantly higher in severe versus incidental/moderate cases. SOFA score was correlated with white blood cell count (0.42), platelet count (-0.41), creatinine (0.38), and lactate dehydrogenase (0.31). ALPL RNA (0.59) showed the best correlation with SOFA score. IFI27 (0.52) and RSAD2 (0.38) were positively correlated with SCV2 viral titer. Overall, 57.8% of COVID-19 patients had a positive RNA biomarker for bacterial or biofilm infection. Conclusions: RNA biomarkers of host neutrophil activation indicate the presence of bacterial and biofilm coinfections in most COVID-19 patients. Recognizing coinfections may help to guide the treatment of ICU patients.

The Impact of Laparoscopic Appendectomy and Open Appendectomy on B7-H3-Mediated Intrinsic Immune Response in Children with Acute Suppurative Appendicitis

Purpose

Surgery impairs immune function and increases postoperative complications. B7H3, a co-stimulatory molecule, plays a crucial role in immune regulation. The present study examined the impact of B7H3 on the postoperative immune response in children with acute suppurative appendicitis (ASA) by comparing preoperative and postoperative B7H3 levels in laparoscopic surgery (LA) and open appendectomy (OA).

Patients and Methods

198 pediatric ASA patients were enrolled. The researcher group performed LA, while the control group performed OA. Perioperative time, recovery time of gastrointestinal function, time to pass gas, length of incision, and length of hospitalization were compared in the perioperative period. Additionally, an ELISA assay was conducted to examine the levels of inflammatory factors and B7H3 and CD28. Short-term postoperative complications were also evaluated.

Results

Compared with the control group, the research group had a short operative time, gastrointestinal function recovery time, gas time, and hospitalization time. The short-term complication rate was significantly lower in the research group. More importantly, B7H3 and CD28 were insignificantly different preoperatively, but they were all reduced postoperatively. Moreover, the reduction was more pronounced in the research group. The same results were noted in inflammatory factors and immune markers, which were non-significant different preoperatively and were typically reduced postoperatively, particularly in the research group. Finally, postoperative B7H3 was positively correlated with both inflammatory factors and immune cell levels.

Conclusion

B7H3 was reduced in both postoperative periods, and the reduction was more pronounced in the LA group. B7H3 may be involved in postoperative recovery by modulating postoperative inflammation and immune responses.

Diagnostic accuracy of novel mRNA blood biomarkers of infection to predict outcomes in emergency department patients with undifferentiated abdominal pain

Abdominal pain represents greater than 20% of US Emergency Department (ED) visits due to a wide range of illnesses. There are currently no reliable blood biomarkers to predict serious outcomes in patients with abdominal pain. Our previous studies have identified three mRNA transcripts related to innate immune activation: alkaline phosphatase (ALPL), interleukin-8 receptor-β (IL8RB), and defensin-1 (DEFA1) as promising candidates to detect an intra-abdominal infection. The objective of this study was to evaluate the accuracy of these mRNA biomarkers to predict likely infection, hospitalization and surgery in Emergency Department patients with undifferentiated abdominal pain. We prospectively enrolled Emergency Department patients with undifferentiated abdominal pain who received an abdominal CT scan as part of their evaluation. Clinical outcomes were abstracted from the CT scan and medical records. mRNA biomarker levels were calculated independent of the clinical outcomes and their accuracy was assessed to predict infectious diagnoses, surgery and hospital admission. 89 patients were enrolled; 21 underwent surgery; 47 underwent hospital admission; and, no deaths were observed within 30 days. In identifying which cases were likely infectious, mRNA biomarkers' AUC values were: ALPL, 0.83; DEFA1 0.51; IL8RB, 0.74; and ALPL + IL8RB, 0.79. In predicting which Emergency Department patients would receive surgery, the AUC values were: ALPL, 0.75; DEFA1, 0.58; IL8RB, 0.75; and ALPL + IL8RB, 0.76. In predicting hospital admission, the AUC values were: ALPL, 0.78; DEFA1, 0.52; IL8RB, 0.74; and, ALPL + IL8RB, 0.77. For predicting surgery, ALPL + IL8RB's positive likelihood ratio (LR) was 3.97; negative LR (NLR) was 0.70. For predicting hospital admission, the same marker's positive LR was 2.80 with an NLR of 0.45. Where the primary cause for admission was a potentially infectious disorder, 33 of 34 cases (97%) had positive RNA scores. In a pragmatic, prospective diagnostic accuracy trial in Emergency Department patients with undifferentiated abdominal pain, mRNA biomarkers showed good accuracy to identify patients with potential infection, as well as those needing surgery or hospital admission.

