Risk Factors for Gastrointestinal and Hepatic Adverse Reactions in Rheumatoid Arthritis Patients on Biologic and Conventional DMARDs

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease treated with disease modifying antirheumatic drugs (DMARDs), which includes conventional synthetic (csDMARDs) and biologic (bDMARDs) agents, and are associated with adverse drug reactions (ADRs) in the gastrointestinal (GI) and hepatobiliary systems. Objectives: In RA patients on combination of biologic and conventional DMARD therapies to identify risk factors associated with GI and hepatic ADRs. Methods: We conducted a multi-centre, observational, retrospective study of 500 RA patients treated with csDMARDs, bDMARDs, or in combination of both. Demographics, biomarkers and clinical profiles were collected. Patient characteristics, treatment types and ADR occurrence were monitored over 24 weeks and statistical analysis was performed to find a correlation between patient characteristics, treatment types, and the occurrence of ADRs. Significant associations were identified with logistic regression and chi-square tests. Results: 24.2% of patients had an ADR, with GI ADRs accounting for 16.6% and hepatic ADRs for 9.1%. Compared to csDMARDs, users (4.2%), bDMARDs users (13.8%) had hepatic ADRs more frequently (p < 0.01). High CRP levels decreased the risk of GI ADRs, but elevated IgG levels raised the risk of hepatic ADRs. Both ADR kinds were predicted by systemic symptoms. Conclusion: Biologic DMARDs present a higher risk of hepatic ADRs in RA patients compared to conventional DMARDs. Key predictors of ADRs include elevated IgG levels and systemic symptoms, underscoring the need for close monitoring of biomarkers and patient-reported symptoms to mitigate adverse events during DMARD therapy.