Specific subsets of B-cells may have distinct functions in psoriasis patients, and their circulating levels may help in the clinical classification of psoriasis, according to new research from scientists at the Shanghai Jiaotong University School of Medicine in China.
The study, “CD19+ B cell subsets in the peripheral blood and skin lesions of psoriasis patients and their correlations with disease severity,” published in the Brazilian Journal of Medical and Biological Research, has shown that patients with distinct forms of psoriasis have different correlations with the levels of circulating B-cells.
Similar to other autoimmune diseases, psoriasis is a disorder characterized by the involvement of the immune system. A variety of studies has provided strong evidences regarding the involvement of T-cell in this disease, but other immune cells, such as B-cells, macrophages, and monocytes, have also been shown to be increased in psoriasis patients, possibly contributing to the development of the disease.
To explore the role of B-cells in the development of psoriasis, the research team examined the circulating levels of specific subsets of B-cells in patients with distinct types of psoriasis. Among the 157 subjects included in the study, 35 were healthy controls; 65 had psoriasis vulgaris; 32 patients exibited erythrodermic psoriasis, characterized by generalized redness of the skin; 30 had arthropathic psoriasis, which affects the joints and connective tissue; and 30 patients had pustular psoriasis, which is generally seen in the palms and feet.
Results revealed that the levels of circulating B-cells in patients with psoriasis vulgaris (at both the active and stationary stage) and arthropathic psoriasis were significantly higher than those observed in healthy controls. However, the opposite was found in patients with erythrodermic and pustular psoriasis, in which circulating B-cells were significantly lower than in controls.
The opposite was found in skin samples of erythrodermic psoriasis patients: When researchers compared skin lesions with non-lesions in seven patients with erythrodermic psoriasis, they found that B-cell levels were higher in skin lesions than in non-lesion areas.
Then researchers examined whether there was a correlation between the levels of circulating B-cells and disease severity, assessed with the Psoriasis Area Severity Index (PASI). The ratios of several subsets of B-cells were found to correlate with disease severity in several psoriasis types. In particular, while patients with psoriasis vulgaris and arthropathic psoriasis showed a positive correlation between disease severity and B-cell levels, those with pustular psoriasis exhibited a negative correlation.
These results suggest that in addition to T-cells, B-cell activation may be involved in distinct stages and types of psoriasis.