Development and Validation of a Differential Diagnosis Model for Acute Appendicitis and Henoch-Schonlein Purpura in Children

Objective: To study and develop a predictive model for the differential diagnosis of acute appendicitis (AA) and Henoch-Schonlein purpura (HSP) in children and to validate the model internally and externally. Methods: The complete data of AA and HSP cases were retrospectively analyzed and divided into internal and external verification groups. SPSS software was used for single-factor analysis and screening of independent variables, and R software was used for the development and verification of the diagnostic model. Lasso regression analysis was used to screen predictors and Lasso-logistic regression model was constructed, and K-fold cross-validation was used for the internal verification. In addition, nonfever patients were selected for model development and validation in the same way. Receiver operating characteristic (ROC) curves and calibration curves were drawn, respectively, to evaluate the 2 models. Results: Internal development and validation of the model showed that fever, neutrophil ratio (NEUT%), albumin (ALB), direct bilirubin (DBIL), C-reactive protein (CRP), and K were predictive factors for the diagnosis of HSP. The model was presented in the form of a nomogram, and the area under ROC curve of the development group and verification group was 0.9462 (95% confidence interval [CI] = 0.9402-0.9522) and 0.8931 (95% CI = 0.8724-0.9139), respectively. In the model of patients without fever, NEUT%, platelets (PLT), ALB, DBIL, alkaline phosphatase (ALP), CRP, and K were predictive factors for the diagnosis of HSP, and the area under ROC curve of the development group and verification group was 0.9186 (95% CI = 0.908-0.9293) and 0.8591 (95% CI = 0.8284-0.8897), respectively. Conclusion: In this study, 2 diagnostic models were constructed for fever or not, both of which had good discrimination and calibration, and were helpful to distinguish AA and HSP in children.

RNA Sequencing in COVID-19 patients identifies neutrophil activation biomarkers as a promising diagnostic platform for infections

Infection with the SARS-CoV2 virus can vary from asymptomatic, or flu-like with moderate disease, up to critically severe. Severe disease, termed COVID-19, involves acute respiratory deterioration that is frequently fatal. To understand the highly variable presentation, and identify biomarkers for disease severity, blood RNA from COVID-19 patient in an intensive care unit was analyzed by whole transcriptome RNA sequencing. Both SARS-CoV2 infection and the severity of COVID-19 syndrome were associated with up to 25-fold increased expression of neutrophil-related transcripts, such as neutrophil defensin 1 (DEFA1), and 3-5-fold reductions in T cell related transcripts such as the T cell receptor (TCR). The DEFA1 RNA level detected SARS-CoV2 viremia with 95.5% sensitivity, when viremia was measured by ddPCR of whole blood RNA. Purified CD15+ neutrophils from COVID-19 patients were increased in abundance and showed striking increases in nuclear DNA staining by DAPI. Concurrently, they showed >10-fold higher elastase activity than normal controls, and correcting for their increased abundance, still showed 5-fold higher elastase activity per cell. Despite higher CD15+ neutrophil elastase activity, elastase activity was extremely low in plasma from the same patients. Collectively, the data supports the model that increased neutrophil and decreased T cell activity is associated with increased COVID-19 severity, and suggests that blood DEFA1 RNA levels and neutrophil elastase activity, both involved in neutrophil extracellular traps (NETs), may be informative biomarkers of host immune activity after viral infection.

Did the COVID-19 Pandemic Prolong the Time Till Diagnosis and Worsen Outcomes for Children with Acute Appendicitis?

