When was defined as severe, 40 patients with psoriasis had mild to moderate and 19 had severe disease. Psoriasis disease severity was assessed by measuring psoriasis area and severity index score (PASI 0-72 points), whereas AD disease severity was determined by scoring atopic dermatitis index (SCORAD 0-103 points) for AD. Patients with AD were diagnosed as described previously. Patients with psoriasis were diagnosed based on clinical features and/or histopathological findings. These subjects were divided into three groups: 59 patients with psoriasis (47 men 12 women age years) 47 patients with AD (19 men, 28 women age years), and 47 healthy controls (20 men, 27 women, age years). The study cohort comprised 153 subjects (86 men, 67 women), with age years (range, 18 to 88 years).
Therefore, the aim of this study was to investigate the correlations among serum LCN2 levels and the degrees of itch and skin inflammation in patients with psoriasis and AD. To date, however, the relationship between LCN2 and itch in patients with psoriasis remains unclear. In addition, LCN2 may be involved in the tendency of patients with psoriasis to develop metabolic syndrome. LCN2 may therefore be a potential target for the treatment of psoriasis. LCN2 may contribute to the pathogenesis of psoriasis by modulating neutrophil activities, including neutrophil infiltration, migration, and activation, inducing neutrophils to release proinflammatory mediators. Serum LCN2 concentration has been reported higher in patients with psoriasis, but lower in patients with AD, than that in healthy controls. In addition, LCN2 derived from spinal astrocytes has been found to enhance itch in a mouse model of atopic dermatitis (AD). LCN2 has been associated with neurodegeneration, cancer metastasis, insulin resistance, obesity, and inflammatory responses. Lipocalin-2 (LCN2), also known as 24p3 and neutrophil gelatinase-binding lipocalin (NGAL), is a protein secreted mainly by activated neutrophils. Despite the importance of controlling itch in patients with psoriasis, effective treatment for itch in psoriasis has not yet been established. Itch causes distress in patients with psoriasis, not only by impairing quality of life but also by aggravating exanthema due to scratching (Koebner phenomenon). Possible mediators of itch in psoriasis include histamine, opioids, interleukin- (IL-) 31, and brain natriuretic peptide (BNP). Psoriasis is a chronic inflammatory skin disease accompanied by itch in about 60-90% of patients. Itch is defined as an unpleasant sensation inducing a desire to scratch. Serum LCN2 concentration is associated with the degree of itch in patients with psoriasis, suggesting that serum LCN2 may be a useful clinical marker for itch in psoriasis.
Serum LCN2 levels in psoriasis patients significantly decreased after the biological treatment along with improvement of VAS. In contrast, serum LCN2 concentrations did not correlate with VAS or SCORAD in patients with AD.
In patients with psoriasis, serum LCN2 concentrations were significantly correlated with VAS, but not with PASI. Serum LCN2 concentrations were significantly higher in patients with psoriasis and AD than those in healthy controls. We further examined the serum LCN levels in psoriasis patients before and after biological treatment. Correlations among serum LCN2 level, VAS, PASI, and SCORAD were analyzed statistically. The degree of itch was assessed using a visual analog scale (VAS), and disease severity was determined by measuring psoriasis area and severity index (PASI) and scoring atopic dermatitis (SCORAD). Serum LCN2 concentrations were measured by enzyme-linked immunosorbent assays (ELISA) in patients with psoriasis and AD and in healthy controls. This study examined the correlation between serum LCN2 levels and the degrees of itch in patients with psoriasis. However, the relationship between LCN2 and itch in patients with psoriasis has not been determined. Spinal astrocyte-derived LCN2 was found to be involved in enhancement of itch in a mouse model of AD. Serum LCN2 concentration has been reported elevated in patients with psoriasis, but lower in patients with atopic dermatitis (AD). Lipocalin-2 (LCN2), a protein secreted mainly by activated neutrophils, has been associated with neurodegeneration, obesity, and inflammatory responses.