<b>A Molecular Approach of Diagnosing H. pylori and Its Correlation with Haematological and Biochemical Parameters</b>

Background: Helicobacter pylori infection is highly prevalent worldwide and has been implicated in diverse gastric and extra-gastric diseases, including iron deficiency anemia and systemic inflammation. Conventional diagnostic methods often have limitations in sensitivity, accessibility, and invasiveness, particularly in resource-limited settings. Objective: This study aimed to assess the utility of blood-based quantitative PCR (qPCR) for the molecular diagnosis of H. pylori infection and to investigate its correlation with haematological and biochemical parameters among untreated dyspeptic patients. Methods: A cross-sectional observational study was conducted involving 120 untreated dyspeptic adults recruited from a tertiary care laboratory in Karachi, Pakistan. Haematological and biochemical markers were assessed using standard laboratory methods. Anti-H. pylori antibodies were detected by ELISA, with subsequent qPCR confirmation on blood samples for positive cases. Statistical analyses included t-tests, Pearson correlation coefficients, and p-values for group comparisons. Results: H. pylori-infected individuals exhibited significantly lower hemoglobin, red blood cell, iron, and ferritin levels compared to controls (p < 0.001), alongside elevated C-reactive protein, amylase, and lipase. Blood-based qPCR detected H. pylori DNA in 70% of seropositive cases pre-treatment and enabled identification of persistent infection in 30% of cases after therapy, indicating potential resistance. Conclusion: Blood-based qPCR offers a sensitive diagnostic modality for H. pylori and demonstrates a strong association between infection and altered haematological and biochemical profiles. Integration of molecular diagnostics may improve disease detection and management in high-prevalence populations.