Background and Objectives: Our aim was to see if the COVID-19 pandemic led to an increase of time until diagnosis, operation, and time spent in Emergency room (ER), and if it resulted in more cases of complicated appendicitis and complication rates in children. Materials and Methods: We conducted a retrospective analysis of patients admitted to the Pediatric Surgery Department with acute appendicitis during a 4-month period of the first COVID-19 pandemic and compared it to the previous year data—the same 4-month period in 2019. Results: During the pandemic, the time spent in the ER until arriving at the department increased significantly 2.85 vs. 0.98 h p < 0.001, and the time spent in the department until the operation 5.31 vs. 2.66 h, p = 0.03. However, the time from the beginning of symptoms till ER, operation time and the length of stay at the hospital, as well as the overall time until operation did not differ and did not result in an increase of complicated appendicitis cases or postoperative complications. Conclusions: The COVID-19-implemented quarantine led to an increase of the time from the emergency room to the operating room by 4 h. This delay did not result in a higher rate of complicated appendicitis and complication rates, allowing for surgery to be postponed to daytime hours if needed.

Association Between NEDD4L Variation and the Genetic Risk of Acute Appendicitis: A Multi-institutional Genome-Wide Association Study

Importance

The familial aspect of acute appendicitis (AA) has been proposed, but its hereditary basis remains undetermined.

Objective

To identify genomic variants associated with AA.

Design, Setting, and Participants

This genome-wide association study, conducted from June 21, 2019, to February 4, 2020, used a multi-institutional biobank to retrospectively identify patients with AA across 8 single-nucleotide variation (SNV) genotyping batches. The study also examined differential gene expression in appendiceal tissue samples between patients with AA and controls using the GSE9579 data set in the National Institutes of Health's Gene Expression Omnibus repository. Statistical analysis was conducted from October 1, 2019, to February 4, 2020.

Main Outcomes and Measures

Single-nucleotide variations with a minor allele frequency of 5% or higher were tested for association with AA using a linear mixed model. The significance threshold was set at P = 5 × 10-8.

Results

A total of 29 706 patients (15 088 women [50.8%]; mean [SD] age at enrollment, 60.1 [17.0] years) were included, 1743 of whom had a history of AA. The genomic inflation factor for the cohort was 1.003. A previously unknown SNV at chromosome 18q was found to be associated with AA (rs9953918: odds ratio, 0.99; 95% CI, 0.98-1.00; P = 4.48 × 10-8). This SNV is located in an intron of the NEDD4L gene. The heritability of appendicitis was estimated at 30.1%. Gene expression data from appendiceal tissue donors identified NEDD4L to be among the most differentially expressed genes (14 of 22 216 genes; β [SE] = -2.71 [0.44]; log fold change = -1.69; adjusted P = .04).

Conclusions and Relevance

This study identified SNVs within the NEDD4L gene as being associated with AA. Nedd4l is involved in the ubiquitination of intestinal ion channels and decreased Nedd4l activity may be implicated in the pathogenesis of AA. These findings can improve the understanding of the genetic predisposition to and pathogenesis of AA.

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.

Antibiotics during childhood and development of appendicitis-a nationwide cohort study

BACKGROUND

Appendicitis is a common disease with a lifespan risk of approximately 8%. The full range of specific causes for the disease remains elusive, but an aberrant microbiota have been identified as a potential risk factor.

AIM

To investigate if use of antibiotics in a paediatric population increases the risk of appendicitis in childhood and adolescence METHODS: We conducted a cohort study from 1 January 1995 to 31 December 2014. A total of 1 385 707 children (0-19 years of age) including 7 406 397 antibiotic prescriptions and 11 861 cases of appendicitis were included. Primary outcome was appendicitis requiring appendectomy according to previous use of antibiotics. Appendicitis and appendectomy were identified from nationwide hospital records, and exposure to antibiotics was identified from nationwide prescription register. Rate ratios (RRs) with 95% confidence intervals were estimated from Poisson and logistic regression models.

RESULTS

Children who received at least one course of antibiotics were at increased risk of developing appendicitis compared to unexposed children (adjusted RR 1.72 [95% confidence interval 1.61-1.85]), mean age of developing appendicitis was 9.8 years (SD 4.1 years). The RR of appendicitis increased by 1.04 (1.04-1.04) per antibiotic course. A higher risk of appendicitis was observed in children exposed to antibiotics within the first 6 months of life (RR 1.46 [1.36-1.56]) and children exposed to broad-spectrum antibiotics (RR 1.33 [1.27-1.39]). After adjustment for number of antibiotic courses, the association between early age of antibiotic exposure and risk of appendicitis and the association between exposure to broad-spectrum antibiotics and the risk of appendicitis both disappeared.

