OBJECTIVE: This study investigated whether using biological disease-modifying antirheumatic drugs (bDMARDs) further increases the risk of malignant lymphoma in patients with rheumatoid arthritis undergoing methotrexate therapy using spontaneous adverse reaction databases in different countries. MATERIALS AND METHODS: Patient data were acquired from the US Food and Drug Administration's Adverse Event Reporting System (FAERS), the Japanese Adverse Drug Event Report (JADER), and the Canada Vigilance Adverse Reaction Online Database (CVARD) from the first quarter of 2004 to the end of 2015. Data subset analysis was performed to investigate whether the use of bDMARDs further increased the risk of malignant lymphoma in patients receiving methotrexate therapy. RESULTS: The FAERS subset data indicated a significant association between Hodgkin lymphoma and methotrexate with infliximab (reporting odds ratio (ROR): 8.28. 95% CI: 5.70 - 12.02; information component (IC): 2.04, 95% CI: 1.59 - 2.49). In addition, signal scores suggested that methotrexate with infliximab (ROR: 3.26. 95% CI: 2.68 - 3.98; IC: 1.31, 95% CI: 1.04 - 1.58) was significantly associated with non-Hodgkin lymphoma (NHL). The CVARD subset data also indicated a significant association between NHL and methotrexate with infliximab (ROR: 22.82. 95% CI: 5.02 - 103.78; IC: 1.77, 95% CI: 0.13 - 3.41). However, the JADER subset data revealed no significant associations. CONCLUSION: The present study shows that using infliximab further increases the risk of malignant lymphoma in patients receiving methotrexate therapy.
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