Examining the link between rituximab treatment, immune cell response and disease activity?

This study looked at the effect of rituximab (Rituxan) and levels of immune cells in patients with rheumatoid arthritis (RA).The authors concluded that certain immune cells are linked to disease activity in patients treated with rituximab. Measuring the levels of these cells could be used to determine if rituximab re-treatment is needed. 

In rheumatoid arthritis (RA), the immune system attacks the healthy joints the way it would a virus or bacteria. When this happens, the body produces too many immune cells. Rituximab is a biological drug that targets immune cells and destroys them to weaken the immune system.

In order to find out if a patient has responded well to rituximab, immune cell levels can be measured before and after treatment. If the level has decreased, the patient has responded well to treatment. Patients who do not respond well have shown to have less of a decrease in one particular set of immune cells called T cells.

 This study looked at the link between rituximab treatment, T cell levels, and disease activity in patients. 

54 patients were included in this study. Patients received up to 7 cycles of rituximab treatment. Treatment consisted of two injections of the drug. Disease activity and immune cell levels were recorded before each cycle and 3 and 6 months after the injections for each cycle.

Levels of T cells were significantly decreased after treatment, regardless of the cycle. This decrease was closely linked to improvements in disease activity. Disease activity improved with repeated cycles of treatment.

10 patients did not respond after the first cycle of treatment. After a second cycle of treatment, 8 of these 10 patients showed a significant decrease in T cell levels and improvement in disease activity. 

4 patients did not continue after the first cycle due to side effects.

This study concluded that rituximab can reduce T cell levels and reduce disease activity in patients with RA. Monitoring T cell levels may be useful to determine when a patient needs another cycle of rituximab treatment.

Larger studies are needed to confirm these results. Some of the authors of this study have received funding from the companies who distribute rituximab.