BAFF levels are increased in lesional skin and sera in patients with cutaneous T-cell lymphoma

B-cell-activating factor belonging to the tumour necrosis factor family (BAFF) is known for its role in the survival and maturation of B cells. It has been recently suggested that BAFF also plays important roles in T-cell activation in T-cell mediated diseases such as psoriasis. Objectives: To investigate the role of BAFF in cutaneous T-cell lymphoma (CTCL).

BAFF expression in CTCL skin and serum BAFF levels are significantly increased and correlate with the severity of CTCL. These results suggest that BAFF may have important roles in the development of CTCL.

BAFF messenger RNA (mRNA) expression in skin samples (24 CTCL cases and seven healthy controls) and in skin-derived fibroblasts (five CTCL cases and five healthy controls) was examined by quantitative reverse transcription-polymerase chain reaction. We also performed immunohistochemical staining for BAFF and its receptors. Serum BAFF levels were measured in patients with CTCL (n=46), atopic dermatitis (n=36) or psoriasis (n=27) and 27 healthy controls by enzyme-linked immunosorbent assay.

Lesional skin of CTCL contained higher levels of BAFF mRNA than normal skin and the expression levels correlated with disease activity. BAFF mRNA expression levels were elevated in fibroblasts from CTCL skin. Tumour cells in the lesional skin of CTCL expressed BAFF and its receptors, while fibroblasts expressed only BAFF. Serum BAFF levels of CTCL patients were significantly higher than those of healthy controls and correlated with types of skin lesions and clinical stages. They also significantly correlated with serum soluble interleukin-2 receptor and lactate dehydrogenase levels. Conclusions: BAFF expression in CTCL skin and serum BAFF levels are significantly increased and correlate with the severity of CTCL. These results suggest that BAFF may have important roles in the development of CTCL.