Figure 6. Effector CD4⁺ CTLs are clonally expanded and correlate with tissue fibrosis in SSc.

(A) Dot plot demonstrates marked expansion of CD57^hiCD4⁺ CTLs comparing SSc subjects (n = 37) to age-matched healthy donors (n = 20). Lines represent medians with standard deviation. Mann-Whitney U test was used to calculate P value. (B) Bar chart showing increased frequency of lung fibrosis among SSc patients with greater CD57^hiCD4⁺ CTL expansions. Proportion of patients in each group is plotted. P value was calculated by Fisher’s exact test. (C) X-Y plot showing positive correlation between CD57^hiCD4⁺ CTL expansion and tissue α-smooth muscle actin (α-SMA) staining. Linear regression was used to calculate P value. (D) Scatter plots with mean and range displaying the percentage of each T cell subset expressing granzyme B (GZMB), perforin (PRF), CX3CR1, and CD127. (E) Dot plots show the TCR repertoire comprising effector CD4⁺ CTLs from 2 SSc subjects (middle and right). TCR repertoire from a naive CD4⁺ T cell population is shown for reference (far left).