Fig. 3.

T cell autoreactivity with MMP-10 peptides in Lyme disease patients and control subjects. PBMC from healthy controls (HC), rheumatoid arthritis patients (RA), and Lyme disease patients with erythema migrans (EM), or antibiotic-responsive or antibiotic-refractory arthritis were stimulated with a pool of 3 peptides, including the single MMP-10 peptide isolated from the synovial tissue of patient LA4 and 2 predicted promiscuous HLA-DR binding peptides from MMP-10. The results were measured using the human IFN-γ ELISpot assay. A positive result was defined as >3 SD above the mean SFU/10⁶ cells of HC (area above the gray shaded region). The distribution of values is shown in the graph, and the number and percentage of patients with positive responses in each patient group are reported below the graph. The distribution of values between groups was compared using an unpaired t-test with Welch's correction, and the identity of groups is compared using Fisher's exact test.