Figure 1. Representative photomicrographs of ELISpot assay.

Peripheral blood mononuclear cells were incubated with a mixture of selected M3R peptides according to the HLA-DRB1 type of participants, M5R peptides (control peptides), or 1% PHA (positive control) for 40 hours. Five replicate wells were examined for each condition. Representative photomicrographs of M3R-reactive IL-17–producing cells in a negative pSS patient (pSS4), positive pSS patient (pSS5), HS (HS8), and IgG4-RD patient (IgG4-RD3) is shown. In patient pSS5, note the higher number of spots after stimulation with the indicated mixture of the selected M3R peptides, whereas no substantial increase in the spots was noted after M5R peptides stimulation. In patients pSS4, HS8, and IgG4-RD3, no spots were noted after stimulation with either M3R or M5R peptides.