Immunophenotyping of inflammatory cells in subacute prurigo

Abstract

Background: Subacute prurigo (SP) is a relatively common disease of papular cutaneous lesions that itch intensely. However, there is a lack of systematic clinical and histological studies on SP.

Objectives: We aimed to immunophenotype inflammatory cells in SP using immunohistochemistry and flow cytometry.

Methods: Lesional and non-lesional skin of 21 patients with SP was investigated. Immunohistochemical staining for CD1a, CD3, CD4, CD8, CD15, CD34, CD68, and anti-human tryptase (AHT) was performed. In order to evaluate the absolute counts and percentages of CD4+ and CD8+ lymphocytes in the peripheral blood of SP patients, flow cytometric methods were used.

Results: Compared to non-lesional skin, there was a significant increase of the median percentage of CD3+, CD4+, and CD8+ cells in the lesional dermis (12.6% vs. 19.7%, P=0.044; 0.8% vs. 3.7%, P=0.016; and 1% vs. 15.6%, P=0.0039, respectively). The mean ± SD CD4+/CD8+ ratio was 0.58 ± 0.6. Median percentage of CD15+ cells was significantly increased in lesional skin as compared to non-lesional skin (11.7 vs. 1%, P=0.027). Median percentage immunoreactivity of CD68+ cells was significantly increased in lesional dermis as compared to non-lesional skin (32.5% vs. 9.4%, P=0.0005). CD1a, CD34, and AHT positive cells did not significantly differ between lesional and non-lesional skin. T lymphocyte subsets in the peripheral blood of SP patients did not show significant pathologies.

Conclusions: We observed that the inflammatory cell infiltrate in SP mainly consists of T lymphocytes, particularly CD8+ cells, CD15+ neutrophils, and CD68+ macrophages.