Clinical Significance of Serum Soluble CD Molecules to Assess Disease Activity in Vitiligo

Importance: It is difficult to determine disease activity in vitiligo owing to the absence of inflammatory signs, such as erythema or scaling. A biomarker that could confirm active disease and indicate likely future disease progression would therefore be of considerable value. Objective: To investigate whether soluble CD27 (sCD27), sCD25, or sCD40L could be valuable biomarkers to determine disease activity in vitiligo and indicate likely future progression. Design, Setting, and Participants: A combined cross-sectional and prospective study was conducted at the department of dermatology at Ghent University Hospital between February 24, 2012, and December 12, 2015. Ninety-three patients with vitiligo were enrolled, including 83 individuals with nonsegmental vitiligo and 10 with segmental vitiligo. Blood sampling was performed, and sCD25, sCD27, and sCD40L were measured in serum. Main Outcomes and Measures: The associations between sCD levels, disease activity, and future progression were investigated. Results: Of the 93 patients included in the study, 51 were women (55%); median (interquartile range) age was 36.5 (26.0-49.8) years. Both sCD27 (21.5 ng/mL [16.1-30.0 ng/mL] vs 18.4 ng/mL [12.5-22.1 ng/mL]; P = .006) and sCD25 (2.6 ng/mL [2.1-3.4 ng/mL] vs 2.2 ng/mL [1.7-2.4 ng/mL]; P = .002) levels were associated with active disease. Moreover, a statistically significant link with disease progression after 3 to 6 months was found for sCD27 (21.7 [17.0-29.1] vs 16.6 [13.5-23.7]; P = .02) but not for sCD25 (2.8 ng/mL [2.2-3.4 ng/mL] vs 2.3 [1.9-2.8 ng/mL]; P = .053). Further in vitro experiments showed a correlation between sCD25 and interferon γ (r = 0.562, P = .005), interleukin 10 (r = 0.453, P = .03), and sCD27 secretion (r = 0.549, P = .007). No associations were found for sCD40L levels. Conclusions and Relevance: This study demonstrates increased levels of sCD27 and sCD25 in patients with active vitiligo. Moreover, these results provide the first evidence that these markers have a capacity to indicate the probability of future disease progression, which supports their role as biomarkers in vitiligo.