CONCLUSION

Children who receive antibiotics are at increased and dose-dependent risk of appendicitis. The underlying mechanisms merit further investigation.

Biomarker discovery in attention deficit hyperactivity disorder: RNA sequencing of whole blood in discordant twin and case-controlled cohorts

Background

A variety of DNA-based methods have been applied to identify genetic markers of attention deficit hyperactivity disorder (ADHD), but the connection to RNA-based gene expression has not been fully exploited.

Methods

Using well defined cohorts of discordant, monozygotic twins from the Michigan State University Twin Registry, and case-controlled ADHD cases in adolescents, the present studies utilized advanced single molecule RNA sequencing to identify expressed changes in whole blood RNA in ADHD. Multiple analytical strategies were employed to narrow differentially expressed RNA targets to a small set of potential biomarkers of ADHD.

Results

RNA markers common to both the discordant twin study and case-controlled subjects further narrowed the putative targets, some of which had been previously associated with ADHD at the DNA level. The potential role of several differentially expressed genes, including ABCB5, RGS2, GAK, GIT1 and 3 members of the galactose metabolism pathway (GALE, GALT, GALK1) are substantiated by prior associations to ADHD and by established mechanistic connections to molecular pathways relevant to ADHD and behavioral control.

Conclusions

The convergence of DNA, RNA, and metabolic data suggests these may be promising targets for diagnostics and therapeutics in ADHD.

Evaluation of CXCR1 as a possible diagnostic biomarker in acute appendicitis

AIM

The present study was conducted to determine the genes with common expression in blood and appendix tissue samples in order to introduce them as possible diagnostic biomarkers.

BACKGROUND

Diagnosis of acute appendicitis (AA) without applying computed tomographytomography (CT), subjecting the patient to significant radiation, can be surprisingly difficult. Blood circulation may have conscious alterations in its RNA, protein, or metabolite composition.

METHODS

The genes related to appendix tissue and blood samples of the patients with AA were extracted from public databases. Fold change (FC) ≥ 2 in blood and FC ≥ 5 in appendix tissue samples were considered to screen differentially expressed genes (DEGs). A protein-protein interaction network was organized using the search tool for retrieval of interacting genes and proteins (STRING) database as a plugin of Cytoscape software version 3.6.0. The main genes were enriched by DAVID Bioinformatics Resources to find the related biochemical pathways.

RESULTS

Among the DEGs in blood and appendix tissue samples, C-X-C motif chemokine receptor 1(CXCR1), leukocyte immunoglobulin-like receptor A3 (LILRA3), low-affinity immunoglobulin gamma Fc region receptor III (FCGR3), and superoxide dismutase 2(SOD2) were common in both sources. CXCR1 was found as only hub gene upregulated in both blood and tissue of the patients with AA compared to controls and those with other abdominal pain.

CONCLUSION

CXCR1, FCGR3, LILRA3, and SOD2 were determined as a suitable possible biomarker panel for diagnosis of AA disease.

Increased risk of appendectomy in patients with asthma: A nested case-control study using a national sample cohort

The study aimed to expand previous data regarding an association between asthma and appendectomy in children compared with the population of all ages.The Korean Health Insurance Review and Assessment Service-National Sample Cohort from 2002 through 2013 was used. In all, 22,030 participants who underwent appendectomy were matched for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia with 88,120 participants who were included as a control group. In both the appendectomy and control groups, previous history of asthma was investigated. Appendectomy for appendicitis was identified based on a surgical code (International Classification of Disease-10 [ICD-10]: K35). Asthma was classified using an ICD-10 code (J45 and J46) and medication history. The crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of asthma for appendectomy were analyzed using conditional logistic regression analysis. Subgroup analyses were conducted according to age and sex.Approximately 15.2% (3358/22,030) of individuals in the appendectomy group and 13.3% (11,749/88,120) of those in the control group had asthma (P < .001). The appendectomy group demonstrated a higher adjusted odds of asthma than the control group (adjusted OR 1.18, 95% CI 1.13-1.23, P < .001). This result was consistent in the subgroups divided according to age and sex.The odds for asthma were higher in the appendectomy group than in the control group.

