Diagnostic Accuracy of Glutamate Dehydrogenase Enzyme (GDH) for Clostridium difficile Infection: A Meta-Analysis

Introduction: Clostridium difficile is a gram-positive, spore-forming anaerobe and a leading cause of healthcare-associated diarrhea globally, primarily linked to antibiotic use. Its enzyme, Glutamate Dehydrogenase (GDH), plays a critical role in the metabolism of glutamate, and its detection has become a key diagnostic marker for C. difficile infection (CDI). This meta-analysis evaluates various diagnostic modalities used for GDH detection, focusing on their sensitivity, specificity, and clinical utility. Methods: A systematic search of PubMed, Google Scholar, and Cochrane Library was conducted. Studies comparing GDH testing with gold-standard methods (PCR, toxigenic culture) for CDI diagnosis were included. Data were extracted from eligible studies, and statistical analyses were performed to calculate pooled sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC). Results: The pooled sensitivity and specificity of GDH testing were 93% and 92%, respectively. The DOR was calculated to be 30.98, and the AUC was 0.9794, indicating high diagnostic accuracy. GDH testing proved effective in identifying both infected and non-infected individuals, reducing false positives and negatives. Conclusion: GDH testing is a highly sensitive and specific diagnostic tool for CDI, supporting its role in clinical settings for early detection and intervention. Despite its strengths, variability in test performance suggests the need for further research to refine GDH-based protocols and ensure consistent outcomes across diverse healthcare environments.