Do the clinical responses and complications following etanercept or infliximab therapy predict similar outcomes with the other tumor necrosis factor-alpha antagonists in patients with rheumatoid arthritis?

OBJECTIVE: To study a group of 29 patients with rheumatoid arthritis (RA) who have been treated with both tumor necrosis factor (TNF)-alpha antagonists, etanercept and infliximab and to determine the correlation of responses and complications seen in these patients.
METHODS: Patients' responses to and complications from either treatment were reviewed retrospectively by determining the joint counts, acute phase reactants, as well as occurrences of infection, hypersensitivity, and cytopenia. The correlation of responses and complications was determined using phi coefficients and exact p values.
RESULTS: There was no correlation between the joint count responses (exact p value for correlation coefficient, 0.70) and acute phase reactant responses (exact p value 0.14) with the use of etanercept and infliximab in the same patient. There was no correlation between the occurrences of drug hypersensitivity reactions (exact p value 0.20) or infectious complications (exact p value 1.00). However, the occurrence of anemia with the use of one TNF-alpha antagonist was correlated with a similar occurrence with the use of the other antagonist (exact p value 0.007).
CONCLUSION: Our study indicates that patients who fail to respond to one TNF-alpha antagonist can respond to the other antagonist. Furthermore, there appears to be no contraindication to using one TNF-alpha antagonist for patients who have developed hypersensitivity reactions to the other. The infections observed in our study were generally mild and did not necessarily recur with the use of the second antagonist. In contrast, anemia, when present with the use of one agent, was likely to occur with the use of the second agent.