| A recent study has demonstrated that rheumatoid | | | | In order to calculate relative risk, researchers often |
| arthritis (RA) patients who use tumor necrosis factor | | | | use multivariate analysis to develop a number called a |
| (TNF) blockers are up to four times more likely to | | | | hazard ratio. If the number is less than one, then it |
| develop a serious bacterial infection than those who | | | | means the substance in question is less hazardous |
| use only methotrexate. While the risk is not | | | | than the control. If the number equals one, then the |
| tremendously high, it is still a factor that needs to be | | | | substance has the same risk as the control. And if |
| taken into consideration by both patients as well as | | | | the ratio is greater than one, it means the substance |
| prescribing rheumatologists. | | | | is more hazardous than the control. |
| Infections are common in patients with rheumatoid | | | | TNF blocker use was associated with a hazard ratio |
| arthritis and related disorders, but it is unclear if this is | | | | of 1.9 for serious bacterial infection. So, TNF therapy |
| due to the treatments or the underlying disease | | | | combined with DMARD therapy is more hazardous |
| process. Previous studies examining the impact of | | | | than methotrexate alone as far as risk of infection. |
| TNF blockers on infection have yielded variable | | | | The incidence of infections was highest within 6 |
| results. | | | | months of initiating TNF inhibition therapy. |
| The goal of this most recent study was to | | | | The most common serious infections in both groups |
| determine if TNF inhibition raised the risk of serious | | | | were pneumonia/ lung abscess (empyema) followed |
| bacterial infections compared to the use of | | | | by cellulitis/soft tissue infection. |
| methotrexate alone. | | | | The efficacy of TNFantagonist therapy for most |
| The study examined 2393 patients treated with TNF | | | | rheumatoid arthritis patients needs to be balanced |
| antagonists who were also on DMARDS, most often, | | | | against the potential harm of an increased risk of |
| methotrexate, and 2933 patients taking | | | | infection associated with these agents. Vigilant |
| methotrexate alone. The most common TNF- blocker | | | | monitoring for infection is recommended when using |
| used was etanercept (Enbrel), followed by infliximab | | | | these agents. |
| (Remicade). | | | | (Curtis JR, Patkar N, Xie A, Martin C, Allison JJ, Saag |
| During a median follow-up period of 17 months, | | | | M, Shatin D, Saag KG. Risk of serious bacterial |
| infection-related hospitalization rates were 2.7% and | | | | infections among rheumatoid arthritis patients |
| 2.0% for the TNF blocker group and | | | | exposed to tumor necrosis factor α |
| methotrexate-only group, respectively. | | | | antagonists. Arthritis Rheum 2007;56:1125-1133). |