The Diagnostic Utility of Volatile Organic Compounds in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Volatile organic compounds [VOCs] show promise as potential biomarkers of for ulcerative colitis and Crohn's disease, two chronic, idiopathic, gastrointestinal disorders with diagnostic and management challenges. Non-invasive biomarkers aid early diagnosis and management. In this study we review studies of diagnostic accuracy of VOCs in inflammatory bowel disease. METHODS: A systematic search was carried out on the Pubmed and Scopus databases; with 16 studies reviewed and meta-analysis carried out on 10. RESULTS: Meta-analysis of 696 inflammatory bowel disease [IBD] cases against 605 controls revealed a pooled sensitivity and specificity of 87% (95% confidence interval [CI], 0.79 - 0.92) and 83% [95% CI, 0.73 - 0.90], respectively. Area under the curve [AUC] was 0.92. CONCLUSION: VOCs perform very well as non-invasive biomarkers of IBD, with much scope for future improvement and research.

The Fatty Liver, Cirrhosis, and Liver Cancer Study (TENDENCY): Protocol for a Multicenter Case-Control Study.

BACKGROUND: Hepatocellular cancer (HCC) is associated with high mortality, and early diagnosis leads to better survival. Patients with cirrhosis, especially due to nonalcoholic fatty liver disease and viral hepatitis, are at higher risk of developing HCC and form the main screening group. The current screening methods for HCC (6-monthly screening with serum alpha fetoprotein and ultrasound liver) have low sensitivity; hence, there is a need for better screening markers for HCC. OBJECTIVE: Our study, TENDENCY, aims to validate the novel screening markers (methylated septin 9, urinary volatile organic compounds, and urinary peptides) for HCC diagnosis and study these noninvasive biomarkers in liver disease. METHODS: This is a multicenter, nested case-control study, which involves comparing the plasma levels of methylated septin 9 between confirmed HCC cases and patients with cirrhosis (control group). It also includes the comparison of urine samples for the detection of HCC-specific volatile organic compounds and peptides. Based on the findings of a pilot study carried out at University Hospital Coventry & Warwickshire, we estimated our sample size to be 308 (n=88, 29% patients with HCC; n=220, 71% patients with cirrhosis). Urine and plasma samples will be collected from all participants and will be frozen at -80 °C until the end of recruitment. Gas chromatography-mass spectrometry will be used for urinary volatile organic compounds detection, and capillary electrophoresis-mass spectrometry will be used for urinary peptide identification. Real-time polymerase chain reaction will be used for the qualitative detection of plasma methylated septin 9. The study will be monitored by the Research and Development department at University Hospital Coventry & Warwickshire. RESULTS: The recruitment stage was completed in March 2023. The TENDENCY study is currently in the analysis stage, which is expected to finish by November 2023. CONCLUSIONS: There is lack of effective screening tests for hepatocellular cancer despite higher mortality rates. The application of more sensitive plasma and urinary biomarkers for hepatocellular cancer screening in clinical practice will allow us to detect the disease at earlier stages and hence, overall, improve HCC outcomes. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/44264.

Influence of seasonal and operator variations on diagnostic accuracy of lateral flow devices during the COVID-19 pandemic: a systematic review and meta-analysis.

BACKGROUND: Lateral flow tests (LFT) are point-of-care rapid antigen tests that allow isolation and control of disease outbreaks through convenient, practical testing. However, studies have shown significant variation in their diagnostic accuracy. We conducted a systematic review of the diagnostic accuracy of LFTs for the detection of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) to identify potential factors affecting their performance. METHODS: A systematic search of online databases was carried out to identify studies assessing the sensitivity and specificity of LFTs compared with polymerase chain reaction (PCR) tests. Data were extracted and used to calculate pooled sensitivity and specificity. Meta-regression analysis was conducted to identify covariates influencing diagnostic accuracy. RESULTS: In total, 76 articles with 108,820 test results were identified for analysis. Pooled sensitivity and specificity were 72% (95% confidence interval (CI): 0.68-0.76) and 100% (95% CI: 0.99-1.00), respectively. Staff operation of the LFT showed a statistically significant increase in sensitivity (p=0.04) and specificity (p=0.001) compared with self-operation by the test subjects. The use of LFTs in symptomatic patient subgroups also resulted in higher test sensitivity. CONCLUSION: LFTs display good sensitivity and extremely good specificity for SARS-CoV-2 antigen detection; they become more sensitive in patients with symptoms and when performed by trained professionals.

The Influence of Mechanical Bowel Preparation on Volatile Organic Compounds for the Detection of Gastrointestinal Disease-A Systematic Review.

(1) Background: Colorectal cancer is the second commonest cause of cancer deaths worldwide; recently, volatile organic compounds (VOCs) have been proposed as potential biomarkers of this disease. In this paper, we aim to identify and review the available literature on the influence of mechanical bowel preparation on VOC production and measurement. (2) Methods: A systematic search for studies was carried out for articles relevant to mechanical bowel preparation and its effects on volatile organic compounds. A total of 4 of 1349 papers initially derived from the search were selected. (3) Results: Two studies with a total of 134 patients found no difference in measured breath VOC profiles after bowel preparation; one other study found an increase in breath acetone in 61 patients after bowel preparation, but no other compounds were affected. Finally, the last study showed the alteration of urinary VOC profiles. (4) Conclusions: There is limited data on the effect of bowel preparation on VOC production in the body. As further studies of VOCs are conducted in patients with symptoms of gastrointestinal disease, the quantification of the effect of bowel preparation on their abundance is required.

Acute testicular ischemia following manual reduction of inguinoscrotal hernia.

Testicular ischemia caused by inguinal hernia repair, and even the presence of the hernia itself, has been recognized in the medical literature, with the latter more commonly in children, but such an event after manual reduction has never been reported before. We present the case of a 67-year-old man who presented to the emergency department with a painful left groin lump. A left inguinoscrotal hernia was diagnosed and reduced "en masse" with manual pressure at the bedside. The patient was discharged but developed acute-onset left scrotal pain as soon as he got home and then re-presented 2 days later with increasing severity of the pain and swelling ever since the hernia reduction. On examination, he was febrile, with a hard, tender, and swollen left testis. Serum inflammatory markers were elevated. Conservative management with intravenous antibiotics and analgesia was commenced. An ultrasound of the testes demonstrated lack of Doppler flow to the left testis, suggestive of acute ischemia. Three days later, there were persistent temperature spikes and significant pain; therefore, the patient underwent an acute left scrotal exploration where a necrotic, black left testis was discovered and excised. He was discharged on the 1st postoperative day; histological analysis confirmed testicular infarction.

SVC obstruction and stridor relieved by nasogastric tube insertion.

Achalasia is an idiopathic motility disorder of the oesophagus of increasing incidence. It is characterized by aperistalsis of the lower oesophagus and failure of relaxation of the lower oesophageal sphincter. Patients classically present with chronic symptoms of dysphagia, chest pain, weight loss and regurgitation, and they commonly suffer pulmonary complications such as recurrent microaspiration of static, retained food contents of the upper oesophagus. However, it has also been described, uncommonly, to present with megaoesophagus and secondary tracheal compression. We present a case of megaoesophagus secondary to achalasia which presented with stridor and signs of acute superior vena caval obstruction.