flow cytometric
Figure 4: Humoral response to vaccination. Geometric mean titers (GMTs), seroprotection and response rates were calculated in sera of rheumatoid arthritis (RA) patients and healthy controls before and 4 weeks post-vaccination as described in the Materials and Methods section. A. There was a significant increase in titer for the H1N1 and H3N2 strains in both groups (columns, geometric mean; bars, standard deviation, **p ≤ 0.01). B. Seroprotection was defined as an antibody titer of at least 1:40. C. Response rates for H1N1 were significantly higher in RA patients compared with healthy controls (*p ≤ 0.05).