Serum and tissue expression of transforming growth factor beta 1 in psoriasis

BACKGROUND: In psoriasis, keratinocyte hyperplasia may be explained by imbalance of growth factors responsible for epidermal proliferation and altered metabolism of their receptors. Transforming growth factor-beta 1 (TGF-beta1) implications in the pathogenesis of psoriasis can be attributed to several mechanisms besides keratinocyte cell cycle inhibition. OBJECTIVES: To evaluate the relation between serum and tissue levels of TGF-beta1 in psoriasis and their correlation with disease parameters. PATIENTS AND METHODS: Serum and punch biopsy of involved and non-involved skin of 22 patients with psoriasis vulgaris and 10 controls were collected for quantification of TGF-beta1 by enzyme-linked immunosorbent assay kit. RESULTS: Serum level of TGF-beta1 in psoriatic patients was higher than controls in a statistically non-significant manner. Correlations between serum level of TGF-beta1 and extent of the disease (P = 0.007) and Psoriasis Area and Severity Index (PASI) score (P = 0.005) were observed. Mean tissue levels of TGF-beta1 were highest in psoriatic lesions in contrast to normal skin of psoriatic patients and healthy controls, but not statistically significant. Correlation between tissue levels of TGF-beta1 in non-involved skin and extent of the disease (P = 0.007) and PASI score (P = 0.013) was detected. Correlation was detected between levels of TGF-beta1 in psoriatic plaques and serum of patients (P = 0.035), but not between levels of TGF-beta1 in non-involved skin and serum. CONCLUSIONS: Tissue expression of TGF-beta1 in psoriasis may be affected by the stage of development of the lesion. The direct relation between TGF-beta1 in psoriatic plaques and serum imply that the mechanisms for TGF-beta1 production and release in both these compartments may be related.