Investigating the Correlation between Growth Differentiation Factor 15 Serum Level and Its Gene Expression with Psoriasis and Its Severity.

ABSTRACT

Psoriasis is a chronic inflammatory dermatitis characterized by an inflammatory epidermal hyperproliferation. Growth differentiation factor-15 (GDF-15), a member of the transforming growth factor-ß family, has immune modulatory roles in autoimmune condition of Psoriasis. This study aimed to evaluate the relationship between GDF-15 serum levels as well as gene expression with psoriasis and its severity. This case-control study was performed on 45 patients with psoriasis Vulgaris and 45 healthy individuals. The severity of the disease was determined based on the psoriasis area and severity index (PASI score). Serum levels of GDF-15 were measured by enzyme-linked immunosorbent assay (ELISA) and its gene expression in peripheral blood mononuclear cells was quantified by real-time polymerase chain reaction (RT-PCR). The mean serum levels of GDF-15 in patients and controls were 1.98±1.57 ng/mL and 0.93±0.48 ng/mL, respectively. GDF-15 gene expression was measured as 9.7±6.6% in the patient group and 7.6±2.5% in the healthy group. The mean of GDF-15 serum levels in mild, moderate, and severe cases of psoriasis were 0.45±0.35, 2.27±0.7, and 3.5±1.6 ng/mL, respectively, indicating that elevated serum levels of GDF-15 correlate significantly with disease severity. The mean of GDF-15 gene expression in the mild, moderate, and severe forms of psoriasis were 5.25±3.2, 7.6±2.8, and 17.8±5.7, respectively which indicate a significant relationship between GDF-15 gene expression and psoriasis severity. Based on this study, in psoriatic patients, GDF-15 serum levels and gene expression are significantly higher than those in healthy controls. Such values were correlated with disease activity, especially in severe cases. Therefore, GDF-15 may be used as a prognostic marker of psoriasis.