The purpose of this investigation is to determine the effects of Rituxan therapy in individuals with rheumatoid arthritis on endothelial function and other markers of endothelial function

Inclusion Criteria:

• Able and willing to give written informed consent and comply with the requirements of the study protocol
• Negative serum pregnancy test (for women of child bearing age)
• Men and women of reproductive potential must agree to use an acceptable method of birth control during treatment and for twelve months (1 year) after completion of treatment.
• IgG & IgM levels within normal limits
• Adequate renal function as indicated by serum creatinine measurements.
• No previous biological use (investigational or approved) except for the three approved anti-TNF alpha therapies
• Patients who have been treated with anti-TNF alpha therapies must be off of infliximab and adalimumab for two months before study entry and off of etanercept for one month before study entry
• No use of phosphodiesterase type 5 inhibitors (PDE5) (i.e. Sildenafil, Tadalafil, and Vardenafil) 1 week prior to the study and during the course of the study.
• SBP ≤ 140/90 for two months prior to study enrollment

Exclusion Criteria:

• Prior history of MI, CVA, CABG, PTCA, or peripheral vascular disease
• Any serious concomitant medical condition that could interfere with the study.
• Patients with insulin dependent diabetes
• Failure to provide written consent.
• Individuals with HIV infections
• SBP > 140/90 at two months prior to study enrollment

per protocol, patients with active rheumatoid arthritis (RA) who had high levels of systemic inflammation