Diagnostic performance of urinary 5-Hydroxyindoleacetic Acid in acute appendicitis: a systematic review and diagnostic test accuracy meta-analysis

Abstract

BackgroundThis study aimed to analyze the diagnostic performance of urinary 5-Hydroxyindoleacetic Acid (5-HIAA) in acute appendicitis (AA). MethodsWe conducted a systematic review of the literature in the main databases of medical bibliography. Two independent reviewers selected the articles and extracted relevant data. Methodological quality was assessed using the QUADAS2 index. A synthesis of the results, standardization of the metrics, and a random-effect meta-analysis were performed. Additionally, a diagnostic test accuracy meta-analysis (DTA) was performed. ResultsTwelve studies with data from 1467 participants (724 patients with a con rmed diagnosis of AA and 743 controls) were included in this review. The randomeffect meta-analysis of urinary 5-HIAA (AA vs controls) included 7 articles (352 AA and 258 controls) and resulted in a signi cant mean difference [95% CI] of 23.30 [15.82-30.77] µmol/L (p < 0.001). The DTA meta-analysis of urinary 5-HIAA included 8 articles and resulted in a pooled sensitivity [95% CI] of 68.6[44.1-85.9]% and a pooled speci city [95% CI] of 82 [54.7-94.5]%. ConclusionsAlthough the evidence is heterogeneous and limited, urinary 5-HIAA emerges as a potential non-invasive diagnostic tool for AA. Urinary 5-HIAA does not seem to be a useful biomarker to distinguish between NCAA and CAA. Future prospective studies with a large sample size and a rigorous design are necessary to validate these ndings.

Role of type I hypersensitivity reaction in the development of overall and uncomplicated acute appendicitis: a systematic review and meta-analysis

“…Likewise, the appendix is a structure rich in enterochromaffin cells (especially at the level of the lamina propria). These cells store and secrete serotonin, a neurotransmitter that modulates peripheral immune system responses [7,8]. Lastly, the cecal appendix contains a significant representation of lymphoid tissue.…”

“…Lastly, the cecal appendix contains a significant representation of lymphoid tissue. Because of these two aspects, the reaction to allergen exposure may be more accentuated in this organ than in the rest of the body [7,8]. This review aims to compile and meta-analyze the existing evidence on the role of type I hypersensitivity reactions in the development of AA.…”