Pamidronate infusion improved two cases of intractable seronegative rheumatoid arthritis

Pamidronate is a bisphosphonate derivative that can inhibit bone resorption by actions on osteoclasts and increase bone density in spite of treatment with steroids. This drug has the anti-inflammatory effect by increase apoptosis of monocytes. 5-10 percent of rheumatoid arthritis patients is seronegative and may be resistant to conventional disease modifying anti rheumatic drugs (DMARDs). Intravenous (IV) pamidronate can be effective in disease control in seronegative rheumatoid arthritis. We report two cases of seronegative and drug resistant rheumatoid arthritis that favorably responds to pamidronate.