We sought to quantify B-cell populations and antibody-secreting cells in the blood of patients with AD, patients with psoriasis, and control subjects.
We studied 34 adults with moderate-to-severe AD (mean SCORAD score, 65), 24 patients with psoriasis (mean Psoriasis Area and Severity Index score, 16), and 27 healthy subjects using an 11-color flow cytometric antibody panel. IgD/CD27 and CD24/CD38 core gating systems were used to determine frequencies of plasmablasts and naive, memory, transitional, and activated B cells.
We measured increased CD19+CD20+ B-cell counts in the skin and blood of patients with AD (P < .01). Significantly higher frequencies of chronically activated CD27+ memory and nonswitched memory B cells were observed in patients with AD (P < .05), with lower values of double-negative populations (4% for patients with AD vs 7% for patients with psoriasis [P = .001] and 6% for control subjects [P = .02]). CD23 expression was highest in patients with AD and correlated with IgE levels (P < .01) and disease severity (r = 0.6, P = .0002). Plasmablast frequencies and IgE expression were highest in all memory subsets of patients with AD (P < .01). Finally, CD19+CD24++CD38++ transitional and CD19+CD24−CD38− new memory B-cell counts were higher in patients with AD versus those in patients with psoriasis (2.8% vs 1.4% [P = .001] and 9.2% vs 5.7% [P = .02], respectively).
AD is accompanied by systemic expansion of transitional and chronically activated CD27+ memory, plasmablast, and IgE-expressing memory subsets. These data create a critical basis for the future understanding of this debilitating skin disease.