Plasma transforming growth factor β1 as a biomarker of psoriasis activity and treatment efficacy

Abstract

Transforming growth factor-β1 (TGFβ1) is thought to be an inhibitor of the keratinocyte hyperproliferation associated with psoriasis. The aim of this study was to evaluate plasma TGFβ1 and TGFβ2 concentrations in psoriatic patients as possible indicators of treatment efficacy. TGFβ concentrations were measured in the plasma of 26 patients with psoriasis using an enzyme immunoassay and analysed with respect to the psoriasis area and severity index (PASI) before and after treatment with salicylic acid and/or sulphur followed by dithranol ointment. Baseline plasma concentrations of both TGFβ1 and TGFβ2 (20.3±2.2 ng ml−1 and 0.14±0.02 ng ml−1, respectively) did not differ significantly from control values (18.3±1.6 ng ml−1 and 0.14±0.03 ng ml−1, respectively). However, a significant positive correlation (r=0.69) between the baseline PASI and TGFβ1, but not TGFβ2, values was demonstrated. The pretreatment TGFβ1 concentration in patients with a PASI ≥15 (26.6±3.2 ng ml−1) was significantly higher than control values. There were no significant elevation of pretreatment TGFβ1 concentrations in patients with a PASI<15, or with respect to TGFβ2 in both groups. Treatment caused a significant decrease in TGFβ1, but only in patients with a PASI≥15. Patients with baseline TGFβ1 concentrations exceeding the mean of the control group had a PASI value that was significantly higher than that of patients with a TGFβ1 concentration below the mean of the controls. These results confirmed an association between plasma TGFβ1 concentration and psoriasis severity, and demonstrated its normalization during treatment. Measurement of TGFβ1 in plasma should be considered as a possible biomarker of psoriasis activity during its management.