Figure 1. Box plots comparing absolute and relative cell densities in the 6 sample groups.

Synovial tissue sections were stained immunohistochemically for CD15, CD68, CD3, CD20, and CD38. The absolute cell densities (left half of the page, labeled “Absolute”, Panels A-E) are expressed as the number of positive staining cells per mm². The relative cell densities (right half of the page, labeled “Relative”, panels F-J) correspond to the cells expressing a given marker as a percentage of the inflammatory cell population, which is defined as the sum of all cells expressing any of the five markers, per mm². Upper and lower borders of the box, 75^th percentile and 25^th percentiles; horizontal line, median; upper and lower whiskers, maximum and minimum; circles, outliers defined as values above or below the box by a >1.5-fold of the interquartile range.