Diagnosis of appendicitis in the paediatric emergency department: an update

PURPOSE OF REVIEW

Concern regarding appendicitis is a common reason for presentation to the paediatric emergency department. We review recent progress in the use of biomarkers, imaging and clinical scoring systems in improving diagnostic accuracy in suspected appendicitis in children.

RECENT FINDINGS

Use of ultrasound, often performed at the bedside, is becoming more widespread with a parallel reduction in computed tomography (CT) use. Protocols for image acquisition and interpretation have been shown to improve diagnostic accuracy. Novel biomarkers have been explored and clinical diagnostic algorithms refined but none have achieved the level of diagnostic accuracy required.

SUMMARY

Appendicitis remains a clinical diagnosis. Point of care ultrasound is increasingly available and offers higher diagnostic accuracy than several routinely performed laboratory investigations. Recent publications provide support for increased use of clinician performed ultrasound, increased use of MRI, less use of CT, less emphasis on basic laboratory investigation and a renewed respect for the value of serial examination, particularly early in the course of illness.

Gene Expression Signatures Can Aid Diagnosis of Sexually Transmitted Infection-Induced Endometritis in Women

Sexually transmitted infection (STI) of the upper reproductive tract can result in inflammation and infertility. A biomarker of STI-induced upper tract inflammation would be significant as many women are asymptomatic and delayed treatment increases risk of sequelae. Blood mRNA from 111 women from three cohorts was profiled using microarray. Unsupervised analysis revealed a transcriptional profile that distinguished 9 cases of STI-induced endometritis from 18 with cervical STI or uninfected controls. Using a hybrid feature selection algorithm we identified 21 genes that yielded maximal classification accuracy within our training dataset. Predictive accuracy was evaluated using an independent testing dataset of 5 cases and 10 controls. Sensitivity was evaluated in a separate test set of 12 women with asymptomatic STI-induced endometritis in whom cervical burden was determined by PCR; and specificity in an additional test set of 15 uninfected women with pelvic pain due to unknown cause. Disease module preservation was assessed in 42 women with a clinical diagnosis of pelvic inflammatory disease (PID). We also tested the ability of the biomarker to discriminate STI-induced endometritis from other diseases. The biomarker was 86.7% (13/15) accurate in correctly distinguishing cases from controls in the testing dataset. Sensitivity was 83.3% (5/6) in women with high cervical Chlamydia trachomatis burden and asymptomatic endometritis, but 0% (0/6) in women with low burden. Specificity in patients with non-STI-induced pelvic pain was 86.7% (13/15). Disease modules were preserved in all 8 biomarker predicted cases. The 21-gene biomarker was highly discriminatory for systemic infections, lupus, and appendicitis, but wrongly predicted tuberculosis as STI-induced endometritis in 52.4%. A 21-gene biomarker can identify asymptomatic women with STI-induced endometritis that places them at risk for chronic disease development and discriminate STI-induced endometritis from non-STI pelvic pain and other diseases.

Metabolic analysis of acute appendicitis by using system biology approach

AIM

Introducing possible suitable compound as diagnostic agent in appendicitis is aim of this investigation.

BACKGROUND

Appendicitis diagnosis is a difficult step in treatment of disease due to complex abdominal pain signal which may be refer to the non-appendicitis pain.

METHODS

Gene expression profiles of children with non-preforated appendicitis in comparison with the samples with non- appendicitis abdominal pain are analysis via protein - protein interaction (PPI) and the critical compounds are introduced by STITCH.

RESULTS

Ten compounds including including MgATP, glycerol, MgADP, calcium ions, chloride, magnesium, phosphate, sulphate, acetate, and sodium are introduced as possible biomarker panel to differentiate appendicitis from the other abdominal pains.

CONCLUSION

A laboratory method such as flame photometry based on metal detection for diagnosis of appendicitis is possible, however more investigations are required.